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Text-Alternative Version: Implementing Recommendations from the Advanced Energy Design Guide for K-12 School Buildings

Below is the text version of the Implementing Recommendations from the Advanced Energy Design Guide for K-12 School Buildings webinar, originally presented on April 16, 2009. You can also view the slides for this presentation (PDF 8.6 MB). Download Adobe Reader.

Jenni Sonnen:  Hi. My name is Jenni Sonnen, and I represent the Department of Energy. I'm here to welcome you to the Advanced Energy Design Guide for K through 12 School Buildings Training. Thanks so much for joining us today. Just so you know, you can receive AIA CES Learning Unit Hours for this training, and we'll provide more information about these credits at the end. We'd like to say "thank you to ASHRAE for providing photos and line drawings from the Advanced Energy Design Guide for K through 12 Schools and also the Advanced Energy Design Guide for Small Retail, and you'll see these throughout the presentation. If you'd like more information about ASHRAE, you can visit them online at www.ashrae.org.

We have a few goals for today. First, we want to introduce you to the Guide and tell you a little about how it was developed and how to use the Guide. We also want to discuss the importance of using an integrated design approach to achieve energy savings in schools. Of course, more energy efficient schools offer key environmental benefits such as more sustainable development and carbon reduction. There are other important benefits that we'll discuss later in the training. We'll also show you the Climate Zone section of the Guide which offers specific recommendations for the various U.S. climates; and finally, we'll go through a detailed description of key recommendations in the areas of building envelope, lighting, HVAC, and service water heating. This training is being brought to you by the Department of Energy's EnergySmart Schools initiative, which is a public private partnership looking to significantly improve the energy efficiency of schools. DOE's program goals are to upgrade new schools to 50% better than current energy codes and improve existing schools by 30% in the next three years.

Now I'd like to introduce our speakers who work at the National Renewable Energy Laboratory, or NREL. NREL is the only Department of Energy national lab that focuses entirely on renewable energy and energy efficiency. First, we have Paul Torcellini, who manages the Commercial Buildings Research at NREL. Paul is an expert in the energy performance of commercial buildings and has extensive experience using computer simulations to design very low energy buildings and even zero energy buildings. We also have Shanti Pless, who is an Energy Efficiency Research Engineer on Paul's team. Shanti worked extensively on the energy modeling to determine the recommendations and also on the development of the Guide. If you have any questions, you can refer them to the email on the slide here. Also, the EnergySmart Schools' website has a lot of great information about building and operating energy efficient schools.

With that, I'll turn it over to Paul.

Paul Torcellini:  Thank you, Jenni. As Jenni mentioned, Shanti and I are going to take you through the Advanced Energy Design Guide for K12 Schools. But before we start that, let's frame the energy picture a little bit. Let's look at building energy use in the United States. 40% of the energy goes directly into buildings to operate them, to light them, to heat them, to cool them, to operate the plug loads that we put in these buildings. Roughly a third of the energy goes into industry, things to - - or processes to make things. The rest of the energy goes into transportation. If we look at the building energy sector, it's divided almost in half between residential, the places that we live, and the commercial sector, the places that we work and learn. We can see in the commercial side the breakdown of where energy is used. Lighting, heating, and cooling take the largest chunks, with water heating following after that. We're going to focus on these areas in the Advanced Design Guide because they represent the biggest areas and opportunities for energy savings. It's also interesting to note that buildings use 70% of the electricity in the U.S. and therefore contribute a lot to the emissions in this country.

Let's define the scales for buildings for a minute. If we consider code as being ASHRAE 90.1, and as a reference point, let's look at the turn of the millennium or the code as it was in 1999, we can establish benchmarks based on this point. This is a pretty good building. If we take that building and increase the energy efficiency by 30%, that is where the Advanced Energy Design Guide sit. Now the opposite end of the scale is a zero energy building. That is quite a noble goal, a building that consumes or that can produce as much energy as it consumes. When we look at educational facilities, they represent the second largest energy use for all of the commercial buildings after offices, that is offices aggregated together use more energy than schools. If we could change how energy is used in schools, we can make a huge difference in the energy picture and the energy futures of this country. That roughly equates to $12 billion in annual energy usage, most of that is publicly funded, and that is spread across a little over 124,000 K12 schools in this country.

Now that we frame the energy discussion, let's talk about the goals for the Advanced Energy Design Guide for the K12 Schools. They were really to develop to help schools make smart investments in energy savings so that more funds are channeled into education rather than into energy expenses. What we did was we were able to illustrate how to build a school that uses 30% less energy than the ASHRAE 90.1-1999 standard. What we're really trying to do is work towards net zero energy schools, that is producing as much as energy as is consumed in the building on an annual basis. What is the Advanced Energy Design Guide? They are Guidelines based on climate zones to help K12 school owners and designers achieve 30% savings over the baseline standard. They are recommendations only, not a code/not a standard. They apply to new construction and major renovation. They include specific implementation tips to help you get going and to make your project a success. Finally, we included case studies showcasing schools nationwide that have achieved or exceeded this 30% goal. We do have to note that in achieving these energy savings that our solution presents a way to design and build schools that use significantly less energy, but it is not the only way. We did try to account for having many variations and many design parameters such that the Design Guide had as much flexibility as possible. We packaged the results in such a way that if you do everything on our recommendation list, you will achieve the 30% savings. It is a pre computed set of solutions to make it easier to implement based on site energy use and typical plug loads for schools.

We do want to mention that there are other design guides available for other building types, including small offices, small retail, and small warehouses. In the works, we also have hospitality and healthcare, small healthcare. The guides were developed through a relationship between The U.S. Department of Energy; The American Society of Heating, Refrigeration, and Air-Conditioning Engineers; The American Institute of Architects; The Illuminating Engineering Society of North America, and The U.S. Green Building Council. For this Guide, we had some additional insights from the Sustainable Buildings Industry Council, The National Clearinghouse for Educational Facilities, and The Collaborative for High Performance Schools. The audience for the K12 Guide is targeting contractors; architects; engineers; designers who design, build, and renovate schools. In addition, there's a special section for school boards, school administrators, school facility managers on the benefits of energy efficiency, which include better learning environments, lower operating costs, lower construction costs, lower environmental impact, as well as using schools and the energy efficiency in these schools as a teaching opportunity to help future generations. The K12 Guide includes easy to follow recommendations that are separated by climate zone, how-to tips for easy implementation, and it recommends strategies that are off-the-shelf and readily available. Case studies illustrate real life advanced energy approaches. Additional bonus strategies are available for savings beyond 30% and a prescriptive path for LEED energy efficiency credits is available through using the Guide.

Let's talk a minute about LEED and the credits that are available. If you comply with all the prescriptive measures for the climate zone and follow the checklist that's provided, you can receive one energy and atmospheric credit in LEED 2009. No additional energy modeling is required. There are some restrictions that apply in that buildings must be under 100,000 square feet and the buildings must include the typical spaces covered under the scope of the Guide.

How are the recommendations determined? A committee of people that were made up of school designers, engineers, and other people who are experts in delivering building school projects came together and developed a list of recommendations. These recommendations were then modeled and verified using computer simulations. If you're interested in those modeling results and a lot of the detail that went behind development of the Guide, there is a technical support document that was developed by the National Renewable Energy Lab. The link is shown on the slide. In addition, there was a focus group that was assembled for conceptual review and the Guide went through two extensive peer review processes through all of the partner organizations involved. The modeling was based on typical school prototypes where the parameters for those prototypes were based on national databases. Three different schools were evaluated, including elementary, middle school, and high school. The photo here shows a rendering of one of the computer simulations to do that energy modeling work.

What kinds of spaces are addressed? Those include typical spaces you'd find in these school types, including classrooms, administrative, corridors, restrooms, gyms, assembly areas, kitchens, and media centers. There are some specialty types that are not included in all schools and therefore are not included in this Guide, including pools, chemistry labs, spaces that need special ventilation requirements such as woodworking or auto shops, as well athletic field lighting. The focus of the recommendations was on building envelope. Building envelope includes the walls, the ceiling, the roof, as well as the fenestration or the windows in the building. Another major focus area was the lighting system, and we emphasized the red lighting system. That system may be made up of daylighting and augmented with electric lights. Next, the heating, ventilation, air-conditioning systems are studied, including looking at building automation, controls, and treatment of outside air. Finally, we're going to look at service water heating. The Guide really emphasizes looking at the integration of these systems. The savings goal is really dependent on the interaction. We want you to think of the building as a whole as one complete system that has been engineered to work together.

Where can you get the Advanced Energy Design Guide? It's available as a free download from the ASHRAE website listed on the screen. You can download a copy of that at no charge. If you would like a print copy, you can also order one on that website for a nominal charge.

Next we're going to talk about using the K12 Advanced Energy Design Guide. Let's talk for a moment about the contents of the Guide. As I mentioned earlier, there's a forward to school boards and administrators. It is intended that a school board could read that, decide that the Guide was appropriate for their district, and handoff the Guide to their design team for implementation. Starting in Chapter 2, we talk about the integrated design approach showing how all the pieces of a building need to work together. In Chapter 3, recommendations are given by climate zone. We want you to find your climate zone and then review the recommendation table. That is what you're going to use to implement your project. In Chapter 4, there are case studies that are specific to different climates. And finally in Chapter 5, there are tips to implement recommendations based on what is listed in Chapter 3. In Chapter 2, which is labeled the Integrated Design Approach, it talks about how to get to savings, how to put all the pieces together, how to assemble the team of participants and successfully deliver your project. It starts with talking about workshops for brainstorming ideas, generating ideas, and buy in from all the stakeholders. Finally, we talk - - the chapter talks about setting measurable and specific goals.

Let's talk about goals for a minute. A lot of people say, "I want to build a green building," and that becomes their goal. There are some issues there. It sounds like a very noble goal, but nobody really knows that it means if you had to measure it specifically; therefore, you can't really determine at the end of the project whether or not you were successful. Unfortunately, it's a far too common goal and we need to strive to do better. A better goal would be design a lead and whatever rating you want building. It might be a lead platinum building or a lead sliver building. That is a measurable goal because at the end of the day, you can evaluate your design and see if you've achieved your goal. There's some goals that become much more specific and can really help fine tune and guide the design process, perhaps design a building to use 30% less energy than code. That could represent using this book that we're going to be talking to today. Even better yet is tying specific energy numbers onto that. Design a school that uses less than 25,000 Btus per square foot. If you are really aggressive, and we've kind of mentioned it before, you can talk about designing a net zero energy building, and that is a measurable goal for a building. If you want to find out more about net zero energy buildings, visit the DOE website.

The following key steps are necessary for integrated design. First, you want to choose a site to maximize the benefit of natural resources. You want to be able to allow for long east/west axis and maximize north and south facing classrooms. This will help you with Step No. 2 in deciding the building footprint. You want to be able to allow for daylighting, passive solar, solar thermal and photovoltaics, and natural ventilation. Number one, daylighting, is much more important than the other three in achieving the 30% goal. Next, we want to be able to reduce the loads through the envelope of the building. You can think of the envelope as wanting to provide as much heating, cooling, ventilating, and lighting as possible. You want to strategize where those windows are, including the overhang, and we want to make sure that you have good thermal insulation in the walls and the roof. Finally, we want to look at reducing plug loads within the building. Once all that is done, we can move to Step 4. Don't do Step 4 until you really have fine tuned steps one, two, and three. Step 4 involves sizing your heating and cooling systems properly, including accounting for those reduced loads. You want to incorporate efficient equipment and systems and design the lighting to complement the daylighting. Lighting and heating and cooling systems should be thought of ways to augment inadequacies in the building envelope. Finally, once all the pieces are put together, you want to commission the building to insure that it is operating as it is designed. The integration is so important that there's a logo shown on the screen that will appear throughout today's presentation that are key to making integrated design work, and they should be considered very early in the design process. The earlier that decisions are made with energy efficiency in mind, the easier it is to achieve the savings at minimal additional capital cost.

Moving into Chapter 3, we have recommendations by climate. The United States is divided into eight climate zones, as shown on the map below. Within those climate zones, some climates have subzones, which include moist, dry, and marine environments. As we develop the recommendations, all of these climate zones were considered and each one has its own set of recommendations. After the maps, come the recommendation tables segmented by climate zone. On this screen is an example of the table shown for Climate Zone No. One. In the first column, we see different envelope components, including roofs, walls, floors, slabs, doors, and vertical fenestration. Each of these has sub pieces. Let's look at walls as a specific example. We could have a high mass wall such as concrete masonry, steel framed, wood framed, or a metal building. In the next column, we have the recommendation. In this case, it shows the minimum R values for those different wall types. In some cases, like for the vertical fenestration, it gives a maximum U-value that's allowable under our recommendation system. Finally in the next column, we see the how-to tips. Those how-to tips reference different tips later in the book. We also have a column that you can check when you meet compliance with each of those. That is to help determine your energy and atmospheric credits under the lead system.

In Chapter 4, there are several case studies. These case studies are listed below and vary between different zones. These are real life examples of schools that have achieved a 30% energy savings or pieces of it using strategies highlighted in this book.

Chapter 5 is the how to implement the different recommendations. It provides good design practices, cautions, and references and is divided into several sections, including commissioning, envelope, electric lighting, daylighting, exterior lighting, HVAC, service water heating, as well as additional savings. These additional savings are not needed for the 30%, but they can be considered bonus savings. Refer to this as you go through climate-specific recommendations.

Next, we're going to talk about building envelope recommendations, and Shanti is going to start that discussion.

Shanti Pless:  Thanks, Paul. I'm going to first we're going to talk some of the general concepts that the Guide includes about getting the envelope right. In general, it's the easiest and least expensive to upgrade the envelope in the design phase. If you don't get the envelope right, it can be very expensive, if it's even possible to fix after construction. Generally getting the energy efficiency gains through envelope improvements is typically considered the best way to get energy efficiency persistence throughout the life of the building. They typically have the least amount of maintenance associated with those efficiency recommendations of the envelope. The Guide provides insulation recommendations for walls, roofs, and slabs among other envelope measures, as well as performance recommendations for glazing and doors.

So here we have a list of all the recommendations in the design Guide, and we'll discuss today the - - in detail the ones that have been highlighted. First, like to get into some tips for the entire envelope that the Design Guide covers. Throughout Chapter 5, there are details to minimize thermal breaks in the envelope. In addition, there are alternative constructions that are provided if one of the wall types that you are using in your project are not included in the Design Guide. There's an appendix that offers U-factors that are appropriate by climate zone for various types of alternative constructions. Another tip for the entire envelope involves a continuous air barrier system, the recommendation's around controlling air leakage to minimize infiltration. Some of the details on how the recommendations are put together for insulation R -values concern the wall construction type. R-values are provided for cavity insulation, as well as continuous insulation depending on the wall type. When a continuous insulation is recommended that's noted by a CI, next to the insulation level, and when a level of insulation for a cavity that does not include the framing is noted, that's the R-19. So an R-19 CI would be a wall with R-19 cavity insulation and R-19 continuous insulation. The design Guide provides levels of insulation for various roof types by climate zone. This table shows what the design Guide recommends for R-values for above deck insulation, a metal building roof insulation, and attic and other insulation type. In addition, the code minimum is also shown to show the comparison of where the Design Guide exceeds code. In general, the colder the climate, the more insulation is recommended. A recommendation is also provided for cool roofs, in Climate Zones 1, 2, and 3, those are the warm climates. Solar Reflective Index or SRI of 78 or greater is recommended, and we have a table showing various SRIs for different types of cool roof products.

For insulation above deck or Envelope Measure 3, insulation or continuous insulation is recommended for the various above deck insulation wall types.

Envelope Measure 3 provides insulation recommendations for ventilated attics, unventilated attics, and metal standing seam roofs. These levels of insulation refer to the amount of insulation and not the continuous insulation level.

Envelope Measure 4 provides a level of insulation recommendation for single rafter roofs, and that refers to a cavity insulation level as well.

Now on to wall recommendations. Again, the table summarizes the level of insulation for various wall types, including a mass wall, metal building wall, a steel framed wall, a wood framed wall, and below grade walls. Again, we show the level of insulation for the Design Guide as well as the code minimum to show the comparison by the - - for the eight different climate zones. Note that for the mass walls that's a continuous insulation and for the steel framed and wood framed walls that's a level of insulation in the cavity.

For exposed floors or floors that have are above parking garage, for example, mass floors, a steel framed floor and a wood framed floor are values are provided for both code and the recommendations in the Design Guide by climate zone. Here are a few examples of how that insulation is applied based on the floor type.

For slab on grade, for both on unheated slab as well as a radiant heated slab, insulation recommendations are provided for by climate zone. The way these recommendations are presented this - - for example, in Climate Zone 6 in an unheated slab, the Design Guide recommends R-10 for 24 inches around the perimeter of the slab. Here's a few illustrations of how that perimeter insulation can be applied to either underneath the slab or at the footing. Envelope Measure How-to Tips 11 and 12 provide more details on this insulation detail.

For doors or Envelope Measure 13, U-factors are provided based on climate zone for both swinging and non-swinging doors. In general, vestibules can be used to minimize infiltration in cold climates and double swinging doors that are difficult to seal to unless there's a center post to seal against.

For fenestration recommendations in the Design Guide, there are U-value recommendations, solar heat coefficient recommendations by climate zone as well as an overhang or projection factor recommendation. For daylighting glazing, visible transmittance will also be recommended, and we'll cover that more in the daylighting section. In general, visible transmittance is an important aspect to the daylighting windows. Windows with a higher visible light transmittance and lower solar heat gain can allow light transmission and minimize the heat gain; and for the daylighting glazing in general, the Guide recommends a visible light transmittance greater than 65%. This table provides a few examples of the insulation value of the window, the U-factor, the solar heat gain, as well as the visible light transmittance options for different types of glazing that - - to get the common, the unique combination of insulation, solar heat gain, and visible light transmittance the Guide recommends.

The how-to tip for Envelope 19 discusses the projection factor as well as the U-factor, the insulation factor. Note that the U-factor includes the whole unit, including the glass, the sash, and the frame, it's not just the center glass value. A note on how the projection factor or the overhang is determined, the Guide recommends a projection factor of 0.5, and that references a ratio of the overhang length versus the height above the windowsill. To further optimize overhangs by climate, there is additional information available in the Solar Radiation Data Manual that can help to further optimize your overhangs.

The Guide also provides a recommended maximum fenestration to gross wall area ratio of 35% for the whole building. This includes both the daylighting and the view glass. There are how-to tips that show how - - that discuss how to minimize your east and west glass while maximizing north and south facing glass for daylighting. Again, this total fenestration to gross wall area ratio represents the rough opening of the window including the glazing, the sash, and the frame, not just the window itself, and the design Guide provides some additional details on that calculation. There's additional window area design strategies that incorporate some of the daylighting strategies, which we'll talk about in the next section.

Paul Torcellini:  Let's move on to lighting systems, and we really want to emphasize that lighting is done as a system and it is made up of both daylighting and electric lighting. Lighting is one of the largest energy uses in schools contributing up to 40% of the total energy bill. It is on the top of the list for meeting the 30% energy savings. Quite often it is inexpensive and offers rapid payback. It also helps reduce the cooling loads. In this Guide, daylighting is provided as an option and it is strongly encouraged. It has significant energy savings potential and many non-energy benefits. The non-daylighting option provides for site… The non-daylighting option is provided for site or other programmatic constraints. Under this option, we focus on high performance lighting. Both options are available for 30% savings over ASHRAE 90.1. Shanti's going to begin this discussion by talking about some of the daylighting strategies.

Shanti Pless:  The Guide provides various daylighting recommendations and strategies. We'll again discuss the ones in detail that we've highlighted here. Some of the general concepts that the Guide covers: First, daylighting in the classrooms is typically the most critical to get right. Then daylighting in gyms is another viable option for daylighting, and the recommendations we'll discuss are focused on those spaces. It's critical that classrooms face either south or north to maximize daylighting. There's more on this in the Daylighting Tip 9. In general, vertical fenestration and toplighting and can provide interior illumination that is superior to the electrical lighting without excessive solar heat gain. It's key to use controls to take advantage of the available daylight to turn your lights off or to dim them. For a well daylit system where the lights are off the majority of the time don't typically meet a high performance lighting system because the lights are off. In general, a well designed daylit system can be paid for with reduced HVAC needs. This can often offset the additional costs for the daylighting system. It's key to design your - - the daylighting system to eliminate all direct beam glare from the daylighting windows for all times of the year. Finally, the solution should be simple with low maintenance.

One of the key how-to tips for daylighting includes the building orientation, this is a key strategy to make daylighting cost effective. For north and south facades oriented within 15 degrees, vertical daylighting can be successful. However, the orientation is less important if the classrooms and the gym are fully toplit, that is roof monitors and the toplighting system can be rotated to be within 15 degrees of north or south. East and west glass is not typically a very good daylighting solution. Finally, consider shading the building with trees or other buildings when you are identifying a site for a well daylit school.

Let's get into some of the strategies for daylighting classrooms. Daylighting strategies 20 through 27 discuss classroom sidelighting strategies. That is: How can daylighting be provided to classrooms from both north and south facing classrooms through sidelit strategies only. Here's a schematic showing how daylighting can be introduced into both the south classroom and a north classroom. This is typically the solution when you have multiple floors of classrooms.

Another strategy recommended in the Guide is through a toplit clerestory strategy. This can be done either through north or south facing clear stories. This is also a common gym daylighting strategy. You can combine a sidelit with a toplit strategy to get various configurations of a sidelit plus a toplit strategy.

Some of the specifics to make these strategies work, the first key one is to be able to separate your daylighting from your view glass. The daylighting glass should be at least seven-foot and above to be able to provide daylighting deeper into the space and DL-6 covers the recommendation for that strategy. The view windows typically provide a connection with the outdoors but don't necessarily contribute to daylighting the entire classroom, only the spaces very close to those sidelit windows. When you separate your daylighting glass from your view glass, as you can see in the picture here, the daylighting glass is typically high up above seven-feet. This can be done through roof monitors or high north or south windows.

Another key strategy to making these high windows work for daylighting is to have high ceiling heights. Typically a minimum of a 10-feet ceiling enables the high sidelit daylighting to be able to daylight the entire classroom. Another strategy is to slope the ceiling down from the perimeter wall to increase the penetration of the daylight into the space.

Another key daylighting technique, as we discussed earlier, is to design your shading system to allow no direct beam solar gain from the south windows at any time during the year. The key is to eliminate uncontrolled direct beam radiation onto the work plane. This can be less critical in some gyms or multipurpose spaces and corridors. DL-12, or daylighting tip 12, provides strategies that either bounce, redirect, or filter sunlight as well as shading strategies to eliminate all direct beam radiation into the classrooms. The key here is to be able to design for eliminating direct beam radiation and not rely on internal shading that relies on the people in this space. Often times we see classrooms with shades drawn and they stay drawn even when glares not an issue defeating your daylighting system.

Another key daylighting technique is covered in daylighting tip 14 refers - - discusses the interior finishes of classrooms. You can see here a highly reflective clerestory. The Guide provides recommendations for those interior reflectance based on the surface type for walls above seven-foot as well as for ceilings. The minimum reflectance recommended is 70%. For ceilings, it's a minimum of 70% and preferable to be up to 80 or 90% surface reflectance. For walls and furniture, a 50% surface reflectance is recommended.

Another key strategy for both eliminating direct beam as well as controlling solar gain are lightshelves with overhangs. You can see an example for one of the case studies that are in the Guide that includes both a lightshelf, an exterior lightshelf and overhang of the view glazing. The key here is to design an interior lightshelf that eliminates the direct beam for the south facing glass classroom windows. There's various options, either a single lightshelf or multiple small lightshelf integral into the daylighting glazing. For each of these daylighting strategies, toplit, sidelit, or a combination of the two, the Guide provides rules of thumb to determine the right amount of daylighting fenestration. This…. These recommendations are a percent of the floor area that should be included as daylighting fenestration for both classrooms and a gymnasium or a multipurpose room. For a south facing roof monitor, for example, 8 to 11% of the square footage of the classroom should be included as south facing glazing, daylighting glazing. Again, for a north facing roof monitor, a little additional daylight glazing is needed to take - - because all that daylighting is diffuse. The various other configurations… For various other configurations, there are additional fenestration glazing recommendations. As those are rules of thumb, there's a daylighting how-to tip that recommends using analysis tools to further optimize this design. The Guide provides general recommendations for about how much fenestration should be used for various daylighting configurations. But to really get at the energy saving tradeoffs faster and optimize the design, we do recommend additional modeling to do so.

Now Paul's going to talk some about the lighting details that the Guide recommends.

Paul Torcellini:  Thanks Shanti. In this section of the seminar, we want to talk about different lamp types as well as strategies for certain classroom types, those are shown in highlighted areas on the screen. There's some general concepts for electrical lighting. We want to use the most current state-of-the-art lamps, ballast controls, and techniques. In realty, we should only be considering electrical lighting where daylighting options are not possible. In fact, when daylighting is not available, we expect the electrical lighting to actually be more efficient than if daylighting were available. Low lighting power densities are not as critical if the lights are off because of daylighting compared with if they were on all the time. The interior considerations for use with electric lights are very similar to those used for daylighting in order to create the highest efficiency system. We want to use light colored interior finishes. In particular, surfaces above seven-feet, those walls, as well as ceilings should have reflectances greater than 70%. Occupancy sensors or vacancy sensors should be used. The preferred strategy is to have manual on, manual off, and then auto off in the case of somebody forgetting. This applies to all classrooms, offices, restrooms, and special use spaces. The intent here is that we do want users to take an active part in energy efficiency. A well trained user will be your best energy monitoring system. Diming controls are important also in non-daylit areas. By this we mean, anywhere there's a window, we should still consider dimming controls within 15-feet of that window, that way we can take advantage of some daylighting even if it wasn't designed in.

Let's talk about linear fluorescent lamps and ballasts. From a term point of view, the system efficacy is the mean lamp lumens per watt; the Guide provides efficacy recommendations for all climates. For the daylit option, it recommends linear fluorescents with a mean lamp lumen per watt of 75 or more. Non-daylit options should have 85 or more. As an example of an efficacy calculation, if we have a fixture that has two lamps, each of those lamps can provide 2520 mean lumens, we multiple those together times the ballast factor and divide by the total input of the unit, in this case 59 watts. In this example, the mean lumens per watt is 74.3.

Linear fluorescent lamps and ballasts form a very important combination. They must be designed and work together in harmony. The table below shows different lighting options that meet the efficacy recommendations. You see that some are lightly shaded and they do not meet those efficacy criteria. There's several that meet the 75 lumens - - mean lumens per watt and several that exceed that. EL3 and EL5 talk about specific lamp types. EL3 talks about fluorescent T5 sources where T5 lamps should have a mean lumens per watt of greater than 75. It also talks about enclosed luminaires and luminaires for tall spaces. EL4 talks about compact fluorescent lighting. The recommendation is to use compact fluorescent lights that have mean lumens per watt of 50 or greater including an electronic ballast. Note that the mean lumens per watt is much lower than that for the linear fluorescent T5 or T8 sources; therefore, they should be used for general lighting but used for smaller areas including utility areas, downlighting in smaller spaces, and wall washing. Again, they should not be used for general lighting as they are not more efficient than the fluorescent T5 and T8 sources. EL5 talks about metal halide fixtures, including use of electronic ballasts and pulse starts for less lumen depreciation. The Guide also talks about lighting for special spaces, including gyms, multipurpose rooms, libraries, media centers, corridors, offices, locker rooms, and restrooms. These sections include tips and layout ideas to get the best energy efficiency and meet the recommendations for the Guide. Shown here is a picture of a library that has a good lighting design; however, note that daylighting is coming into this space and the lights are on. In this case, the space was not designed for daylighting and should've been; or at least at a minimum, the lights should've turned off on a photocell.

Next, we're going to talk about heating, ventilating, and air-conditioning the space. We can't stress enough the need for integrated design and that the HVAC should be designed after the rest of the building is designed and the loads preferably accounted for. There are some general notes about HVAC design. We want to make sure we use practical off-the-shelf technologies and strategies that are available from multiple manufacturers. It is important to keep it simple. The system will only operate as well as the people who are operating it, so keep that in mind during the design phase. The Guide provides for climate specific recommendations for very typical system types. Schools across the country use many different solutions and the Guide accounts for this. Recommendations look at the whole system, including features like duct design. HVAC system types tend to vary regionally across the country from small package rooftop units to unit ventilators in the Northeast.

Because of this, the heating and cooling systems are varied and the Guide addresses these varied systems. Included in the Guide are single zone packaged DX systems or split DX systems, water source or ground source heat pumps with dedicated outside air systems, unit ventilators with chilled water and boilers, fan coils with chilled water and boilers as well as adding on a dedicated outside air system, and multiple zone VAV packaged DX rooftop units as well as VAV air handlers with water chillers.

The Guide recommends the following for each of these systems: The seasonal energy efficiency ratio, the energy efficiency ratio, the coefficient of performance, the annual fuel utilization efficiency, combustion efficiency, as well as some other parameters. It also talks about ventilation control and how to best precondition ventilation air. It also has recommendations for when economizes should and shouldn't be used, fan efficiency, as well as duct design.

Shown on this slide are the recommendations based on climate zone, HVAC system type, system size or system capacity, and the fuel type. The analysis was done both assuming natural gas was available or you had an all-electric building. In the columns, in the first column, we show the type of system that we have. In the next column, we have the different components for the system listed in the first column. The recommendation column gives a performance specification based on the metrics that we just talked about. The how-to tips are in the next column and refer to specific areas and cautions one should look at in designing with these systems. Finally, the checklist is used for compliance to insure that you've met the requirements for this recommendation guide.

Looking at integrated design concepts in HVAC, first we need to reduce the load. We've talked about many of these strategies and again doing this is most important in creating a holistic energy efficient school. Siting and orientation, appropriate glazing, envelope and insulation, lighting including daylighting, and minimization of plug loads, then and only then designing an efficient HVAC system to meet the remaining loads.

Next, we're going to talk about HVAC design practices. Highlighted are the topics that we will discuss today; however, the Guide covers all the topics in this list. Let's start with tip HV8, part-load dehumidification. Basic constant-volume systems don't hold dehumidification well. We want to minimize the hours of the space relative humidity is above 60%. Because of this, dehumidification can often account for 30% of the total cooling load. Part-load air-conditioning can be a problem if dehumidification is coupled to the AC. Should be able… You should be able to control the air-conditioning system so that it can be cooling and/or dehumidifying. The consequences of that design is overcooling the space in order to keep it - - keep the humidity low enough.

HV11 talks about ventilation air. It is determined based on ASHRAE 62 2004. Let's talk about some tips on system sizing. Over ventilating will cause excess energy to be used and will not substantially increase air quality. Use actual occupancy for calculations and not the egress or exit population. Use diversity when using multiple zone recirculating systems. By diversity, we mean that the school has a certain population and often that population moves around from room-to-room. We should be able to account for that. If you account for the maximum loading in each space, you'll end up over ventilating the space. Use time of day schedules to introduce ventilation air only when a zone is expected to be occupied. We will talk more about controls in a minute or two.

Moving on to HV9 and HV14, exhaust energy recovery and demand-control ventilation. Exhaust energy recovery is when we take the energy in an outlet stream of air leaving the building and put that energy into the inlet stream. Demand-controlled ventilation is only providing the ventilation needed to provide fresh air for the occupants. In the Guide, we recommend using either exhaust air energy recovery or demand-controlled ventilation depending on the system type. Energy recovery ventilation lends itself well to central ventilation or dedicated outside air and demand-controlled ventilation lends itself well to packaged single zone systems. When using energy recovery, specify that the device should have a total effectiveness of at least 50% as shown in the recommendation tables. Using demand control ventilation, control the outside air based on the zone by one of the following: Time of day schedule in the building automation system, an occupancy sensor, or carbon dioxide sensors.

In HV12, we talk about dedicated outdoor systems. Dedicated outside air systems should use energy recovery and are recommended for water source heat pump systems, fan coil, zone air handlers, and parallel fan box systems.

Thermal zoning is discussed in HV20. It is critical to orient and layout the building such that thermal zones are easily combined. This is often based on building size, orientation, space layout and function, and after hours use requirements. Multiple zone systems should serve zones with similar occupancy and internal load patterns. Add smaller systems dedicated to spaces that have different occupancy uses. An example of this might be administrative offices that may be in use year round and classrooms are only used part of the year; therefore, those two should be separate systems so that classrooms can be shutdown when school is not in session and administrative offices can continue to serve the school. Use multiple air handlers so that those serving unused areas of the building can be shut off when not in use. Use the building automation system to define separate operating schedules for different areas of the building and shutoff air flow to unused areas.

Although not tied directly to energy efficiency, HV29 talks about noise control. This is especially an issue with distributed systems. Use the room criteria rating that is required for classrooms by LEED and make sure that vibration isolation is provided. Sound engineers or acoustical engineers can help with the goals and the design and should be included early on in the process. One of the reasons that this is critical is that if sound is not considered ahead of time and the system is too noisy, later retrofits often lead to high pressure drops and can result in large inefficiencies in the system. The spacing is key. Mechanical rooms should be away from the classrooms and HVAC should be installed above mildly occupied area such as storage rooms, restrooms, corridors, or acoustically treated closets.

Proper maintenance of systems is very important. Again, energy efficiency is a long-term challenge and persistence or keeping those strategies going is important. Design the systems for simple maintenance. Make sure it's easy to change filters and it's easy to replace equipment. Shanti and I once did a field visit of a school and found that it took two hours to get the housing off of a piece of equipment to change the filter, not really a practical situation and the end result is that the filters were rarely changed. Energy savings can often be negated by not maintaining those systems. Some things that are important to think about, and there are several more that could be added to this list: Replace the filters regularly; clean the ERVs periodically; inspect and calibrate dampers, valves, louvers, and sensors; employ asset management strategies to know what is there and what the efficiencies are; and make sure that maintenance documents are available, including schematics and plans of the facility.

Next Shanti is going to talk about service water heating.

Shanti Pless: Thanks, Paul. We're going to cover two of the how-to tips in the Guide related to the system description as well as the equipment efficiency for service hot watering in schools. Water Heating Tip 2 discusses the system types that recommendations are provided for, those which include gas-fired storage water heaters, gas-fired instantaneous water heaters, as well as electric versions of those for both storage and instantaneous, and each of the recommendation tables in Chapter 3 performance recommendations are provided based on these system types. For a gas-fired storage water heater, the 90% efficiency level corresponds to a condensing storage water heater. For instantaneous water heaters, the energy factor in the thermal efficiency corresponds to what's commonly available for instantaneous hot water heaters. Efficiency recommendations are also provided for instantaneous electric water heaters. These types of systems can be an acceptable alternative to high efficiency storage - - gas storage heaters for small distributed loads. It can often times be more efficient than electric storage water heaters. However the impact on peak electrical demand, carbon impacts, as well as the fuel costs differences between the gas and the electric should be considered during the design.

Finally, we'll talk some about the additional savings recommendations that are provided in the Guide. The Additional Savings section includes ideas for other ways to save energy. These are not needed for the 30% energy savings in the Guide; however, they are good design strategies to consider. Lots of schools have used these and do either exceed 30% savings or these are strategies that in energy efficiency measures for unregulated loads in that these loads are not affected by the energy code so they are strategies that go beyond what the Guide currently has. The Design Guide has various additional savings best practices. These include electrical distribution, phantom loads, ground-source heat pumps. We'll go into detail for all of these in this webinar.

The first additional savings how-to tip refers to the electrical distribution in schools. Energy efficient distribution transformers should be provided in all construction and repair projects, new construction, renovation, or replacement. Minimum transformer specifications as of January 1, 2007, are classified by DOE as TIP1 and they're the lowest efficiency available. Energy efficiency transformers that are 30% more efficient than the minimum TIP1 classified by DOE as CSL-3 transformers. DOE recognizes that current step down transformers contribute to energy waste throughout the country. The CSL standard has been established to improve the energy efficiency of distribution transformers. This standard recognizes the low loading, especially in schools, and the no load losses with current transformer design. In addition, energy efficient transformers should be specified using DOE CSL-3 standard as the basis.

The Guide provides a technology case study looking at the use of energy efficient transformers and electrical distribution systems. Twenhofel a middle school in Kentucky, installed both energy efficient transformers, the CSL-3, as well as typical - - the typical specified transformers, the CSL-1s. Each of the three grade wings of the school had distribution transformers. The sixth grade wing had the energy efficient transformers and the other two wings had typical transformers. The following are the results: The testing of the transformers revealed that the loading for these transformers during the day was very low, between 2 and 3%. The efficiency of the transformers at this loading was 79.5% for the typical transformer and 91.5% for the energy efficient transformer. This meant an improvement in efficiency of more than 15% in addition to the no load losses improvements between 500 and 700 watt hours. In general, the electric use in the sixth grade wing with the high efficiency transformers was continuously lower than the other wings. So for… So this analysis showed for a typical middle school, $13,000 per year if all the wings in this school used energy efficient transformers in energy savings. The additional savings, TIP2, provides recommendations for energy efficiency in plug and phantom loads. Plug loads are devices or appliances that plug into a school's electrical system. Plug loads found in schools include computers, DVD players, LCD projectors, copiers, fax machines, fish tanks, refrigerators, vending machines, drinking fountains to name a few. In general, plug loads can contribute up 25% of the electrical load in a school at a density of 0.6 to 1.0 watts per square foot. A larger contributor to this load is equipment and appliances left on after use and equipment that has a phantom load when not in use. To reduce this load potential, consider controlling the top outlet of each duplex outlet with an occupancy sensor used to control the lighting in the room. In addition, creating a personal appliance policy in the school district and conducting constant energy awareness training on equipment appliances should be undertaken. The school board policy should also be established that requires all electrical equipment and appliances placed in a school to have an Energy Star label where an Energy Star label rating is - - for equipment is applicable. The table here shows some of the common types of plug loads that have Energy Star ratings as well as the operating recommendations for those equipment including implementing the sleep mode software or delamping the display lighting in vending machines.

Additional savings TIP3 provides recommendations for using ground source heat pumps. Ground source heat pumps are a variation to the water source heat pump systems included in the Guide's how-to tips. A ground source heat pump system takes advantage of the earth's relatively constant temperature and uses the ground instead of a cooling tower and boiler. A closed loop ground source heat pump system does not actually get rid of the heat but store in the ground for use at a later time. During the summer, the heat pumps extract the heat from the building and transfer it to the ground. When the building requires heating, this stored heat can be recaptured from the ground. In a perfectly balanced system, the amount of heat stored over a given period of time would equal the amount of heat retrieved. Ground source heat pump systems offer the potential for saving energy because they can reduce or eliminate the energy needs to operate a cooling tower or boiler. Eliminating the cooling tower also has architectural and maintenance advantages and eliminating the boiler frees up floor space in the building. We're often seeing schools that are attempting to go beyond 30% savings use ground source heat pump systems because of their many efficiency advantages. But to get to 30% savings, the ground source heat pump systems are not necessarily needed. There can be some issues related to sizing and performance for ground source heat pump systems in heating or cooling dominated climates. For example, in a cooling dominated climate, a large amount of heat must be rejected to the ground during the cooling season, but a much smaller amount of heat is extracted from the ground during the heating season. This imbalance can cause the temperature of the ground surrounding the geothermal heat exchanger to increase over time. In many areas of the country, this imbalance requires the geothermal heat exchanger to be larger to prevent the ground temperature from changing over time. Using a hybrid approach can often make these ground source heat pump systems more economical and address some of this imbalance. The hybrid approach involves adding a small cooling tower to the loop for a system that's installed a cooling dominated climate or adding a small boiler to a system in a heating dominated climate. This approach reduces the size of the geothermal heat exchanger by avoiding the imbalance.

The additional savings, TIP4 provides recommendations for peak demand reduction using thermal storage in a school. Adding thermal storage to an HVAC system can reduce the utility costs associated with cooling by shifting the operation of the chiller from times of high cost electricity, typically during the day time, to times of low cost electricity, typically at night. The chiller is used at night to cool or freeze water inside storage tanks storing thermal energy until the on peak period. During the nighttime hours, the outdoor dry bulb and wet bulb temperatures are typically several degrees, up to ten degrees lower than during the day. This lowers the condensing pressure, which allows the chillers to regain some of the capacity and inefficiency it lost by producing cold or fluid temperatures to recharge the storage tanks. Another potential benefit to thermal storage is a reduction in the size and capacity of the chiller. When thermal storage is used to satisfy all or part of the design cooling load, the chiller may be able to be downsized as long as it has enough time to recharge the storage tanks. An additional approach to reducing peak cooling demand is to take advantage of the buildings thermal mass. Many school buildings are constructed to have concrete or masonry walls which have high thermal mass. The thermal mass of these materials can absorb excess solar heat in stabilizing (inaudible) temperatures. To maximize the benefit of a buildings thermal mass, masonry walls that have a portion of the mass on the interior of the insulation is recommended. There are some new technologies and wall assemblies that are becoming available that have lowered the cost and increased the options for insulated masonry construction strategies.

Additional Savings Tip 5 provides recommendations for thermal displacement ventilation or often [sic] called just displacement ventilation. Displacement ventilation systems are different from a conventional overhead delivery system in that they deliver air near the floor at a low velocity at a temperature of about 65 degrees. The goal of a displacement ventilation system is to cool the occupants, not the space. Cool air flows along the floor until it finds warm bodies. As the air is warmed, it rises around the occupants and is exhausted up high. The intent of displacement ventilation is to improve air quality and reduce cooling loads. Air quality improves because containments from occupants and other sources tend to rise out of the breathing zone rather than being mixed in the space. Similarly cooling loads decrease because much of the heat generated by the occupants, lights, and computer equipment rises directly out of the occupied zone and is exhausted from the space. On the slide, you'll see a schematic of a school that used this type of displacement ventilation through an on the floor delivery system combined with a high return above the corridor. The school also used a south facing clerestory strategy integrated with this displacement ventilation concept.

The Additional Savings Tip 6 and 7 provides recommendations for including renewables, both photovoltaic systems and solar hot water systems in schools. PV systems have become an increasingly popular option for energy production and for teaching opportunity in schools. Currently most PV systems in schools are relatively small compared to the total energy use of the school. This is mainly due to the initial cost of PV systems; however, these smaller PV systems are typically used mostly as teaching devices. They're usually installed in plain view and make them visible to students, teachers, and the surrounding community, as you can see in this picture of again Twenhofel Middle School in Kentucky that has a 24-kW PV system available, highly visible and is used as a teaching opportunity in that school. In addition, there are many unique funding opportunities for PV systems in schools. In addition to the many rebate programs offered by state and local utility companies, they're often significant incentives, loans, grants, and buyback programs for PV systems. A great resource for finding those up to date is at the Database for State Energy Efficiency and Renewables, and you can see the link there.

Another option for renewables in schools are solar hot water systems. Because of the high hot water demands associated with cafeterias, solar hot water systems are often viewed as an important strategy reducing energy bills; and they can be fairly cost effective in middle schools and high schools, which have additional significant hot water loads for gym showers and sports programs. The final additional savings tip provides recommendations for using the school as a teaching tool. Schools that incorporate energy efficiency and renewable energy technologies make a strong statement about the importance of protecting the environment. The effort to make a school building energy efficient are no longer being hidden behind walls and inside mechanical rooms. They're being used as teaching aids in the schools allowing teachers to introduce curriculum that focuses on energy usage and environmental issues, as you can see two examples there. PV systems are also a common area of interest for energy efficient teaching tools. The PV systems allow for real-time information that can be added to the school's curriculum. The Guide has many examples of various schools that have Web-based monitoring systems that show the PV systems performance.

Our next section provides recommendations for using a commissioning process to implement the Guide's recommendations. The Guide provides best practices and recommendations for applying a commissioning process in both the design process as well as the how-to tips. In addition, Appendix B of the Guide contains details on the activities and related responsibilities for a commissioning process. Chapter 2 contains the integrated design strategies which commissioning is a critical piece, and Chapter 5 has detailed how-to tips related to the commissioning process. We will highlight a few of these in the following slides.

The first commissioning how-to tip provides recommendations for selecting the commissioning authority. To reduce a project risk, commissioning offers a quality oriented process for achieving, verifying, and documenting that performance of facility systems and assemblies meet the defined objectives and criteria. In choosing the commissioning authority at the beginning of the project will insure that this process is fully integrated with the design team. The selection of a commissioning authority should include the same evaluation process the owner would use to select other project team members. The owner should investigate the quality of providing commissioning services, the in depth technical knowledge, including the building envelope, mechanical electrical plumbing systems, as well as operational construction experience. The owners may select a member of the organization, the design team, or the construction team as the commissioning authority. However an independent party, whether a third commissioning professional or a capable member of the owners organization is recommended to ensure that strategies - - that the strategies and recommendations contained in this Guide are implemented as intended.

During the design review in the early phases, Commissioning Tip 3 provides some guidance on the early design review. A second pair of eyes provided by the commissioning authority offers a fresh perspective that allows identification of issues and opportunities to improve the quality of the construction documents. Issues identified could be more easily corrected early in the project providing potential savings in construction costs and reducing risk to the team. Commissioning Tip 4 provides recommendations for defining the commissioning process at the pre bid stages. The building industry has traditionally delivered buildings without using a verification process. The commissioning process must be reviewed with the bidding contractors to facilitate the understanding of and to help minimize apprehension associated with new practices. Teams who have participated in the commissioning process typically appreciate this process because they can resolve problems while their manpower and materials are still in place. Systems must be tested to insure that a project following this Guide will attain the energy savings that can be expected from the recommended strategies. Owners can use the functional testing process as a training tool to educate their O&M staff about how these systems operate and for system orientation before training. Commissioning Tip 10 provides recommendations for involving the commissioning process throughout the construction phase. Issues identified during the construction process are documented in an issues log and presented to the team for collaborative resolution. Then they are tracked and reviewed at progress meetings until they're resolved. Commissioning Tips 12 and 13 provide recommendations for continuing the commissioning process through maintenance and monitoring. Continued performance and control of operation and maintenance costs require a maintenance program. Detailed operation maintenance systems manual and training requirements are defined in the commissioning process and are executed by the project team to insure the O&M staff has the necessary tools and skills. The commissioning authority can help bridge the knowledge gaps between the O&M staff and help the owner develop a program to insure continued performance. The benefits associated with energy efficient buildings are realized when systems perform as intended through proper design, construction, and operations and maintenance. Commissioning Tip 13 provides recommendations for monitoring post occupancy performance. This is a critical step in that schools are typically and school districts are typically capital rich and maintenance poor and so the design for maintainability is critical to insure performance. In general, it's a good idea to pay a little more upfront to save on maintenance costs long-term. A good example of this is to the do the daylighting right and pay for the daylighting control - - daylighting design and not have to rely on systems that require significant maintenance. For Commissioning Tip 13, establishing a measurement verification procedure with a performance baseline can help a commissioning authority identify when corrective action or repair is required to maintain energy performance. Using Energy Star's portfolio manager is a good example of a tool that can be used to help track energy use and costs. A post occupancy performance monitoring can typically help owners understand when operational tolerances are exceeded and can help define the actions that may be required to return the building to peak performance.

Finally, we'll talk some about some of the case studies that are in the Design Guide. This is an elementary school in Climate Zone 4 in North Carolina. You can see there's extensive daylighting. A lot of the strategies that the Design Guide recommends this school has used, including well insulated envelope, north and south facing classrooms with high performance windows, good lighting design with occupancy sensors, daylighting with overhangs on the south side and lightshelves in the classrooms, high efficiency HVAC with DVC control systems. The measured energy performance is at 60 KBGs per square foot per year, which is a 30% savings over 90.1-'99 which was part of their lead goal to energy modeling.

Another case study we'd like to highlight that's included in the Design Guide is a high school in Whitman, Massachusetts, the Whitman-Hanson Regional High School. This high school is in Climate Zone 5. It's a 234,000 square foot high school designed for 1,350 students. It was built a total construction cost of $175 per square foot. The school is a pilot project for the Massachusetts Green School's Initiative. Whitman-Hanson is 39% more efficient than ASHRAE 90.1-1999. It makes use of extensive daylighting, a well insulated envelope, energy efficient mechanical systems; it does have a white roof, as well as energy efficiency appliances throughout. Daylighting is used in the library, a two-story lecture hall, and classrooms. In addition, high performance lighting system is used with T8s for an overall school lighting power density of 1.15 watts per square foot. The exterior walls are insulated with R10 continuous insulation, in addition to six inches of wall cavity insulation. Under slab insulation is also used on the slab on grade floors. The windows are also highly insulated and low E coated to reduce heat loss. A high efficiency hybrid chilling system is used. The primary base load chiller is a high efficiency water cooled chiller, while an air cool chiller provides additional capacity for peak periods. High efficiency condensing boilers, demand control ventilation with an energy recovery system and variable flow pumping are all additional HVAC systems utilized. Finally, a 51-kW PV system on the roof supplies approximately 5% of the annual energy use at the school. It is also part of the school's curriculum.

Just a quick reality check for using this Guide. This Guide was published a year or so ago now and so some schools have been starting to use it to see how far - - to develop their design strategies. This is an example of a high school in New Orleans that used the Guide right when it was published. Some of their lessons learned in using the Guide, they exceeded some of the recommendations in the Guide because they did additional analysis to show that they were cost effective. This included a higher efficiency chiller. They incorporated dedicated dehumidification which the Guide didn't necessarily discuss. They also went lower on their lighting power densities than what the Guide provided. They analyzed each of these and felt that additional energy efficiency in these areas was - - were cost effective. They…Because their site was constrained, they used the high performance lighting option, but they also combined that with daylighting where they could. As part of their LEED modeling, they achieved 30% savings over 90.1-2004. By using the Guide, they felt that they got to about 23% savings over 90.1-2004, which roughly equates to 30% when you compare it to 90.1-1999. So by using the Guide, this school was able to get to around 30% in an actual project, so it's a good reality check for the Guide.

A final case study, we want to spend some time on is the Smith Middle School, North Carolina. This case study provides a lot of good examples of the integration of all the concepts that the Guide covers, in particular a lot of the daylighting recommendations which is so critical to getting energy efficiency included in the schools. So this is a middle school completed in 2001, 700 students in 125,000 square foot. The school has been exhaustively studied over the last few years for both capital costs analysis to see how much these strategies cost as well as post occupancy energy monitoring performance and interview with maintenance and teaching staff to evaluate their perceptions of the systems. In general, this school was designed for daylighting in mind early on. The site and orientation favored daylighting. You can see here an aerial picture of the school, north and south facing classrooms. Daylight monitors provide daylighting to all the classrooms, the media center, the gym, and the main corridor, and you can see the white roofing material to reflect the additional lighting off the roof to reduce the cooling loads while at the same time providing additional light to the roof monitors.

Let's get into some of the specifics of the daylighting strategies that this school used. A lot of the recommendations in the Guide were based on what this school initially tested. So for the specifics on this south facing roof monitor, to minimize glare there's unevenly spaced fire retardant UV resistant fabric baffles within the monitor. The monitor includes clear double-glazed glass that allows the most light with the least amount of glazing. This reduced the cost of the surface area needed to fully daylight these classrooms. You can see in a picture here of what one of these classrooms looks like with this roof monitor above it and the fabric translucent baffles. They distribute light uniformly. It's a nice diffuse light over the full surface of the ceiling, completely eliminates glare problems, both direct beam and a high - - or a high glare diffuse light that is often seen in south facing roof monitors. By having a high ceiling, this keeps the hot air in the monitor from entering the condition space in the room, and this strategy enables the electric lighting to be off during most of the day, significantly reducing the peak cooling.

Some of the details on the window. These are south facing in this picture for the classrooms. The classrooms have a recessed window equipped with a clear low emissivity double glazing for all the windows. The south facing windows have a lightshelf above the view windows to both provide shading for the view windows and increase the amount of light that is reflected back into the daylight upper windows. This provides more lighting without glare. Note that on the north facing windows in the classrooms, they do not have these lightshelves.

Let's take a look at their gym. The gym is fully daylit with a similar roof monitor strategy and baffles. Again, these baffles and south facing roof monitors completely eliminate all direct beam and glare and effectively diffuse the light through the space. You can see here that picture, it's a great daylit space and the lights are off in the picture which is fairly uncommon when you see interior pictures of daylit spaces, the lights are typically on. The windows are constructed of clear double-pane glazing, again to minimize the amount of glazing needed to provide all the daylighting, which is a big cost saver. Very high visible and transmittance glazing when it's clear double-pane glazing. There are overhangs on the roof monitor to protect the spaces during the summer from adding additional cooling load on the space. Some of the additional techniques employed. This is an eight-year-old lighting control system, so T8 lamps were fairly - - with dimming ballasts were fairly start-of-the-art at the time, but they were used successfully in 2001 in this project. Occupancy sensors in the classrooms so that 90% of the time no lights are necessary in the classroom because of the daylighting.

So as I said, this school has been extensively studied over the years and here's some of the results of some of those studies. The daylighting strategy reduced the size of the cooling system by 19% or 78 tons. The cost of this downsized cooling system helped pay for some of the daylighting strategies. Measured data shows that a reduction of electric lighting of 85% on sunny days and 60% on cloudy and partially cloudy days. These results are also consistent with the modeling from - - performed from DOE-2. The RPI Lighting Research Center has surveyed 130 students and faculty over the years; and in general, the teachers favor the amount and quality of the daylighting, as well as the experience of a feeling of spaciousness. Finally, the principal uses this daylighting design to attract new teachers. Some of the maintenance considerations experienced over the last few years is that when dimming ballasts have failed to replace individual ballasts ends up being somewhat expensive and that maintenance budgets and financial analysis in the lifecycle costing of these systems should account for this. There's been some difficulty cleaning the cloth baffles in the roof monitors. They've been able to accomplish that. It's been somewhat difficult though. Calibrating and maintaining the lighting control systems, if they're too complex and too many parts can be difficult on the maintenance staff, so a simple lighting control system is always important. Another key part to making this whole system work is an administration effort to educate and encourage the proper use of daylighting. You can see here is one of the signs in the spaces to encourage the students to make sure that the lights and the daylighting systems are working appropriately.

If you take a look at some of the measured summary results for the daylighting performance in one of the classrooms, again this is results from the RPI Lighting Research Center Study. They installed data loggers to collect lighting levels, indoor temperature, and measure lighting energy use. So on average over three days of sunny days and three days of partly cloudy conditions, on a sunny day the average lighting energy use in the classroom is with daylighting is one kilowatt hour. On an average day that without the daylighting, it's 8.8 kilowatt hours. The average daylit room lighting is at 550 lux, which is similar to about 50 foot candles on a sunny day. On a partly cloudy, the daylighting performance is slightly less but still there's significant savings on partly cloudy days of 2.6 kilowatt hours with the daylit design and 8.4 without. Again, 32 foot candles or 320 lux measured averaged over the A classroom.

If we take a look at some of the cost, the capital costs associated with making this system work, it's been estimated that the daylighting system as a whole cost additional $158,000 or $1.23 per square foot. This additional capital cost includes all the bracing and framing, wall and roof insulation for the roof monitors, the additional glazing in those monitors, the controls and the dimming ballasts, the lighthselves and the cloth baffles as well as the wall finishes, the high visible transmittance on the walls. However, there were significant capital offsets as well which is the reduced cooling load and the lower chiller capacity from providing lighting from more efficient daylighting rather than the electric lights. So considering these additional costs with these costs offsets, capital cost offsets, and the energy savings over four years would pay for this system with the simple payback of 4.2 years.

There's lots of great information on this project that uses a lot of the recommendations that are in the Guide. You can see here the RPI Lighting Center has many of these studies published as well as the Architect Innovative Design and North Carolina Green Technology Database has additional information as well.

Paul Torcellini:  As we wrap up this seminar, there's some final thoughts we want to share with you recapping what you've heard over the last period of time. First of all, energy savings is easy to show and easy to achieve; however, it must be well integrated and considered early in the process. It diligently must be considered throughout the whole process through construction and operation. This has been shown with several case studies and the how-to tips. The recommendations that are provided in the Guide were developed based on exhaustive simulations using energy models and known energy data sets. One of the keys is to use daylighting in the classrooms whenever possible. It saves energy and provides for a better learning environment. Energy education and awareness training is also important. A continuous program is needed for students and staff and it ensures that design efficiencies and savings are achieved. Daylighting must be well integrated. It's not just about slapping a couple of windows here and there. It's really a strategy that provides lighting for the building without using electric lighting. These strategies must be designed to eliminate direct beam, address the glare, understand the user interaction with the daylighting system, as well as being able to make adjustments to the system to meet users' needs. In this picture, the teacher took on some of the design responsibility that the architect and engineer did not consider. Glare was an issue and the teacher taped pieces of paper over the daylighting glass, not the most effective solution.

There's several benefits of advanced energy strategies and using the Guide to save energy. More funds can be channeled into education. We can see an improved learning environment for students and the staff in terms of air quality and lighting, lower environmental impact for the construction, as well as lower environmental impact because of reduced energy needs, as well as an opportunity for teachers to introduce students to energy efficiency and renewable energy. Schools represent those living laboratories.

Finally, we want to hear your stories. What works, what doesn't work, how did you use the Guide, what pieces were helpful, what was not so helpful? We've provided a website for you to help us document case studies and provide this information. We have assembled a set of resources that will help you take this further and answer some questions. First, is the Department of Energy's EnergySmart School website. Included in this is a financing guide for energy smart schools. One of the questions we get quite often is: Is alternative funding sources available for renewable energy? There is a website based on different state incentives. 50 Green Strategies That Cost less is also included in this resource list. In this are many of the strategies you've seen today in detail. A wealth of knowledge is housed at the National Clearinghouse for Educational Facilities and their website. Finally, the details of the analysis and the pieces that were used to put the simulations together to achieve the 30% energy savings is in a Technical Support Document on the Advanced Energy Design Guide and is available at the National Renewable Energy Lab's website. Finally, we want to remind you that free downloads of the Advanced Energy Design Guide are available at the ASHRAE website at the link listed here.

Rosemarie Bartlett:  Well thanks very much for such an informative webcast, Paul and Shanti, and thanks to all of you. The U.S. Department of Energy appreciates your attendance. I'm going to put on the screen right now the link at which you can go to provide us some feedback on the webcast today. If you are a member of AIA and want to have us submit you for credit for attending the webcast today or if you are able to self-report to a professional organization for credit, you can also go to this link and generate and print a certificate for yourself. So if you're interested in that, please write down this link. Go into your browser, enter this link, and follow through the process.

At this point, we'd like to get to the questions that have come in, and Shanti's going to start us off. Shanti.

Shanti Pless:  Great. Thanks. So we've got a lot of questions that start here about where to find this presentation online and so I'd like to give you the website real quick here. It is… It will be available for download at www.energysmartschools.gov/pdfs and then backslash aedg_slides.pdf. So you'll be able to navigate to that and find a PDF version of all the slides.

Rosemarie Bartlett:  I've just gone ahead and put that link back up for everyone.

Shanti Pless:  Great. Thanks. You can also at that same energysmartschools.gov, this webinar will also be available. You can browse through the slides and then hear the audio again. So that will be posted shortly, stay tuned for that.

Paul Torcellini: So we also got some questions on plug loads, and I'm going to change the slide. Could we get back to I think it was Slide 8 there? There is it. There's some questions on computer usage that this slide actually does break out the computer usage is about 3% of the overall commercial building load. That is predominately the data side of it, data center servers, et cetera. There's also some IT or computer infrastructure and the actual computers under the other and the office equipment.

There was a question about definition of plug loads kind of related to that. We basically call plug loads anything that is not heating, ventilating, air-conditioning, or lighting loads, but it ranges from all of the things that we plug in, which could be computers and coffee pots and microwaves, all the way to equipment that is hardwired into the building such as elevators, smoke alarms, security systems, et cetera, are all classified in the plug load category. It is important to remember that those things add up and are significant. I was recently in a school and they had a small auditorium with a rack of equipment that did audio and some projection, et cetera, and it was on all the time and its load was about 3,000 watts running continuously and so we need to think through the plug loads because they are a significant portion of what these buildings use.

Shanti Pless:  Great. Thanks, Paul. So we got another question about some more definitions. We're going to try and go through all the definition questions that we got here just to start. One of the questions was: What's a mass wall? The Guide has recommendations for insulation levels for what we call mass wall. Typically that's a tilt up or a concrete or a masonry wall construction type and that the code specifies different types of insulation for those construction types versus a steel stud or a wood stud construction type and so we refer to mass walls as those that are typically have more mass and are built and have different construction techniques and therefore different insulation techniques in the Guide.

Paul Torcellini:  We also got a question on U-factor and U-factor is the reciprocal of R-factor. R-factor is the number that you quite often see on the back of insulation that's printed there. U-factor is the reciprocal of that. So if you have an R-10 piece of insulation, its U-factor is 0.1 or one-tenth. It represents… It's proportional to the amount of heat transfer that that wall can conduct. It is usually used in specifying window and window constructions and therefore the lower the U-value, the better the window is at resisting the heat flow.

Shanti Pless:  We got another question about in general how do we… When we talk about energy use intensity or energy use per square foot, what square foot is that actually so it is gross area for the total square footage in a school even for spaces such as a high volume gym; it's the square footage of - - gross square footage in all our square footage numbers.

Paul Torcellini: We had several questions dealing with why was 1999 picked as opposed as to 2007 or 2004 version of ASHRAE 90.1? At the time that the Guide series was developed, 1999 was the most common and widely available guide that was out there and that information has carried through the standard. We have on the current K12 Guide provided information according to 2004 in our technical support document, which the URL was on the screen a little bit ago in the presentation.

As far as trying to compare that Energy Star rating, do you want to address that, Shanti?

Shanti Pless:  Sure. So part of the issue with comparing to Energy Star rating versus a percent savings over code in that Energy Star compares your energy use to what an existing stock of schools whereas energy code analysis where you calculate percent savings compares to a theoretical code minimum building and so there's… It's not necessarily a one-to-one mapping of if you get 30% savings in your school to an Energy Star score of 75, for example. We have seen some schools that are 30%/40% savings have very good Energy Star scores, but it's not a direct one-to-one mapping. So we encourage you to do both analyses to determine what those area.

Paul Torcellini:  Just to follow on my comment a minute ago about 2004 compared to 1999, in general you can meet the 30% over 2004 if you pick the daylighting option in the Guide.

There's some questions on producing guides for individual types of spaces that you might find in schools. At the moment, there are not plans to do individual subsections of buildings. We have provided some specialized guidance in this Guide, as well as other guides in the series. There is a guide on warehouses, highway lodging; small healthcare is going to be coming out shortly and small office. So you might refer to some of those other guides if you think that you have a need for more specific information, especially if you were designing say the office area of a school and you want more information about making the office area more efficient, I would refer you to the small office guide.

Shanti Pless:  We got a couple questions about how the recommendations were developed, whether they were based on a lifecycle analysis or were they just based on best practices or lessons learned and so some of the… It's a combination of both really. So there's a lot of lifecycle analysis done on the envelope recommendation, for example. The way the current codes have been developed, they've done a lot of lifecycle analysis based on the different insulation levels of the various wall types and so we did a lot of that analysis for developing the envelope recommendations, the wall insulation, the roof insulation, the windows, and such. So that analysis was carried through to develop the recommendations for envelope measures. A lot of the other recommendations, such as the HVAC systems efficiency were generally based on the best practices available from our project committee, the industry experts that have been designing high performance schools, and so it was a combination of both some lifecycle analysis as well as best practices.

Paul Torcellini:  We've had several questions around the lighting and daylighting portion of it that we will address now. One of the questions had to do with why we specified in the guide lower lighting power densities when daylighting is used. The Guide represents methods to get to 30%. It is not the only way to get there but suggestions on how to do that. If you've got a system that is well daylit and you don't need the lights, the efficiency of the light fixture isn't as important as it might be if you don't have daylighting and you're running those lights all the time. It is important to remember that if you have daylighting, it doesn't do you any good unless you can either get the lights dimmed or the lights off and so there is a tradeoff there that the Guide does allow an additional amount of energy from a lighting power density to go into the lights if the daylighting is there and it's functioning than if you have no lights there. That is not to say that you shouldn't design for high performance lighting systems and low power densities for Daylit systems. That can then be a bonus savings and will certainly get you beyond the 30%.

There was a question about the responsibility of the design team to inform the owner that he needs to operate or how to operate the building in the future. Certainly as part of the design and construction process of these buildings, the design intent should remain clear to the owner to do this. The owner needs to be engaged in that process. They need to buy into the technologies that are selected and typically we find that the more simple the solutions, the better they will work and the longer the persistence of energy savings. We've also seen systems that are very, very complex and the owner turns or the contractor turns the building over to the owner and they don't know how to operate it and at that point a lot of the innovation and sales and so it is important that the owner understands and is willing to maintain any technology that's put in the building.

Shanti Pless:  We got a question about where daylighting should be applied in a school and particularly about do we recommend clerestories in the hallway of a school, even for a multistory school and so in general we provided kind of the where daylight should be is most beneficial including classrooms and gymnasiums where they're typically most occupied. Hallways are also a good application for daylighting if they have access to a toplit system. So a hallway on the first floor of a two-story school typically isn't a good application for daylighting, but the top floor is especially. One item of note here is that trying to use share daylighting from this type of hallway daylighting into a classroom is typically not recommended. It's very difficult to get sufficient daylight into a classroom through a share daylighting strategy from the hallway.

Paul Torcellini:  Quite often we call that strategy the "magic eras [sic]" where you see nice cross-sections of buildings where light is penetrating through the building according to an era but in reality you need a lot more analysis to get it to work effectively and that lighting going form an area that does not require a lot of lighting such as a hallway into a classroom usually does not work real well.

Shanti Pless:  We have a question about issues with birds or pigeons on any type of lightshelves or overhangs exterior and I think our only caution there would be that if that is an issue to design to mitigate that. The Guide doesn't have specific recommendations for that, but it should be a design consideration where that's an issue.

Paul Torcellini:  Certainly there's lots of different variations of daylighting systems out there including external shelves versus interior shelves, actually putting light direction devices between the panes of glass is another alternative. It could be that your external shelf is designed to have some kind of bird spikes on it too if that's an issue, but you certainly need to understand the climate and the environment that you're in in looking at these integrated solutions.

Shanti Pless:  And, Paul, to add to that, in the daylighting recommendations for each climate zone for the daylighting strategy, there's a range of glazing to floor area ratios that are provided. In general, we've seen that as… Our industry experts that are on the project committee have seen that as kind of an optimal level of daylight glazing to minimize those HVAC loads and so it's not over glazed but is designed to provide daylighting and sufficient daylighting without over sizing your glazing system.

Paul Torcellini:  In general, if you are designing for daylighting and providing a good high quality light, it is amazing how little glass you need to accomplish that, and we do exhaustive studies on how much glass is necessary. In most cases, they will reduce the glass to the point that most people would not really be in that space and that they still want additional view glass, which does come as an additional load, heating and cooling load to the building. We did get a question about: Does the glass actually produce high… At what point does the glass produce higher heating and cooling loads on the space? The thing to remember here is that the efficiency of daylight is about three times higher than it is for the best electric lighting that is out there. That is a very efficient source in terms of a light versus heat ratio.

Shanti Pless:  Paul, that system… To add to that, that's if it the glare and the direct gain is controlled appropriately. To caveat, that's very important to understand in comparing daylight efficacy to lighting, electrical lighting efficacy.

Paul Torcellini:  Right, and a glass box does not necessarily mean you have a good daylit environment. That usually you end up with a lot of glare, a lot of heat, and other factors which don't make it very comfortable from a lighting point of view.

Rosemarie Bartlett:  Guys, I just wanted to jump in. We have received a few questions related to the certificates. So I wanted to just reiterate that if you need to write down the link that's on the screen right now, type it into your browser. You do not go directly to a certificate generator. There is a feedback form, a very short one that we ask you to fill out first. If you're AIA members, then you'll see that part kind of in the middle; and if you want the certificate, you have to follow the feedback form a few pages in in order to get the certificate page. There is someone who is having trouble generating the certificate, so I want to put up this slide. If you're having certificate issues, you can send an email to techsupport@becp.pnl.gov; and Jenni Sonnen also wanted me to remind everyone that a webinar, an online version of the webcast today, will be available later today at the energysmartschools.gov website that's listed on this slide. So I'm going to leave this up for just a couple of minutes while the guys continue to answer questions, and then I'll go back to the certificate link and keep that on the screen.

Paul Torcellini:  Thanks. We've had a lot of interest in the fabric baffles that we showed on some of the case studies and alternatives to that. The key on the baffles is to have some material that has some ability to block any direct gain that you might get, especially with lower winter sun, and then you can diffuse that light into the space. There are lots of different strategies that can be used with that. You can either use a fabric material. Some jurisdictions will require that that be fire treated. But you can also use kind of - - some kind of grid or mesh such that you might find as an egg crate material in a light fixture. Depending on how you design it, you may even use some smaller suspended pieces of solid material that then could reflect light and bounce light off. So there's a lot of flexibility and a lot of strategy. The key is to design it so that you don't have direct glare on the work plane or in people's eyes and that it becomes a very nice uniform light.

Shanti Pless:  Paul, a related question is: For these daylight systems, the questionnaire wanted to know how you would modify a daylighting system to allow for projections and darken the space for a presentation, for example, and so there's some strategies where you can build in some internal overhangs in the space, a teaching wall that is slightly shaded from the daylighting and build that into the roofline of the space. Typically for the current generation of projectors, they need less light or they don't need to have as dark surfaces to function and so that definitely combines well with the daylit space.

Paul Torcellini:  There's definitely… We've definitely still seen some specs out there where people are trying to use 16 millimeter projection equipment and filmstrip projectors, things that have for the most part long ago gone away and that a lot of the newer technologies, especially in terms of computer screens, other things are much more robust and much more forgiving with more glare in the space, and that definitely has helped our ability to put daylighting in.

We've had some questions about some of the look and the feel in terms of whether the - - how come the lightshelves recessed as opposed to an exterior strip? There's a lot of architectural freedom in how to do these things; and in those case studies, that is what the architect chose. It may not have been the least cost solution, but it was an integrated solution such the total project came in at a certain budget while meeting certain energy goals. That also brings up the question on a lot of the questions coming up on trying to cost justify this. What we have found is that people upfront that say, "I want to build a school that has a set energy goal," and in this case today we've been talking about 30%. If it is part of the design criteria upfront that the design team will work to integrate all these pieces together just like all of the other project requirements that are out there to get a project that meets a fixed budget and we've seen that quite successfully in many cases.

Shanti Pless:  So we have two more minutes here it looks like. I've got a few other questions. One is about how do PVs hold up in colder climates and with snow and ice accumulations. In terms of their durability, PVs work great when they're cold. They're more efficient when they're cold; and durability long-term, they have been tested in very cold icy climates. They're used oftenly in the South Pole, for example, so the issue is more how much snow accumulation is on your panels reducing output rather than durability and longevity.

Paul Torcellini:  We would also like to encourage people if they've learned things on here and have schools that have met this criteria that they can go to highperformancebuildings.gov and on our case studies' database actually enter your schools and your projects to show other people your success stories much like the success stories that we have shown here today.

Shanti Pless:  I guess we'll keep going until we end out of time here, a few more questions to cover. There's a question about: Does the Guide have recommendations for air barrier design? If you have the Guide… If you take a look at let's see…

Paul Torcellini:  EN18 is the…

Shanti Pless:  EN18, sorry, I was pulling out my Guide here to find exactly the right one. It relates to air barriers and specifically what controlling infiltration, how to minimize the infiltration or exfiltration through your envelope, so there's lots of good recommendations there.

Jenni Sonnen:  Rose, are you ready to wrap it up or…

Rosemarie Bartlett:  I am. Do you have one last question, or are you guys all done?

Shanti Pless:  Sure. There's a question about why do in some climate zones that are fairly mild, like in Climate 2 and 3, why the wall insulation recommendation seem seemingly low. In fact they do not… The recommendations in the Guide do not exceed code in some climate zones that are fairly temperate, and the idea being that a lot of the energy savings, percent savings come from things like daylighting and lighting design and as well as outdoor air control because the climate is so temperate and that it increase inflation in walls or in roofs so where there's fairly little heat loss or gain because the climate is so temperate, the Guide focused more on another strategies to get the 30% savings.

Rosemarie Bartlett:  All right, great. Well good job on getting through so many questions. I appreciate that. We'd like to thank everybody for participating in today's webcast brought to you by the U.S. Department of Energy. You may all disconnect.