U.S. Department of Energy - Energy Efficiency and Renewable Energy
Building Technologies Office
November 29: Introduction to the 50% Advanced Energy Design Guides (AEDGs) (Text Version)
Thank you, Stacy. My name is Emily Laidlow and I'd like to welcome you to today's webinar titled "Introduction to the 50% Advanced Energy Design Guides". This webinar is presented by the Better Buildings Alliance Program, formerly known as the Commercial Building Energy Alliances Program at the US Department of Energy. We're excited to have with us two of the experts who developed the Advanced Energy Design Guides or AEDGs.
Before we start, I have some housekeeping items to cover. I just want to mention, as Stacy said, that everyone is in a listen-only mode. We will have Question & Answer session at the end of the presentation. You can participate by submitting your questions electronically during the webinar.
To submit a question, click on the Q&A link on the top bar of your screen, type the question in the box, and click "Ask". Please be sure to click "Ask" and not the symbol of the raised hand. Our speakers will address as many questions as time allows after the presentation.
Today's speakers are Shanti Pless and Bing Liu. Shanti Pless joined NREL in 2000 and is a Senior Research Engineer with the Commercial Building Research Group. He focuses on applied research and design processes for commercial building energy efficiency and building-integrated renewable energy. He chaired project committees for three of the 50% savings Advanced Energy Design Guides, including guides for K-12 schools, medium to big box retail buildings, and large hospitals.
Bing Liu joined the Pacific Northwest National Laboratory in 2002, where is a Chief Research Engineer. Bing has more than 17 years of experience in building energy efficiency analysis and simulation, and high-performance building metering and measurement. She oversees PNNL's Building Energy Codes Program and she also chaired the project committee to develop the first Advanced Energy Guidebook targeting 50% energy savings for small to medium offices.
Shanti and Bing will provide an overview of features of the 50% AEDG, which will allow design and construction teams to achieve advanced levels of energy savings without having to resort to detailed calculations or analyses. And with that, I'll turn the presentation over to Bing and Shanti.
Thank you, Emily. For today's presentation, we'd like to cover the following topics. We will provide an overview of the AEDG series; and specifically, we will focus on the 50% AEDG content and the recommendations to get to us design buildings and have 50% more efficient compared to design constructed buildings that meet the codes requirements; and also we will provide some factoring analysis for energy analysis and analysis result into the recommendation. As Emily mentioned earlier, the last 30 minutes, we will reserve that for Q&A session.
So the first question is, "What is AEDG?" It stands for the Advanced Energy Design Guide. This is a series of books. They are developed through the collaboration among several professional organizations and the Department of Energy. I will talk about a little more about organizations.
So the AEDG, the first Advanced Energy Design Guide, was published back in the year of 2004; and in the last eight years, we have published two series of the books. The first series of books are targeting 30% energy savings over the standard 90.1-1999; and when we started working on the project at that time back in the year 2003, at that time, standard 90.1-1999 was the law of the land and that was their most recent baseline code standard. So that was the target for the first series of the book.
Then several years ago, we started to develop another series book which is targeting 50% energy more efficient, but compared to 90.1-2004 as their energy code requirement.
The different — I mentioned 90.1 Standard — and we know that's the national model code for commercial building. And this AEDG book guidance — one thing we had to make very clear, they're not code of standard. More, the book is used to provide a best practice in terms of efficient design. So they are really tools to more educational guidance.
And another really good thing we'd like to share with you is all the AEDG series books you can free download as a PDF from their actual website at the URL we provided down here; and also you can purchase a hardcopy of the book at their online bookstore as well. We started working on the 50% series of AEDG books. We have to have some ground rules in terms of developing these recommendations.
The first one is we had to make sure all the systems, all the products we recommend as a more efficient requirement, had to be commercially available; and also we make sure it had to be at least two manufactures can make the similar product at a similar level of efficiency as we recommended. And also when we're looking at a building component of the HVAC system, we are keeping in mind in terms of their first cost. So the system that we recommended in the AEDG guides, they are not very expensive systems, and so we make sure they are within their cost — within the first cost range compared to their conventional systems.
Also, as we mentioned earlier for 50% series, the baseline bar has been raised, so the comparison is 90.1-2004 Standard as their base system. But at the same time, we keep in mind when we start working on a 50% guide, the 90.1-2010 Standard has been published as well two years ago. And at that time, 90.1-2010 Standard we know had a significant jump in terms of efficiency, which is like in the range of 25-30% more stringent than 2004 version. So for AEDG guide, we have to ensure our systems and products we recommend in the guide must be at least complying with the standard 90.1-2010 level.
And also, we know the focus of the guide is in terms of their deep energy savings; but on the other side, we also had to ensure we were going to design and construct buildings, provide indoor air quality, and also make sure the buildings provide comfort occupants. So that's why the guide, we make sure in the guide all the systems must comply in the way of the Standard 62.1-2010, which is their minimum ventilation standard, and ASHRAE Standard 55-2010, we call that a conference standard.
So this slide is showing the partnership of AEDG. It's not a single author who wrote this book, it's two collaborations among the professional organizations from ASHRAE, AIA, Illuminating Engineer Society, US Green Building Council, and the Department of Energy.
So the guide also is overseen by a specialized committee as well. So each of the guides is designed by the building type, so each of the guides have a specialize project committee responsible to write this guide. And the entire series of AEDGs is overseen by a steering committee called AEDG Steering Committee. Another whole series of the guide also have been backed by DOE's national labs, including PNNL and NREL; and the role of the national labs, we provided the leaderships and also energy and technology analysis and support to the guide as well.
During the development process, the draft portion of the AEDG has been posted on the website and open for peer review; and we're looking into the review comments and finalized the guide based on the review comments.
I think I mentioned the structure of the steering committee and the project committee. Again, both of the committees have a committee of the members representing all the professional organizations; and especially for the project committees, the members are usually the leaders, designers, architects. They have all the firsthand experience to design and practice high-performance building design. And also as the author, they contributed to the writing of the guide itself.
This is their slide. It's really capturing all the published AEDG guides. So for 30% targeted guides, they covers mostly small buildings like around 20 square-foot, and some small office buildings to small hospital and health care facilities.
So we have six building types covered. And for 50% AEDG guide, currently we have published four building types and four guides, from small to medium office buildings, K-12 schools, medium to big box retails, and large hospitals. So for 50% service guides, five of the buildings have been increased from small buildings, to small to medium buildings, even to large buildings. We will talk more about each of the 50% guides later on in the presentation.
In addition to the AEDGs, we also as a national lab, publish a technical support document as a precursor to the AEDGs. So the main difference between the TSD — we call the technical support document — a TSD compared to AEDG is, on this technical support document, we have documents that are technical analysis and result, you know, all about the same analysis in terms to get us into the recommendations in the guide. And also in the TSD report, we have some analysis showing the cost effectiveness of this AEDG guide. And the AEDG itself doesn't address the cost directly, but the TSD report has their cost analysis for your consideration.
So if you're interested in really other analysis methodologies approach and a cost effect analysis, you can free download the TSD at ASHRAE's website as well.
I want to talk briefly on the impact and distribution of the guide. Up to date early this month, they're close to half a million copies of AEDGs in circulation. And you can see most of them are electronic format, and there are also a lot of hardcopies that has been filled also. And also from their distribution, we also saw acknowledges that the users in United States downloaded and using AEDGs. We see a lot of our distributions across other countries — Canada, China, India, etcetera, and the European countries as well.
And we also have seen the AEDGs has been called out in owners RFP specifications in terms of the design. And another impact is really I think also a design intent at the beginning of AEDG is, we see their influence, you know, that some of AEDG requirements through the years, how they moved into and show up in member codes like 90.1, a high-performance building standard like ASHRAE Standard 189.1.
Also the AEDG guide has been reported in the LEED rating system as their prescriptive compliance path. So if you have a small building, for example, you don't need to go through the whole building simulation if you're complying with their prescribed path, their checklist; and AEDGs, you can get I think four credit from for LEED.
So this one is really showing the path from AEDG to how they move and influence the market. And as I mentioned earlier, our intended impact is that we see the recommendations, you know, show up as recommendation in the early stage of the AEDGs, and it move into and it influences their Standard 90.1 and 189.1 as well.
Well, I will give the floor to my colleague Shanti Pless and he will talk a little bit more about how the AEDG influences in terms of industry application as well.
Great. Thanks, Bing. So, yeah, this slide kind of demonstrates how we see the AEDGs being used in influencing the market. And so the top part of that of the training, the webinars, that we're doing today. And other examples of that I've heard about — YEA, the Young Engineers in ASHRAE is a group I think has a good story I've heard about, how young engineers that join consulting firms, they are often given AEDGs to learn about energy efficiency as part of learning their job, and so I thought that was a good example of how AEDGs are impacting young engineers out there in learning about energy efficiency.
We also see showing up in the industry, whether it's commercial building partnerships that set CBP down there — those are demonstration projects by major building owners like Target and Walmart and such — that are attempting to use the similar AEDG recommendations for retail, for example, in actual facilities. So some PNNL in the labs and NREL's other work involves working with those major organizations to demonstrate that 50% savings can be done and there's a business case for it. And so those commercial building partnerships is what that program's called are often using these AEDGs as a starting point.
I spent my other efforts over the past few years in helping other owners understand how to apply these AEDGs. For example, in Greensburg, Kansas, they rebuilt their whole city after a tornado a few years back with the AEDGs as the common starting point for all those buildings; and so it was great example of a whole town rebuilt using AEDGs. And we've given webinars and there's a lot of good published content in there, their measure of energy efficiency using the Advanced Energy Design Guides.
Another good example I've heard about the AEDGs impacting market is showing up in owners RFPs for new buildings. And whether it's a small healthcare RFP thing, you know, demonstrate your experience using the 30% savings for small healthcare for design build teams looking to respond to RFPs to build new efficient facilities. And so I've seen that multiple times in RFPs looking for — for owners looking for design build teams to meet their minimum requirements.
And so overall, I think there is a pretty good impact on a market, and everyone involved in delivering high-performance buildings. And, you know, over 450,000 in circulation is a good way to look at that; but you've got to combine that with specific examples of how the market is adopting these advanced recommendations.
In addition to the 50% recommendations being used, after the 30% series was completed, DOE and ASHRAE commissioned a study of the market impact for the 30% design guides. And so this report is available here, you can see the length. But in general, we found that the majority of the AEDG users rate the AEDGs very favorably in terms of the credibility, the technical content, the ease of accessibility; and it's up there with the other resources that the industry has available for high-efficiency buildings.
We did find that they're used in all sorts of ways. We kind of intended them to be used maybe one or two ways, but we're finding they're being impacted in the markets in lots of different ways as well.
Here's kind of a review of some of how the survey responders felt the guides were credible, were easy to obtain, good enough technical content, effective actually resulting in energy savings, well organized, and as flexible as possible there. So in general, we felt that they were providing a useful resource; and the 30%, it was valuable for DOE and the AEDG process that continued to the 50% series.
So we want to get a little bit into some guide content details, kind of review what each of the 50% guides — how they're structured and what they include. Here's, in general, how each guide is structured. There's a forward and each one's specific to each of the billing type decision makers: A general how-to you the guide chapter, and integrated design process chapter, Chapter 3 on case studies and performance targets. Chapter 4 is really the meat of the guide where all the recommendation tables by climate zone are provided, and then Chapter 5 in general is the details of how to implement each of the recommendations.
So this front matter, the forward, it is written specifically to each decision maker for each building type, whether it's an office building, a retail facility, a healthcare or a school board are the different types of forwards written for each decision maker — and really makes the business case and the nonbusiness case for why 50% should be considered by each decision maker. And we cover things like the cost and operating cost and other sustainability issue that might be part of the decision making process for a new facility.
There's a lot of things like public perception and the general marketing of your organization by doing 50% savings. And so that also comes with a decision maker flowchart — you can see an example of that here — and just how to use the guide at various project phases from the ownership point of view and when they should expect to pull out the guide as an owner and understand how it applies in each of the phase of the process.
The integrated design chapter: It's a high-level example of how to apply a more integrated process to get at least 50% savings really is — the guides are a way, but not the only way to get to 50% savings, and so this process is critically important in getting the most cost effective, best value project at 50% savings as possible. And so there's a tutorial on how the various elements of an integrated design process have to be considered at the various stages so that you kind of know what to look for at each stage and how to apply the 50% savings recommendations.
And there's a lot of attention paid — you know, when you do modeling, how to apply the modeling process at the various stages of design so that you can get a more optimal solution for your specific case with the 50% AEDGs as a good starting point for that. You can get more effective efficiency, more cost effective, more energy savings if you go to that modeling process for your specific site and climate and billing type.
Where possible? We do incorporate some high-level best practices. This is an example of what these look like in the AEDGs of cost control; and there's a lot of best practices we're seeing from those that are actually reaching 50% savings out there in various building types and how they approach the cost control question. All the AEDG recommendations have been done before by someone out there in the industry; and if you can pull out their cost control, the best practices, you can understand how they are able to make a business case around that 50% savings.
So we try to capture some of those best practices where possible, incorporate them as key strategies, whether it's through the integrated design process, cost tradeoffs, or alternative financing. We'll go through some of the details of what each guide incorporates and how those that have got to 50% savings have done so within their own business models.
So the recommendation tables are really the meat of the guide for each climate zone. We'll go into the details of each of these, but in general, they're structured from envelope recommendations first that vary by climate zone. They get into things like daylighting and lighting design that are specific design that are specific to the billing type.
Plug load control: This is the whole business energy savings — 50%. So we cover things like plug loads and kitchen equipment selection. Service hot water heating is covered for each building type. And then into various mechanical systems that are the most common way design teams are reaching 50% savings on their HVAC system selection.
So there's a range of HVAC system types that are being optimally used to reach 50% that the guides all incorporate. And then where appropriate, we discuss the level of commissioning and verification, and oftentimes, renewable energy that's often needed for 50% savings. And we try and group all these recommendations on a few pages, and so it is a one-stop shop checklist type of format so that you can quickly and easily understand a level of efficiency needed to get the 50% for your building type and climate zone.
In a few of the 50% guides where possible, we offer up an alternative way to get the 50%, and that using a whole building energy use target, meaning an absolute energy use intensity at kBTU per square foot per year that we would expect the building to have to reach to reach 50% savings. So if you hit that AEDG EUI target, it's an alternative way to get to 50% savings if you're hitting that EUI target.
And those really allow for a measurable goal in operations, and it's more of a performance path for 50%, and we often hear, "What's the EUI target we should be hitting? Are we on track?" and, "They want that number." So some of the guides have some discussion about how to use energy targets.
And they do vary by climate zone and billing type. And even within the billing type, they vary, depending on the school, or the retailer, or the hospital, or the office building that you are building. And so it's a pretty useful tool that the 50% guides have looked to incorporate above and beyond what the 30% series did.
Some of the how-to tips look like this. There are specifics about addressing thermal bridging and various details of carpets or where walls meet with foundations, and how to advance energy efficient wall systems here. You can see an ITF wall system going in. How to do that cost effectively on typical budgets where appropriate, and so there's a lot of discussion about how to do that and how to integrate these types of advanced wall systems in this case here.
Daylighting for each of these building types is a key strategy and it can often be done poorly we've seen, and so there's a lot of attention paid to, understanding how to do an integrated daylighting system — and you can see some examples of schools here. We'll get into more details of how individual billing types are recommending daylighting. But it's often a key strategy, but it needs to be done well integrated and a lot of attention to these details to get the savings out of the daylighting.
Lighting tips are usually structured around common floor plans on whether it's a school, or a gym, or a common premier office, or a patient room — all the different common space types that these guides incorporate. There's a detailed discussion of lighting power density, lighting layout, how to get to the lighting power densities the guide recommends in a common way.
Similarly with HVAC in the how-to tips discussion about how to layout systems and best practices for efficiency and integrating dedicated outside air systems with the local zone level, and in obstructed discussion of these different strategies the guide recommends in a fairly detailed way.
And as I said, each of these AEDGs are incorporated recommendations that someone else has done before well and so we have a lot of good case studies to pull from, whether they're whole building case studies. You can see an example of a school here in Kentucky. That is with a school whole building case study that used a lot of the similar AEDG recommendations. And so anytime we have a whole building example, we try to incorporate it to demonstrate that it has been done and the results they've achieved.
Here's another example of a large hospital that also incorporated similar recommendations in the large AEDG, and so we definitely wanted to focus on this can be done in demonstrating the best practices that are out there and trying to translate to all the climate zones and building types so that the market can start to adopt some of these best practices.
There's also a fair amount of detail, the technology case studies. This is a little different than the whole building case studies in that they focus on a specific application of a daylighting technology. For example, a variable speed compressor on heat pump is a pretty common strategy that guides recommended. So we wanted to spend some more time on the details of that technology as an example of how it was applied, how it was integrated, and the level of savings that each of those technology case studies incorporated. So each guide has technology case studies as well.
And finally you'll see something called bonus savings, and these aren't necessarily for the 50% per se, they're not incorporated into the recommendation tables, but they are incorporated in the how-to tips, because they're often used as on the strategy. They may or may not be applicable in all climate zones, and they're not necessarily needed to get the 50%, but there's a lot of examples of teams incorporating these bonus savings — things like extra renewables or — you can see a transpired solar collector schematic here, thermal energy storage.
All great ideas and great strategies that can save a lot of energy. They weren't necessarily incorporated into the minimum prescriptive recommendations that the guides incorporate to 50%, but still a good idea when they can be integrated.
All right, so we're going to get into some of the details of what makes each of these AEDGs unique and we'll start with the 50% small office and let Bing talk some on the 50% Small and Medium Office Guide.
Thank you, Shanti. As I mentioned earlier, each of the guides we really especially tilled into their particular building height, because they have their own different low profiles, and also unique challenges we need to address in a practical way in terms of targeting to reduce energy in that building.
For small to medium office buildings, the guide itself is covered to the building up to 100,000 square-foot in gross floor area. And also the spaces we covered in this guide is a typical office building — administration, professional, government building bank and financial services, and medical offices — but without heavy-loading process load with their medical diagnostic equipment. But this guide, what we don't have is some specialty space, such as data center, which is more typical to say that in a large office building, but not in a small to medium office building. Now in the guide, we do cover the products and process load that we do see that in typical office buildings.
Here is the highlight of what's in the 50% office guide. And Shanti mentioned earlier, this is really looking at whole building entity use and also how to integrate a way to design buildings to use much less energy, but still provide their thermal comfort and indoor air quality is really to try to provide also health, very healthy building environment to our occupants.
So for envelopes in general, there are insulations or other requirement is much more stringent than 90.1-2004 minimum code requirement; and, also, this is the guide also we have address their façade optimization. So we have recommendation as when you design their office building, what you need to keep in mind in terms of their perimeter zones with what we can do to optimize the façade so we can provide more opportunity for daylighting, etcetera.
And for interior lighting in general, there's two big strategies. One is really targeting to keep their illuminating levels — would provide sufficient illuminating levels to the occupant, but still able to, using better technology, to reduce the lighting power density. So in typical office buildings, rules standards are 1 watt per square-foot for lighting power density, and the recommendations in the guide is targeting 0.75 watts per square-foot in terms of lighting power density. And as you go to the other sections, we provided their recommendations basically showing how other people — you know, they already figured out how to do that without losing the quality of the light.
Also, again, the layout of the office building is also critical to provide better quality interior lighting, and also their control of their lights and lighting fixtures is one other very effective strategy as well.
Another big indicator is definitely daylighting; and in the guide, we have very detailed recommendations in term of the lighting design requirement for different space types — from open-plan office, private offices, conference rooms, and public spaces.
We also learned a lot through other metering work we did for other project is exterior lighting — a parking lot, oversight lighting entries, etcetera — actually is one of their major energy users of the building. We a lot of times try to ignore that; but in terms to really reduce their energy consumption for entire building, we usually need looking into reducing their energy uses on their exterior lighting as well.
Also we have a lot of recommendations in terms of the plug load and process load control in office buildings from monitor, computer, servers, printers, and fax machine off-setters. So if ENERGY STAR® has that particular appliance covered, that's the recommendation in the guide. If not, we have recommendation on best-in-class plug-in equipment recommended data. In source water heaters, the target is really 13% more efficient compared to minimum code requirement.
Another very unique recommendation in a 50% service guide compared to periods of service end service guide is we provide a lot of flexibility in terms of HVAC system selections. For example, for office guide, we have six different HVAC systems with specific design requirement. They all can help us get to 50%. So you can see it's from packaged single-zone air source heat pumps all the way to radiant systems. So it's different climate locations. You might consider different systems, but we give a lot of flexibility and more option choices for mechanical system selections. And, also, we have additional HVAC recommendations such as demand controlled ventilation energy recovery.
So that's a very high-level summary of what kind of recommendation you can see in a small to medium office building. And Shanti is going to walk us through the rest of the building types of recommendations.
Great. Thanks, Bing. So very similar to the small office, medium office guide. The next one that we did was the 50% savings for K-12 schools, and this really applies to all types of Kindergarten through 12th grade — elementary, middle, high schools — with the typical spaces that those types of schools incorporated from classrooms, and office areas, and gyms, and assembly, and food prep of kitchens, libraries. Most new schools do not incorporate swimming pools nowadays and so those are not part of our recommendations or our modeling for 50%, or things like wet labs or other unique spaces that maybe some unique schools might have; but we're really focused on what's in a typical K-12 school for 50% savings.
So in general, similar to the small office guide, the envelope was roughly 45% more efficient than the standard — and you'll see that in all the AEDGs that use similar level of high-performance envelopes. We've got significant energy savings on the lighting power density of 42% reduction over code. There's a lot of opportunity there to still maintain a great learning space, but not a significant savings there with layouts for the various typical space types to reach the lighting power densities and the luminous requirements in the classrooms.
Of all the building types, daylighting might be the biggest opportunity in schools. There's a lot of reasons to have good views and good daylighting for enhanced learning environments, and so you can also pair that with the energy savings that daylighting can offer if done well and done right; and glare-free daylight is an absolute requirement for a classroom, for example. And so the details of how to get glare-free daylighting into either gyms or classrooms are the two most common spaces to do daylighting from both the top and the side, the south and north of those spaces that are fully covered.
Again, exterior lighting, roughly 33% more efficient than the standard. And then for schools, those that are done well and have a great envelope and good lighting design. Plug loads and kitchens and cafeterias end up being a predominate 25%, 50% level of the total load, and so there's a lot of stuff now we're learning in the kitchens, for example. And so there's a whole section on high efficient kitchen selection, layout, design, especially in the hood design and how the hoods are put together and specified in design — all part of reaching 50% savings in this building type.
Again, ENERGY STAR® when available, as well as best-in-class when it does not apply for all equipment. Again, similar service hot water on saving strategies there.
For 50% schools, we saw three primary types of HVAC systems being used in the industry in our case studies, all with a dedicated outside air system. A lot of schools are understanding that ground source heat pumps can be done cost effectively and with reduced maintenance cost compared to other system types. So where possible, that's usually the preferred system type. We still are seeing four-pipe systems as well with the dedicated outside air system as well as an advance VAV system.
But in general, everything's got a dedicated outside system. The outside air is separated from the space heating and cooling, and that allows you to do a lot of grade efficiency strategies separate on the zone level heating and cooling separate from the outside air. In things like energy recovery and dedicated demand control ventilation were all great strategies when you are committed to decoupling the ventilation air as the guide recommends.
And then lots of great value added for schools — things like how to use your school as a teaching tool and really make your efficiency strategies or renewable strategies part of a science curriculum are often great best practices we're seeing in a lot of these high-performance schools.
So we have seen some good success on how design teams in progressive school districts are attempting to really get the 50% savings on their typical construction budgets, and so we tried to understand those cost control strategies and document them so that others can use those best practices in how to control these first costs so they can incorporate these levels of savings. And so it's really about applying the heart of an integrated design process to fine-tune the design so that you can really control the high cost elements and get to this level of savings from integrating your team to aligning your program in your budget and goals at the project inception.
Life cycle cost analysis is always a core part of a good integrated design process and understanding how can you reduce maintenance costs. A lot of school districts are capital rich and maintenance poor, so if you can reduce maintenance costs through investment in efficiency — things like ground source heat pumps or LEDs that last a lot longer than other types of lighting systems — those are all good life cycle cost savings to incorporate into your financial decision-making process.
And then things like cost tradeoffs and investing in the first cost savings from removing extra amenities and putting that into efficiency, or trying to cost tradeoff between mechanical and envelopes, for example, is a common strategy that schools do.
The value added we talked about — anytime you can create an efficiency strategy that does multiple things, not just save energy, there's always extra value there, and so that's always a great strategy. Things like enhancing the learning environment; and if it's efficient as well, that's a great way to get efficiency incorporated; or if it's part of a core curriculum on understanding energy efficiency and renewable energy — the energy systems of our country in a learning environments, that's a great strategy as well.
And then anytime you have alternative financing, whether it's rebates or third-party ownership of renewable, for example, those all should be considered for reaching 50% savings.
So let's transition to the next guide that was in the process the third of the fourth here. This is the 50% medium to big box retail. This is typically between 20,000-100,000 square-foot, single-story — typically multiple big boxes that are around the country. A lot of the recommendations will still apply to the bigger boxes or the smaller boxes; but in general, that would be our scope here for this retail type.
In corporate spaces predominately, the sales floor area, but also the back of house and administrative office areas, hallways and restrooms, and then storage areas. They're all core parts of an efficiency strategy.
We do not incorporate specialty space types, such as commercial refrigeration that you might see in a grocery store, for example. Where a grocery store refrigeration system might be 50% of your total load in a retail grocery store building. So a lot of the non-grocery space of a grocery store might be able to implement these 50% retail recommendations, but will save the 50% commercial grocery store AEDG recommendations maybe to a later guide.
So, again, similar recommendations for the envelope — 45% better than standard. Lighting is in general 38% lighting power density reduction for retail space — and part of that is the accent lighting here — and we see a lot of retailers going to LEDs throughout for all display lighting. That's a great strategy to get to that 38% reduction.
Daylighting in some cases; some cases not, depending on the retailer and their willingness to bring daylight into their sales floor. Some are great at it, some are not necessarily interest in it, but there are still pathways for both to get to 50% savings.
And a lot of these retailers have a portfolio building — so not just focusing on one building on a time, but understanding your portfolio and how to optimize your portfolio over time is a core part of big box retailers; and so there's a discussion there about portfolio energy reduction, testing out various strategies and understanding which ones work or not for a typical retail, and then enhancing your portfolio going forward rather than one store at a time.
Again, plug loads — there's a fair amount of opportunity that's been untapped at this point I think in the retail sector for how to reduce plug loads in the sales floor or ENERGY STAR® throughout, where possible. We have four types of HVAC systems that are typical for 50% retail, from all variable standard rooftop to dedicated outside air systems with multiple ways to do zone-level heating and cooling from a standard rooftop to heat pumps are ways we've seen the big box retailers, or the small box retailers, attempt to get to 50%. So there's a series of recommendation of how to best do that cost effectively.
One that we have seen is probably one of the biggest savings opportunities at getting to 50% is this idea of a performance-based ventilation reduction strategy. One example we have document around understanding what drives a ventilation requirement in a big box retail — and it turns out being the indoor air quality from all gassing of all the product in the store rather than the people. And so if you ventilate for the product, that's a different ventilation type and strategy and significantly reduce ventilation in back than ventilating for the max a day after Thanksgiving ventilation required in these retailers. And so there's a significant amount of first cost savings as well as energy savings if you really understand how much ventilation is actually needed in these stores.
So on some of the cost strategies we've seen in cost control strategies for getting to this level of savings that have been successful, really understanding what the tradeoff is of enhanced envelope load reduction in the number of rooftops you have. And can you start to invest in load reduction to the point where you can actually eliminate a rooftop. And when you're doing that, you're maybe investing in efficiency a little more, but offsetting that first cost with smaller mechanical systems or less of them. And so if you can get into that understanding by climate zone, that's a great strategy for really optimizing your system to be cost effective and 50% savings.
So on the HVAC system type — if you can design your mechanical system rooftop system where you're putting in one big dedicated outside air system, usually the costs of incorporating things like energy recovery, demand control ventilation, high-efficiency compressors and such, that's a little more manageable for a retailer if you can do one big unit rather than a bunch of the smaller ones. And so it's a key strategy for incorporating a lot of these efficiency recommendations in the layout of your rooftop system, and so that strategy is pretty well covered in how to do this cost effectively.
One thing that we heard a lot is if you can look at your actual loads in your other examples of your portfolio of retail spaces and understand what your actual peak cooling is and your actual outdoor air loads are, and then base your future sizing on your measured performance of previous stores — and you can really fine-tune the sizing in your equipment and save if for an amount of capital. That cost savings can be reinvested in additional efficiency. And so we're seeing a lot of retailers going back and looking at what they actually use so that they can get better as they go forward in their new prototypical designs.
A T1: I think a fairly standard tentative of integrated design is understanding things like interior color palettes and how that impacts your overall install lighting power density to get to a required foot candle on a shelf. And so understanding that is I think a good example of how an integrated design process can save a fair amount of energy, and just through a good decision-making process, that's fairly well integrated. And then alternative financing, again, is a core strategy that everyone should take advantage of, from rebates to incentives to third-party ownership.
All right, the fourth of the four guides that we're going to be talking about today is the Large Hospital Advanced Energy Design Guide, and this is really meant for large stand-alone hospitals — 100,000 square-foot or larger typically, with all the common space types that a large hospital might incorporate. I know there's a lot of specialty hospitals out there or things like teaching hospitals or more laboratory-type hospitals. This is really a fairly standard stand-alone hospital.
I think a lot of these recommendations will apply to all those other speciality-type of healthcare facilities. But in general, this is our target market here. And so everything from cafeterias, to offices, to patient rooms, operating surgery suites, triage emergency rooms, physical therapy, and all the laundry and mechanical electrical telecomm rooms associated with a large hospital are all covered.
Things like data centers or parking garages, or if you have a campus, hot water/chilled water steam system that may be typical for your specific healthcare. But we don't necessarily cover those space types. I think there's a lot of recommendations and other resources out there at the energy alliances or through ASHRAE and the other professional societies that are available that cover those space types.
Again, the envelope is similar: 45% better than 90.1-2004. Some fair amount of detail of discussion on how to get to a 25% lighting power density reduction across the whole hospital — and that varies depending on the different space types, whether it's a patient room, nurse station, operating room, recovery room — all the standard space types that have different levels of opportunity for an efficient lighting design. But overall, we're looking for around a 25% reduction at a minimum in the interior install lighting power density.
Access to daylighting is key from both a healthy recovery environment and patient well-being, as well as the opportunity for opening up a hospital for daylighting and for views. And so there's the recommendations discussion about how to approach the massing and layout of a new large hospital to both create a nice environment for both the recovery in the patients as well as the caregivers.
Exterior lighting is covered. Task lighting: There's a great example of how LED surgery light recommendations can save a significant amount in the surgery suite, but also understand how the cascading impacts of reducing the amount of heat that's being put onto the docks in a surgery can result in other changes in efficiency in terms of set points and other patient warmers, because the surgery suite is so cold, because they had old inefficient surgery lights.
Elevators are usually typically pretty multiple floor hospitals — and there's some discussions about elevators and then a whole discussion on high-performance kitchen design.
I think you've seen ENERGY STAR® as a minimum throughout on all the guides. We're going to talk about that and specifically to their billing types. I think the one key strategy in 50% hospitals is this idea of aggressive reduction of reheat.
In a typical hospital, reheat might be 40% of the total energy use, and so it's the first thing we do to try and get to 50% savings is understand why there's so much reheat. This is simultaneous heating and cooling, often done for dehumidification or for multiple zone types that have the same air system but different types of loads. And so reheat is something that can be almost completely eliminated if thought of early enough and systems are approached to do so.
And so there's three HVAC types that are recommended in the large hospital guide that cover strategies for almost eliminating reheat from zone-level heating and cooling with dedicated outside system to a dedicated outside air system with a large built up variable volume with heat recover chillers, which is the big central plan concept, central air handler concept — and most healthcare owners are used to and that it can be done in those system types as well.
And then a whole host of additional HVAC recommendations for large hospitals that are also key from elimination of steam boilers for heating to airside energy recovery and demand control ventilation where possible.
On the cost side on some of the key strategies we've seen, some of the healthcare systems utilize to get to this level of savings and maintain their first cost budgets. Anytime you can relate an energy efficiency strategy to the healthcare mission of patient outcomes and quality of care, that's always a pretty simple sell. If you enhance the healing environment and be more efficient, it makes a lot of sense.
Overall health of the community is the key strategy, and understanding that your energy use of your hospital can impact the overall quality of health of the community; and that if you understand those connections, it makes the sell of efficiency and energy reduction a little bit easier, as well as opportunities of reduced medical errors and more satisfied care givers, and more happy nurses and docs because of the quality of the space can go a long way in incorporating energy efficiency.
Again, integrated design: Reducing errors and rework is always a key strategy for a better design process that can optimize the size of equipment rather than rules of thumb that can save a fair amount of money and be more efficient if done well, to the overall lifecycle cost analysis is also understanding the maintenance cost and how many maintenance techs you have to have on staff just to change light bulbs, for example, right; and you can reduce that overall maintenance burden because you've invested in LEDs that are more efficient and last longer, and you can have reduced amount of maintenance staff dedicated to just changing light bulbs. So those are the kinds of things that work well and are covered in this guide for 50% savings in healthcare.
A few others here: I think we've seen all these on the other guides as well the idea of a cost tradeoff. Anytime you can build something off-site and prebuilt that reduces the onsite construction time, that's always a good idea for reducing delivery costs and first costs; and so you can reinvest that into energy efficiency.
Value added: Things like the idea of being able to use your daylighting during the day to extend the amount of time you can run off your backup generation systems. That's a strategy we've seen some healthcare systems attempt to apply to alternative financing and rebates. There's healthy rebates for the most part of the country for owners investment to help to defer that first cost.
So real quickly here, we're going to go through some of the modeling that went into these and to wrap up and to just get a sense of what goes into demonstrating 50% savings on the modeling side. This is in general how we approached the modeling. We start from a typical energy model — this idea of a prototype model, and that represents a standard hospital, standard school, standard office building. We might have multiple ones of those, depending on the building type. And then that prototype model is run through about the baseline that's co-compliant 90.1-2004 as well as run through the low energy recommendations that the guides incorporate, and then compare to demonstrate 50% savings in all the climate zones.
You can kind of see the process here of how that applies. And so we're hitting minimal ventilation needed in ASHRAE 55 Thermal Comfort as well as 90.1-2004 minimums, and then compare that to the low energy models. We incorporate plug loads in the operational processes all gathered from the project committee; and the owners and the design experts that are out there that design and operate these buildings have a pretty good sense of what their plug loads are and what their schedules are. So all that's incorporated into our prototype models.
And so with that, we're to run you to our models across every single climate zone and sub-climate zone in the United States to verify that we are in fact reaching 50% savings, and so we'll kind of review real quickly where we reached in a few of these for the various billing types. So Bing, I'll turn it over to you to go through the office.
Okay. Thank you, Shanti. Well as you can see on the screen, for office buildings, we actually developed two different shapes and sizes of project buildings. One is a smaller office building. It's a two-story building, 20,000 square-foot, and it's a square building, and you can see the window is your typical punched window we have down here.
On the other is a bigger size of the building, like 54,000 square-foot and three-story buildings; and they're rectangular buildings with a ribbon window. So that's important, the shape and location of the window is in the daylighting design we have in the guide. We passed this idea saying, "Okay, we recognize not all the building design windows, etcetera, will not be maximum as their daylighting, as in terms of design."
Our recommendations in the guide: If we can get 50% reduction of energy use using the same size and shape of the building window — like punch windows — we still can get the 50%, and that really means it's foolproof.
So this one really demonstrates where the energy savings is coming from. So on each of the groups of the bars, you can see it's really by the different climate locations, from 1A, which is typically, say, in Miami — a very hot, humid climate — all the way to 8 which is seen in Alaska, Fairbanks — very cold climate. And also on the stacked bar, each of the group locations on the left of the bar is the energy use for an entire office building by energy use intensity kBTU per square-foot, per year energy use, and a breakdown by other energy user for 90.1-2004 minimum code requirement.
On the right side of the same group of the bars is, if you design your same buildings by incorporating the recommendations in the guide, that was their energy use. So you can see on each of the climate locations, we're able to cut energy use at least by half. And each energy users tells you who are the contributors, all the way from plug load and HVAC lighting and HVAC system and service hot water.
So, Shanti, you can go through the rest of the building types.
Yep, great. Thanks, Bing. So similarly for the schools guide we had two prototypical schools: A primary school — one-story, 74,000 square-feet, roughly 650 students; to a secondary school — two-story, mostly middle school/high school type, with over 1,000 students and 211,000 square-foot. So those are the two models that we started with.
And you can see, they kind of oriented — and with classroom wings fairly advantageous for the layout. But when we apply the recommendations and the guides, there's a significant change to the types of windows, the location of windows. You can see top lighting in the gyms for both the primary school and the secondary school, and how that's a model incorporated I believe in the library as well. So it's what the guides recommend — and you can see how that looks.
And so there's also a fair amount of daylight modeling that has happened in these classrooms to really understand how to get good quality, glare-free daylight — whether it's from the south or the north into classrooms. And so there's a various sample of daylight models that are incorporated there and what those look like, and the recommendations that are based off of these types of models.
And so you can see similarly what types of energy savings were reaching up to 60% back in some climate zones, all the way down to some of the more difficult ones — 50% in the more temperate climate zones in 3A, 3B, and 3C. But this is what the FRC pump system. It significantly was reduced over the baseline. Some of the other mechanical system types was very close to the 50% savings, but in general, you can see energy use intensity between 20-40 kBTUs per square-foot per year across the United States is where we're expecting schools to be for 50% savings.
And for the retail, this is what a retail box — not a very exciting energy model. It is truly a box, but still lots of opportunity there. A medium box and a big box — 20,000 and 100,000.
We do see a fair wide range of plug loads in retail, whether it's an electronic store where they're selling plug loads basically. There's a fairly high plug load component to their overall end uses. And so we actually had a prototypical model baseline in low energy case. They had a high plug load example as well as a low plug load example. And so just to make sure that the recommendations were in fact still reaching 50% savings for a range of store types.
Here's an example of where those savings are. You'll notice the energy uses are significantly different from the office and from the schools. The majority of it is interior light, because they are open for so long and the luminous requirements are a little bit higher in retail stores. But in general, again, over 50% savings in all climate zones. There is some equipment energy savings that is evident here as well; but through better lighting design, and LEDs, and daylighting where appropriate, there's over 50% savings in lighting alone that is reachable and attainable now.
So for the hospital energy modeling costs, this area was a single large hospital that looked somewhat like this. It was seven stories with a five-story patient tower and a two-story diagnostic and treatment block underneath that patient tower.
Fairly standard layout. Roughly 500,000 square-foot. But that's scalable as you add more floors, patient towers expands or contracts the treatment D&T block there. So that's what we represented our prototypical large hospital. This is actually based on a hospital that looks similar to this, so we have a model to base off of an actual design.
And the results here: One key difference in large hospitals is that the overall energy use is significantly higher — almost an order of magnitude higher than all the other building types. So we see around 250 kBTUs per square-foot, per year, typical of large hospitals running now without necessarily a significant emphasis on energy efficiency. So that changes slightly by climate zone; but in general, we're starting around 250 kBTUs and trying to get down to 125 or even 100 kBTUs per square-foot, per year for these large hospitals to reach 50% savings.
And this example is with this water-source heat pump system. All the other mechanical system are modeled as well shown in the TSDs and in the AEDGs I believe. This is just an example of the level of savings by a climate zone and where we're getting these savings from. That big dark red for the baseline for all these different climate zones, that's mostly reheat; and so you'll see in the low energy cases, that has almost been eliminated as we talked about. So that was a core strategy there is to eliminate that reheat.
So I'm going to quickly wrap up here. I think to conclude, I think we've heard a lot of good positive feedback at the AEDGs are actually fairly simple to use and simple to understand. All the recommendations are concise and put into one spot, and so that helps and you don't have to hunt around a whole book to find all the recommendations that you're looking to apply. And so we've heard a lot of good feedback — and that was actually the original intent of the AEDG, so it's good to hear that that's still part of a highly valued part of the AEDGs.
I do think that in many ways, the AEDGs are kind of a simple interface to the more complex interview modeling that we just kind of reviewed. There's a fair amount of modeling — a significant amount of modeling that both Bing and I had energy modelers back in our labs to really try and understand all these inputs and create all these energy models.
Modeling all these different building types in 16 different climate zones multiple times is a significant modeling effort, and so I think the AEDGs are kind of a simple user interface into that complex modeling process that the labs do behind the scenes that using EnergyPlus in our case opens up the usability and access of the complex EnergyPlus modeling capabilities to the industry. And so I think that's what I see as a key part of how these are simple and easy, but based off complex modeling and optimization routines.
I do think that the case studies are critically important; and whether they're technology or whole building case studies to show that this has been done before. And so if it's a model, that's one thing; and as everyone should rightly be, I think skeptical of what a model says and use that as a good starting point, but then base actual designs and concepts on what's been done successfully in the past based on energy modeling I think is a good way to approach that.
So I think it's critically important to look at successful examples of those that have done this in the past, both from the detailed technology implementation, the integration to how they did it with their typical construction budgets, and how they made the case — the business case, the mission, the enhanced learning environment case — all those go into making or breaking, I think, 50% savings designs. And so that's critically important understanding I think how these recommendations will work for your projects.
And going forward, I do see these guides as a step towards the idea of net zero energy. We didn't talk too much about that, but on the cover of each of these, it says 50% savings on the path to net zero energy. And so going forward, we see that industry and certain building types are starting to create examples of net zero energy offices, net zero energy schools, even net zero energy retail now. And so I think the next generation of AEDGs we should attempt to look at what the industry is doing now with the case studies and the recommendations by climate zone for a net zero energy series of AEDGs. So I know I at least will be looking for that going forward in trying to continue the AEDG process with that in mind.
I think having almost a half million of AEDGs in circulation can be considered a success, and so I get pretty excited about that to see something that we've worked on in the project committees and everyone involved — everyone from the steering committee and the DOE support, financial support, for us and for the project committees to write these guides has been absolutely critical — and I see that as a huge success in impacting the market, and so that's great that we can be involved in something like that.
And the AEDGs are available again — I think that Bing said this earlier, but it's a different link here. But you get it free at www.ashrae.org/aedg — it's the way to get you there, and continue to add to that AEDG in circulation to really understand how to get to 50% savings across these different building types.
So with that, our contact is there. If you have more questions, please submit them or contact us there. I do want to thank Jeremiah Williams at DOE. He's the Technology Development Manager for the AEDGs, the 50% ones over the last few years, and so I want to thank him for his support; and, Bing, thank you for co-presenting with me. And if you have questions, please — I'm taking it out of your conclusion here. So thanks and give me an email or contact me for additional questions. Thanks for your time all.
Yeah, thank you Shanti and Bing — and we still have about 15 minutes for questions. It looks like we have a few here. If you haven't submitted them already, just as a reminder, you can go to the Q&A bar on the top of your screen and submit the questions. And, Shanti, I'll let you.
Sure. So we've got a question from Mike Easy — thanks, Mike — about where those EUI targets are in the guide.
So the three guides that specifically talk about EUI targets are the schools guide, the retail guide, and the hospital guide — and they're all in Chapter 3. There's tables of EUI targets for both end uses and the total whole building EUI targets by climate zones, and they're in Chapter 3 that talk about how to use targets and why whole building targets may be more appropriate than a percent savings target for you, and what the differences are about how to apply those. And I believe you can pull out similar EUI targets from the energy savings that Bing presented in the small office guide as well.
I think the idea of energy use targets has quickly evolved in the industry and so we started to incorporate that when we first did the K-12 schools. But that's how we've incorporated targets. So Chapter 3 for each of the guides and you'll see those tables there and discussion of how those apply to each of the building types.
So another question there I got is, "What's the status of the net zero energy AEDG series?"
I don't really have too much of a status update there for you other than I think it's a good idea. In general, I've been trying to study the net zero energy industry and where people are, what building types, what climate zones — collecting case studies to make the case that the AEDG series is needed to extrapolate individual case studies best practices to the rest of the industry in climate zones. That's probably the best I can relay back to and respond to that question.
Bing, anything you want to provide there on the idea of status of net zero energy and AEDGs?
Sure, Shanti. Actually, I want to brag a little bit on some of his work — and he's too humble down here. I just learned he's actually one of the authors to publish the net zero energy book with other architects who has practices net zero building design. So, currently, we don't have a formed plan and timeline in terms of publishing their AEDG net zero book, but as Shanti mentioned, definitely this is in the planning stage. So, Shanti, maybe you want to mention the book you guys recently published outside of this whole AEDG stuff, but that's also net zero building design book.
Another thing I want really to emphasize down here is still under Department of Energy's building technology program, another program we have been working on, both Shanti and I have been involved, is their Commercial Building Partnership Program. In that partnership program, we actually have firsthand experience to help their design teams to design net zero building.
The one with my particular involvement in the last couple of years is a design net zero energy use bank branch in Florida — a quite hot humid climate and dominated by cooling load — and within their cost budget. So I think we're at a stage in correcting more — and more net zero design before we get into to drive and share the best practice down there. So I hope we will work towards better goal and working on a net zero book in future.
Great. So the next question here is, "Can we get a copy of the slides?" And I might focus that question in understanding what the process is to do this to.
Yes. The slides will be available on the Alliance website within a few weeks. You'll have your recording and the slides as well.
Great, so the recording of — okay. So, yeah, so the recording of the whole webinar and the questions will be available for you to spend time going through.
All right, so the next question we got is, "Is there any plan to convert the EnergyPlus models to an interactive computer program? It seems the models may be modularized to zone type and they may recompose to take care of building geometries and sizes."
Absolutely. We get a lot of requests for access to the energy so that design teams can take them and apply them to their own process trying to get to 50% in their own building type or their own building — and these are prototypical, but they have a lot of efficiencies already incorporated in them. And so if you contact us, we can share those models with you at this point. There's been a lot of discussion how to create a process to automate that where you can run your own AEDG models or you can pull down your own EnergyPlus models for climate zone in AEDG type so that you don't have to go through email with us. But at this point, they're available to anyone that would like to just start using them as a starting point.
We do share them, and have heard that as a need in the industry to really enhance the market impact of the AEDGs to make models and interactive tools available so that design teams, especially energy models for these design teams have a great starting point for 50% rather than to have to recreate a full energy model to get to 50%. If they can base their starting point on what we've already done, I think that would help the industry in general adopt these 50% recommendations more seamlessly.
So it's a great recommendation and we've heard that multiples times. And so if you want them to do that, give us an email, or if you're interested in — and then stay tuned as we attempt to find the best way to make that more of a streamlined process.
Great. So I think we're about done. I don't have any more questions. Bing, anything else that you'd like to share with everyone online before we wrap up?
You can put in your description of the buildings; and then we could give you a recommendation and we're going to help you to check what the minimum requirements — I mean the code requirement; and we also can produced their recommendation so that if you additional design like that for your buildings, you can actually get it AEDG level. So that's a progress we're planning to work on to start from next year. So just stay tuned.
Great. Thanks, Bing.
Emily Laidlow: Okay. Well, thank you. We would like to thank our speakers again, Bing and Shanti, for their time today. We would also like to thank all of you for participating. As I mentioned earlier, the presentation, the recording, and the slides will be available on the Alliance website soon, so check back for that. This concludes our presentation. Thank you and have a nice afternoon.
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