 Great. So this is the Amherst School Building net zero building subcommittee. And today is August 4, 2022. And we're going to have a presentation from our design team. Kathy, I think you have an agenda and maybe we could put that up just to quickly let all our guests know what what topics we're going to be talking about today. Yes, and Jonathan just make sure we can do our verbal yes we've got to do our see and be seen. Peace. Yeah. So I'm just going to do thing do things in the order I see them with our committee. I am Jonathan salva and I am the chair of the subcommittee. Kathy, we can. I'm sure we can hear you. Rupert can we hear you and are you there. I am here. Great. And then Ben Harrington. I am also here. And can everyone see the agenda. I think I pulled it up. Yes. This is the agenda for today. We're going to we've just had our call to order we're going to review the basis of design, including daylighting and talk a bit about ground source versus air source options for our HVAC system. Get an update on the incentives from ever source. And hopefully we'll get to a vote on a recommendation to recommend to the full committee, which, which HVAC approach we're going to take. And then we're going to talk about other issues and get public comments. And so I guess I will, I will start to dive us in here and probably turn things over to Tim to walk through the presentation. Okay, just before we start, I see that Margaret and Shelly are in the waiting room participants. If they just want to hang out there, that's fine, but. I'll bring them in. How do I end share does anyone know that should be where the share button is should be an end share. When you're sharing, or something like that. It doesn't have any end share select. Well, let's hope that I can let the other person share. Okay, now I need to make this bigger. I didn't. Oh, there it is way down. Thank you, Jonathan. There's a little button. And participants attendees. Margaret. Okay, and Shelly. Can I catch everybody or. I'm trying to, oh, shelly should be coming in. Okay. Yeah, I'm, I'm in. Can you hear me? This is Margaret. Yeah, I'm going to be on mute, but I'm here. Hi, Shelly. Okay, we're ready. Great. I'd like to introduce, we have a couple of new faces that you haven't seen from Thornton Thomas had before. They like specialists and Ali, maybe you want to introduce yourselves and so. Hi, I'm a lemon checker. I am a vice president and sustainability. And Eric is in almost are here with us. And then we already put up the agenda. I just want to say that what we're basically intended to suggest is updates that we have since the last meeting. There were some questions that were asked and we'd like to have discussion. Hopefully we can answer them and then get into the daylighting a little bit. I'm going to share my screen and start off with the updates. The first updated slide. And we'll probably get back to this a little bit as we talk about the energy budget and some of the answers to the question is just an updated version of the total energy consumption for the two options air source and ground source with a breakdown by eating, cooling, lighting and other loads in the building. And then the update that perhaps a lot of people have been waiting for is the revised incentive structure that ever source has recently proved that significantly increased. The ground source each pump incentive from $600 a ton to $4500 a ton with the other incentives for the construction and post occupancy phase which has to be verified that brings the total incentive package. If we were in fact to go the ground source route and meet the 25 the UI, the total incentives would be 1.6 million. An updated chart that we have seen from last time with the total capital investment for each system. With the incentives added the cost difference between the two options is narrowing significantly to say the least. And then with the incentive and the changed capital cost. The lifecycle projection costs also narrow over the lifetime of the building. So that is a fairly brief and quick update. Go ahead. Sorry. Did you, I just, I guess they're only four of us, but I have a I have a couple of questions on it the incentives. As I understand it are the, the big bucks. And the construction the first two are if you all submit, you all working with the town submit a memorandum of understanding and ever source has to endorse that they think 25 is likely. Is that correct. I mean, this is, we don't have to have achieved it. They just have to think we can achieve it. Is that for the 1.4 million part of it. This is a validation process and I think I'm going to speak to this or Alonzo because they've gone through this floor as a but there is a there involved throughout they will view the models. They will make sure that they believe that the targets are realistic. The first half of the incentives are awarded for design and tension construction, but yes, there is a chunk of the post occupancy that requires verification. If you do not hit the 25 the UI. That incentive me goes away. And is post occupancy 1 year. It is 1 year, I believe, which aligns with your bylaw in terms of net zero commissioning and verification. Okay. And then my only other question, it's more. I think you have it already but if we're at. If we go to the ground source and 770 kw is what it's estimated. I think when I took a quick look, that's either add a little bit below what we're already using in two schools, and it's, and could you just, Tim, you don't have to get that now but I think it's, this is an efficient enough system that it's either lowing or electrical costs are about the same electrical use, even though it's a lot fewer square feet. It's just something that would be useful for us to know if, if that is a statement we'll be able to make. Well, EUI itself is a energy per square foot. You will be more efficient on a square foot. I know we're much more efficient but I was thinking we're running two buildings very inefficient. I'm just thinking Tim, in terms of explaining why one of the many pluses of the heat pumps is how efficient they are, along with the building. The many determinants of the current buildings as they leak. They have very little insulation. So, just, it's, it's a, I think it's an easy calculation because the schools now have a full year of operating, you know, pro COVID it wouldn't have been accurate. So it's just, it's a request for not right now. Understood. I need to point out something is that it's almost comparing Apple to oranges. The current building does not meet that comfort, not even close to it or code mandated ventilation requirements. Yeah, so, so it's even worse than what I'm saying, you know, I'm just, we're going to have to. We got a question yesterday at MSBA, just on a facility review on a, this is an expensive building and the attention was drawn to the site costs, which was a combination of the HVAC system and also what we're doing to raise the building and bring the dirt in. But I just think we're going to need what you just said Simone to create a case on how much better this will be on multiple levels. So, and then just to add to what Simone said. There is the comparison of the efficiency but also, if you use energy costs rather than energy use the disparity between new and existing will spread even further because you're going to be producing and getting credit for the electricity that you're producing outside which will further offset the case as we've discussed before reducing your utility bills by a very wide margin. Thank you. I have a question about the utility company incentive. It sounds like we're saying air source heat pump doesn't get the $45,000 per ton. Does it get some other amount per ton. And my second question is, if that's the case that ground source gets a bigger incentive. Is that because ground source heat pump is using water to distribute heating and cooling instead of refrigerant. Or is it because of some other reason. Well, there are two parts to that question the first part is there is an incentive for air source. What you see on this screen though requires an EUI of 25 and as modeled an air source system in the project would not achieve that. And so there would be additional money that have to be spent on bumping up the envelope or various other things that would add to the total costs to get the air source shown on this graphic. And there are other ever source incentives that would get you some money if we chose their source. And this is a reasonable projection of what that would be for a building that performs better than baseline, which is essentially energy code or stretch code. There is a certain amount of money per square foot that you can get from ever source, but it's nowhere near what you would get for a ground source system. So we're not exactly sure that what that would be because we haven't projected it, but it would be in the neighborhood, and this is taking the high end of that incentive so it would be about $80,000 verse 1.6 million. And so the second part of the question, why is it that the ground source heat pump is a little bit better than the air source heat pump? That is just due to the fact that the ground temperature remains constant and it's a little bit warmer during the winter than the air temperature and it's a little bit cooler during the summer than the air temperature. So the efficiency is related to that temperature. And because of that smallest swing in the temperature of the ground with respect to the air, the ground source heat pump is more efficient. Understood. Thank you. I guess I do have one other question to follow up. In the past, I think we've been hearing that there's some concern about refrigerant going through the building if we went with air source. And my understanding is technology is well on its way, at least in Europe and developing in the US for air source water distribution type heat pump systems. Is that something that we might consider, or we really stuck with, if it's air source then it's refrigerant distribution. I don't know if I can, I can answer a little bit of that question and then as a moment, please, you know, also feel free to chime in. That is, that is correct. There are options with their source heat pump that would have water distribution. They are generally somewhat equally efficient as those ones, but obviously as the infrastructure of the water part as well. And you know that that adds to the cost as well. And in the case of the area, or a building of this size, the amount of refrigerant that would be in the in the lines is generally small that there is no concern about about that. You know, an extreme refrigerant. So did you want to add that. Yeah. Yeah, only thing I could comment is that if you do use water distribution versus a refrigerant distribution costs would go up. So, we'll probably have a longer payback period than if it was based on just refrigeration distribution. Thank you. Other other questions from the committee on this part. What the subcommittee I should say. Yep. If there are no other questions on this part, maybe we can, since this is sort of related answer some of the questions that were submitted in writing and give a fuller understanding of all the issues in general. Yeah, that sounds good. I do not have any specific graphics, but maybe we can cycle through as they're pertinent, but just a few of them in the order that they came through. There was a question of the energy budget. And Jonathan, you were saying as we were starting that you'll have a little more information from the town's point of view on what the requirements are. And I don't have an answer. I just have the updated slide that you have seen and know that we can break it down, but we are actually turning the question back to you or what is required and another question. And that's really related to what we were just talking about is the amount of refrigerant as that differs between air source and ground source. Even if that is small amount of lines, maybe some you could talk to the estimates that you provided. You need to unmute. The high source heat pump system has much more refrigerant. And I should have better said, at least minimum of 850 pounds of refrigerant probably more close to 1000 pounds of refrigerant versus geothermal system will be factory assembled and it will have about 40 pounds. So it's about 120th or even of difference. And it becomes a number of field refrigerant connections in both alternatives. Air source heat pump. We have was it a estimate of approximately 27,000 linear feet of refrigerant piping, and we specify hard drawn pipes so it comes in 10 foot length and even if you don't have any elbows which is not true, you will have about 2700 field ground source heat pump will have a zero field refrigerant connections. Another question re received was about the basis of design and if we could make any changes. Now we're going forward and the short answer is yes, basically to anything in the system. I will add the qualification that the project funding agreement is set at the end of SD so large changes in terms of systems materials and things like that to be fully accounted for in the cost of the project. I want to be well on their way by that point, but if we decide that there is a more or higher performing system or better material, those changes are on the table throughout the design process. Kathy you have a question. Yeah Tim. You know I know we're getting in you were looking at some variations on cafeteria on the north side gym on the south side different, you know potential floor layouts. If, if you extend one of those to say the gym which has a taller ceiling so you're not really building on top of it. Substantially, you know make an L make a nook on it where we've got a pretty rectangular building. Two part question does that substantially raise the cost of the building itself from the way you've estimated and to do we get anything back because we potentially have room for solar panels on the roof, rather than can be so it's a, I don't have an understanding of which changes would be kind of neutral and which changes would be. I don't want, I don't want the cost to go up where I should start. I can answer the question generally in that design changes and layout changes are slightly different than basis of design changes that basis of design is materials and systems that are applied to the design. So design changes in general. The more turn and surface area, the more cost you're going to have the higher skin is going to be. But, and then in terms of PV on the roof by increasing repair yet and design and messing up the building such that repair is not shadowed by other elements of building. So we would be optimizing the area for PV, but all of these decisions will be made with utility and cost in mind because, well, we know how important that is. Okay. Kathy, if I get to add a little to that. The other thing that everyone should bear in mind when we're talking about costs at this point is that the cost estimates that have been done to date would typically have what's called a design in them, because we didn't have a true design yet when it comes to floor plan layouts and things like that. And so they're, there should be should be some buffer in the numbers that we've been looking to it to date to account for, you know, Tim's having to pull or prod different parts of the floor plan. This way or that way shrink or grow or shrink or grow, you know, glazing areas, you know so there is a certain elasticity. That's expected in the in the next couple of days. That is absolutely true. Yeah, it was actually pretty substantial. It was like 12% was a pretty big number. It is big. And it needs to be at this stage and it'll shrink as says Tim develops things and we go from face to face. Tim, are there other questions you were going to address at this point or should we move on to daylighting or some more questions. A specific question was, does the basis seven design include an age 50 number for essentially asking if the building can be tested for airtightness with a blower door test and respond to respond that no we do not include that in our specifications for various reasons. The simplest is it's in practical on a building of this size built by many trades over the time scale of a typical school building project. By the time the building is tight enough to do a blower door test. The building is essentially the masonry is over there paper barrier and you cannot do anything with the knowledge without great expense. In terms of going back so we designed with details that we expect to be airtight and then we often test mock ups to make sure that the installation is performing to the standard of the details and the materials that we have supplied. Just a few more questions. Plug loads. And the standards that they're just into in the building. Whether or not we go for lead or chips. There was a requirement that appliances and some other things being energy star requirements. And so that is baked in. That was a specific question I wanted to answer. And with that, I think we can have further discussion or we can move on to daylight. We have a presentation prepared. Walk us through. I guess I will see if anyone on the subcommittee has any related questions before we move on. Okay, I think we can we can move on and then without fully remembering exactly the order of things on the agenda, I think it might make sense to pause after the day lighting piece and kind of open it up to the to the public comment at that point, if we aren't already there agenda wise. I think the, the data in daylighting piece will be one of the interest and comment. And Jonathan, the only other thing we want to get to today is if we're ready to vote and I'm totally agreement with what you just said because we want it might want to do day lighting because there's a certain wall to window ratio assumed in in all of the modeling. And with that, I think I might hand it over to and do you want to share your screen or should I I'm happy to share my screen if that's an option. You can say here. Get it going. Yes, she was sharing the screen wall also and present getting it into the presentation mode. I do. Correct. Do you all seeing the title slide there. Yes. Okay, great. So, I just to introduce myself again I'm, I'm remarked around I'm a senior associate at Thornton Thomas Eddie in the with the Boston sustainability group. And have quite a bit of background experience with daylight modeling, understanding the value of daylight and views. I've done quite a bit of research on the topic and my PhD and in the past and and within our sustainability practice applying these ideas to to projects like this one. And what we wanted to share today is just a, just the bar approach to how we're looking at daylight design for this particular project daylight design. By that I mean both daylight and visual comfort. I'm going to start off with, why doesn't do these matter in schools particularly in schools why are we interested in daylight and views. And there's been, you know, there's a very broad swath of literature that has been that has been published on the topics, particularly in school environments why daylight and views are so critically important to the health and the well being of all the occupants, and in particular the students in the building. And so just to, to give you a smattering of some of the findings that have been shown and these are just a few of the many findings in this area we know that studying in daylight classrooms leads to better sleep quality and longer sleep time for students. We know that having access to spaces with sizable windows but also with shade controls increases student test results as much as 20%. Having access to natural window views impacts how students are able to recover from stressful experiences. And lastly, students tend to be more satisfied and happy in spaces where they have visual access to be outside in particular to particularly to views to nature they tend to rate courses higher and perform better on assignments. So, we know that daylight and, you know, access to windows visual access to the outside has an impact, both the physiological health, the psychological health of students and consequently also their performance in the schools so these are, these are sort of the motivating drivers that that sort of dry guide how we approach daylight design in in school buildings. And so we know is that we want to bring the light in, we want the sun. We also want the views we want to have spaces where you can visually connect to the outdoor environment. But we want all of that with control. So we want to bring it in but we want to be able to bring it in purposefully in a in a way that sort of fosters the learning environment inside. So when we're talking then about design strategies pertaining to daylight. We tend to think in in three different categories. We think about how much daylight we're getting in the spaces so the question we could ask is how much daylight is distributed throughout the space. But then alongside that we want to consider how that daylight is coming in and is the daylight that's coming in creating glare or moments of discomfort visual discomfort. So that's when all of the light is coming into the space. And then lastly, where are their views to the outside, because we can have windows up top we can have windows at the bottom, but where are the windows and relationship to where the occupants are in the space and how does that create visual connections to the outdoors. So through the large sort of overarching umbrellas of kind of characteristics that we are factors that we think about or thinking about specifically the visual experience in in school buildings. And I wanted to also just as a sort of post script note that there are other considerations. Importantly, one of them is thermal comfort and in particular having, you know, direct access to daylight or direct light coming into the space tends to impact how we are thermal sensation in the space in a space, anywhere from 10 to 20 degrees. And so, that's where we're focusing this presentation that is also a consideration that we have when we're thinking about bringing natural light into our buildings. So, daylight design these are the these are sort of the questions and the the parameters that we're considering. Now to actually design for daylight, we have a number of tools and approaches that we can employ in order to understand how the light is coming in, and how it's going to be experienced by the occupants inside. So, we have we use a number of different computational tools that can evaluate how light is coming into the space and how it's being distributed. We can model how you know the light and the dark spaces. And that contrast which creates issues with glare. And then we can also model you know how much light or how much of the outside you can see from a particular place. And associated with these different methods there's also a whole number of different metrics that one can use to assess performance in these different categories. And this is not I'm not going to go through each of these metrics. This is just to give you an example of what kinds of measures we might use to evaluate how much daylight there is house coming in and all that. And just to say that there's lots of different ways to evaluate the performance of daylight in our spaces. So, we can, and we think about all of these when we are considering the design and developing the design we think about which ones of these methods and modeling metric modeling approaches is most appropriate. Now, if you think about lead, we have some guiding, you know, rec, you know, certification systems that can give us some direction with regards to understanding performance in these areas. If we think about lead, lead particularly, you know, picks essentially one metric in each of these buckets that uses spatial daylight autonomy annual sunlight exposure and then direct line of sight. I'm oversimplifying here but that's just to sort of break it down into these different categories. And while each of those approaches to understanding that the performance of daylight in the space gives us some information. I really think that none of these in metrics alone is really, and I, you know, a comprehensive assessment of how we get into how we get daylight in the space and in fact, if we were to break down and sort of look under the hood of how lead is approaching daylight views, we can, we can pick it apart a little bit and see why both spatial daylight autonomy or annual sunlight exposure, or neither of them is really a perfect measure of daylight or visual comfort for a number of reasons. In particular, this project, these two metrics tend to make it very difficult to in fact meet the daylight credits from a lead standpoint, because, you know, classrooms tend to have deep floor plates. And that doesn't really give you credit for all the daylight you're getting in a deep floor plate. And then ASC tends to trigger some requirements for shading dynamic shading devices that are not always feasible in classroom spaces, similarly. So, I bring this up just to point out that we lead as a guiding tool for us, something that we consider chips is another guiding tool and, and we could go into all of the details of either system. And these are things that we consider we're looking at the daylight, but they're not necessarily, they are not the drivers of our design, we're looking at the daylight design, holistically, thinking about all of the different sort of dynamics of how we experience our spaces and sometimes they line up with how lead as measures daylight performance and sometimes they don't, but just to push forward here to the last slide so what we're, what we're really looking at is thinking about all of the different the whole menu of strategies that we have to bring light into our spaces in a way that both creates well naturally lit spaces, but in a purposeful in a purposeful manner so in a way that's controlled without creating moments of discomfort or over exposure. So that we can, we can make each tweak each of the spaces to make them really respond to the, the learning from the occupant needs in, in these spaces. And so I'll leave it at that. I just wanted to share sort of how we as a project team are approaching daylight and all of these spaces and happy to open up to questions or 10 if you have further comments or all a, please chime in. I see that now. I just wanted to tie it back to examples that we have seen and maybe I'm only speaking to Kathy because I think she was the only one that on the tours but some of the elements that are not described about the location of lighting in the room. That's who needed Williams that glass in the classrooms was higher and it allowed light deeper into the space. The art room at Hastings was south facing and you notice that the shades were down so orientation location of glass, all of the factors that we are talking about here have very real impacts on the quality of the experience and the daylight and the space and as we've designed the building and tourism other schools will be able to apply these lessons and go back and forth. So I guess I'll open up to the subcommittee and see if, if folks have comments, good or questions. Kathy. Okay. This is partly on what I saw Tim in the two schools we just visited but I also walked around the Amherst college campus they had those, I don't know what you would call them shelves off the top of windows on the outside. I don't know what they had inside. So on relative costs or some of the windows and your pictures were deep set. So I would think you know they're getting sunlight but not, it might reduce the glare. So relative costs of thinking of where the shades are versus shading outside or some of the Amherst college ones don't go away across the top they go across and down one side, so they're picking it up. It's probably morning and so that's the question and the other is, I can't remember whether it was in both schools, the stairwells were Florida ceiling windows or appeared to be so you got lots of light coming in. So if we did that in our building and I think that was in Lexington if we did that in ours that does, I think that counts toward your 24% of the envelope is a window. So if you had something less but still plenty to bring in light with that enable more in classrooms where you felt you might need at those high. My third question is Miss Anita Williams one in at least a few of the classrooms the highest windows were clear glass they they had something in them, you know so light was coming through but it was not. And that seemed to be built inside the window and I don't know what that was and I don't know whether that was for a light lighting purpose so since, as you know I don't know anything about building and building or architecture. I'm, if we wanted more like you know where do you have some leeway and what you've already been thinking about to make changes. I'm just thinking about how to organize the answer to that multi part question, but starting with the cost of the sun shades and the purpose of them, I will start and probably finish with a better answer but the shades. I'm saying somewhere horizontal vertical and most likely that has to do with the direction of the window that you're trying to get it's east to west you have vertical and it's a south facing window or wouldn't have it on the north but it's where the sun is coming from shades typically on the outside or more expensive than the inside. And on the inside, they're not blocking their probably bouncy light up which requires a high ceiling which all of which there's a cost to all of these things that as we go through and look at them. We will consider and I don't know. I'm not going to add any to my simple explanation. I'd say that, I mean it's, as, as Tim was saying it's it is primarily the, the, whether the shade is vertical or horizontal depends on how where the sun is, you know which orientation it is so are you getting sun from above or are you getting it really low ankle sun and that'll that'll determine where you want the shade and how you want it and in some cases when it's in some cases what you're trying to do is bounce the light so you don't have direct light coming into the space well in all cases you're trying to do that, but in some cases the motivation is to prevent discomfort so those glare issues so there was an image I showed with a really light and dark shadows inside the space you're trying to mitigate that. In other cases you're trying to bounce light further into the space so you're trying to distribute the light further into the space. I'll, I'll I'm going to hand it over to you because I know that we've done lots of studies that always led in this realm and so maybe you have something to add here. Yeah, happy to add. I mean, or Mac and Tim covered almost everything very well a few things to know are that you could have. They're called these light shelves I think is what you're referring to, you could have these light shelves in the exterior or in the interior. In the exterior they definitely help you cut the solar gain as well. In the interior there are many schools that have them in the interior and some things to consider. In the reason why we don't recommend them very frequently is because you end up having your window broken up into two. And so if you have shades of at any point you want to have a classroom that is all blacked out, you would need to have two sets of shades. Not only that, but when the upper set of shades comes down, it rarely goes back up. And so you end up having an upper section that ends up being just counter contradicting what you originally designed the light shelves for and so ideally we have looked at light shelves extensively light shelves, depending on the orientation, bring more or less daylight in. And the key question really is, is whether those light shelves are contributing in any way to also block the direct sunlight. Sometimes we would, in fact, most of the times we want to prioritize exterior systems that block as much direct sunlight as possible, because then you don't have the shades down. So we presented very well the fact that daylight is important and views are important. In the moment your shade they're down, those two are gone and so our entire design will really. We care a lot about daylight but we care a lot about daylight without direct sunlight or without glare. And so we will be spending a lot of time focused mostly on that and then making sure that daylight penetration is not impacted and ideally enhanced through those methodologies. And just to add what we what we know from empirical studies is that those shades come down in schools and office building their their modeled we design we model them to be totally dynamic people are going to open the blinds in the morning, put them down. People don't do that. They put them down and then they leave them down and so we want to try to be really deliberate with the fixed shading elements and the fix and the windows the glazing so that we're not relying upon someone coming in and you know, changing the blinds or the shades in the space every day. And then I think I can answer the other parts of the questions. Yes, the glass in the stairs and some of the projects contributes to the overall 20. We're targeting to get the building performed so a big part of the design process will be setting priorities in terms of where you want that dialogue or it's in the classroom. And that is, you know, a very large part of what we'll be considering as we are designing. And then the third part. Yes, there was an interlayer. The glass at a lot of the windows, which the purposes to diffuse the light coming in because with that much glass high up there without that diffusion layer. You would have a lot of probably uncomfortable light situations I would imagine for the described. I don't know exactly what that product was we've used similar products and there are a lot on the market but as we get into the side we can think about it and if it becomes a better way than movable shades to deal with direct light and lighting and exterior windows that are high in a room. Other other questions from the supplement. Rupert. You're muted Rupert. Yes, you could see my lips moving through my mask. I'm just thinking about school security and reflective glazing so that shooters on the outside of the building. I don't have a good visual for what's going on inside. I'm wondering what kind of impact that has on the benefits of the day lighting is it's does it supplement is it a trade off. How do you think about all that. Do you have any modeling information on the various films and what they contribute in terms of visual like transmission. Energy performance. Obviously they're like separate conversations there in terms of security and what the district actually wants but to have a sense of the impact might be germane to this conversation. Yeah, I think I think I'll actually has more experience on this topic. And so maybe I will hand it over to her. Thanks, Mike. Yes, so we have. We consider reflectivity in most of our projects. A lot of the times it comes from a just an architectural intent more than anything sometimes it has to do with birds, and how do we mitigate bird collisions. The reflectivity you can get on the on your exterior so what you're describing is a measure that is that has a particular focus. If that makes sense in there would be a way in terms of daylight penetration there's always ways to combine that strategy with different types of glass and different other types of coding. So to ensure that there is enough daylight the more you add as the simple math, right the amount of light that comes in is the light that was outside minus what was, you know, absorb very rarely absorb minus what was reflected, right. And so the higher the reflectivity, oftentimes you have less like without getting too technical the spectrum also matters and so you could have, you know, it's, it's not a straightforward and I would not be concerned if it's a desire. Let me summarize. If higher security using highly reflective glass is a desire. I would not see that as a huge detriment to daylight we would figure out a way to, you know, to make it work and to ensure that there is a high quality daylight in the space. Your high reflectivity is not going to eliminate the direct sunlight. So you're still going to need either interior shades or exterior shades, right. But I would not. They should not be that you know we'll make them complimentary we'll make them work with one another. You want to try to control the percentage of visual light coming in and solar heating coming in anyway so there's there's mutual benefits there for having some of the light reflect back out. And if anything I'll just add very quickly but I don't think for the amount of glass we're talking about high reflectivity glass has in particular is might just increase our heating gain or heating load a little bit more right because you're reflecting more sun and so in the wintertime you're not going to be able to capture that. I would not worry about that. I don't think it's going to be for the, the range of graphic reflectivity that we're talking about. I would not be concerned that this is going to put us over or under, you know, our goals for any US from any US simple. Yeah, thank you that's very helpful. Thank you very much. I mean it made me think of an interrelated you talked about the comfort level in the class with when there's thermal gain from sunlight does. So thinking about our potential high backs HVAC system. It's a South North facing school so in the wintertime, you would get more of that thermal comfort right now it's I would call it thermal discomfort on a 95 degree day. So, but does the geothermal the way that air is distributed allow us to say it's south side. In the wintertime those classrooms. Don't might not. I know the way our house works certain parts of our house don't need to be heated as much because they're getting sunlight, and other parts are really cold because they never get sunlight on the north side. So does it can the heating system can be adjusted to that, and I flip it in the summertime, when the south side is super hot, but the north side is is protected, and then how that interacts with glass so it just maybe think of the reflective side of glass so it's mushing that together. Mechanical system wise, it's just made for that so that in the wintertime, let's say if you have a south side is under the cooling. That's perfect exactly what your thermal systems me so that it will cool and use that rejected heat to heat the north side. So it's got good heat recovery system. I can add that there's two. There's two factors that play here there's the actual heat there so you will have some solar heat gain in the summertime as you're as you're suggesting, when you have a this, particularly in southern facing spaces. So there's the actual added heating in this phase or lack thereof in the wintertime, but then there's also from a thermal sensation standpoint, when you are in the direct sunlight. It's not necessarily the room around you is warmer but you're going to feel warmer. It's like standing next to a fire it's a fireplace it's it's it's the actual radiation that is making you feel much warmer so there's, there's also that that's that's just one more reason why you want to control the direct sunlight coming into the spaces. Thank you. Tim I have kind of a kind of timeline question. Today we're discussing this is kind of a high level fear, you know, what is how is it going to be approached. You're still kind of working on, you know, plans and elevations of it. So as the schematic design progresses, which eventually will get presented at the full building committee. When, when does this level of kind of, they like review happen in the schematic design and when would be, we would likely be talking about this on a more kind of practical basis about the actual building that we're going to be building. Absolutely with visual elements to discuss. Probably the next meeting will be planned and then the meeting after that will beginning to discuss facade and fenestration so within the next two meetings of the full building committee I would imagine that the principles that we're talking about at a high level, we could apply and compare to drawings and models on the screen. So, a couple of weeks. And then just kind of more of a comments. In the presentation, I think, I think I got an answer at least to why potentially some of the day lighting points on the lead list were not initially checked off. Am I correct in that assumption that because of the some of the ways that lead measures these things and the way schools are designed that there's a little bit of a inherent mismatch. That's exactly it there's a there's a bit of a mismatch I mean the lead, the lead credits for daylight are constructed for general spaces and classrooms don't necessarily classrooms have specific needs and so the metrics that are used don't always line up with and don't always reflect how much daylight and the quality of daylight coming into the space. And the other thing I should that maybe of note because the stairwells came into conversation is spaces like stairwell circulation spaces don't count towards the lead credit so you might have really had hallways and stairwells but we're looking at only regularly occupied spaces which is spaces where like classrooms spaces where people are spending long periods of time. Do we have other subcommittee member questions or or could we open this up to public comment. Okay. No, let me get to the right screen. Okay. Yes, so we do have I'm allowing Bruce to talk. Bruce, I believe you are with us. So you can. I think I think you can hear me is that correct. I guess I should ask if I got three minutes, or can I have more than three minutes if I need it. Please keep it to three Bruce because we're actually, you know, unless. I mean, we can share my hand up again later and you can see whether you want to hear more. I'm, I'm, I'm a, I thank you for the presentation that was reassuring. I'm not entirely convinced by the observation about why lead is less valuable, because it seems to be associated with metrics not being valuable as much. And the, the, the, the, the, the prospect of looking holistically I think is good, but it can be come an excuse for dodging metrics and a lot of arm waving associated with we can do this and that. And, and I've spent so many years being frustrated by people who simply wave their arms about what they're going to do and really ungrounded in in saying we can, there are measurable objectives. I really want measurable objectives associated with daylight measurable objectives associated with the lighting please. Secondly, I certainly agree with light shells. I don't particularly think they're available in this climate. And it's because we have 51% of our daylight hours in overcast conditions and daylight shelves are really suppress good day lighting, particularly around the perimeter and they don't bounce so much their strategy for the Southwest. So, I agree that day light shelves are not a suitable solution concept, but possibly for a different reason, but please note that we are operating in an area where we have slightly more than half of very slightly more than half of the daylight overcast. The multi reflective glazing question that Rupert asked, I would think that the solution there is a solution concept there is it drives the separation of higher day lighting glass and lower view windows. And you'd only put it on the view windows would be no point in putting it so to the another strategy for getting around that with people mitigating that would be to slightly amplify the play lighting windows and raise them up above a level where that would be a problem and then only put the glazing lower shades. Shades are dynamic elements. And I think that to the extent that we can avoid dynamic elements, things, and I'm sure Tim will agree and I know Rupert will agree. Because I've seen this so many times these anything if you can solve the problems with static elements, please do please avoid dynamic elements moving elements that require power the break that require maintenance that they don't get and so anything, anything you can do to eliminate dynamic elements from the design I think will be a net benefit and Rupert will love you. I, I, I think generally that in the Hastings building at Lexington is a little too little glass in the classrooms I would think we should try for more. Again, measurable day lighting will there be a daylight model or some kind of thing constructed. I'm going to be modeling this. I mean, in my day we built physical models, but nowadays I think electronic models can do an acceptable job will an electronic model for day lighting for the classroom I don't really care about anything else personally, I mean, other people I don't, because I think if we can get the classrooms to be. And if we can get all classrooms, not just some classrooms, but all classrooms I think I'm this is really difficult and I'm asking a lot, and I realize that and I would like this to be better than other schools you've not that they're not good but I want you to do better for us than you've done before because I want you to be proud of what you've done for us and what you've done before and then you can do it for other people after us and be even more proud. And that's probably three minutes and I haven't finished but I'll shut up. Thank you, Bruce. We don't usually typically do this but I think I will be worth the design designing comment commenting on the daylight modeling I would assume you're going to do daylight modeling I mean the conversation we've had today suggest that but it might be good just to get that on the record as to what the approach there is. We put that on the record that we will be modeling it will not be likely the entire building, but enough to tell us what's going to happen in the classrooms as they face different directions and I see how it has our hand up so she'll probably give a more complete answer. Yeah, I'm happy Bruce. Thank you so much. I mean you're you're spot on on so many things. The, I just wanted to give you a little bit more detail with respect to our approach, because we fully agree that quantifying quantifying and using the right metrics or the right set of metrics to define high quality daylight is very important. If we had another full hour be happy to walk you through other studies we've done but some of the focus we we take particularly in schools have to do with understanding, not only daylight penetration as I mentioned but glare and direct sunlight because we know that any direct sunlight just as you pointed it out is going to lead to shades being pulled down and never being pulled back up and so we've worked we worked on one school where classrooms had we had seven different possible orientations for the classrooms which was already complex and looked at various shading systems, but we also looked at what the impact of the direct sunlight would be on the team was actually open to considering putting the whiteboard on one side or the other of the classroom. And it turns out that if you're on an east orientation then putting the whiteboard where you're not going to have direct sunlight or the kids are not going to have direct sunlight in their eyes. Let me rephrase choosing where you put the whiteboard and in which direction the kids look can already be a design solution to mitigating glare because if glare is on the side you know coming through the shoulder direct sunlight is not it is not as bad that if it's coming directly as if it's coming directly towards the children and so we actually quantified that spatially for every orientation and understood that for various orientations. There were actually, you know, there was certain orientations were certain shading strategies just to care of all the glare. There are other orientations where and you'll agree with us that you know East. You know straight the wind is going to the other one sorry the sun is going to come straight perpendicular to the glass at some point during the day at some point during the year. And so we might we identify when is glare inevitable without the use of interior shades, but we have a very good understanding of when that is. And so that just makes it easier for the team and for everyone to just understand what the conditions are and think about if those shades are going to be deployed how do we bring them back up. And we don't but I just, I think what you said I mean Bruce was concerned that if we don't have lead as our metrics do we have metrics and I think what you've said is we are going to have metrics and maybe. I just said, within the next few weeks we've got a meeting on the 12th of full committee of August meeting on August 26 but just come in with these are the metrics we're going to be using for daylight. And the, I don't know enough to what those might look like but it sounds like not only you're modeling them but you're quantifying the settings written targets, and I think that's, I think that would be great. We can do that. I guess I want to. Oh, now, now to other hands went up so I'm going to. Before you admit someone I just want to make sure that the public knows that while we've paused after the, the day laying pieces, folks have comments on the, the vote we're going to take and maybe about 10 or 15 minutes on the topic of recommending a HVAC approach. This would also be the time for those those comments as well. Okay, so we have two other hands up I'm bringing the first person in Tony. Hi, thanks, Tony Cunningham own drive. I just wanted to put a plug in for ground source as the preferred HVAC system. It seems like with the updated lifecycle cost. It's actually lower as than air source and the replacement cycle is less frequent and it's further out. So less likely to collide with another of the four major capital projects. And it should push the design team to exceed the 25 EU I target whereas the air source is projected at 31.5. So just a plug for ground source. Thank you. Thank you. Thanks Tony. Yeah, I'm getting the next person got got. Okay. Maria. Thank you. And Jonathan, thank you for clarifying that we could comment on that was going to be my next question. I also, I think that there was a great presentation on the lighting and I really appreciate the team that's going to be working on it and I have confidence that you guys will will do a great job there. I also want to speak in favor of geothermal and doing the ground source tea pump. Fantastic that we've got this additional incentives. I think it was a great idea before that even but very nice to have the finances there as well. Also, keeping us to our goal that that we set in the beginning to get to that 25 or under EU I the the team has done a terrific job there and I'm also confident in the end that we've got working with denisco to to get this done so. Yes, please, please. Thank you for the pitch for transfer seat pump. Thank you, Maria. And there's one more, Jonathan. Chris. You should unmute Chris. You're, you're here Chris if you unmute. Am I unmuted. You are. I don't want to duplicate the same sentiment but I will illustrate it by saying that I have an air source sheet from putting in in 2014. And it has been okay and it is keeping me cool now and it. It's it's it's been a real pleasure to have. It has been problematic it has had tip marks living in it and had to replace large chunks of it the motherboard a couple of times. It's a, what am I trying to say, we're going to throw it away, and we're going to get a ground source heat pump system, because it will have a much better COP, and we will be definitely have a surplus. In our house after we do that so it's a better system, we're going to spend $56,000 on the thing. There's no return on that, but it's a better way to do things. Thank you that's all. Thank you Chris. Any other public comment. I'll put his hand up again Jonathan so I don't know what you want to do time wise we're at to, we're at 12 after two. I think we can give Bruce another, another three minutes, and then assuming we don't have any additional public comment I think we should probably close the public comment period and then move on to a, you know, a conversation time for the subcommittee and then a motion and a vote. Okay, Bruce you're back with us. Okay, thank you, Jonathan. This is about the ground source heat pump question and I just wanted to, I did send a public comment by email, and I wasn't sure how well that was distributed. Basically, it links. It represents one another well I think advantage of the ground source system. And that is because we are using cold water distribution and so forth, rather than the air distribution and I'm not sure how much ducting they would be associated with the air sourced systems but possibly some, and certainly not with the ground source system. It seems to me, and I discussed this possibility with Rick and with Tim during the tour of the schools that I was fortunate enough to participate in. So when you've got that kind of distribution with a ground source to come. You've got potentially I think, much less space being consumed in the ceiling plenums, and therefore theoretically that the ceiling could be raised or tilted, and that theoretically then you could get more exterior wall area in the classroom available for day lighting more and higher day lighting. And that is my thoughts discussed with the team but it's not I'm not reflecting what the design team are intending to do I'm reflecting what I think is a potential advantage and possibility that's associated with ground source heat pump so I for we've had many other reasons that have been submitted associated with refrigerants associated with footprint associated with noise associated with, I went through the whole this now but this is one more reason why I think the project could benefit from that technology. Thank you. Thank you Bruce. That, that's it, Jonathan. Well, I will close the public public comment period. And then open it up to subcommittee members to either make make a motion or reflect their thoughts on this choice of recommending something to the broader committee. Rupert. Oh, you're muted. I love the opportunity to reflect out loud for just a moment. Thank you. All right, a couple of moments, because because I'm have some internal conflicts. On the one hand, I think whatever system requires less replacement over the lifetime of the building. That's better for whoever sitting in my chair down the road, fewer of those projects, more manageable control the building. I do like the idea of the more efficient system that just appeals in general. At the same time, it's my understanding that even with the rebates the ground source system has both higher initial cost and higher lifetime costs. I'm being very concerned about the traffic and access issues which have not been resolved. And I'm very concerned about getting public support for the amount of money that we're asking. So, I'm sort of, I'm sort of divided and I just wanted to share that and, you know, see if other folks have insights that will help me figure out what I, what I decide. That's the best. So, Kathy or benefit if you want to. Maybe Tim can put the charts up again but I think the bigger incentive group or just narrowed the differential the initial to, I'm not going to say just but I will use the word $400,000 or slightly less so instead of a, you know, one and a half million or one and a half million where we're at, we're at less. And that is contingent on us getting that and so the, the life cycle. Tim, were they equal or is ground source less in life cycle now that's what I wasn't sure of. Ground source is less now. Ground source is less over the lifetime so two things happened with this incentive one being, which isn't surprising since the initial cost went down, and the replacement so we can be arguing that we've picked of the electric systems that we have to choose. One that is both more efficient in terms of the electrical will be better for the way the air feels in the school. You know that I think even the heat, and then Bruce pointed out a couple other potentials and you know Bruce Bruce sent you sent your public comments I think you might have just sent them to Jonathan me if you want them general public I'll post them. You know just on your other observations but we had a nice graphic, two weeks ago from from Thornton Thomas Eddie on a long list of quieter and other pieces on what this does for the children. So I think they're because the costs are now so much closer. So we need to find another $400,000 somewhere else in the building cost that would be really nice, but for of the electric. This looks to me like the better investment. Because we can't, it sounds like without spending a lot more in the building we can't hit 25 with their source. So, and I don't want to see the building get more expensive. I guess I'll just stop there and Tim that I did have one question the, the plan on the wells, you're going to be doing the wells really soon right, you know if this gets the green light. So does that, does it add to the timeline of the building at all, or, or not. And today we would release the test for which would give us information on how well we could expect each geothermal well, which would give us a revised size for the total system. These incentives are based on a certain size system 280 tons of cooling. It would be large variation, but if we find that wells are performing better or worse than we would expect that number would go up and down the total capital cost would go up and down as would the incentives. So, as with all of these numbers these are educated guesses that are the best we can do at this point, but they will all be refined and narrowed in and be more accurate as we progress. And as in terms of the impact on the overall building schedule with a with a decision imminent. No. We are on schedule. If that answers your question. Yeah, and Shelly, do you have any comments, you know, give you an opportunity as we're moving toward to make a recommendation from. Yeah. I mean, I personally would lean towards geothermal. I think that that that price difference at this, you know, for the scale of building and the overall budget is pretty minimal. And I, you know, my sense about geothermal systems, I mean, not always a more efficient but I just think that it's less finicky over time, less moving parts, less connections. You know, I think all those things add up to it. It's a good investment. So I, you know, that's, that's my advice. I think that that these guys have done their due diligence. So that's my sense on that. And then in terms of daylighting, I think they're right on par with everything that needs to happen and the considerations and the daylight modeling will inform what's the best solution and, you know, until that's, that's done, you know, as the design progresses, we'll know more about that and then there'll be more time to kind of comment. All right, well, is it this option versus that option, based on real metrics, you know, that come from the daylight modeling. So I think these guys are right on, I think they're doing well and I, you know, I would go geothermal. Thank you. Ben, do you want to make comment or have a question? Yeah, I just have like, kind of like a brief comment just just based on what I've seen here so far like the need for less or less of a need for the photovoltaics that are involved with geothermal. Overall, it just seems a lot more efficient. I probably lean towards geothermal personally. Also, in from my day job perspective, the decreased need for maintenance is also an incentive for me and the incentive, the financial incentive is an incentive. Tim, I have one last question or it's more in the way of a reminder. The cost that the most current cost estimating what was carried as I believe this is a geothermal was carried as the as the basis. So, in a way, we shouldn't think of this necessarily as an addition of $400,000, but that there would be some theoretical savings of 400,000 if we didn't go with geothermal, that would probably get eaten up somewhere else but the structure of the estimate was that geothermal was the base and there was a deduct alternate for air source. So actually, Tim, if I restate that it's, it's a reduction of 1.6 million. If it will, let me take the 200,000 that are the post occupancy to reduction of 1.2 million on the construction costs, correct. I would get a $1.6 million credit from the utility that you wouldn't that you would apply to the construction costs. Yes. I mean you would you wouldn't include that, but it's a bunch of last that that you would then apply to the construction costs. The short answer is yes. First of my kind would be that while while there is some, you know, it's somewhat more expensive. I think the incentives really make it hard to not choose it given the efficiency, the quietness of the system. You know, the longevity of the system. I am personally favoring the, the, the geothermal approach. I unmuted first this time. I would like to make a motion that the net zero building subcommittee recommend to the school building committee that we adopt the geothermal model for the HVAC system. Do I have a second. Kathy seconds. Does anyone want to comment, or shall we go to a vote. I will take that as no comment and so I'll just ask people in the order I see them on my screen. And since Kathy's at the top. Yes. And then. Yes. Rupert. Yes. And I am also a yes. So that's a unanimous recommendation. Jonathan, on behalf of our committee, can you write a paragraph worth that to go with that? Yes. And then we can just attack, then we can attach these charts. So, you know, and I would, we might. I figured out a way to take their PDF support to individual charts, but I thought a couple of the charts from last time that showed you why geothermal all its pluses, you know, that graphic we could just attach it to your note. So that people don't have to look at the whole presentation. And we are happy to reassemble in any way that you show desires. So don't, don't, don't hesitate to ask. Do remind me Kathy, do we have anything else on our calendar for today? I don't have anything else for today. The, the full committee meets on the 12th, which is a week from tomorrow. And then there's a scheduled meeting on the 26th. So this, this will be reported up. And I must say, I do want to say in Mac, and I'll do her full name, Alejandra or Ali. I thought your presentation was terrific. So I, you know, just on a why we want to think about daylining so I think we'll put it in the packet for the full committee. The video will be available and but I thought the words that went with it were really good. So maybe when we come back, Tim, to the actual what you're going to recommend it, having them come on for the full committee to just talk about why this emphasis and why we ended up going the way we did. It would be, it would be good for the larger group with the teachers to hear as well. So, so we can just figure out what the timing of that is. And we don't have any other meetings of this subgroup. So you would have to signal basis of design Jonathan I'm just thinking of there are things that people were asking about insulation or what goes underneath the building or things that had to do with sustainability as the topic. If that's full committee or subcommittee, I think it's just thinking that we probably should have a meeting that discusses the energy budget. I think that would be a valuable and probable next meeting, if Tim agrees, because there has been some, you know, thinking in the background about that. And I think it would be worth a public conversation about it. I think that would be appropriate then you mentioned that this might be a overall sustainability group. And I think that there are certainly big chunks of things that would be appropriate to chew on and a group like this rather than the committee as a whole before a recommendation is made. Robert, did you have something to say? I just topics to add to the agenda. One of the concerns that I think we all have on the subcommittee is how do we educate the building users to use the building sustainably. And I think some brainstorming and discussion of various approaches might be valuable at this level to then bring forward but that's up to Jonathan and Kathy. No, I would hardly agree with that. I have a suspicion that it's a topic that we should return to again and again until the building is open. But that's my personal perspective. I would say again and again even after the building. Well, yes. With that Kathy, I think I'm going to adjourn us for today. And so thank you. This has been the net zero subcommittee for the Amherst School Building Committee and have a good afternoon. Thank you all very much. Thanks team. Thanks everyone. We're adjourned. Thank you.