Great. Thanks for the introduction, Stephanie, and thanks to everyone that took time out of their busy days to attend the webinar today. Lynn and I are very excited to talk about precast concrete, some of the high-performance components of that particular material, and with that, we'll get going. So our learning objectives today, we're going to define energy modeling and enclosure commissioning or envelope commissioning. We'll discuss some of the advantages and challenges of energy modeling, explain some of the core components of envelope commissioning, and describe how precast concrete, both energy modeling and envelope commissioning, some of the concepts there. So a brief introduction of sorts on high-performance precast. Certainly, precast concrete as a material has come quite a long way since its origin from the perspective of really a couple of higher-level concepts that we'll talk through today and focus on particularly a couple of them as it relates to versatility and efficiency and resiliency or durability. So from the versatility perspective, really that kind of comes in the perspective of aesthetics and some of the design versatility. You have the fortune or misfortune, depending on your bent to have a couple of engineers here speaking with you today, so we're not going to spend a whole lot of time on the aesthetic design component. Really, what we're going to focus on is efficiency with some durability or resiliency component and really sort of the middle part of that table that you see there from an energy and operational efficiency perspective. From thermal efficiency, we'll talk a good bit about air leakage and to some degree about projected energy costs. So with that, we want to talk a little bit about building enclosure or building envelope commissioning. A little bit of different terminology out there. I think we're consolidating into calling it enclosure commissioning in our industry. So what is commissioning in general? It is a quality-oriented process for achieving and verifying performance. Now, most of us on the call have probably had some experience in the AEC industry and really that word commissioning has meant to most of us up until maybe four or five, six years ago, primarily mechanical systems and energy systems. Really, that concept of commissioning, of introducing a quality-oriented process to planning, design, and construction really has branched into several different disciplines to include building enclosure commissioning, part of the topic here today. So why would we commission the enclosure of a building? Well, there could be a lot of different reasons really depending on the owner or the project team. Here's a number of them. Certainly, reducing energy consumption is one that is and has been a hot topic and it plays a key component there. Lowering operating costs and improved HVAC performance. Certainly, the enclosure as a system, it plays an integral role in the HVAC and energy systems as they relate to each other and as they perform together as a system. Certainly, minimizing callbacks and improving occupant comfort and air quality play a role. Construction defect risk management is one that's of keen interest to a lot of people in the industry and here's really why. This is kind of my scary slide here and this is a study from ASHRAE from 2007 that ASHRAE Journal published and they looked at quite a few construction defect claims and ultimately found that about two-thirds of those claims had something to do with moisture intrusion into the building enclosure and ultimately into the building. That's quite a bit and we have the opportunity to present this kind of slide in person, certainly to the general contractor audience. We try to kind of correlate that to their callbacks and generally that's the case. They finish a building, they've got a couple of years worth of warranty or maybe a couple of years and about two-thirds of the phone calls that they get have something to do with moisture in the building. It's a big deal. The second component of that scary slide is $9 billion is what we spend, billion with a B. That's how much we spend as an industry dealing with, repairing, fixing, investigating, litigating some of these damages that are from moisture intrusion. It's a big deal and really it speaks to some of the resiliency durability topics that we'll talk about. So we talked a little bit about the why. Let's talk a little bit about where building enclosure commissioning is starting to play a role. So I've got a LEED version 4 language here and really it's in the LEED construct, enclosure commissioning is started in somewhat arcane places and has gotten to the point now where it is a point that people can pursue in the energy and atmosphere environment. Particularly, it's option 2 in enhanced commissioning for those that work on LEED type projects. Here's what the USGBC is looking for in commissioning the enclosure under the version 4 construct is a submittal reviews for enclosure systems, verifying the systems manual, operator and occupant training, seasonal testing, reviewing operations, and developing a commissioning plan. Now if you read these, they certainly read a lot like mechanical systems, energy systems that are active systems, operator training, seasonal testing. What we're finding with LEED is they're continuing to make progress in including and describing what an enclosure commissioning could be, but it's still to some degree focused or sounds a lot like active system commissioning when really the enclosure systems, components and assemblies that we're dealing with are passive systems. You build them once, they sit there, they probably don't move and they're there for the life cycle of the building. So there's some other places that enclosure commissioning is mentioned or referenced. This is a great standard, the National Institute of Building Science has a lot of great information and this is their Guideline 3, which was updated in 2012. It's a partner of Guideline 0, if some are familiar with that document, that really talks more about the process but is not discipline or system specific. This Guideline 3 is particular to building enclosure commissioning. Now, one of the tricky parts with this document, it is great, it is comprehensive, it's massive, it's 200-300 pages long and really as it relates to how do I want to incorporate enclosure commissioning into my project, what we found over the years is this is a good resource or reference, but ultimately owner's project requirements or a specification, something needs to further define what enclosure commissioning is and means because it can be almost too much for some small to mid-sized projects within NIBS Guideline 3. It's a great document, if you can go onto the NIBS website, you can probably Google it and download it for free. It's a good document. What a lot of the people that were involved with NIBS Guideline 3 development formed and ultimately launched an ASTM standard in 2012. I say new, it's a year or two old. We're starting to see a little bit of traction. It gets mentioned from time to time in project documents. We really like this standard from the perspective of it being a standard and so it has a lot of language that's standard-like, as in shall and will. It has very specific requirements for if you want to do a fundamental level of enclosure commissioning. If you want to do an enhanced level of enclosure commissioning, here's what that would look like. Lists of the tests that are optional or mandatory. Certainly it could be a document that's tailored, but it's almost a standalone. If someone were to say, I want to commission my enclosure per ASTM E21-2013, really that's a sort of a biddable document. You can go launch it right from there. There's other jurisdictions that have either institute an enclosure commissioning requirements or really just owner by owner, project by project, that have incorporated enclosure commissioning. Just a couple of examples. Here in beautiful Colorado, the city of Fort Collins, a college town in the north part of the state, and they have adopted an enclosure commissioning program as a requirement in their building code. Lots of other non-federal or non-jurisdiction different entities here. You see a lot of owner operators. You see museums and universities and healthcare systems. These people are going to live with their building forever. Resiliency and durability and even smaller level energy efficiency components make a lot of sense to them. Lastly, what I'd like to talk through is the International Green Construction Code. This is part of the ICC code family. It's been out for a little while. It's been adopted by a number of jurisdictions in some form or another. Again, it reads just like IBC or IRC. The table you're looking at there identifies some of the requirements for inspection of foundation waterproofing and some other items. Again, another good document that talks about BECX. With that, I'm going to pass it to Linda, who's going to talk more about energy modeling. Linda Abbruzzese Thanks, Matt. Getting into energy modeling, the work that Ambien Energy does has to do with helping design teams and owners get the very best in performance-based decisions. Our energy models can look a lot like what's shown here, similar to the Revit 3D platform, where we've got the building on its facades. We also have a weather database, so the temperature, humidity, rain, wind, cloud cover for every hour of a representative year. The people that are in the building, the systems that are in the building, we're doing an energy balance each hour on all the loads in the building. The outcomes for energy modeling can be in... It's a very versatile tool, so you can get a lot of different things. The common ones would be an energy use output, so energy use intensity, EUI, has units of kBTU per square foot per year. That is a way of normalizing one building to another on that energy kBTU per square foot per year, so we can discuss it and compare. Also, on costs, on loads, and the other side of the energy coin, which is always on comfort as well. When we're working with projects that have specific goals, we will also look at other specialized tools. Some of our net zero energy projects have additional analysis done, such as daylight analysis, looking at wind rows for natural ventilation data and wind driven ventilation. We might have a spreadsheet that lists the energy use for office equipment. We might have specific analysis done for solar thermal systems or photovoltaics. We can come in a couple different forms and fashion and be linked together to create one overall message of performance. Why do energy modeling? In our industry, we only get to build it once, so it's helpful to simulate ahead of time and make the design trade-off decisions. The auto industry has done such a great job of simulating before getting into production. It's the same kind of thing. As the expectations for buildings and their performance increase, even more important, some of those expectations take the form of the 2030 challenge, which is targeting carbon neutral buildings by the year 2030. Also, zero net energy buildings are interesting to many, but targeted by the federal government and the state of California in the same timeframe. We have a regulatory push for improved energy performance as well. This slide lists the outcomes of energy savings versus code. We looked at a portfolio of different architectural firms. Basically, what it's seeing is that the firms that had 75 percent or greater of their total projects being modeled had the best performance. Why is this? You can probably intuit that some of it is knowledge, is power. Also, the architect and the team were focused on a specific goal. They tested their assumptions instead of using general rules of thumb so they could really drill down into best applications. They also got information about the best return on investment, whether to invest their money in lighting, HVAC, windows, or an envelope system. Energy modeling, as I mentioned, has a variety of tools. It can also answer a variety of questions. We want to understand what specifics are being looked at ahead of time. Some of the energy modeling questions that are commonly asked might fall into the family of being a comparative energy performance, where one, the design is compared against a nominally effective code-compliant building. That's what LEED does. That's also what Title 24 does. We're comparing one model against a code. That's opposed to predictive modeling, which would be used where the absolute energy performance is really what's of the highest order. That would be used in buildings that are going for an Energy Star rating, which has a specific target on total energy use, or a net zero energy building where, again, we need to tally up the energy that's being consumed and offset it with renewable systems. That might drive different software as well as outcomes for energy models. The energy model, being a holistic tool, will take into account different systems across the building and provide a look at all the different interactions. Things like envelope loads and radiant HVAC systems can have some different interactions than air-driven HVAC systems. I wanted to present this look at how energy is broken down for a commercial project. I wanted to point out the concept of our commercial buildings are considered internally loaded. This is opposed to residential buildings, which have few internal loads and have very light occupancy, relatively speaking. In the commercial world, you can see that the equipment that's brought to the project, office equipment, servers, kitchen equipment, that kind of thing, can be significant loads, have a significant slice of that energy pie. Lighting, and then we get to the HVAC loads, which would be indirectly affected by the envelope design. We do certainly encourage integrated design among all members, especially folks like IT and kitchen because of their loads they're bringing. Moving into the envelope loads, we want to make sure that we're communicating well on what the options are that are being evaluated. Really, we're looking at them on a case-by-case basis to get the best return on investment for the project. We're interpreting the results in a way that the client can really relate to. Sometimes that's in money, that return on investment, also potentially in lead points, but it's important to talk about what that ultimate goal is, that code compliant or that predictive hard energy target. As we're presenting energy modeling results, sometimes they don't necessarily look dramatic. I wanted to show this as a optimization study over a project located in the Denver climate that compared different amounts of continuous insulation on walls and roof. We have a relatively small change in that energy use index, hovering right around 53 for each of them. Keep that in mind. Sometimes it's hard to move the needle as we're looking at the whole building energy total use, but in reaching these high performance goals, each step that's taken to reach them can be very significant. We also want to look at the potential outcome of fuel switching. In this slide, two different heating systems that use natural gas are compared to a ground loop heat pump system, which uses electricity. The ground loop system has lowest end use for energy, but highest cost because of the electrical charges, so something to keep in mind when trading off. Diving into PRECAST a little bit further, here's some information from IECC and also from ASHRAE and their definitions. Obviously, this classification is a mass wall. Some of the characteristics would be excellent heat capacitance, thermal mass, and a slow response time. ASHRAE has some guidance in Appendix A, Section 9, regarding how to calculate the U values, so the thermal properties of the mass wall. The air permeability is not considered to be greater than 0.004 CFM per square foot, so functioning as an air barrier as well. How does a typical PRECAST concrete wall compare to the code minimum that's required? This study compares the 3-4-3 PRECAST concrete, so 3 inches concrete, 4 inches of expanded polystyrene, but also very similar for extruded polystyrene, and another 3 inches of concrete. In each case, that assembly is performing better than the minimum code compliant wall, so definitely a good standard assembly with better performance than the minimum requirement. Looking at the value for a more detailed section of PRECAST concrete wall, Panel A has continuous insulation to the perimeter, and from an energy perspective, this is the best. We're eliminating the potential for thermal bridges through that. Panel B has 3 inches of solid zones at the perimeter around each of the window openings, and we can see what the impact of that is to its overall thermal performance here, where Panel A, with that continuous insulation, has the 0.049 U-value, and the one with solid zones, 0.083. In this case, of course, U-value, the lower is the better number, so about 50 percent increase in performance on thermal insulation properties. That will have an energy impact, but it would also have an impact in comfort in the building. Potentially, somebody stationed close to that Panel B would feel radiant temperatures of hot and cold more strongly than Panel A. Also, Panel B, if it's in a space where there is humidity or it's a humidified space, might find a condensation risk or a greater condensation risk. Looking at the energy modeling for their deep dive for precast, we want to be sure that we're getting the weather data that most closely reflects the actual weather conditions at the site. Typical meteorological year 3, TMY3, is a common standard of weather data. That data is averaged, it can be 30 years old. For a specific project, you might want to move away from TMY3 and get 15 year or 7 year to have a more relevant data history for that. We want to look at the cost, so we want to be sure we're getting the utility costs that are effective on the project. This is especially important because that thermal mass will cause the loads to lag. We want to credit a project for reduced cooling costs if the demand isn't seen at 3 o'clock in the afternoon but is shifted until later when the building perhaps isn't occupied. We also want to capture the interaction between HVAC and the first cost due to loads. Here's a test case. It's a 130,000 square foot office. It's basically compliant with ASHRAE 90.1. It's got 40% windows in every wall. We added exterior shading of two feet, so that's not in the code. We also changed the glazing to be more representative of current standard practices, so it's a Solar Band 60 glazing product. The walls are the only thing that changes in the outcome of this energy model. The alternate one is a steel frame compatible with the 90.1 2010 steel frame. You might ask yourself why I'm using a steel frame as this example. That's because of the LEED and 90.1 performance rating method compares all wall assemblies to a steel frame. That might be an interesting point as you're making your comparisons for the precast products. The precast wall is the one that we looked at before, the 343 panel with no solid zones. We chose to put that in several different locations for the effect of weather. On an intuitive basis, you can probably think through the changes between Denver, has certainly winter and summer dry climate, high diurnal temperature swings, a difference between day and nighttime temperatures, Seattle, that more temperate climate, Dallas, warm and humid, also has a heating load, but very little diurnal temperature swings, and then Phoenix, that hot climate again, temperature swings. That's really going to show in the results coming up here. The first result is that total annual energy use, energy use, the EUI, KBTU per square foot per year. We're comparing each of these weather locations with the steel frame wall and the concrete, the precast concrete. We get a range of outcome that shows a 1% savings, that's Seattle, up to a 5% savings for Phoenix. Again, that tracks along with what that weather pattern and the diurnal temperature swings. I should also state that the energy modeling software that's used in this needs to really account well for thermal mass and thermal lags. We've happened to use the IESVE, IES virtual environment software for this. There's other products that are widely used by the industry that tend to overlook the thermal mass and the thermal capacitance of materials. You just want to be sure to have that check question with your energy modeler. This would be that 5% energy savings, again, might feel small, but is significant, especially when we look at the way that the energy is broken down, because we are taking into account equipment loads and lighting loads, as well as heating and cooling. You could prepare this information so that you're just looking at heating and cooling if you like, and that would obviously show a bigger percent difference. I wanted to also show you the peak load. This would be basically what's used to size HVAC equipment. In the heating loads, we've got a reduction of 1% in Dallas, but up to 22%, 23% in Denver and Seattle, so pretty significant on the heating. On the cooling side, up to 15% for Phoenix, so a pretty significant reduction that may impact both in footprint and area of equipment, as well as the size of equipment and its first cost, so certainly a good story to be told there. Then in overall energy costs, this includes rates where the rate structures and the time of use or demand charges are known, or it's the average as compiled by ECI. We get an energy cost savings of 1% in Dallas, up to 7% in Denver. All of these results are based on the thermal properties of precast concrete alone. I'm going to pass this back to Matt, and I'm going to come back to you and discuss further some of the implications on infiltration that he's going to talk about. We talked briefly about the concept of airtightness or infiltration previously, and I want to dive a little bit deeper into that topic with a case study. This case study is a precast concrete structure here in Colorado, happened to be a military installation headquarters building. Just about all of it was precast concrete with a small framed area adjoining the two areas of the building that you see here, the three story area and the two story area. This particular building was a design build project, and the design build team opted for a precast concrete solution for their proposed and ultimately designed and constructed building. A component of that was that this, as well as just about all military projects, certainly Army Corps of Engineers projects in the last, say, five to six years, have a whole building airtightness or infiltration requirement. In other words, the whole building has to meet a tested specific performance rate in order to basically turn the building over. The design build team opted for a precast solution and wanted to hone in particularly on airtightness as it relates to building enclosure commissioning, which certainly is more than airtightness, but that played a key role in this particular project. As Linda mentioned earlier, concrete, and certainly precast concrete, meets the requirements for an air barrier material, and so that's what we use. Also, because it is a whole building or system test, there has to be a top and bottom to the box. So, the single ply TPO membrane, we treated and used as an air barrier for the top of the building. Otherwise, it was a slab on grade. So again, in the enclosure commissioning construct, we had the opportunity to look at the design and do a couple of third-party reviews of the enclosure at the early stages of construction documents and put together some recommendations for specifications and details. Some of the things that we looked at in the detailing world is continuity. We talk a lot about that, certainly as it relates to airtightness, and so how are we achieving continuity between our walls, which are our air barrier on the walls vertically, and horizontally, how do we transition that to a single ply TPO roof membrane. A relatively simple transition, but certainly something that we wanted to pay close attention to, and what we found, as we'll see here shortly, is that what's on paper didn't necessarily... It's what showed up in the field, but with some nuance to it that you don't necessarily catch in 2D drawings. So roof-to-wall interface was critical, and then you saw from the image there's a fair amount of windows, and so the transition between the precast wall and any fenestration, certainly the windows, is critical as well. So we looked quite closely at that in the design reviews. And sliding into construction, here you see kind of a traditional precast concrete set up with some kickers there to hold up the structure as it's being constructed, and some relatively smaller items, but you don't want to miss. We don't want to come back and miss the sealant joint, where otherwise there was some structure temporarily holding up the wall. And this is, by the way, this was a sort of a traditional approach to panel-to-panel sealant, where there is an interior sealant joint and an exterior applied sealant joint. We've certainly lots of different ways to do that now, but this was a pretty traditional approach. What we found in that critical roof-to-wall transition as we got into construction was there was the exterior sealant joint that you see there, and the interior sealant joint, but actually underneath that wood blocking you see, the two never actually met. And so, similarly, at the interior of the building, there was a couple of different floors if you recall, and at every floor line, it's a difficult area to seal, and so the interior sealant wasn't installed at floor lines either, and that actually became an air leakage path, so air from the inside could enter the floor line, come up through the precast assembly at panel-to-panel, and if not treated properly, actually exfiltrate the building. And that's what you can see in sort of a plan view from above is where those joints were prior to the blocking being installed. So, again, just things that we look for during construction. We've got lots of time to address anything that we saw during construction prior to going into testing. And because it's a whole building system test, lots of other things that we're looking at, not necessarily precast-related, but how things like roof appurtenances and rooftop units, how they sit on the curbs, how the curbs are handled, also air leakage sources. So, in the end, I've got some numbers here on the table. The Army Corps of Engineers and the RFP for this project had a requirement of 0.25 CFM per square foot of building envelope. That square footage is the six sides of the box, I like to call it, so four walls and a roof and a slab or a basement area. And 172,000 square feet of envelope for this building, that allowable leakage rate or allowable leakage, rather, looked like it was 43,000 CFM. So, you have 43,000 CFM of air that were allowed to exfiltrate this building and have it be compliant with the RFP and the Corps' requirements. What we found in the two different pieces of the test, pressurizing the building and depressurizing the building, was significantly lower than what that requirement needed to be, to the tune of almost a sixth of the allowable leakage. So, where that building came in was a 0.04 CFM per square foot of building envelope, one of the tightest buildings that we've had the opportunity to test, and really, I think the precast concrete played a role in that. So what does that mean? This has a couple of different implications that Linda will go into from an energy use perspective, but I wanted to frame the different kinds of wall assemblies, and these are grouped, they could be grouped in finer terms, but on the aggregate, we put concrete and precast and class-in-place concrete walls together. This is a plot, by the way, of all the tests that we've done and what the air leakage rates of those tests were for the different wall types. So you see pre-engineered metal buildings, you see CMU walls there that typically have some kind of fluid-applied coating and framed walls. So a couple of things I wanted to call your attention to, first is the gray box is basically the average of all the tests that we've done for that particular type, and you can see on the left that the concrete and precast concrete are some of the tighter buildings that we've had the opportunity to test fall into that group. Some of the other items to certainly compare to some of the other wall types, and the other items to call your attention to as it relates to enclosure commissioning is the blue boxes you see there are efforts that were done to commission the enclosure, both in design and construction, not merely a test at the end of the building. That includes things like the design review, things like quality assurance observations in the field. What you see there is a pretty significant difference between the blue boxes that are relatively low on the scale and the red boxes, which are really all over the board. In simple terms, to have a test requirement for your enclosure for infiltration or air tightness at the end of the project does not necessarily mean design the building as you did the last one. It certainly can be fun with good design and construction practices, but there's quite a bit of scatter, if you will, in some of those results. Ultimately, what we see across all wall types, and taking it a step further, really all the buildings that we've tested, a couple hundred buildings, and what we've seen is with that testing requirement in place, what you're seeing for an average air leakage rate in CFM per square foot is .16. So, if you remember that number as we transition back to Linda here shortly, that requirement being .25 and with a good enclosure commissioning program that focuses on air tightness when it's necessary, you can get definitely lower results than required. I want to shift to another, a different case study here, and we're moving away a little bit from the energy efficiency component and more towards the durability component of buildings. So, certainly one of the primary functions of a building as it relates to resiliency and durability is keeping water out of the building. So, I wanted to talk a little bit about some best practices for what you can do for a precast concrete building. Certainly, this is not a code requirement by any stretch, but I wanted to walk through a case study as an argument to why to embrace and hopefully convince project teams that some of these are a good idea. So, this is a precast concrete building. We're going to focus really here on this clear story area that has a translucent panel window assembly across the top of the clear story. So, this is a building that we got involved in kind of later in construction, but prior to turnover, and they started to have what was characterized originally as, yeah, we got some window leaks, we don't know what's going on, can you give us a hand. Water at the window sill transition looked like some dirt there, I mean, evidence that there was some water in that area. A little bit of evidence of water as we continue to look around those windows areas, and if you see in the picture, there's what looks like a crack kind of in the mid-span of that translucent panel assembly. So again, just things were information that we're collecting as we're looking around what was characterized as a window leak problem. So we did want to focus on windows, and what we did to test that sill pan area is block off the weeps from the outside, introduce some water to what should be a watertight bucket of a sill pan, where if the weep is blocked, we fill it up with water and the water just sits there, and as it turned out, there was some water leakage to the inside and outside of the building, indicating there were some window sill problems, and we did some more kind of damming tests to, again, validate and take a closer look at some window issues. So, okay, we're good to go, right, we got a window problem, problem solved, here's what we think you should do about it. Well, not quite. So we wanted to take a little bit more, a closer look, having seen that small crack in the precast concrete above the window, and so we started wetting some of the non-window areas, particularly above the window and towards the sides of windows with an AMA 501.2 nozzle, kind of an industry standard test for introducing water to windows. Actually soaked, really, this whole wall area, and beautiful, this happened to be in the upper Midwest, beautiful sunny day, and as we let the wall dry out and water flash out, start to see a little more of hairline cracks with water in some of those hairline cracks. Coming to, and looking a little closer, cracks right above the window head, and there's a sealant joint you can see there that seals between the precast concrete and that metal head flashing, and cutting that sealant joint away, and you can see some water coming out there. What that indicates is that we're starting to see some water getting really trapped inside that window assembly, above the window. Even coming back a couple hours later, and you can see that there's some water still trapped in that assembly. What the fix is, is originally with the window particular project, or problem is a sill pan you see on the left side there with end dams and back dams that collect water and direct it to the exterior. What we did is introduce the same concept to the window head as really a best practice. If there happens to be any cracks in that precast concrete, we basically have a pan at the head as well as the sill, and that's what that looks like in 2D, where we're keeping water, really the same concept, collecting the water and directing it to the outside of the building. In this scenario, you see on the right that head flashing, you really can have any issues or any cracks or any other otherwise problems with the precast wall, and you really will never know about it. Again, just wrapping that up, there really are some best practices for how to almost be defensive towards some of the things that we can come across in precast concrete if it's not formed well and delivered well and installed well. Lastly, I wanted to talk a little bit about and build upon Linda's slide about U-value and R-value calculations. Just a very simple look at that. We've got a very simple, this is a 3-2-3 precast panel, got some solid zones there, maybe some solid zones between ties, and then a traditional metal, very highly conductive tie between inner and outer lice of precast. What does that look like from an R-value perspective? 6.37 for an insulated panel that's not fully thermally broken. If you take those solid concrete zones away, similar to the scenario that Linda described, and you see a pretty significant jump in the R-value of that assembly, calculated R-value when you go to a true continuous insulation, insulated wall panel. Finally, if you remove those metal ties and go to a better thermally broken system, and there's all sorts of different composite ties that are on the market today, and again, you get a nice bump in the R-value for going to those kinds of ties. With that, we're going to shift back to Linda, and she's going to talk a little bit more about that air leakage infiltration rate as it relates to energy modeling. Matt had described some cases where the potential allowed infiltration rate 0.25 CFM per square foot, or I should say, an improved infiltration rate, but getting a tested value on average for the precast assemblies was 0.16 CFM per square foot. That's where the potential for additional savings really comes in. It might not show up in an energy model that is done for purposes of weed, because infiltration is not necessarily accounted for there, but certainly very important for an owner understanding their total impact of the energy component of infiltration. Here we have savings of up to over 20 percent on energy use versus the neighborhood of three to five percent when we just looked at thermal components alone. I think that's the thing that I wanted you to leave with here is a look at the total performance, infiltration, energy performance, and the energy cost performance can be significant. That concludes our prepared material.

precast concrete

energy modeling

enclosure commissioning

thermal efficiency

air leakage

building enclosure commissioning

HVAC performance

cost savings