U.S. Department of Energy - Energy Efficiency and Renewable Energy

Building Technologies Office

U.S. Department of Energy Commercial Reference Buildings - Benefits and Applications (text version)

Below is the text version of the Webinar titled "U.S. Department of Energy Commercial Reference Buildings – Benefits and Applications," originally presented on May 18, 2010. In addition to this text version of the audio, you can access a PDF of the slides, and a recording of the Webinar.

Operator: Welcome and thank you all for standing by. At this time I would like to remind parties that your lines are in a listen only mode until the question and answer session at which time you may press * 1 to ask a question. Today's call is being recorded. If you have any objections you may disconnect at this time. I will now turn the meeting over to Anthony Perkins. Thank you. You may begin.

Anthony Perkins: Thank you, Rose. My name is Anthony Perkins and I'd like to welcome you to today's webinar titled "Commercial Reference Buildings, Benefits and Applications." This webinar is presented by the Building Technologies Program at the U.S. Department of Energy. We're excited to have with us today four speakers who will talk to you about commercial reference buildings and how they can be used as a tool for whole building energy analysis. They'll provide some background on how they were developed, the benefits, current applications, and plans for the future. Before we start I have some housekeeping items to cover. First, as you just announced that everyone today will be on listen-only mode.

We will have a question and answer session at the end of the presentation. To participate, you can submit your questions electronically throughout the webinar. To submit a question simply click on the question and answer link at the top of the bar of your screen, type in the question in the box, and then click "ask." Please be sure to click the "ask" and not the symbol of the raised hand and our speakers will address as many questions as time allows after the presentation. Also I wanted to point out that the URL you will see on your screen, www.buildings.energy.gov/webinars.html. On that web page is a link to today's slides. Also today's presentation is being recorded and a video of the presentation will be posted in the near future. You can also view past webinars on the archives page from that link.

Finally, we have a few quick questions to ask to help learn more about the audience and target our future presentations. We're going to start with two questions now and then we will have two more questions at the end of the presentation before we go into the question and answer sessions. So on your screen you should have a first question. Please review the question and answers and it has at your location how many people are participating in today's webinar. Once you review, please click on the appropriate answer and we'll give you a few seconds to answer those. We'll leave it open for another second or two so if you can click your answer now.

Okay, so we'll go ahead and close this question and move on to the second question we have. What best describes your affiliation or organization? Again, if you just choose the best response for your organization. We'll leave it open for just a short second or two longer. We'll go ahead and close that question. Thank you for your participation, and now I'll introduce our first speaker, Jim Rannels. Jim leads the commercial buildings integration and deployment team at the U.S. Department of Energy Building Technologies Program. His team works to improve the efficiency of commercial buildings through fostering industry alliances and partnerships and research and building technologies and strategies, and developing energy simulation software. With that, I will turn the presentation over to you, Jim.

Jim Rannels: Thank you, Anthony. Building reference models are very important to the federal government because as you may know commercial buildings account for 18 percent of the U.S. energy use, 18 percent of the greenhouse gas emissions, which is slightly less than India's entire energy consumption and greenhouse gas emissions. Understanding and acting on energy use can make a significant impact on our total consumption. The amount of floor space that's available for commercial buildings is estimated by our Energy Information Agency and is about 72 billion square feet in 2003, projected the increase to 82 billion in 2010.

This has been estimated to decrease to about – excuse me, the existing space will decrease to about 66 billion over the next 20 years, but the good news is we will have a net increase of about 38 billion new square feet that we can impact the energy use and emissions from over the next 20 years. Having good applicable models will help us estimate how to do that best. In DOE's low emissions buildings research simulation has been critical for making and operating buildings, but the need for reference models to represent new and existing buildings for research and technical evaluation is critical. NREL, PNNL, and LBNL have developed reference models, which can be used to estimate the sector analysis, can be used to set performance targets, and they also can be used to show progress towards goals.

Understanding these energy applications can help the United States improve its national security, import our energy consumption, and reduce our impact on the environment. Our next speaker is Michael Deru. Dr. Deru is a senior engineer for the Center for Building and Thermal Systems at the National Renewable Energy Laboratory. He leads the national commercial reference building project, which is developing standard energy models of commercial buildings for DOE research.

Michael Deru: Thank you, Jim, and thank you everyone for joining us today. I'm just going to cover quickly the development of these reference building models and then we'll move on from there. So why did we do this? As many of you know, developing good energy simulation models is a lot of work. There's thousands of inputs and we just don't have all the information or data that we want to fill in all of those parameters and oftentimes we depend on using the default values that come with the energy simulation program. So DOE and several of the national labs went together and worked for several years to develop the standard reference building models and we put a lot of work into trying to validate each of the inputs and come up with some common sets that people can believe in that have some review by recognized experts and something that we can trust, and something that everyone can start with the same values and then move forward and change them as needed.

So as we're going through all of this information and trying to distill it down into just a few sets of models there's a lot of decisions that have to be made along the way. We try to get a balance of accuracy and practicality. A lot of times we had to make estimations because there was limited data for the inputs, and then as I said earlier we really worked hard to get expert review and buy-in from the modeling community so these models have been reviewed by DOE researchers and some of the ASHRAE working committees for standard 90.1. Now that doesn't mean that they're perfect and these are an evolving and constantly improving model, so if there are comments as people use them please let us know and we'll take those into consideration as we're able to try to improve the models.

So the data that we use, the most common data out there for commercial buildings in the U.S. is probably the commercial building energy consumption survey or CBECS. That was a big part of our data sources. We also use construction start data from 2003 through 2007, ASHRAE standards where applicable, and then a really great resource has been the Advanced Energy Design Guide subcommittees or committees that are working on these guides for DOE and ASHRAE and they've really been a great resource because it brings in these experts that know these building types and have firsthand experience in building and operating those buildings. We've relied a lot on output from those efforts to guide the development of our reference models, and then where we still didn't have information that we tried to use, we tried to find existing research the best that we could find available.

We've come up with 16 building types that we feel represent most of the commercial building stock, somewhere between 60 and 80 percent depending on how you look at it and which age of buildings you look at, and then we've settled on 16 locations across the U.S. to represent the different climate zones within the U.S. Then we went one step further and we have three sets of buildings right now. There's new construction 90.1 2004, which represent everything that you would put into a building that would meet standard 90.1 2004, and then there's a post-1980 construction and pre-1980 construction, and that 1980 we picked out of the year because that's kind of a standard year for when energy standards, we started seeing energy standards in the U.S. building industry.

Those existing building models are probably less reliable than the new construction models as far as representing what's out there in the building stock just because it's so diverse and it's really difficult to try to represent all of that with a few models. But if we take all of these models and the locations and the vintages and we – there's actually 768 models available, and here's a list of those reference building models. There's three offices, two schools, three retail buildings, two food service buildings, the lodging, healthcare warehouse, and one residential building. Over on the right hand side you can kind of see the source of the information that we used to develop at least the area and the number of floors and then a lot of the other inputs were from various other sources of information.

Across all of these building types and the vintages, the area and the shape of the building stayed the same just because we didn't have enough information and we wanted to simplify the models and also be able to compare performance across locations without very many changes in the models themselves. Here are the 16 locations. In the U.S. right now following the DOE climate zones there's 15 climate zones in the U.S., but we have selected a 16th city because 3B really is a very different climate zone for between Los Angeles and the rest of 3B.

The coast along the California there has a very different climate, so we selected one extra city there. The other thing you'll notice is that the DOE cities that are often used to represent the climate zones, we have some differences. For example 3A we selected Atlanta, Georgia compared to Memphis, Tennessee because we felt that we were not only trying to represent the climate but also the number of buildings or the population of buildings, so we went with climate and population for a selection of our cities.

Then finally we've created some weighting factors such that each of these weighting factors, and here's just some examples at the bottom of the screen for these different climate zones and a few of the buildings. So those numbers in this table here represent the number of buildings that are similar to that reference building in that climate zone. So if we take the small office and it's like 5,500 square feet and we multiply it by this row of numbers there, that will represent the small offices in each of those climates and then we can add those up and get the national total. So that allows us to take the results from running these reference buildings and project that across different regions or across the whole country, and then we can do sector analysis to understand what the impact of a certain energy efficiency measure might be across different building types and across different regions.

These weighting factors were developed from construction start data over the period of 2003 to 2007, so they are mostly representative of recent construction, not at all for existing buildings, so these weighting factors are really for the new construction and it's difficult to get good weighting factors for existing buildings because within CBECS there's great information there but there's not very good geographical information to separate all these different building types by location. I'm just going to run through a few of these models so you can kind of see them. These are images made through our open studio addition to energy plus. There's the office buildings. There's the two schools, very similar in appearance, but the secondary school is two floors.

These models were from the advanced energy design guide effort for the schools. Here is our lodging, small hotel and large hotel, and our two healthcare facilities, there's an outpatient building from the Advanced Energy Design Guide for small healthcare and then our hospital. So what is available to you as users that you can go to? You can download from our website, which I'll show you in a moment, there's the energy plus input files, so that's the IDF files. We have run all the models and we also provide the HTML output files, and then we have the spreadsheet that we call a scorecard that records all of the input parameters so you can go in there and see, like right now it shows the zone summary that's there. You can see what the inputs are at the zone level and some of the references for where that information came from.

Then we also in that scorecard have the results from running it, so you can go in there and look at how these buildings performed at different climate zones. Here's our website. You can go there and download all of these models and you can download past versions of the models. Soon we'll be coming out with a new version of all of these models for Energy Plus 5.0 and those will be available and you can download those on the website soon as well. That concludes my portion of the presentation and our next speaker is Kristen Field. She's a mechanical engineer at NREL with several years of building energy simulation experience and most recently primarily exclusively with Energy Plus over the last year and a half, and Ms. Field has been the primary person over the last year and a half responsible for putting these models together and working them out and running them and getting them ready to present to users on our website.

Kristen Field: Thank you, Michael. So I'm going to continue where he left off and Michael gave you a good sort of background of what's in the reference models and how they were developed and we also wanted to focus in this webinar on how you can use them because it's great to understand what they are, but we made them so people can use them. Just some guidelines at first. There are some ways that it would be beneficial to use these reference buildings and then some ways that it wouldn't be so beneficial, so we're going to go over those. First of all, one way that they can be used are as common referenceable starting points. As Michael mentioned it's nice for people to be able to start from the same model so that you can more easily compare across different studies and you can reference them. You can reference all of the sources that are shown in the scorecard and the IDF models themselves as comments.

It's nice for a large group of people to be able to start from the same place, so this is a big DOE effort to give us good starting points for the whole modeling community really. Also they serve as fully functional, vetted Energy Plus example files, so anyone who has Energy Plus knows that you download it and you get a lot of example files, and a lot of them tend to focus on whatever modeling component that they're titled for really. These ones instead of focusing on one certain Energy Plus object they're really focused on the entire functioning building, which is helpful I think especially for a beginning user to see what a full building model looks like and how it works. It also can kind of serve as a storage body of buildings knowledge about typical lighting power densities let's say in post-1980 construction for plug loads, our best guess at plug loads for this building type versus that building type.

So there's all kinds of knowledge that's actually sort of stored in the inputs there as well as in the comments and in the scorecards, so it's kind of useful that way. Another way that you can use them as far as getting to studies is basically because of these weighting factors that DOE has developed as Michael said mostly for new construction, you can use those and you can use the results that you have to look at one building type in many climates. So let's say you were interested in the effects of raising the COP of your air conditioner, meaning raising its performance in retail stores across the country. So you could run these models. You could run them again with a higher COP air conditioner and use the weighting factors and kind of see across the country, in general what effect might this have?

Now by contrast what if I raise the efficiency of the furnace and sort of compare and contrast? So they're good for sort of climate-wide studies like that. Also if you're really focused on one climate, I noticed there are some people on the call that are from government, if you are focused on your area that your government serves you could say, "I'm in this state and we have this climate and this mix of buildings", maybe you have your own sort of weighting factors. You could approach the study that way and then have 16 different building types that are already made for you that would help you progress in a study like that.

We've had people request our hourly profiles before to get sort of very rough community load profiles, which would mean you get the electric power draw for each hour from each building and you combine them with weighting factors. I put "rough" in there because that would be a very, very rough estimate. Certainly no power companies are going to be using this to predict their loads, but it could help give you sort of a building load profile versus community load profile difference and that can be interesting. Just some caveats on how maybe they should not be used.

First of all as with any energy model they are not intended to predict any utility bills, so people that do energy modeling know this, but I thought it was good to repeat since we have such a large audience. Also if somebody is designing a specific building, say a large office building, you shouldn't use the large office building reference model and assume that the energy use is the same. Any proposed building should have its own model. You could certainly use the reference model as a starting point for it. Also as Michael said these 16 different building types do a good job of representing the commercial building stock out there, but they can't represent everything, and I gave some examples here of certain buildings that wouldn't be well represented, for instance refrigerated warehouse versus warehouse. You could certainly use our warehouse model to start, but the refrigeration component is very important.

Some other examples on here, large theater is not in there. Something like a pool varies significantly enough from what we have that you should put in the extra effort and really develop that model separately and use your good judgment as energy modelers, but it just bears repeating, we captured a lot of it but of course there's still plenty of other building types out there. So with that, I thought I'd get into some example applications since examples are usually a clearer way to see what we're trying to talk about. There are four different types I'm going to go over. First one is Ice Storage Modeling.

So this was a private sector company and they specialize in ice storage technology, so they have a broad knowledge base about this. They understand of course the performance of an ice storage system depends on the building load profile. It depends on what your cooling needs are at any hour of the day, by season, by day, by day of the week, and they have some sophisticated software in-house that predicts the performance of their product. They developed it, they do the R&D on it. What they didn't want to spend as much time doing was predicting building loads. It was easier for them to start with an hourly load profile that had been generated from a reliable source based on a lot of accumulated buildings data and so they used our reference buildings to sort of get a good source for hourly load profiles and look at the performance of their systems in different building types.

That's a pretty good application to where you use them as a good starting point and then you use your own tools that you've developed and take it from there. Another example is a research institute study that did a comparison of rooftop units, but they wanted to test the effect of a high efficiency natural gas furnace section on rooftop units. That is something that hasn't been used a whole lot and so basically they wanted to look at how does the energy use differ by building type and in different climates and the whole reason for them doing this was to answer the question, when is it worth it to install these when there is some capital cost? Of course as a lot of you probably understand, capital cost can easily be offset if you have good energy savings throughout the year, which would be operating cost savings.

So at some point the extra capital cost becomes worth it and is that point different in different climates, different building types? So they wanted to use our models to sort of get them started on that, and really the last bullet point here is just to say as with the ice storage example before, their expertise is in their natural gas equipment performance, and so it helps them to have sort of some expertise stored in these building models to apply to their studies so that they don't have to spend a whole bunch of extra resources sort of redoing what energy modelists have been doing for years.

Our next example, and this is something that Michael alluded to before when he was talking about our different building vintages, but I thought it would be worth it to go over it here a little bit. You can use these models to sort of estimate the effects of building vintage, and by vintage we mean age. So there are a few purposes, but basically if you were to look at just the new construction models and say to yourself, okay, this represents our commercial building stock, that wouldn't really be accurate because there are a lot of existing buildings out there. We wanted to look and see, okay, what difference does that make, just as an estimate?

There are three building vintages again. There was the new construction, which right now is represented by 90.1 2004. What we call the post-1980, which is 1980's or 1990's, before 1980, and just as an overview the major changes to these energy models from the new construction, so the major changes of existing over new construction. Lightning power densities were a big one, heating and cooling efficiencies, infiltration, so the amount of air that leaks into the building. There were some system type changes although for the most part they were kept constant, and then envelope. You would have typically less installation the older the building was because the codes didn't require it.

This is just a brief – I'm not going to enter the results 'cause I don't wanna get us off on a tangent of that particular study too much, but basically what we were able to see is that the lighting power changes and the infiltration amounts were the most influential changes of all those that I listed. Another conclusion basically comparing vintages, going from new to post-1980 was a much bigger change than going from post-1980 to pre-1980. Now some of that is related to our modeling assumptions. I think one of the big ones is that infiltration is the same between post-1980 and pre-1980, but it's very different and new, and so I think that was a huge factor. It almost quadrupled going to the existing buildings.

There also were a wide range of EUI's and some of them saw huge increases. Some of them didn't really see so much of a change. The buildings with really high process loads, and those process loads we didn't vary across the vintages. Basically it's not because they wouldn't vary. It's because we didn't have a real reliable source that we could point to to say, "Yes, we know that we should increase the plug loads by this much." So they were kept constants. Buildings like restaurants and healthcare that have really high plug loads, you saw the changes from lighting power and infiltration and everything, but they're kind of dwarfed by the big process loads, so that's why in those types of buildings you see less of an effect of vintage versus buildings like offices that have to where the envelope and the internal gains have a lot more of the impact, I should say non-plug internal gains.

Just another reminder, we didn't do these to predict how utility bills would increase 20 years down the line from your new construction building. That's not – utility bill prediction is not what we're in the business of. Another important application of these models, these reference buildings, has been an evaluating ASHRAE standard. I'm going to go over two brief standard types before Bing Liu our next presenter goes into 90.1 in more detail, but more briefly it's used to develop standard 100, which is for existing buildings, and use CBECS 2003 for baseline comparison values, which we also extensively use CBECS as Michael mentioned.

There is a difficulty when you look at the CBECS data set, which is basically that not every building type in every city has the representation that you would want to sort of give you a good baseline value. So probably in the interest of time I'm not going to go through this example in detail, but it's here, it's on the webinar. This just shows a good example of how you could use this data set and all the results and sort of be able to extrapolate to things that they don't have explicitly in them.

Another standard that the models were used for was standard 189.1, which is sort of a newer high performance building standard. The reference models were used almost exactly with some variations, one thing being that they had appendix G system types, which is important to note that the reference models don't always have appendix G system types. There were times in discussions with the ASHRAE mechanical subcommittee that it was determined that maybe that wasn't the most appropriate system type, so anyway, but for these 189 models they did all have the appendix G system type.

Basically the overview of this, the goal was to reduce consumption by 30 percent over ASHRAE 90.1 2007, so we used the reference models, did a first iteration of what the standard was going to be, realized that the consumption savings fell short, and so that enabled the labs and ASHRAE to go back and say, "Okay, well let's make a few other modifications. Okay, now let's run them and see do we get close to the 30 percent?" Turns out we got 29.7 and of course this is an approximation. That's not to say that we're going to actually see those numbers in the news, but it helped the committee gage its progress towards this goal, and just as a point of information, roughly 20 percent of those savings came from energy efficiency measures, 10 percent came from a required renewables component of that standard, so that's just an interesting breakdown.

With that, the standard 90.1 studies have been done a lot by Bing Liu at PNNL, so with that I'm going to sort of turn this over to her. I'd like to introduce her. She's a senior research engineer at Pacific Northwest International Lab or PNNL with more than 15 years of experience in building energy efficiency analysis and simulation and high performance building metering and measurements. Bing leads PNNL commercial building simulation team supporting the development of ASHRAE standard 90.1.

Bing Liu: Thank you, Kristen. This is the last discussion of today's presentation, using 90.1 standard development to demonstrate how we're using DOE reference building models to support the next generation of the code standard development. A little bit of background: standard 90.1 is an energy design standard. It covers the commercial buildings and also it covers multi-family residential buildings if your total stories of the building is greater than three stories. So it's covered two sides, the commercial and the high-rise apartment buildings.

Standard 90.1 has been used as their baseline standards for many programs including as Kristen mentioned earlier the ASHRAE high performance building standard 89.1, the one for the Advanced Energy Design guide, and also the lead certification developed by U.S. Green Building Council. The process to develop standard 90.1 is strictly follow the NC consented process, and it's the standard by ASHRAE and Illuminating Engineering Society, IES. Starting from the year of 2004 standard 90.1 is published at a three-year cycle. That means for example when 2004 standard is published, their committee continue to work on addendum to 90.2004, then all approved and published addendum is going to be 90.2007 standard.

This slide is giving a little bit of historic data, the development of the standard 90.1. It all started to respond to the energy crisis back to the 1970's. The first standard was called standard 90-75. It was published the year after '75, and then another standard published in the 80's. It took nine years for next standard to be published but that's pretty stringent energy savings as 14 percent when the standard 89 version was published, and it took another ten years to get a standard 99 published with a little bit more stringent savings as 4 percent, as I show down here. It's starting from as I mentioned earlier, it started from like a 2004, it gets into the three-year publication cycle. So between standard 90.2004 and 2007 we see a 5 percent more stringent of the standards.

The 90.2004 committee is working very hard trying to get published new standards, which is they're targeting to publish later this year. This is their 2010 standard. Before they started working on the 2010 version of the standards, ASHRAE and also with support of the Department of Energy set up a very stringent goal. They said, "We published a 2010 standard. We're shooting and we're targeting 30 percent energy savings" using 90.2004 as their baseline. So if you look at a historic trending, 30 percent more efficient than 2004 is a very, very ambitious goal. I will talk later on on my slide how we're helping the committees to track the progress and also their development of their particular addendums.

So the trending I am drawing down here is one of the reasons the U.S. Department of Energy is really trying to provide technical support and also financial support through the National Labs particular for PNL through their building energy code programs to support a goal. One way to have a big impact on the energy efficiency in new construction and major renovations is to tighten up on the minimum codes and standard requirements. Eventually if the codes and standards can get into net zero, the goal, so that means we could possibly to have all our building stock to be independent to using the energy from the grid.

This slide is showing PNL's whole building simulation support to ASHRAE standard 90.1. We have three major missions. One of them is by their Energy Act and by Congress and by law basically, when ASHRAE publishes a new version of a standard, DOE has to make a determination. The purpose of the determination is from qualitative and quantitative analysis point to determine the new version of the standard 90.1 is more stringent than previous versions. So the whole building simulation support actually provides the support on an analysis point showing their energy savings and energy cost savings among the different version of the standards. We recently finished the cumulative analysis for 90.1 2007 determination and will be published at DOE's website pretty soon, and we are working on 90.1 2010 standard published pretty soon. DOE is going to launch another round of determinations for 2010's version.

The other big part of the map, the support using these reference building models is we can directly look into particular addendums and value the potential energy savings and energy cost benefit to first test and do the life cycle cost analysis to make sure the new addendum is technically visible and cost effective. The other thing I want to mention because as my colleague Kristen Fields just mentioned earlier, some organizations and the research institute, they're interested in using low profile derived from our reference models to value the certain type of knowledge. We're also doing a similar exercise here. Specifically we're trying to develop a set of spreadsheet tools helping the mechanical subcommittee.

For people who now may not be familiar with the whole building simulation or may not be able to use Energy Plus quickly, we profile all different kinds of locations and the different building types, and that populates the spreadsheet tools. Then committee members can use the low profiles to further look at the impact such as energy recovery ventilation, economizer, and chiller performance based on the low profiles we develop. The other part of the use of the suite of the reference buildings is really trying to closely measure the progress towards the improvement of 90.1 2010. I will tell a little bit more on that part.

We call that a progress indicator. What that means is because it's a three-year time process, in the past when DOE was working on determination it's only doing so after the standard is published then through DOE's determination quantitative analysis we will tell the percentage of the new centers compared to previous version of the standards by the percentage. What we did was during the development of the standard 2010 when the new addendum we know is going to be approved by ASHRAE board of directors, we're using the new addendum compared to baseline 2004 and the report of that back to the committee. Basically we tell them where we are, how far we are to the 30% improvement goal, so we call that the progress indicator.

We maintain three different sides of the buildings as I mentioned earlier. Starting point is 90.1 2004. We also evaluated their 90.2007 standards and also 2010, which is our approved addendum to 90.2007 standards. We provided the progress upgrade to 90.1 committee as a basis for the last two years. The way we also calculated it is we develop the new construction weighting factors, which is representing the total floor areas of the different product buildings and the different climate locations and then we assigned each of the product buildings the weighting factors at each location, so then in that way we are able to calculate. First we will calculate their national weighted energy cost and also the weighted energy cost for each prototype building.

Then we provide the weightings across the different building types and that way we will get one single national weighted energy and a cost saving percentage between 2004 standards, 2007 standards, and the 2010 standards. It's a lot of simulations. So PNL's, we build simulation for structure. So if I do my math calculation correctly you can see for each set of the progress indicators we have to run our 1,632 models because we have modular buildings, portable buildings, locations, we're looking at three standards. We also take into account – we're also looking at the two different violation standards, standard 62, '99 version and 61 2004 version. They have a different renovation requirement.

We were able to automatically read into the input file and extract the modeling results automatically as well. You see the similar tables from my colleague, Michael Deru, slightly different compared to the work we did for 90.1. I wanna highlight the differences. In one we're not using the supermarket in the 16 prototype buildings we have down here. The reason is most of their energy use in the supermarket is all the process loads or refrigeration loads, which is not covered in the current scope of standard 90.1. We also add one more apartment building down there. We call it high-rise apartment building. In that way we will have a category under multi-family greater than three floors apartment residential buildings, mid-rise and high-rise buildings, and their mechanical systems are different among those two buildings as well.

You may ask, given all the 16 prototype buildings and new building construction data it's representing about 80 percent of the commercial and the certain apartment buildings. We're not representing the rest of the remaining of the 20 percent, and what we do have down there including the public assembly buildings like rec centers, concert hall, etc., and the food sales, the supermarket, grocery store, and other buildings. If you're interested in using the new building construction data I provided you are all linked down here. You can download the report. They have a lot of information regarding how we develop the new construction weight as well.

The table showing is quite busy. I hope you can see some of the numbers on your screen. This one is really I want to give you a flavor about the new building construction weights. The weights is really representing the total square foot of seven buildings in certain locations, so it covers all the 16 buildings we're using and you can tell the construction weight is quite changed if you're in a different climate location as well, and it's changed pretty dramatically among the different building types as well.

These are the snapshots of what the building looks like. You already see the similar building type from Michael's presentation. I will not repeat all of them, but in the last three slides it's showing all the 16 prototype buildings we're using for 90.1 standard development. So they are the standalone mercantile building. You can see the street view and the shape is quite different. This is a primary secondary school developed from the Advanced Energy Design guide. Small hotels, large hotels, functions different. Large hotel we have retail spaces on the first two floors and the mechanical system use is quite different as well, and also the restaurant buildings and also the slide showing the mid-rise and the high-rise apartment buildings as well. Again their system is quite different. The mechanical system is also different.

Well so by now so far where we are regarding 90.1 2010, this is the summary about the development of the 90.1 2010. You can tell when the 90.1 2004 standard was published they are total 44 addendum to 2004 and so far by now, which is by April or last month, we had 61 addendum to 2007, which is part of the 2010 standard, and the amount there are at least 20 or 30 of them in the pipeline waiting for approval from ANSI procedures. So if we're using the current 90.1 2010 standard compared to 2004 standard, totally it's 105 addendum, but there are 86 addendums in section five through section ten, which directly has an impact on that energy savings.

Their addendums shows a lot of energy savings impact, and also some of them we're not able to capture through the 16 prototype buildings. Some of them maybe have energy savings but it is going to be extremely hard, almost impossible to quantify those savings.

These slides are showing most recent update of the progress indicator as we present reported to 90.1 committee last month. So I have all the 16 prototype buildings showing on the first column. Then the next column is showing the national weighted EUI member among their 2004 standards and April 2010 we call PI, progress indicator, and then that's two columns in showing the energy cost numbers as well, and the last two columns it's showing the energy savings and energy cost savings. Then as I mentioned earlier we calculated their national weighted and EUI members by factoring into the weighting factors. So you can see if it is close to their site energy savings, it's close to 15 percent as of today and energy cost savings about 14 percent.

The next slide is showing the progress. We started to have a meaningful progress indicator report, the committee started last year and you can see the number is still single digit and through the qualitative progress when a new addendum is generated into their progress indicator you can see it's really moving to the right direction. Also we feel like that progress indicator is really helping the project committee, 90.1 committee focus on energy saving addendums but also other addendums. Maybe they will change the strategy to put to the backburners if they don't have a big energy saving impact. So for single digit members they really start to think hard what else we can do to achieve to their service and the goals.

This one is showing an example of the energy savings. We also presented the energy predictions by end use. Using the secondary school as one example, it's showing across all the 17 climate locations we have down here the bar is in the same section we have in the legend from bottom to the top including interior lighting, exterior lighting, the plug loads, fan energy, pump energy, recovery, cooling, heating, and water heater. You can see the same addendums. The energy impact is different by climate locations.

Next step, we're working to get prepared to present the next version of the progress indicator when we get to the ASHRAE annual meeting next month. There are a lot of addendums we're still working on, so this is the addendum name. It starts from A, B, C, D. You can see we are running into a very long standard because we get to C. We then get into D something, DADB.

So we have a lot of addendums we're working on now, and we are also trying to forecast and trying to see a snapshot of what final numbers are going to look at when 90.1 2010 is published. That's including addendum BB, addendum BY and CY. All three of them have a pretty big impact on the energy ceiling. So that's really the next step that we're working on. We're going to see appraisal energy saving numbers when we get all these addendum implemented into our progress indicator. With that, I will turn it back to Anthony.

Anthony Perkins: Thank you very much. As I mentioned we also have some additional questions now that we want to get into before we start the Q&A session. We're going to go ahead and put that first question up now asking you what you were hoping to learn from today's webinar. Just take a moment to go ahead and review those and choose the best option. Go ahead and close this question and move on to the next one. Based on your expectations, how satisfied were you with today's webinar? We'll again let you go through and choose the best option for you. Okay. We'll go ahead and close that.

Now we'll get to the questions and answers. As I mentioned we asked everybody to submit their questions online. Each of our speakers will address as many as possible with the time we have allotted. We'll go ahead and I believe we'll let Michael start.

Michael Deru: Yes. Thank you, Anthony. I'm going to read the questions and then I'll provide an answer. So the first question was what are the ADG's? These are advanced energy design guides and they were prepared by DOE, ASHRAE, IAS and other groups and specifically pulled together experts in each of these building areas. You can download these advanced energy design guides from ASHRAE.or/adg. There's several that are available. Electronically you can download them for free, and then the second question, related question, are recommendations in the ADG's based on these reference buildings? Actually what happened was during the development of the ADG's they would develop a reference model and use that for the development of the recommendations in the ADG's, and then we would adopt – so far this is what's happening – we adopt those buildings into our reference building set after the work on the ADG's were completed.

The information didn't go from our work back to the ADG's, it went the other way around. Next question, "Will DOE commercial building research use these models going forward?" Yes, as much as possible and as practical. We're trying to – one reason for doing that was to – or one reason for developing these models was for DOE research needs to provide consistency but also to give everyone a quick starting point. Next question, "When can we expect residential benchmark models?" Well there's the apartment model right now, the mid-rise apartment model, and potentially in the future we'll also have the high-rise model that's being talked about for the 90.1 development.

As far as single house benchmark models, the DOE Building America program has a residential benchmark model that is available and I think if you Google "Building America benchmark model" you'd probably find that. That again is created through the residential program and these reference buildings were developed through the commercial building program. I'm going to turn it now over to Kristen to answer a few more questions.

Kristen Field: Okay. Thanks, Michael. There are a few other questions and some of these are kind of basic but I imagine important. One of the questions is, "Would these models ever be built into Energy Plus?" They're already in Energy Plus format. I imagine what the asker meant is will they be included in the Energy Plus release, and they already are actually. When you download Energy Plus and you look in the example files I think they currently have the word "benchmark" in them, but we're changing the name over to "reference buildings." In the existing Energy Plus 5.0 you'll see them with the word "benchmark" and the next release you'll see them with the word "reference building", but yes they are already currently built into there.

The models that we'll be releasing on the website soon as Michael mentioned, those will be slightly different from what you see in the Energy Plus 5.0 release for the basic reason that we've had some more time to work on them and make some more tweaks to them, so they'll be mostly the same but with some improvements. So another question is, "Are these files compatible with E Quest?" The short answer is no. These are Energy Plus input files. I mean you can definitely make an E Quest file looking at all of the inputs it would take some effort. The Department of Energy mainly uses Energy Plus as its simulation tools, so they were developed in Energy Plus. There are not any current plans to use DOE2 or any other simulation tool for these reference buildings. Right now it's just Energy Plus.

Another question, "I don't use Energy Plus. How can I use these models?" So they are useful to both users of Energy Plus and non-users of Energy Plus. One of the best ways to use them if you're not an energy modeler or not familiar with Energy Plus would be to look at those scorecard spreadsheets and those are available on the website. I think most of you would be familiar with Excel. Those are Excel spreadsheets that have inputs and then they have a very detailed list of all the outputs. Basically as long as you didn't need to make any modifications to the energy models they would kind of be all that you need, so you can still get a lot out of these. It's also worth mentioning there isn't a converter program.

I believe there is a converter program from DOE2 to Energy Plus but not the other way around, so I don't have an easy answer as far as just quickly converting the files over. Let's see, and then another question, "Are you working on assembly models?" Examples were churches and mosques. No, at the current time we're not working on those models. That's not to say we wouldn't in the future potentially, but we don't have any plans to at this time. I'll turn it over to Michael for some other questions.

Michael Deru: Thank you, Kristen. I just wanted to comment on that last question about the assembly buildings. Assembly buildings tend to be very different from one building to another and it's difficult to come up with one building type that kind of is representative of all of those. That was definitely probably the next building on the list if we were going down the list of largest impact and largest number of buildings, but it was just really difficult to try to come up with a representative building for those.

Another question that I received was, "Good models, but how will DOE measure building energy use? Will it be calculated using full fuel cycle analysis?" So just to make it clear again, these are hypothetical buildings used for really research purposes to understand impacts on energy codes or certain energy efficiency measures. They're not necessarily meant to represent actual or real building performance, but DOE does have a separate project right now that I am working on called performance metrics for sustainability and we are looking at including full fuel cycle analysis, and there's also a paper that I wrote a few years ago that has fuel and source energy and emission factors for energy use in buildings that is also a good reference for that.

A kind of related question was – this is a long question so bear with me while I read it – "The reference model seemed to be hypothetical rather than actual buildings." That's true. "This is useful for examples of generic analysis, but have you modeled real existing buildings and then validated the models against actual consumption and change in consumption of the function of energy efficiency measures. If so, have you used actual weather data versus TMY data? Do you or DOE intend to perform or sponsor such modeling or validation work? Do you know of any publicly available work modeling and validating models for actual existing buildings?"

That's a great question. We do a lot of case studies and we have done a lot of case studies of building performance in the past where we've built models of existing buildings and then calibrated those models with actual weather data and actual measured energy use. Usually when we do that we try to go in and get sub meter data down to the hour or 15-minute level so that we can get good calibration. It's very difficult to calibrate a model if you only have utility data, but it can be one. It's just not as accurate. If you go to nrel.gov and you go to the publications website you can search for case studies on buildings. You can look for lessons learned from high performance commercial buildings and there are several case studies there that are available.

One last question, "With a variety of building types have you found a predictable relationship for energy loss with window area or perhaps window area per unit volume?" You know we haven't done that study specifically with these reference building models, but this is a great question. That is really what we've built these reference models for is to answer these types of questions, however just from my personal experience I don't know that you could come up with a predictable relationship that is valid across all building types and across all locations. You could certainly come up with a predictable relationship for a specific building type.

Let's say you picked the medium office building and you wanted to look at window- to-wall area ratio. You could certainly come up with a predictable relationship for that building type in one location or one kind of climate zone, and that might change as you go from a hot, sunny climate to a cold, cloudy climate. That relationship probably won't hold up. That was the last of my questions and I'd like to turn it over to Bing to answer some other questions.

Bing Liu: Thank you, Michael. I do have a few questions. I will go through them as much as I can. The first question is, "Do you see these models influencing building energy codes?" The answer is definitely yes because of the time limitations. So I only use the progress indicator to show the support we have to the 90.1 committee. We also are theoretically using these models to evaluate the cost effectiveness of a particular addendum. We at PNL started their analysis using other prototype models or reference models across their different locations, and we try to see if that particular addendum is going to be cost effective in certain climate locations or not. Then work on that to put together a requirement of the addendum, new requirement. So that's directly using these models to develop the new standard codes.

Another question, "Would you please provide the URL for PML's construction weights?" As I know if you go to the slides you see on your screen now you can download today's presentation at this URL we're providing you on your screen now, and then you'll see my presentation slides, and one of the slides showing the URL, the link where you can download our report. The other question is a terrific question is, "Let me understand, 90.1 2010 is expecting improvement over 90.1 2007 by 30 percent. Is that correct?"

No. The goal, 90.1, ASHRAE leadership and DOE is both available to 2004, not 2007 targeting 90.1 2010, so baseline is two times four, not two times seven. Another standard is called high-performance building standard, standard one 89.1 has a target of 30 percent more than 90.1 2007, but as Kristen Field presented, 20 percent is really coming from efficiency and 10 percent from renewable, but that's another standard.

Next question is, "How do you develop the high-rise apartment building model and why did you include that in your analysis?" Well the high-rise apartment building model was developed based on PNL's effort to support the state of New York because they want to look at what they can do for envelope and mechanical equipment efficiency requirement for mid-rise and high-rise apartment buildings, so they went with the building, especially high-rise building stocks from their data provided by the state of New York and the providers of high-rise apartment building model. The mechanical system we are using in the high-rise apartment building is the water cooled heat pumps, which is quite popular on the East Coast where the high-rise apartment buildings are mostly located.

Why we include it in our analysis? As I mentioned in my presentation slide, 90.1 standard covers commercial buildings, and it also covers mid-rise and high-rise apartment buildings. So the reference buildings have mid-rise apartment buildings and the high-rise apartment buildings so we can cover a pretty big range of the residential buildings with stories greater than three stories. So that's why we have to have an analysis.

The next question is, "What is the biggest challenge you face in determining the 90.1 2010 standard?" That's a really great question. The challenge is really dependent on addendum. There's a lot of addendum requirements such as addendum M, which is the new requirement for the chiller performance included in both their peak efficiency and the efficiency. We have to start from research and working with industry experts, professionals, and also trade associations and manufacturers. The first thing is to look at what is the baseline? If you look at 90.1 2004 sometimes there's no clear baseline but the new addendum has more requirements. So there's a lot of research going on many of the addendums to make sure we are taking our estimated energy savings in the very expensive way, so that's really very time consuming to do the research but also we have been working with the expert on the 90.1 very closely, so they provide a lot of input in addition to our own research as well.

Next question, "Was there a particular building technology that helped achieve the energy savings goal of the 2010 standard?" Well it's a really good question, but I think all the low hanging fruit are done. There's no silver bullet to help 90.1 standard to get to the goal. So you can see each of the components of the buildings and each of the subcommittees has been working really hard from their requirement of envelope, lighting from the fenestration, windows glass requirements, mechanical systems, controls, water heater, and they even started thinking about how we could reduce the plug loads as well. So it's getting pushed to a really integrated design.

The next question is, "What building type is most difficult to achieve the design and the experience and why?" The most difficult building, if you look at one of my slides it's showing a summary of the indicator by building type and the energy savings and experience. You can see we have very, very low energy savings for two restaurant models. The reason is about 67 percent of the whole building energy use in the restaurants are coming from process load, which is the kitchen ventilators and all the cooking appliances. Especially for cooking appliance energy uses are not regulated by 90.1, so we're not touching 60 or 70 percent of whole building energy uses for restaurant buildings even when we have a title requirement on the envelope, lighting, and even for a kitchen ventilation system requirement has been changed to 90.1 standard. So far we only get a 4 or 5 percent savings of the whole building. I think that's really one of the reasons the buildings with high process loads we're not able to get a lot of savings.

Let me see. I will have one more question. "How much emphasis will be placed on the building envelope R value in the future?" When we get the building title for the whole building energy point I think the plug load the percentage of their end use from the plug load, the number gets bigger and bigger, so I don't know how much emphasis we should continue on envelope R value, but I think from the future standard personally I believe the emphasis will be on the integrated design, performance base, and also somehow we have to find a way to tackle the plug load. With that, I will turn it back to Anthony and I don't know if we should take another round of questions, etc.

Anthony Perkins: Thank you. Actually we're about ready to wrap up, so we'd like to thank all of our speakers for their time today. We'd also like to thank all of you participating. Remember to visit the buildings at energy.gov/webinars.html to download a copy of the slides and please keep checking the website for information on future building technology program webinars. So this concludes our presentations. Thank you and goodbye.

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