Strategies to Cut Energy Use by 50% in Commercial Buildings (text version)
Below is a text version of the Webinar titled "Strategies to Cut Energy Use by 50% in Commercial Buildings," originally presented on October 28, 2010. In addition to this text version of the audio, you can access the presentation slides and a recording of the Webinar (WMV 23 MB).
Operator:
Welcome, and thank you for standing by. At this time all participants are in a listen-only mode. Today's conference is being recorded. If you have any objections, you may disconnect at this time. Now I'll turn the meeting over to Anthoney Perkins. Thank you. You may begin.
Anthoney Perkins:
Thank you, Candy. My name is Anthoney Perkins, and I'd like to welcome you to today's webinar, entitled "Strategies to Cut Energy Use by 50 Percent in Commercial Buildings." The webinar is presented by the Building Technologies Program at the U.S. Department of Energy, and we're excited to have with us today five speakers that will talk about the new technology support documents they've assembled that can help create high efficiency commercial buildings. But before we start, as Candy had mentioned, you are on listen-only mode, so we will have a Q&A session at the end of the presentation.
To participate, you can submit your question electronically throughout the webinar. To do so, you can click on the Q&A link at the top of the screen, type in the question and click the Ask button. Please make sure you click the Ask and not the symbol of the raised hand. At the end, our speakers will address as many of the questions as time allows for the presentation. Also, wanna point out the link on the screen — the URL of www.buildings.energy.gov/webinar. On that webpage is a link to see today's slides. Also, today's presentation, as we said, is being recorded, and a video of the presentation will be posted in the near future. And you can also view past webinars on our archive page from that location.
And finally, we will have a few quick questions to ask you to help us learn a little bit more about the audience and target our future presentations. We'll start with two questions now, and then we'll have two more at the end of the presentation before we go into the Q&A session. So if you click on your screen to indicate the appropriate response, we'll look at the first question now.
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"At your location, how many people are participating in today's webinar?" We'll give you a few moments to answer that before we go on to the next one. We're gonna ask that you go ahead and vote now if you haven't. We're gonna close out in just a moment. Okay, we're gonna go ahead and close out this question and go on to the next one.
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"What best describes your affiliation or organization?" And we'll do the same. Just go ahead and click on the screen for your — the best answer for your situation. We'll give you just another moment to answer that question before we close it out. Okay, we're gonna go ahead and close out that question. But thank you for your participation in those. And now I'll go ahead and introduce our first speaker: Jerome Lam.
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Jerome is an Energy Technology Program Specialist with the Commercial Buildings Integration and Deployment Team in the Building Technologies Program here at Department of Energy. He'll give us an overview of today's webinar. So with that, I'll turn it over to you, Jerome.
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Jerome Lam:
Thanks, Anthoney. Thank you, everyone, for taking time to attend this webinar. Let me provide you an overview of our Commercial Building Program.
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The goal of the Commercial Building Integration and Deployment Team is to significantly improve the energy efficiency of new and existing commercial buildings by researching technologies, strategies and tools for improving energy saving over the current building codes. We partner with commercial building owners and operators who help us vet and pilot technologies so that we can more quickly and effectively deploy successful strategies with the industry at large. In return, it will help influence more stringent codes and standards. It's also the main goal of the Advanced Energy Design Guide. Ultimately, we aim to impact three types of commercial buildings each year.
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Some of our deployment programs include the Commercial Building Energy Alliance, Retail Energy Alliance, Hospital Energy Alliance, and Commercial Real Estate Energy Alliance.
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The Commercial Building Partnership, which are the Real Building Construction and Generation Projects being construct by company in hospital, retail and commercial real estate sector with assistance from DOE and the National Labs. These buildings target advanced energy savings and will serve as prototypes for the industry. Most commercial technology solutions, which are specific for building components and equipment, can meet energy efficiency goals.
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The specifications were combined by the National Labs and tested by our alliance partners in the industry.
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And the Advanced Energy Design Guide, which this webinar will cover today.
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You can learn more about all this program online at CommercialBuildings.Energy.gov. So now our next speakers, Shanti Pless and Adam Hirsch with Commercial Building Group at National Renewable Energy Laboratory. Shanti Pless is the Senior Research Engineer Lead AP with ten years' experience in commercial building energy efficiency research. Adam Hirsch is a Senior Mechanical Engineer with a focus on system integration. Both speakers were instrumental in the development of the recent large hospital and large office 50 percent savings technical support documents. So let's turn to Shanti Pless and Adam Hirsch.
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Shanti Pless:
Great! Thanks, Jerome! Thanks, Anthoney. We're loading up our set of slides here, and so we're gonna get into some of the details of what an AEDG and a TSD actually are. AEDG, again, stands for Advanced Energy Design Guide. TSD is a Technical Support Document, and we'll be talking about those within the next few hours.
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So let's talk some about what an Advanced Energy Design Guide actually is. The concept here is that there are packages of energy efficiency solutions by building type and by climate zone that are easy-to-use recommendations to reach 30 percent savings. We looked at 30 percent savings over the current generations of codes when we first started these advanced energy design guides about five or six years ago — 90.1, 1999, which is the energy efficiency minimum standard — was the official DOE standard at the time. So we've been consistent with that all along for the 30 percent advanced energy design guides.
These guides present common ways to reach these levels of savings by various building type. There's lots of ways to do that, but we spent a lot of time developing some of the ways to get the 30 percent savings and documenting that. These are just recommendations and are written to be easy-to-use strategies for reaching 30 percent savings by climate zone. They are not a code or standard and not written to be as such. The recommendations were developed by a series of project committees with members that represent the various professional societies for architects and engineers in the building sector.
ASHRAE, which is the engineering — the building society — the architectural professional society, AIA, U.S. Green Building Council, the Illumination Engineering Society, which has a lot of lighting designer members, as well as DOE and the laboratory support for development of these guides. In general, these apply to new construction or to major renovations, and we've worked with U.S. TBC to incorporate alternative compliance paths for the energy and atmosphere points by building type. All the advanced energy design guides and background on them are — for 30 percent savings are available at ASHRAE's website there — ASHRAE.org/AEDG.
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So here's the screen shots of the covers of the six advanced energy design guides for 30 percent savings that are currently available. We started with a small office guide, and then the small retail guide. There's a K-12 Schools Guide for 30 percent savings, a small warehouse guide, a highway lodging guide, and then the final one, which was completed last year, advanced energy design guide for small hospitals and healthcare facilities, which I was the chair of that project committee putting that together and involved in a lot of modeling on that as well.
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Some of the concepts here of how these guides are put together — we really tried to focus on what's considered good design practice out in the industry. We're not recommending strategies that aren't available from multiple manufacturers, and it's basically putting all the good concepts — good design strategies into a common place and really understanding how far we can get with the energy efficiency by building type and by climate zone. The project committee members are made up of volunteers of the professional societies with support from DOE to publish these as well as to support the technical modeling needed to show that these, in fact, reached their recommended efficiency savings.
All the recommendations were at least as stringent as the current code that's out there — the energy efficiency code of ASHRAE 90.1-2007 so that none of the recommendations become outdated. There's a significant peer review process to ensure we're on the right track throughout the development of each guide, and we leverage our Commercial Building Energy Alliance partners to heavily influence the direction of these guides.
All the recommendations are supported by in-depth energy modeling to ensure that in fact these recommendations reach their percent savings requirements as well as some analysis on what the cost savings as well — the first cost savings and paybacks are for our conceptual prototype models.
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Some of the examples of how the design guides have been used over the last three or four years — currently, there's over 275,000 of these guides — of those 30 percent advanced energy design guides — in circulation — a combination of free downloads from ASHRAE's website and purchases of the actual — the guides themselves from ASHRAE's bookstore. ASHRAE also commissioned a market analysis to really understand how these guides are being used with the industry perception of how they're being used, and basically they are used as part of the toolkit from architecture and engineers for their tools needed to reach advanced energy efficiency strategies, and it's part of what's available and a valued component of all the things that design teams and owners need to reach advanced designs.
They have been proven to be easily used. It's not like trying to reach an energy efficiency code and understand what's in there. The idea has always been that an owner can understand what 30 percent savings is. They know their climate zone. They know their building type, and they can take the that and give the guide to their architect, to their engineering team to say, "This is what I want." And then the architects and engineers can use the details of the guides to do — in a checklist format — almost like a cookbook of efficiency recommendations to reach that level of savings. And all the recommendations have been pre-engineered and modeled up front to show that in fact by climate zone and that building type, for a typical building of that type, they will in fact reach 30 percent savings.
One example of a widespread use has been in a town in Kansas called Greensburg that is rebuilding from a tornado, and all their commercial building projects use the advanced energy design guides, and they were proven fairly easy to use and easy to meet the recommendations for 30 percent savings.
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And so some of the supporting documents that go into all the modeling that is needed to show that we're reaching the prescribed level of recommendations, all that information goes into what's called a technical support document, and this is what the labs generate in support of the advanced energy design guides, and so there's a whole series of corresponding 30 percent technical support documents for the advanced energy design guides. So the DOE has moved on from the 30 percent to the 50 percent level to get more and more prescriptive in the energy efficiency. And so over the last two to three years the labs have been developing a series of 50 percent technical support documents. We don't have the advanced energy design guides completed yet.
We were doing the technical support documents first to show that it can be done and where it can be done. And so currently we have a series of about seven or eight technical support documents completed. They're all available at DOE's website there on the bottom of the screen. And there's a general merchandise, a grocery store, small and medium office, highway lodging, a large hospital TSD, a large offices and a quick-service restaurant, and we'll be talking about the most recent of those completed this year today: the small/medium office technical support document, the large hospital technical support document, large offices and the quick-service restaurant.
I do wanna point out that the 50 percent advanced energy design guide process — working with the professional societies — has commenced this year. We are currently in the development of a small/medium office advanced energy design guide as well as the K-12 schools advanced energy design guide both for 50 percent savings. And so if you're interested in reviewing those, take a look at ASHRAE's website over the course of this year. There'll be a few peer review opportunities to evaluate and insert your comments and to direct the direction of those guides long-term.
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So with that, I'm gonna turn it over to Adam Hirsch to get into some of the details of the large office technical support document.
Adam Hirsch:
Thank you very much, Shanti. My name is Adam Hirsch. I'll be talking to you about ways to cut energy use in half in large office buildings. Speaking to you from the Research Support Facility at the campus of the National Renewable Energy Lab in Golden, Colorado — that's the large building you see in the middle of this picture. It was completed this past June, and it's actually designed to use half the energy of a code-compliant office building. It informed much of the analysis that I'll be presenting, along with the medium office technical support document, which Brian Thornton will be talking about in a couple of minutes, and also the input from several engineers and designers from the private sector who gave us a lot of valuable input.
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So we wanna provide guidance not only in Colorado. We'd like to provide analysis for the entire country. So for this study, we looked at climate zones that really span the extremes of the U.S. climate. We simulated using the software, Energy Plus, the energy use of both low- and high-rise office buildings — a 4-story low-rise prototype, and a 12-story high-rise — and the total floor area was taken from the Department of Energy Commercial Reference Buildings — and these are 16 building types modeled in 16 climate zones using Energy Plus. They're a great starting point for energy analysis of energy efficiency.
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This slide provides a portrait of both the baseline and low-energy designs that we studied. In the baseline case, which is our point of comparison, the lighting loads, the equipment efficiencies, and the envelopes were specified to be compliant with the prescriptive requirements of ASHRAE code 90.1-2004. Ventilation meets the 62.1 requirements. The plug loads, which aren't regulated by the ASHRAE code, were taken from a study that was performed as part of the Research Support Facility design process. In the low-energy case, we began with best practices based on the RSF, the 50 percent savings medium office technical support document.
We assessed the savings of those strategies. We had very helpful input from engineers and designers from the private sector to check all of our assumptions to make sure they were reasonable. And then finally we optimized the envelope properties of the low-energy design to see if we could even stretch the savings further while not costing a lot more up front. So you can see typically lighting power density is quite a bit lower in the low-energy model. And I'll be talking more specifically about the strategies that show up here.
You can also see, of course, the mechanical systems that are used in the two cases — the baseline VAV system and then the dedicated outdoor air system and radiant heating and cooling that we used in the low-energy design is presenting a way — not the only way, but we think a very promising way to save a lot of energy in large offices.
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You can see here the baseline energy usage. So these are the minimally code compliant models. For reference, I've put the CBECS average energy use intensity, which is the total building-wide energy use divided by the gross floor area. So the CBECS for all offices in that study are included for reference. In all climates, almost — or more than half the energy goes to lighting, office equipment, and especially the data center there you see using almost a third of the energy in the building. We felt that these are — this presents the common feature of large office buildings and is important to capture both the energy use and the possible energy savings.
One thing that a lot of people ask is, "Why is there heating energy in Miami?" And in the baseline case, that's the reheat energy required to provide comfortable air while removing moisture from the high humid climate of that region.
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Here's the take-home message, which is that 50 percent energy savings in our modeling study is possible without the use of renewables in all of these climate zones for both low-rise and high-rise buildings averaging about 56 percent over these different climate zones. The set of strategies that you see on the left, reducing data center loads, plug loads, lighting power — we really needed to hit all of the major end-uses to save 50 percent. It's a set of strategies that, again, represents a way to reach this goal.
We aren't specifying specific technologies in the technical support document. That's left more to both the design guides, and specific projects I think have to really look very carefully at the actual design. But all of the strategies that we — that I'll be talking about are based on realistic designs and technologies that are currently available.
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So I mentioned before the data center — very important piece of the puzzle here. A lot of our information here is really based on the data center that's in the Research Support Facility of the National Renewable Energy Lab. One important piece is much more efficient computing equipment in the data center, replacing single-processors in the racks with blade servers, which have very efficient power supplies, variable-speed fans. They share power and cooling infrastructure. And you can really also reduce the amount of energy required to condition — basically cooling the data center — by carefully containing the hot and cold aisles and using economizing where it's possible.
You see that I've mentioned the power usage effectiveness. That's basically the ratio of the total amounts of power going to the equipment and the conditioning and the lighting of the data center divided by the power to actually run the servers themselves, and the closer that gets to one, that represents more and more efficient data centers. And we're aiming 1.2 in the low-energy case here, and even I think 1.1 in the RSF. The schematics there showing the common strategies — or the strategies to hit those PUEs.
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When you have hundreds or even thousands of employees in an office building, one really important piece is the office equipment that's used. Here you see a visualization of the top floor of the RSF by the RNL designers of the RSF. And you see some of the key points there. In the TSD, we simulated using laptops and also thin clients. Thin clients — basically just a way to access the computing nodes down in the data center — but a really substantial savings possible over the standard desktop computer. Also, point to multifunction devices for printing and doing faxing rather than having everybody with their own printer. When you multiply that by a large number of people, it really does add up.
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In terms of the mechanical system, really the key piece here is moving — delivering heat and removing heat from the office spaces using water, and the strategy that we simulated and that's used in the RSF is using a dedicated outdoor air system for your ventilation, and then using in-ceiling radiant heating and cooling to condition the space. And this is very effective because when you are able to separate your ventilation and your conditioning, you can properly size each system to handle each of those loads and avoid reheat. Also by using water, you can move heat a lot more efficiently than you can with fans blowing air around to deliver that conditioning.
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One — basically a little bit of a side study that we did that I thought you might be interested in is a study looking at — let's say you had an owner with a high-rise large office building, and you wanted to have a very sort of standard high window-to-wall ratio and low insulation, could you still hit 50 percent energy savings. And we found that really the envelope for large office buildings is a key piece of the puzzle. With the high window-to-wall ratio and low insulation, it was not possible to hit the 50 percent savings without really substantial amounts of renewable energy generation. The optimized envelope case here refers to — we were able to lower the window-to-wall ratio, increase the insulation in the opaque envelope, so this really would have impact on the payback that you — that we would calculate, which I'll show on the next slide.
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We did work with the Abo Group and RMH Engineering and the Cumming Corporation, which is a professional cost estimator to establish envelope and mechanical system costs for the baseline and low-energy configurations that we studied. We performed a very simple, but I think that tells the story, economic analysis just dividing the capital cost increase for the low-energy building divided by the energy savings, and you can see there the paybacks, especially in the high-rise building with the optimized envelope, fairly I would say reasonably short. So that gives you a sense — I must say, of course, any project that you do, you'd want to do this analysis in a very detailed manner with your own assumptions.
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Finally, just a quick mention of the RSF — the Research Support Facility, where I'm sitting right now — 800 occupants, 220,000 square feet of floor area — it's projected to use only about 33 kBtus per square foot per year. On the bottom there you see the strategies that were used in this building to hit the 50 percent savings, and the ones in green are ones that I've just been talking with you about. There's also natural ventilation, which is very challenging to model, and is appropriate to certain climates, and also a very interesting feature of recovering energy from the data center and transpired solar collectors and storing that heat under the building for the heating season, a very good integrated design feature — one that was outside the scope of this modeling study.
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I would like to acknowledge my colleagues, Matt Leach, who is the lead author on this study, Chad Lobato, Shanti and — who you just heard and will hear again — Paul Torcellini, and our collaborators who provided cost estimation, HVAC design, analysis for our assumptions and a very thorough review of our energy efficiency measures.
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Now I'm going to hand it over to Shanti to tell you about the large hospital technical support document.
Shanti Pless:
Great. Thanks, Adam.
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So we're gonna transition here to a different building type significantly, and you'll see the recommendations that come out of this study are significantly different. The technical support document is available there on the link for you to read up on the few hundred pages of detailed information about how to get the 50 percent savings; we'll cover some of the highlights of that.
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So we started with an actual hospital to really understand what a typical large-scale acute care hospital — how it's put together, what kind of loads it has and what kind of spaces they have so that would inform our modeling study. And we basically developed a prototype model that we ran in all the different climate zones to really understand are the recommendations reaching our level of savings for this prototype hospital. And so this prototype hospital is based on the picture you see there, Greenfield Hospital. It's 500,000 square feet, significant window-to-wall ratio.
It's basically a "tower on a pedestal" concept, very typical form for a large hospital — a patient tower and surgery suites on the first few floors. You can see the rendering from our energy model there of what that looks like. There's also a five-story medical office building attached to that — become a very typical part of large healthcare installations.
Fairly typical envelope with standard windows and window orientations. Internal gains, plug loads and occupancy density based on this prototype hospital. Our ventilation was based on ASHRAE standard 170, which is, again, based on the standard AIA guidelines for air changes and pressurization requirements for various space types in these large hospitals.
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So with that prototype — those prototype inputs, we also combined other sources of information needed to create our prototype model. The Green Guide for Healthcare has a modeling section about how to generate modeling for various large healthcare spaces, all the different standards that determine outdoor air requirements, whether it's ASHRAE standard 170 or the outdoor air requirements for non-critical spaces like 62. With that prototype model generated, we then applied both the code minimum, ASHRAE 90.1-2004 parameters to that prototype and then the climate-specific energy efficiency recommendations to create our low-energy model, compared those in the 16 different climate zones across the country from Climate Zone 1A down in hot, humid Florida all the way up to Minnesota, Climate Zone 7, and Alaska, Climate Zone 8. So there's 16 different unique climate zones in the U.S., and to make sure that we cover all those in the technical support document, that's the climate zones we used.
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So the first set of strategies focused on the lighting. And this is electrical installed lighting by space type, and we spent a lot of time in the development of the small hospital advanced energy design guide really optimizing the lighting design and trying to understand how low could we bring these LPDs — lighting power densities or LPDs — down by space type compared to code. And you can see a table here of all the different space types that are covered under code and their LPD for both the baseline and what we've recommended, and apply that to a large prototype hospital, and you can get down to 0.88 watts per square foot compared to a code minimum 1.12.
And so there's significant savings there just by understanding what good lighting design can get you by space type. And so there — you can see the range there, but the whole — the overall facility total is at 0.88 watts per square foot, and that was incorporated in our prototype low-energy model.
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For the envelope, again, we based all the recommendations on what were in the small healthcare advanced energy design guide. You can see the ranges of all insulations and roof insulations that were recommended as well as the thermal performance of the various windows and from the insulation value — the U-factor — of each window by climate zone. These ranges are in colder climates we typically have better insulating windows, or lower U-factors, and in warmer climates they're usually a little higher. So our heat-gain ranges depending on orientation and climate again as well as visible light transmittance, and where daylighting is appropriate in these large hospitals the visible light transmittance becomes critical to really maximize that daylighting. So all these recommendations were incorporated by climate zone into our prototypes as the envelope measures.
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And so typically, when we talk about energy efficiency in commercial buildings, there's no one single strategy that will get you significant savings. It's a combination of usually 100 different things or 50 different strategies that really add up to get you a total significant savings. But in large hospitals, if there is one magic bullet or silver bullet for energy efficiency, it's "Just say 'No' to reheat" is kind of what we always say about strategies for large hospitals. And so one of the key strategies to do that is an HVAC system that really focuses on zone level heating and cooling and then providing outdoor air with a dedicated outside air system.
In specialty spaces — surgery suites and such — that have fairly low operating temperatures and strict relative humidity requirements, a dedicated low-temperature chiller and air handler for that space can be separated out. But in general, the concept here is to take a standard constant-volume VAV system with standard hot water reheat and central plant chillers and boilers and transition to more of a distributed water-to-air heat pump model is the way we modeled this concept. And because that has been done in large hospitals — not very frequently, but it has been done — and it has been proven to be a strategy that can be incorporated in large hospitals.
And so that was the strategy we modeled here to really address this reheat problem. You'll see the benefit that that had. There's also some details here on some of the component efficiencies in terms of heating — coefficient performance for the chillers, for the operating suites as well as the heat pumps and the heating COP for those heat pumps as well. And things like fan efficiencies and pump efficiencies and waterside economizers were all strategies fairly commonly used that were also incorporated.
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Here's a snapshot of where we're seeing the savings. There's a few of the climate zones here — the hottest, humidity climate zone 1A is the top — those top bars there. We showed both the baseline and low-energy savings and by end-use, and so the biggest chunk you see there is the reheat. That's the bar that basically disappears in the low-energy case for each one because of the HVAC system configuration. There's also small levels of savings on the lighting as well as on the cooling from going to more efficient cooling system.
The second most significant savings are on the fans because we are moving from big central air handlers that take up typically about 40 percent of the volume of a large hospital — we're able to downsize that interstitial plenum space because we don't have to have air handlers that are big central air handlers for all the air — for all the heating and cooling and all the air changes that are needed in a hospital — that can be significantly downsized — that internal volume dedicated to those spaces. It's another key strategy to incorporating this type of system. There are certain things you have to understand and study up front to do this related to maintenance of heat pumps out in the hospital, and there's a different maintenance strategy needed for that, but it definitely can be done.
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Just wanted to show two case studies of two large hospitals that have incorporated this strategy. They went even further, and because these were Greenfield Hospitals and they had the opportunity to build lakes next to the hospitals, they're able to use those lakes for heat rejection. And so that's even a more efficient strategy. We didn't model lakes next to our prototype hospitals, realizing that most large hospitals don't have access to a green field to build a new hospital. We modeled cooling towers and chillers on the heat rejection for those heat pump loops. But if you have that opportunity, it's another significant savings strategy. Both these hospitals have a mid-30's to 40 percent savings just with this strategy alone.
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So I acknowledge those that have spent the last year doing a lot of the modeling: Eric Bonnema and Danny Studer, who are sitting next to me here and will answer some of your questions — really the technical analysis when we get to the question and answer period as well as Andrew Parker and Paul Torcellini. The engineering firm, KJWW and Jeff Boldt in particular were very key to helping us understand the ins and outs of modeling this unique system and based on their designs of those hospitals as well as Donald Wojtkowski, I guess, of SSM Health Care was also a key industry partner in this.
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So with that, I'm gonna turn it over to Brian Thornton and Jian Zhang with the Commercial Buildings Group at the Pacific Northwest National Laboratory. Brian Thornton is a Senior Mechanical Engineer and Lead AP with more than a decade of energy efficiency analysis experience. Jian Zhang is an engineer who focuses on commercial building design and performance analysis, and both speakers were instrumental in the developments of the small/medium office and quick-service restaurants 50 percent technical support documents. So with that, Brian, I'll turn it over to you.
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Brian Thornton:
Thank you very much, Shanti. I am with Pacific Northwest National Lab that was involved in the small and medium office TSDs, and Jian will follow with the quick-service restaurants.
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In the small and medium office, we utilized prototype buildings similar to some of the work was done I the large office developed by DOE and NREL and others, and we looked at a small office building and a medium office. The small office was intended to represent a class of buildings with varying different sizes and shapes. There wasn't a dominant size or shape in the national datasets that we looked at. And so this is meant to be a neutral shape. It's a two-story building with CME walls and a 20 percent window-to-wall ratio using punch style windows and constant air volume DX package units for the roof.
The medium office is a larger three-story building. We did put in a longer east-west axis and a shorter north-south axis which we found to be representative of those types of building. In this building, we used steel frame construction and ribbon style windows, a curtain wall, and a higher window-to-wall ratio, and the base case is variable air volume with gas furnace and electric heat. We wanted to show what could be done with neutral shape buildings without an optimization for daylighting. Those types of strategies could be pursued as well. This was the starting point as we moved into looking at an integrated approach to reducing loads through envelope improvements, lighting efficiency, plug load efficiency and selecting efficient HVAC systems to meet the remaining loads. And I'll go through those.
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In order to evaluate the potential for energy savings, we began by characterizing the energy usage of the baseline buildings. This is an example from Baltimore — kind of an intermediate climate. We looked at the 16 climate zones, as mentioned in some of the previous discussions. But for Baltimore, we found that the small building was heating dominated with about half the energy from HVAC and half the energy from lights, plugs including exterior lighting; and fan energy was a part of the HVAC as well. And the same with the medium office building, although cooling became more significant and less so for heating as the interior gains became more important than the envelope losses. We also found that of the heating, a bulk of that is from ventilation. There's a large ventilation component to that. And in the medium office, VAV, baseline reheat is a big part of the heating energy.
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So beginning with building envelop — this is a representation of all of the parameters for building envelope. There's a lot of detail in the slide, and there's more information in the TFC. But I did wanna highlight that in the walls — you know, we have a mass wall for the small office building and steel framed walls for the medium office, so there's separate recommendations for both of those types of construction. Note that in the advanced case, the R13 insulation — that's in steel studs — so the effective R value of that is 6 instead of 13.
And then there's exterior rigid insulation on top of that. The other element I wanted to highlight here is that we had in the small office punch style openings with manufactured windows, and in the medium office site-built windows like curtain wall or ribbon windows. And the manufactured windows are able to achieve lower U values than the site-assembled windows. So if there's an opportunity to take advantage of punch style windows and manufactured windows, you can achieve more aggressive U values with available window systems.
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Focusing on lighting — we did a space-by-space lighting characterization with the Seattle Lighting Design Lab. It also utilized work that's been done to develop ASHRAE 90.1-2010 standard, which will further reduce lighting power density values from the previous standard. In order to achieve that, there was the use of newer style high-performance lens fluorescents and instant start electronic ballasts and then a particular level of temperature lamps — a 3100 lamp. And then we also looked at lighting controls — adding additional occupancy sensors to open-office path lighting, in private office, storage rooms, restrooms and mechanical spaces.
Some of these are going to become required in the 2010 standard. And then also during — the occupancy sensors provide benefits during off hours in addition to sleep control, and the egress lighting can be reduced, too, with security lockout measures to allow some of that egress lighting to turn off at night. Lastly, we did daylighting in the perimeter. Daylighting can be optimized with building shape. We did not incorporate that, so there is additional opportunity for daylighting. And then on exterior lighting, there is — in the simulation there is parking lighting, some building mounted lighting, canopy lighting and entry lighting.
And through efficient design with more efficient metal halides than the standard 90.1-2004 would allow, you can get a 35 percent reduction in exterior lighting. And then if you still need to have lights on at night, which you shouldn't in most office applications, you can dim or turn off the bulk of the exterior lighting.
[Next Slide]
One of the areas that was highlighted earlier and is really the kind of frontier, I would say, for office building energy reduction, is reducing plug loads. And we looked to some various studies to determine where the opportunities were. As mentioned shifting to laptop computers from desktop computers — there is Energy Star — on their website lists a lot of different office equipment that can be optimized for low wattage equipment such as printers and LCD monitors and information on the laptop computers that are Energy Star. We also look to control strategies to reduce the energy usage of this equipment such as network power management software, which can take full advantage of shutting computers down at night, and then allowing if necessary, for central software upgrades at night can power those back up and then power them back down again, whereas in some cases computer management teams wanna leave their computers on at night so they can go ahead and do their work whenever they want to.
So there's a big opportunity there. Occupancy sensor controls at the desk — there are power strip devices. There's also some exploration going on on tying in some of the plugs to the overhead lighting occupancy sensors. And then there's devices that don't need to run at night, such as water coolers and coffeemakers and vending miser controls of vending machines that they can power down. From this, starting from a baseline of 0.75 of a watt per square foot, you get a significant reduction in the wattage down to 0.55, and the controls measures don't reduce the total power. They reduce energy. But the effective total reduction we think can reach 40 percent.
[Next Slide]
On the HVAC side — this is a brief overview; more detail in the TSD, and there will be extensive design information in the upcoming small and medium office advanced energy design guides. For the small office, we looked at going to air source heat pumps with a dedicated outside air system. In the small building, there's often a great number of small HVAC units, such as the small-volume units serving different zones. By going to a dedicated outside air system in those buildings, you can centralize the control of your ventilation and cost effectively apply energy recovery, whereas applying energy recovery to a number of small units is not cost effective and really pushes the size of those units down to a level where it's definitely not economical to apply. You also then have an opportunity to apply demand-controlled ventilation.
In the medium office, we also investigated radiant floor systems. Those could also be radiant panel ceiling systems, and the DOAS system to centralize outside air with heat recovery. That's provided by the — the hot water and chilled water is provided by condensing boiler and efficient air-cooled chiller. We also investigated in the TSD work enhanced variable air volume systems. VAV systems are kind of the standard for those size buildings, and there was an interest in exploring if further work could be done on VAV to achieve a 50 percent savings along with the other elements of the package. During the work that we did in the TSD, we were not able to show 50 percent reductions in all climate zones.
In subsequent analysis work that's being done to support the AEDG, it does appear possible to get there with enhanced VAV adding strategies such as low temperature cooling air down to 50 degrees with supplier temperature reset to control reheat, and also to control reheat going with perimeter convective systems, particularly in the colder climates using condensing boilers and radiant thin-tubed systems, and we'll be presenting that in the AEDG. We also looked at fan coils with dedicated outside air and water source — for the smaller office, water source heat pump with dedicated outside air; that may also be a viable strategy with medium offices. We don't have results to share yet on the enhanced VAV of the fan coils, but we are showing 50 percent savings is quite possible.
[Next Slide]
So I've got some results to show for the packages that we have available now. The small office heat pump — these are selected climate zones. We did a model of all 16 climate zones that are achieving the 50 percent savings for all those climate zones, and as you get to the colder climates, the reduction in ventilation energy usage requirements goes down considerably with the dedicated outside air, and the energy recovery. And across the board you get the big savings from the interior lighting and the plug loads. One of the things we found is by reducing those core loads, we were able to achieve substantial downsizing of the equipment, which we'll show in the cost effectiveness, which I'll talk about.
Again, here's water source heat pump — there's a small and additional savings that we're showing with these types of systems. One of the reasons we explored this, though, was to kind of define a starting point. If you have an opportunity in a specific climate zone to go with a ground source heat pump or a groundwater heat pump system, you can go well beyond the 50 percent. We didn't evaluate those systems specifically, but we did wanna look at what would be the starting point for that if you could eliminate the boiler and the condensing — the cooling tower for a water source heat pump system, you could go well beyond these levels of savings.
[Next Slide]
And then with the medium office, we show, again, a big reduction in reheat due to the use of the radiant system for the space flows and separating out dedicated outside air. And then on the cooling side, there's an opportunity for energy recovery and control of humidity, again, through the dedicated outside air providing all of the latent cooling.
[Next Slide]
So here's — back to the Baltimore case showing where the savings come from. In the small building, heating was dominant to begin with, and we're getting a big savings on the heating side, again, primarily driven by energy recovery. And then half the savings come from lights and plug loads. And then on the medium office side, similar spectrum of savings with a little less on the heating side.
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In terms of payback then, we utilized industry data and reduced the payback in the order of seven years for both types of systems.
[Next Slide]
So in conclusion, we feel that there's a demonstrated opportunity to get 50 percent reductions. Other technologies could get there as well. Design teams should consider all the options at their specific sites and possibly do their separate modeling analysis to take into account site-specific alternatives, such as building siding and orientation and shape to optimize daylighting. The advanced energy design guides will provide significant additional design-related information from the analysis report in the TSD. So with that, I'd like to turn it over to Jian Zhang to explore the savings potential in quick-service restaurants. Thank you very much.
[Next Slide]
Jian Zhang:
Thanks, Brian. This is Jian Zhang from Pacific Northwest National Laboratory. In the next few minutes, I'd like to focus on some highlight of our 50 percent energy saving technical support document for QSR project. The research methodology of the QSR project is similar to other TSD reports you just heard. And the first step was to develop a baseline building which just meet the minimum prescriptive requirement of ASHRAE standard 90.1-2004 for characteristics that are not specified by 90.1. PB code design practice are used in baseline buildings.
The second step was to develop a baseline for energy efficiency measures. So let's start from baseline QSR building space review for many actual design drawings, we define the QSR to have a typical floor space of 2,500 square foot with kitchen and dining zones. All the windows are on the dining zone façade, and the window-to-wall ratio is 14 percent. The thermal performance of the building envelope just meet the minimum requirement of ASHRAE standard 90.1-2004. There are two separated constant air volume package rooftop unit. Each serves one zone.
One of the challenge at the beginning of the project was to decide what type of food the restaurant served, because different food menus needs different cooking equipment. So we decided to study the hamburger-based QSR and assume it open 128 hours per week. Therefore, a full list of cooking equipment and their schedule would develop.
[Next Slide]
Here are three examples of baseline building EUI results in Houston, Baltimore and Chicago. The national weighted average EUI is about 1,000 kBtu per square foot. The simulation results have been benchmarked with actual building use data. On the lower right part of each chart, the three large end-use categories are cooking using electricity and natural gas and the refrigeration. On a national average level, these three account for over 60 percent of the total building energy consumption. They are not only the direct energy consumers, but also impose a large thermal load to the space. So other categories — we see more heating in Chicago and more cooling in Houston.
[Next Slide]
The most effective way to reduce the restaurant energy is to improve kitchen appliances. A new list of equipment was developed. Some of them are based on the best-in-class Energy Star qualified appliances. They are selected to ensure equivalent cooking capacity as the baseline kitchen. With the efficient appliances, we were able to reduce the natural gas cooking energy from 423 to 246 kBtu per square foot per years and to reduce the electric cooking from 110 to 83 kBtu per square foot per year. The recommendations for refrigeration system reduces the energy consumption from 7.3 to 5.5 kilowatts.
[Next Slide]
The second largest impact on the energy is from energy efficiency measures for building mechanical systems. The baseline kitchen had two canopy exhaust hoods with a constant flow of 4,600 CFM. With the new hooded kitchen appliances and the proximity type of hood will reduce the flow to about 1,800 CFM. A demand-controlled exhaust fan based on cooking schedule further reduces the flow on off peak cooking hours. In cold climate zones, a runaround coil heat recovery system can reduce wasted heat — recovery wasted heat in kitchen exhaust air to preheat ventilation air through a dedicated outdoor air system.
Based on new requirement in ASHRAE 90.1-2010 on the air side economizer extended the economizer usage to more climate zones and smaller units than baseline buildings. Higher efficiency cooking equipment — cooling equipment and water heaters were also suggested.
[Next Slide]
Although the lighting and the envelope measures had less impact on the QSR than on some other type of a commercial building in terms of the percentage of energy reduction. We still recommended them, since our goal was to cut the energy use by half. With efficient lamps and ballasts, the lighting power density was reduced from 1.44 to 0.83 watts per square foot. Occupancy sensors was admitted to have additional 7.2 percent interior lighting energy reduction in office, active storage and restrooms. In dining area, we'll using daylighting to dim two-third of our lighting power. Exterior lighting power was reduced using the new requirement standard 90.1-2010.
Bi-level switching and photocell control allow most of the exterior lighting only on during the business hours and after dark. We've also made recommendations to improve the performance of building envelopes, such as the increased insulation levels of opaque components using high-performance window glazing and use a cool roof in some of the climate zones.
[Next Slide]
So this chart shows the energy usage, the percentage reduction of six climate locations as examples, with the baseline compared to the modeled buildings. We totally performed our analysis for six locations, and the savings is between 41 to 52 percent, and the national weighted average energy savings is 45 percent. The cost savings was 43 percent.
[Next Slide]
So in summary, the QSR is a very intensive — energy-intensive building. The average baseline EUI is about 1,000 kBtu per square foot per year. The chart on the right shows the proportion of energy savings from different end-use categories. Our analyses for different bundles of measures show that the measures from kitchen appliances and mechanical systems are the two most effective ways to cut the energy. The overall recommended package can provide a national average energy savings of 45 percent and the average incremental cost would be around $16.50 per square foot or 9 percent. The average payback year is about 2.1 years.
We didn't — in this project, we didn't reach 50 percent in all the climate locations. The major reason is that the building is highly energy — building energy use is highly driven by cooking energy use. We have to ensure that the low-energy restaurant building have the equivalent cooking capacity as the baseline building.
[Next Slide]
I'd like to take the opportunity to acknowledge the contributions of our industrial collaborators. Seattle Lighting Design Lab help us on small and medium office and the quick-service restaurant project, and the professional experience of Halton Company and Food Service Technology Center brought us a lot of good ideas on kitchen energy efficiency measures. The recommendations we made have been used in actual design practices. The TSD report of small/medium office and QSR are achieved truly teamwork. Our colleagues Bing Liu, Weimin Wang, Mike Rosenberg, Yunzhi Huang, and Rahul Athalye all contributed to our project.
[Next Slide]
So today we have covered the TSD for small, medium and large office and large hospital and quick-service restaurant. Due to the time limit, we will only focus on some high level findings of our research. For more detail, you can follow the URL link at the bottom of the slide, and you will be able to find the published — the AEDGs and the TSDs. So with that, I will turn this back over to Anthoney.
[Next Slide]
Anthoney Perkins:
As I mentioned, we're gonna have some additional polling questions before we go into the Q&A session. So what we'll do is — same as in the beginning — we'll ask you to submit your questions online — your answers online. We have the first question up now. "What were you hoping to learn from today's Webinar?" So we'll give you a few moments to choose your best answer for this question before we move on. Give you just another moment to answer the question. Okay, we're gonna go ahead and close this question and move on to the next one.
[Next Slide]
"Based on your expectations, how satisfied were you with the webinar?" Again, we'll give you a few moments to go ahead and answer that. If you haven't done so, please go ahead and answer, and we'll close this out in just a moment. Okay, thank you. We'll go ahead and close that.
[Next Slide]
And now we'll move on to the question and answers portion. As we mentioned, we asked everybody to submit the questions online. Our speakers will address as many of the questions as time allows. You had the option to go to the top of the screen and click the Ask — type your question and click Ask. So I'm gonna go ahead and turn it over to Shanti and Adam. Go ahead and start with the questions and answers.
Adam Hirsch:
Thank you, Anthoney. This is Adam. I'll kick things off — do a couple of questions that are specific to the large office and then pass it over to Shanti. So there are lots of great questions. I don't think we'll have time to cover them all. One question that is a very good one is, "Is it feasible to use radiant cooling in humid climates and not have issues with condensation?" This makes a lot of sense; you don't want it raining inside your building. There are two aspects from the design level that you really have to focus on to make this approach work in humid climates.
One is really making sure that the building is tightly sealed. You don't want air infiltrating into the building that has a lot of humidity in it because that's a real recipe for problems. The second is making sure that the dedicated outdoor air system is properly sized to meet the latent loads, which is removing moisture from the ventilation air. So dehumidifying that air to the degree that you're — the dew point in your space does not go up above the temperature of the radiant surface.
One other question that stands out is, "How does optimized window-to-wall ratio affect daylighting?" So daylighting, of course, is a very important piece in saving energy in large office buildings, particularly in the building that I'm sitting in now, the Research Support Facility. When thinking about daylighting, one also needs to think in a whole system perspective also about the thermal energy gains and energy losses of the building envelope. So as you increase your window-to-wall ratio, you're also going to be perhaps allowing in more solar gains or in a heating dominated climate losing heat through that.
So what we did is we actually optimized the window-to-wall ratio, including both the daylighting energy impact and the thermal heating and cooling impacts and found that the 20 percent was able to both daylight the building and not take a hit on the thermal side. One other thing to think about is people often think that you need to have huge amounts of glass to daylight a building. In fact, the Research Support Facility only has about 25 percent of the wall glazed, and by using daylighting glass up high and view glass down low that have tailored properties for those functions, and also using light redirection devices, you can really increase the amount of the space that's daylit. So I'm gonna pass it over to Shanti to take a couple of questions now.
Shanti Pless:
Great! So I also have a few of my cohorts here on the modeling side, Eric Bonnema and Danny Studer, who are also gonna jump in. You'll hear them talking about some of the — answering some of these questions. So the first question I wanna address is related to the energy use of our baseline large hospitals. And so the question was, "Are baselines energy-use intensive? They're quite high — around 400,000 Btus per square foot per year, and when you compare that to commonly seen datasets such as the Commercial Building Energy Consumption Survey, they typically are slightly lower — you know, 250 kBtus per square foot."
And so there's a few reasons we've seen related to that. And so the CBECS dataset — those facilities are a few years old now, and so a lot of the new hospitals that are being built have significantly more medical equipment infrastructure — lots of CTs, lots of MRIs and such that do use a lot of energy that we did incorporate into our models. In addition, we spent a lot of time looking at energy use of both our prototype hospitals — the hospitals that we showed in our slides there — and tried to understand what they're actually using. And so in the analysis of the energy bills of those facilities, we were — even the efficient ones, we were often above 250,000 Btus per square foot per year.
And so it's a good data point to compare to, but my understanding is that many large hospitals are significantly above that. And we tried to represent what was typical rather than what CBECS had. And when you really dive into the details of what CBECS does have, it can skew some of these numbers somewhat. So we focused on trying to really compare to actual hospitals and the utility bills from those actual facilities and how they're actually run. And so it's a good question, and we were somewhat concerned early on, but when we started to dive into utility bills from actual hospitals that we thought were pretty good or very typical, we realized that we were pretty close to what we should have been.
So Eric or Danny — any comments there? Okay. Another question here was, "What is 'reheat'?" And so I think we'll let Eric or Danny address that.
Danny Studer:
This is Danny Studer. Reheat is essentially the phenomena you get when your heating and cooling systems fight each other — when you've got spaces that require cool air to be delivered, but other zones on that same system that don't require as much cooling, so you end up cooling your supply air down very far usually to meet a cooling level that can also be to remove humidity in humid climates, to remove that latent load. And then in order to maintain space comfort you have to reheat that air typically at the terminal box in order to maintain comfort for the occupants. So you'll get your main cooling coil cooling your supply air down to very cold temperatures, and then you reheat it typically with a variable air volume reheat box at the terminal box when it's delivered to the space.
Shanti Pless:
So the way I think about it — this is Shanti — is like driving your car with your foot on the gas and the brake at the same time. You're simultaneously heating and cooling, and so whenever you can avoid that and supply the air in the temperature that you actually need rather than overcoming for different temperature regimes in your air systems, it's a significant savings. And so that's the primary strategy for efficiency in these facilities.
Eric Bonnema:
And this Eric. I'd also like to add that hospitals are particularly bad in this reheat case because of the varied space types they have. They have these imaging rooms with CTs and MRIs and stuff that require a tremendous cooling load, and any other space that's on that same system is penalized by that, and so the reheat numbers are much higher, whereas an office or something with a similar type of system, all the spaces have the same kind of loads, and so you don't see as high reheat numbers.
Shanti Pless:
Another question was related to how we defined our baselines, and there were two or three questions about why we picked constant air volume systems, and is that something that 90.1 code allows or not. And so I can say that looking at typical hospitals, which is what we tried to use to generate our baselines and our prototypes, most typical hospitals historically have maintained constant volume systems, and so they're assumed to be operated 24/7, which most hospitals have some component of them operating 24/7. Majority of the square footage is not 24/7, even though they might all be constant volume systems assumed to be operated 24/7.
There's a movement in industry to really understand where VAV and variable systems can be employed in large hospitals, even though they are 24/7 facilities, to respond to the actual use. Even surgery suites aren't typically used 24/7, and airflow setbacks and temperature setups can be employed in those surgery suites and save significant energy in the air flows. And so it's starting to happen, and code has some influence in the way healthcare facilities are designed. But health and safety always rules. And so it's — what 90.1 says about VAV systems doesn't always apply.
I will say that 90.1-2010, the newest version that's coming shortly will — is attempting to eliminate constant volume systems in hospitals specifically. And so it's a strategy that has been proven now. The industry is starting to adopt it. Healthcare system operators and owners are willing to consider it now that others have shown that it can be done. There's a key control strategy that you need to employ to make sure that it works efficiently and appropriately for the users in the space, and they can have overrides from the airflow setback, for example, if they need to perform emergency surgery in a surgery suite when it's scheduled to be down — things like that that allow you to really effectively apply variable volume systems.
So I also wanna point out that we really tried to use a combination of what's typical, what's a prototype hospital, and then apply what typically is used for code in those hospitals. We weren't strictly using the Appendix G of ASHRAE 90.1 to pick our systems, even though for a LEED modeling exercise you may be forced to do that. For our case, we were trying to say for a typical hospital and typical design team how can you get the 50 percent savings. And so we used 90.1 and Appendix G for picking system types and control where appropriate where it represented some typical design strategies for large healthcare but didn't necessarily follow the letter of the law in Appendix G.
All that is laid out very clearly in the technical support document and the justification for using various system types and control strategies. Okay, so I'd like to turn it over to Brian to answer some of the questions he's received, and if we have time we'll come back to this side of the country.
Brian Thornton:
This is Brian. There were a number of different questions that asked about LED lighting. LED lighting is certainly a good opportunity. The efficiency of those is really very competitive now. For the interior — the recommendations we're getting from Lighting Design Lab is that there's still some work to be done on LED. There are some good fixtures and things there now. The cost is a little high still, but for exterior I mentioned that we modeled metal halides for the exterior. That's partly because that work was done for 90.1-2010 showing it was possible to meet that standard, but LEDs are definitely appropriate now for exterior lighting and parking lighting.
Paybacks might be a little bit longer, but there's a lot of opportunity there. I think LEDs should be evaluated on an ongoing basis. With these projects, there's a lot of activity there that's bringing down the costs and improving the quality and creating more fixtures. So I would agree that those should be evaluated.
There were also several questions regarding applicability of the recommendations or sources of information on existing buildings. Certainly in terms of the market, existing buildings is vastly more important as we go forward to addressing the huge amount of energy that's used by buildings. There is work underway to begin developing some existing building advanced energy design guides. I don't know yet when those will come out, but it is an area that DOE is supporting for future analysis and development. Certainly, there are things in these guides that are applicable for existing buildings, and the lighting opportunities are good places to look for retrofit.
It's gonna be challenging to do retrofit for the systems going to radiant systems or DOAS systems from a starting point of more conventional systems. It will be very challenging and costly, so those may not be the place to look. Plug loads is also another area where there's great opportunities to do retrofit work. Let's see. There were questions about the cost. We did address cost in the study. We have presented some paybacks and some first costs by square foot information in the TFC, and it sounds like some of the other guys have done the same thing. So there is some cost information out there.
On the plug loads, there was a question about network power management software information — the Energy Star website is a good place to start for information on plug loads. And there are case studies and information available there on the use of network power management software, so I would definitely recommend going there as a starting point to begin researching that area. Let's see, in terms of HVAC systems, there was a question regarding variable refrigerant flow systems, which are common outside the U.S. and beginning to get a significant share here. There are some challenges in modeling that, which has affected the ability of analysts to look at it.
But it's a system that is worth considering. When we were looking at it, there were some projects that had some concerns about the controllability and how those were being set up. So it's somewhat newer in the market, and there are things that need to be worked out there. But it's definitely work evaluating and can be a good cost-effective alternative in some cases. I think that those are kind of the primary threads that were raised. There was a question as well of when the advanced energy design guides will be released. The medium office and small office advanced energy design guide is expected out in late spring of 2011. With that, I will pass it on to Jian Zhang to field any questions on the quick-service restaurant.
Jian Zhang:
Thanks, Brian. I receive several questions regarding quick-service restaurants. One of them is that, "Do we have examples of a restaurant that are using the recommendations that we suggested?" The answer is yes, although I don't have permission to speak their name. But there are some restaurants that have got LEED certified and you can maybe send me a private email; I can send you some more information. And the question about, "Are these recommendations applicable to large facilities? And how about is it very climate-specific?"
Some of the recommendations are applicable — most of them are applicable to large facilities: for example, lighting and cooking equipment, reduction of exhaustive flow using demand-controlled ventilation exhaust fans. Some of the measure, even in the quick-service restaurant, is already location-specific. You can refer to our report to have a more detail. And one of the question is whether heat recovery coil has a grease issue. We've considered this and we have seen some actual design applications using the heat recovery — runaround loop heat recovery, and it should not work in heat recovery. And with that I will hand it back if we have a second round.
Brian Thornton:
This is Brian. I wanted to jump in. I have another question. There was a question regarding the baseline — the baseline that we used for our work was 90.1-2004. There's been some interest in keeping that as a benchmark, but people were concerned that the '99 standard was used, which was much less stringent. But 2004 was a significant improvement in the efficiency standard versus earlier versions, particularly for lighting. And then going forward, there was a question about, "To what degree is ASHRAE 90.1-2010 going to approximate some of the recommendations?"
Certainly, work that was being done for 90.1-2010 influenced the lighting recommendations that we had. There was cases where the recommendations go beyond 90.1-2010. 90.1-2010 is going to be a substantial upgrade in terms of all across the board in terms of lighting and HVAC. There has been some delay in incorporating envelope improvements there, but there's a basis for doing that in future standards.
Shanti Pless:
Hey, Brian. This is Shanti at NREL. I'd also like to point out that all the 50 percent TSDs use 90.1-2004 as a baseline. And 90.1-1999 baselines were used for the 30 percent AEDGs and TSDs, which have been developed over the last five years. And so there's a clear delineation between the 30 percent AEDGs and TSDs and the 50 percent AEDGs and TSDs. And so I wanted to make sure that's clear about the baselines we did use. I also wanna point out that the 30 percent AEDG recommendations — a lot of those have been incorporated into both ASHRAE standard 189 as well as some of the current revisions of 90.1-2010, and the AEDGs have been a testing ground for advanced beyond code recommendations and really to allow the industry to understand what can be done to exceed code.
And the long-term goal of that code slowly ratchets up the bottom of what's allowed, and the advanced energy design guides really test out what strategies go beyond code so that the ones that become fairly standard to implement and cost-effective can then be integrated into code long term. And so it's — that's kind of how the interactions between the advanced energy design guides and 90.1 and 189 have evolved.
I think we've used up our hour and a half here. So thanks all.
[Next Slide]
Anthoney Perkins:
Okay — so we wanna go ahead and thank all of our speakers for their time today. And we'd also like to thank all of you for participating. Please make sure you visit buildings.energy.gov/webinars.html to download a copy of the slides, and please check the webpage for further information on our future Building Technology Program webinars. This concludes our presentation. Thank you and goodbye.
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