 to a few of the slides and he is not here. I expect him to be here. I talked to him not long ago. So is he in the attendees? I see Sunny now, so they must be coming up. Okay. Well, let's start the recording and I can do the introductory stuff. So this meeting is now being recorded. It will be uploaded to the Town of Amherst YouTube channel by our IT department. Kathy, I'm going to go ahead and make you the host. Okay. Thank you. Okay. Good afternoon. This is the net zero subcommittee of the elementary school building committee. It is Tuesday, March 29th. And I'm going to call the meeting to order and make sure that all my subcommittee members can be seen and be heard. And I'm just going to go on the order of folks that I see them on the screen. So I'm going to call on Kathy first. Yes, I'm here. And then Ben. I am also here. And Rupert. Yes, I'm here. And I can see we have Sean, who's also on our building committee meeting. He's a building committee member. And since he's here, I'll ask him to identify himself. I can hear and be heard. I don't think I'm technically part of the formally part. Yeah. Good. Thank you. And so with that, I'm going to turn to Tim and say, do you have all your folks that we're going to present here, or should we pause another minute? I do not see Steve Coffrin, but he is not going to present. He's going to be available for questions related to PB. So I think we can start and hope he joins. I'll turn things over to you. Great. It's good to be here. I just want to say that we have the team, Simone from BAP, I'm Sean from Thornton City. We're going to go through a brief, well, maybe not so brief presentation, and then get to a discussion with some questions and answers. With that, I will share my screen. Are you able to see or do you see black? I see black and I see it clearly. Yep. We can see your slides. Excellent. Okay. So we're going to be talking about life cycle cost analysis and projected expenses, capital costs and operating costs for air source versus ground source heating system and new construction and renovation addition today. Just as background, the assumptions that we've made and the geometry that we're using to do these projections are the options that were submitted as part of the PDP. We have just begun meeting last week to design the actual building with the approved program that with Mike and some of the school staff. And as we move forward and have an actual building footprint and building massing, all of these projections will be refined and revised to reflect that building design. But what we are talking about now are assumptions that we have made up to the PDP and moving forward. That is not to say that we are not already beginning to see information revealed and trends that are beginning to show differences between the different eating sources and or mechanical systems, I should say, and construction approaches. So to review the difference between or some of the major differences between a renovation addition and new construction will be the ratio of envelope to the amount of conditioned volume in the building, which will have an effect on operating costs and building performance going forward. Another difference between will be the amount of roof area, which will then inform how much PV will be accommodated on the roof with a smaller building footprint for a new building. Less PV can be accommodated on the roof and more will have to be supported on the ground. I should note that one of the questions asked that has been passed along to us is why the footprint of the building is not roughly one-third of the total area of the building for the three-story version. And that's due to a lot of factors, some of which are some of the spaces like the gym are required to be a little bit taller than other spaces. So they take up spaces on multiple floors and therefore things don't get distributed evenly. Also, just the adjacencies of the program elements within the building, you can't always evenly distribute them between three floors. So those are all factors that lead to the footprint of the building not being one-third. And then when we do arrive at a building footprint, we will know how much PV we can accommodate on the roof and how much we can accommodate on the site with canopy mounted solar. And that distinction is important because as we get into the different types of systems, the total amount of PV required will be different. So all of these different factors that I'm talking about are going to, in various ways, affect the numbers that we talk about as we move forward. So those are baseline assumptions on the geometry and the options that we are talking about this point. And now we're going to move into the systems and projections of operating costs, capital costs, and with that I'm going to hand it over to Tom Sheehan and Sunny. Thanks. Yeah, we can go to the next slide. And so Sunny and I will just tag team to go through some of this information at the risk of preaching to the choir here. We are going to be looking at life cycle cost analysis is a long-term impact of ownership of these systems. So there are a lot of assumptions that go into it. So we summarize the details behind this, but we'll just talk about the high-level input parameters and the outputs. And I believe like most of the committee members have already seen this data and there are some questions, so we'll address them at the end of the summary here. With that, Sunny, do you want to take on these quick input assumptions just to walk through quickly? Yeah, sure. So as Tim said, we studied two geometries, one is for the renal, one is for the new construction. And for both geometries, the envelope are assumed to have the same attributes. That is, they have the same window tour ratio at 23% and same level of installation in roof and wall. And also for the internal loads, we're assuming 0.55 watts per square foot, which is typical for new schools with LED lighting and a plug load of 0.61 per square foot. And they're same for both schools. And this is the operational schedule we assumed, which is come from the school. And there's the school year and summer, and it's different for each space type that was separated. And so for two geometries, we also have two HVAC options. One is the air source heat pump. And for air source heat pump, we have ducted fan core units for classroom and offices, and energy recovery unit for ventilation for these spaces. And for the rest of the bigger assembly spaces, they're air source heat pump HUs for these spaces. And for kitchen, there is the makeup air unit with electric heat backup and air source heat pump, too. And similarly for the ground source heat pump option, we have active chill beams for the classrooms and energy recovery unit for ventilation again. And all other bigger spaces have their delicate air handling units. And geothermal, the ground source heat pump will provide hot water and chill water to these units. Okay, I'll go next. A snapshot of the four options that we've had, the Adreno options and the new construction. And with the two systems that we just talked about, air source heat pump and the GSHD. So what you're looking at is the EY is on the top of those bar charts for each of the options, and the black line actually indicates the required amount of PV system or the PV service to offset all the energy used on the site itself. Now one key thing to note here is if you look at the Renault option with ASHP versus new construction with ASHP, the difference is not a whole lot. It's a very minor difference in the EY. And the reason is we are assuming for the Renault option we will bring up the envelope the same way as a new construction. So essentially we are reskinning and so that the thermal envelope is going to be exactly the same. So essentially if you are comparing whether it's a Renault option versus new construction, the different systems types is going to be, you are taking about the same. So with the air source heat pump option, we are in the range of 31, 31.4, 31.5 EY. And for the geothermal system, ground source heat pump system, we are 24.9 and 25.3 respectively. Let's move to the next one, Tim. These are some of the capital cost information that we assumed. On the left side table, we see the capital cost of HVAC system geothermal wells and also the photovoltaic system cost. And also we included the mass save incentive for each of these options. As you can see the air source heat pump has a little bit or have the incentives that is available than ground source heat pump. Based on the EY that we can achieve for each of these options. And on the right side, we have the replacement cost for HVAC system and also the photovoltaic system. Again, these costs that we are looking at is for the life cycle of the building, which is 50 years. So we have these replacements happening at different point in time in the life of the building. Just to give you a little quick snapshot, visual snapshot, we have created a chart just showing that. So what this is showing is the GSHP option, which is the blue or the t-line and the orange is the GSHP option. So the replacements are happening at different time of the system's life. As you can see, they're not exactly overlapping and some systems may need to be replaced more often than the others because of the nature of the systems themselves. One more thing I'd like to point out here is for the purposes of this life cycle cost analysis, we assume that utility costs are going to be zero because we'll be negating with the photovoltaic system. Again, this is not exactly what you will see. There are meter charges and those kind of for the infrastructure that you have to still pay. But from energy cost perspective, that's how we presented it and obviously we can adjust depending on how people want to see this data. So the gist of this is if you look at the right side of the chart, the life cycle costs of each of these options are within half a million to about half a million within each other, which is a good case for a geothermal system as well, a ground-sorcery pump system as well. But there are other factors that play into it and we can discuss those things. I wonder if it might be good to just kind of touch on what's happening at those kind of milestones. What is ground-sorcery pump replacement one and two because I think my suspicion is you'll answer some questions before they're asked if you touch on that. I would also, Simon is online too, right? I'll have Simon also chime in here. So based on our internal discussion within the design team members here, we talked about 50% of capital cost replacement for air-sourced heat pump at year 16 and at year 31 we expect 80% of the cost of replacement and this is going to repeat after that in the year 46 for the air source heat pump or 41, sorry. And for geothermal system we anticipate similar kind of schedule but a little bit more stretched out one around 21 year and one 41 years. As for the exact systems, what will be replaced? Simon, if you're online, could you speak to that? What kind of systems would be replaced? Yeah, for both air source and ground source, first cycle, life cycle, most likely replacement is not wholesale replacement, but it'll be like compressor replacement, some of the fan and motor replacements. So we estimate it to about 50% of the capital cost versus the second round. Most likely it would be almost wholesale replacement with the exception of some of the piping and the cork distribution to somebody in there. And Simon, for the ground source, the wells themselves, what's, you're not replacing those at the 80% line. The wells are good for longer or not? Just some clarity. There was varying predictions actually from what I available documents as anywhere from 30 to 40 years. Yeah. And just when I had the GZA or other consultant on geothermal said that it's not uncommon for the components of the wells themselves, not the distribution system, but the HDPE, the lines that are in there, you could get a warranty for up to 50 years. So this calculation does not assume a replacement of the wells themselves, but the plumps, this regulation, stuff like that above ground is replaced in the lifetime of the building. Next slide. This is just a very simple summary of what we have for the different options. EUIs that we only looked at annual electric city use. Again, this is before photovoltaic system. And the same thing with annual carbon dioxide emissions. Again, our idea is that the net emissions would be zero once the PV systems are accounted for. But just to give us, you know, how much the building itself is going to be generating and how much will be, we will have to offset it. Again, from our perspective, the idea is to make these numbers, the emissions as small as possible. So ultimately, the photovoltaic system is also reduced the size of it. And then we also have the 50 years electricity use for each of those options as well. The next one. So this is what I was alluding to earlier about, you know, the utility cost is not necessarily exactly going to be zero. But you still have to pay for the infrastructure and other things. I don't know if you want to add more to that cause that are showing up on our options compared to the existing utilities. We just lost it. Yeah, the slide. There you go. There you go. Sure. The system, the PV system is going to be designed to offset all of the energy use of the building. You know, so theoretically, every kilowatt hour used will be produced either at that time or some other time, and then there will be a bill of credit from the utility. But as Banshee alluded to, there are metering charges. There are peaks that have to be accounted for in terms of maximum usage. There is also a schedule that was used to assume the design at this lifecycle operating cost that was a few slides ago. If the building is used outside of those design parameters, you could exceed the amount of energy produced on site. So it would not be totally accurate to say that the energy bill, the electricity cost is going to go to zero. This assumes 95%. We have done the solar design an hour-by-hour comparison based on the assumption so far, and they predict a slightly higher. But we tend to be conservative. So this is where we are right now until we get more detailed and refined designs to analyze. The other columns in this slide that we should talk about are the natural gas and oil costs that are associated with the current schools, Wildwood and Fort River. This will be an all-electric building, so those will go away, save for the cost to maintain an emergency generator, which would be natural gas on the Fort River site or most likely oil burning on the Wildwood site. Generators do have to be run periodically to make sure that they run when you need them, but that is a very small portion of the cost of the natural gas or oil that is used for heating at the existing schools. So what this slide in total is showing, the operating cost in terms of utility bills, you're going roughly from $250,000 to $10,000 a year with these schemes. Granted, some of the, as shown in the previous slide, options, air source for ground source, use more electricity than others. So if you were paying for it, there would be more savings, but they're all going to be offset by the different size PV array that will be associated with the project, which brings them close to each other at the end. And then one more thing to circle back on, which we just briefly mentioned before, there is incentives as part of ever source that will contribute to the project and offset some of the capital costs that will allow you to realize these savings. We have already started discussions with ever source, and those incentives might be getting a little bit more generous, but we can't really count on that yet, but they should be in the very near future. And then there's also a smart program with the state that will help offset the cost of the PV and other capital investment that the project will have to make to realize these energy and use savings. If we could stand this, I just have a question. It's more for the future, Tim, but underlying the electricity costs for the schools, I believe we can get kilowatt hours, it's a sense per hour. So for the future, can we do a cost would be in 2026, if we can continue to operate the schools using kilowatt hours, and then also compare the kilowatt hours we use now with the building even before you've done the offset, because my understanding is this building, we've got a sieve for a building right now with no insulation. So we're probably using a lot more electricity than we need to use just because of it not having a good envelope and all the other things. So I think it just would be good for us to have later in a fact sheet if we can do the expected kilowatt use in the new building compared to kilowatt use if we continue to operate these two. So you will be able to do that for us, right? If we can get you the kilowatt hour. We do have the, sorry, I keep trying to unmute, and I lose the slide. We do have the current usage for actually the whole district and those numbers and the current average kilowatt hour rate that you're paying is what was used to generate these numbers. But absolutely what you're saying would provide more context in terms of maintaining the current status quo and what that would mean. We can do that analysis to show you what the real savings are. I was also mentioned in some of the questions that, you know, we're sort of comparing the existing building to the building that is required by the that's your energy bylaw. And there are some meaningful informative comparisons that would also give further context to these numbers. Basically a building that would meet the MSBA funding requirements in terms of performance but not your bylaw and the amount of savings that you would not the difference in illustration I'm trying to say of what this investment will save you in terms of operating cross going forward. So we can provide those examples and comparisons going forward. So Tim, if you finish the sort of formal presentation, I'd like to open it up to questions from the subcommittee and then we'll we'll move on to questions that that we've gotten from from public members. Absolutely. I will stop sharing. So we have additional questions from from the subcommittee at Rupert and then Kathy. I have a couple of questions. In terms of the life cycle cost analysis, I assume that that does not make any assumptions about inflation. So my question is with the different time periods for the different systems, is the effect of inflation going to be stronger on the system that costs more later instead of more earlier? Thamshi, you want to answer that? Yeah. I mean currently in our analysis, we did take into account inflation, but these were the standard inflation rates that are published by FEMP. But obviously as we all know that the inflation rate right now is nowhere closer than standard rates. We need to take a look at it and see how that impacts see if it's going to be any different for one system versus the other. We need to do a little bit digging so we can get back to you on that. But it's a really good question. I'll make a note of that. Kathy? I have a few questions and they're slightly different topics. So maybe I'll just rattle them off. The first is for the consultants. I know you've worked with other schools, not just necessarily the Dinesco schools. And to the extent we've got examples in Massachusetts, Dinesco and other schools or other places that have made one of these other two choices, either ground source or air source, would you be able to get us there after the building opened experience? So I'm interested in not just cost performance, but also what the building feels like, noise, air ambience. So from a not theoretical, but what actually happened once it's opened. And I see Shelley Pottoff is here. She's with answer. So I don't need an answer right now, but I just think some of that would be helpful for us as we consider not just the price tag, but the actual experience. That's my question. Should I do each of them first, Jonathan, and then let them answer? Okay. So my second question is, I know on your first slide, Tim, you said any of our options would, the roof would not be enough for PV. So do you have a rough, with a three story building or add or no, is it about 50% and does it make a difference if our new was two stories rather than three stories? So that sort of, because I think canopies are more expensive than roof mounted. So just, so that was my PV question. Then my third is when air source, I think you said that the ground source heat pumps would provide the hot water. There are ground source hot water heaters that are hot water pumps that I think could be coupled with air source. So I don't know what's assumed for how we're heating the water. Our house put in a ground source hot water heater. So that's not pure electric hot water heater. So I didn't know what you'd assumed was heating the water in the air source building. And I think that's it. The one other one is more construction time. And this is for the larger committee. If we go ground source, does it mean the number of months that we're spent construction is longer because we have to put the wells in or can some of it happen simultaneously? Is there any impact on the duration of construction with one version versus another? That's my... I can answer the PV and the construction schedule question. Then I'll hand it off to Simone and Franchi for the second part. For the PV, you're correct that we're not going to get the entire array on the roof based on the two options that have been modeled so far. Just under half, maybe 45% was on the roof of the renovation addition, just because it has more roof area. And the other one was closer to 30% on the roof. And you are right, there is a cost difference. What we're using at this stage is $2.25 per watt installed on a roof and $3 for canopy mounted. So the more that you can get on the roof, the better. I will say that we're sort of conservative with the amount of PV that you can get on the roof just because a lot of things that you do on the roof control how much you can put up there. One, there's equipment that takes up space. There is a possibility to put racks above the equipment, but that comes with a cost that pushes it closer to the canopy price per watt. Another thing is simply that parts of the building are probably taller than the others. There are stairs, a coaster, a roof, there may be a gym. And the shadow of some of the building makes some of the other parts of the building not good for solar. So, yeah, you have identified all the variables in the equation of how much we can fit on the roof and what the total cost will be in terms of maximizing what we put on the roof and the rest has to go on the site. And just to add to that, the air source with its higher electricity demands will require more total PV, which will also probably mean that more slide to the site because the lower percentage will get on the roof. And then for the construction schedule, the well drilling can be concurrent with the other activities that will happen. I mean, it is a process that takes time. It has to be scheduled, but it will not have an impact with the options. And the impact between new construction and phase renovation is much greater than... So, that's the big difference between the two different schedule lines. And then, Simone, can you speak to that question? Yeah, I will start then. I want to let Vamshi finish it up to see what he actually used. In both air source and geothermal system, domestic hot water production, you can't quite make it hot enough. So, you have to use it as a preheating system. Then you do the final trimming with electric resistance heat. In the case of air source heat pump system, payback is longer because you're buying this equipment that is heating and cooling, and you're only utilizing for the heating purpose only. So, return investment is much longer. Vamshi? I was going to add to that the same question that in our model, obviously, domestic hot water is a very small piece of the pie. We are talking about, anyway, from 0.5 to 0.75 EY. It's not a big amount, but at the same time, as a design team, we are always trying to find means to reduce wherever we have chance and opportunity to reduce the load. Currently, the efficiency-wise, we assume the same for both of them. For domestic hot water, for the service hot water, I guess. But we'll keep plugging away. I mean, our focus has been primarily on the mechanical system, the HVAC system here. And the question that your first question, Cathy, that was about the actual experience of the systems, we are also always interested. I mean, obviously, we are looking at the performance of the systems. But also, it would be great to get some feedback on their actual experience of the space, the comfort, and then they have any issues, which we haven't really done, gone back to these schools and done it. They're not as many schools which are zero net energy and have same system. But there is one about done and a couple of them about done. So I'll reach out to them and see if I can get somebody to speak to that. And I was particularly with or without the PV, but the interest of going ground source versus air source, the experience. And I don't, either within the world that you've operated in, I know there are, when I read some of the literature, Virginia has some schools that have ground source. I just don't, I don't know what's the easiest to get, but I think it would be useful for us to know about in helping us make a decision. If I could just kind of touch on part of that. I think it would be useful for us to understand at some point, whether it's today or not, what the experience of the teacher and the students in a class in an average classroom would be with the ground source versus the air source when it comes to ambient noise or, or, you know, the sensibility that, you know, physical sensation of getting warm between the two systems or getting cool for that matter. Because that, that, that may have a bearing on how people view the systems. And, and we do have several schools which have geothermal systems and air source heat pumps, not necessarily all of them are zero net energy schools. But let me try to find out any contacts and maybe I can just put in touch with, with the committee here. Yeah, I think, I think it's helpful for, for all of us to kind of reach out and kind of do a post occupancy evaluation, which is what I think Kathy, you're asking and Jonathan really, and that should occur. Actually, if, if they're lead projects, they're supposed to do that I think for a design credit or something like that. So, so we have a few that we have one that uses ground source and air chill beans and the other one is air source utilizing VRF. So, we can certainly do that. And Shelley's on the call, maybe Shelley has some contacts as well. The interesting part would be in they might not know what to compare it to, right. And so, and so what, you know, we could, we could ask Allison or any of the principals within your district and they're going to have a before and an after and they're going to say, Oh my God, it's like we actually get air, we actually get heat. So sometimes it's a little hard to quantify that. But we can certainly try to pose a question in a way that we get some, some helpful responses. Thank you, Rupert. Thank you. Yes. So I wonder if you could comment on the between the two systems, ground source and air source, any differences in relative complexity. And also, I'm curious about a non energy operating expenses, additional training for personnel, regular annual preventive maintenance, recalibration, sensory placement, if there's if you first see any difference between the two systems. Thank you. Yeah, I mean, in geothermal system, basically, aside from the geothermal plant itself, everything downstream is literally four pipe system that's been around for 4050 years. So, regardless how complexity it is, it's very familiar thing that all the country is familiar with. And it's time proven system, nothing fancy about it. And it's very robust system. So, however, VRF system, or air source heat pump system is all that most of the energy is distributed by refrigerant system. And it's a little complex. So about, let's say, half of the contractors are familiar with it, but not all of them are familiar with it yet. I think you will change after time, but it's a lot more complex. Shelley? I would just add to the questions back to schools that have one or the other. And I would ask the facilities managers what their experience is, because that's, I think, completely agree. You want to know what the experience is in the classroom, but you also need to know what the facility managers experiences and to get some real feedback from some actual places that would help to make these decisions. Yeah, we would agree. And I think for us, the challenge is both of these schools became occupied right before COVID. And so, they really haven't even had a full year cycle since the students have been back. And that goes to from, how well was our energy model? How does the energy model stack up? Because we don't really have a full year of data as well as the use of the system going from, we just haven't really experienced both shoulder seasons yet. So it's a little hard, but we can certainly reach out to see what their experiences are to date. Shelley, do you have another comment or question? I do. Another question is unrelated, but back to the building envelope. Just I want to make sure everyone understands what complexities might be presented with the renovation in regards to the slab. So I'm wondering what's in the model for the under slab installation, and what, particularly for the renovation, is the plan to get the existing slab up to the same level as new or with something different placed in the model for that. So just curious about that. That's a good question. I can touch on that. So in the model, we assumed same installation for both cases, which means the renovation will have slab installation as well. Just to clarify that, obviously you can't remove the slab from the existing. It's not, it's going to be cost prohibitive, but primarily the slab installation, what we are looking for is perimeter heat losses, because when the slab is sitting on the foundation, that's the weak link there. So the two aspects we consider, one is that perimeter heat losses and whether we are insulating above grade from inside or outside. So the first part is, essentially, if you are trying to attain the same level of insulation in the existing, you could do perimeter insulation on the outside. It will require a little bit of digging outside and then just insulating it. And the other piece, about grade insulation, we obviously really prefer to do a continuous insulation, because that's where you get most of your thermal performance. You won't have many thermal bridging issues, which I'm supposing is how we are going in this and that direction. The only challenge is the challenge that we would face about grade, if we are trying to insulate from inside, we want to pay close attention to the condensation point to ensure, like, you know, we are not insulating overly and creating some moisture issues, but those things we are getting into details, but, you know, we can figure that out as the design progresses, but that there are ways to bring the envelope to pretty much the same level as the new construction. But just to recap for clarity, in the new construction, because it would be required by code and would be good practice, you would be providing continuous underslap insulation. Is that correct, Tim, and the rest of the team? Continuous underslap actually is not required by code. You need two feet from the perimeter. Depending on what we need to get the performance, we could consider it, but we would certainly be providing an envelope that is going to get the building to perform the way it needs to to meet these energy targets. The only time we do, you know, have the insulation under the entire slab is where we have radiant systems, because you have much higher temperature slab and then the ground temperature. But if you do not have that, which in this case we're not looking at any radiant systems, as Tim has mentioned, you know, just at the perimeter is fine, because your ground pretty much remains consistent throughout the year in the middle of the floor plate, if you want. Okay. The other thing we would not be getting at the slab level for renovation would be a vapor barrier under the slabs. And in a new construction, we would have that. And that has actually been an issue in our schools is that they don't have a proper air barrier, or actually an air barrier or vapor barrier, under the slabs. That is true. It would be expensive to remove the whole slab. We probably selectively have to take some out and we can talk about how we do the details, but there are surface applied moisture mitigation systems that are effective moisture barriers, but I mean, you absolutely correct. You could not get a continuous under slab vapor barrier, which is the idea. I think we would want to make sure that we're including that surface applied system, at least cost-wise, it's probably not a significant cost, but given we've had problems with moisture in our slabs, kind of an off-topic conversation. Well, no, but it is off the topic on the net, zero, Jonathan, but I think when we're comparing our options, the risk of moisture, the risk of other things not being fully addressed, you know, cannot be completely addressed. I mean, Tim had said with the ADRENO, if it was the Fort Rivers site, they're going to raise the foundation up for the new, but they wouldn't be raising it up for the old. So I just think we need to have that kind of list when we're looking at these. And we can provide that and that level of detail will be informative for making the decision between the sites, absolutely. Other questions from the subcommittee? Not seeing any. I think we could probably move on to public comments, although I don't know if, Tim, you'd like to kind of walk through some of the comments you've gotten already. That might speed up our public comment. I should also probably note one thing, or ask you to clarify one thing before I have you take on those close questions, which is, are you looking for the subcommittee today to be putting forward a recommendation, which is kind of .5 on our agenda? If we don't have to do that, I think folks would probably feel more comfortable. We are not. That's the short answer. Now let me give a bit more in-depth answer. Short answer, no. So as I said at the top, you know, all of our assumptions and modeling are based on, you know, what was submitted at the PDP, and we are continuing to refine our assumptions, our design, and that will in turn refine our projections. But what we are looking to do is develop a basis of design that will be part of the PSR, which is going to be submitted in June. The documents are going to be costed in May. So as we move towards those goals, we want to have a discussion to make sure that we have a level of confidence that we are providing the information that you need to make a decision headed up to those milestones. It doesn't have to be today. It doesn't have to be the next meeting. It just has to be tailored to get to that point in June, so we can comfortably move forward from there. The final cost and design of the system is not really till the end of the year, but it's going to make the entire process a lot more efficient if we can come to decisions on some of these major variables with the PSR in June. Yeah, just to add to that, Jonathan, the the preferred schematic report is we identify what the amorous preferred solution is, and with that comes a dollar amount. It's still preliminary. It will be more refined and will feel more comfortable about it, but hopefully it's within the range that we've already promoted or advertised. But in order for us to move into schematic design, because at that point we would have picked a site. At the end of preferred schematic, we'll have a site and we'll have renovation, addition, or new construction. We're not saying it has to be a two-story or a three-story option, but the systems, or I should say the ground source, if we are going to utilize ground source, that would be really important to know as we start developing the schematic design, because there are so many implications to the ground source and where we place the school compared to the ground source because that needs to be done and complete before. Does that help? That's why we're asking just to have an answer and direction by the end of PSR. That makes sense. I somehow didn't suspect we were needing to make a vote today, but I just wanted to make sure it was clear that we're going to give this conversation, give this topic a robust conversation, but still knowing we need to bring closure to it. Yes, and we will also have, so we submit our cost estimate information to the cost estimator in mid-May, and he is here, they aim for, we'll be costing both air source and ground source options. So that hopefully will be a little more refined. We have Steve Coffrin on the call with Solar Design as well, and every discussion we're able to refine our costs a little bit more. And so the layout of the buildings are going to inform how energy-efficient they are, how much energy we use, therefore we can, and we can continue the conversation, whether it's a hybrid model of air source and ground source, whatever, but we will have some updated costs at the beginning of June. And I know we're going to have public, we're definitely going to want to have public input once we have the costs and more details on the options in June, so. It just, before I'm ready to bring, we have two hands in the public, but Donna, you just mentioned hybrid system. It would be probably useful for us to know whether those are more difficult to operate, you know, what are the pluses and minuses of thinking it that way, and I'm not asking for those answers now. So I'm just saying to put that into the equation of the subcommittee making a recommendation one way or the other, if we can keep everything open that it could be hybrid, but at one point someone told me it might have been Margaret, they're more complicated if you've got more than one system operating in the building, it increases the complexity of running the building, but I just, I don't, I don't know again what the experience has been and how many places have even gone that route, so that would be one more piece of information. And I'm not sure how much money we save versus an all ground source, so. Yeah, right. I mean, there's, you know, again, as everyone has seen, and, and because these are all preliminary and certain assumptions have needed to be made, but I think, I think everyone were all in agreement that a ground source utilizing something like a ACB is a more efficient building. Therefore, you need less PV, whether it's on the roof or the cannabis, air source just isn't as efficient, therefore, you're going to need more PV. Now, maybe you can get more PV on the roof because it doesn't require as large of equipment, but you know, so, so proportionately, right, there's, you can just see how both systems respond to the increase, the increase in energy or decrease in energy use or efficiency and how that translates to PV. So we're not going to have exact comparisons and we appreciate everyone's thoughtful. I mean, it's so wonderful to be working with such a group who truly understand it and, you know, are really trying to hone in on the details, but right now we don't have those details because we don't have a building because we don't have it right. So, so comparatively, though, I think we can demonstrate what a hybrid would look like and show you comparatively what that might look like. That's from a cost perspective and then we can, we have Samoom, we have Vamshi, we have others that could help explain the complexities of having two systems. Kelly. Yeah, just a quick, like, general comment and this just is to go off of something Kathy was talking about earlier. When you look at the cost difference between all four options that we're looking at right now and you compare the difference between them to the energy savings over that same 50 years, you're talking about chump change, right? And that's why I think it's really important to show that inhabit front and center as these decisions are being made because to me it's less about the difference in cost than it is about these issues of the user experience and the maintenance experience. So I just want to put that out there just to help everyone to be kind of, you know, clear that we are really, you know, these costs are coming in very, very close relative to the overall savings. Could I say one more item is that the air source heat pump system is like a modular system. So the largest capacity is like 20 ton modules. So when you go from let's say 100% air source heat pump system to 80% you save let's say 20%. Geothermal system is not necessary that way. The smaller it is, the higher the cost per candidate is. So when you go down from 100% geothermal to 80% you don't save 20%. You probably save 10% or even less than that. Thank you. Thank you. So Jonathan should I bring? Yes, let's bring folks in and just going to remind folks that we'll try to answer as much as we can today. But some answers may have to come as more detailed develops. So with that Bruce we can see you're coming in. And so Bruce once you see that you're in you have to unmute yourself. I have no idea where I am. You are in the room with us. We can hear you. Good. I thought Tim might continue on his addressing some of the questions that were sent. But he didn't and maybe he just didn't get a chance to. Like Rudy I've got a number of questions but there's one question that really concerns me and that's the it relates to page five is it or six six. It's the EUIPV comparison. And as I understand it well frankly I can't understand it and that's my concern. It seems that there's a mistake there. I'm going to take you through my logic which I did in the email but I'll do it again because I want to I want you to explain to me why I'm wrong. If I'm wrong and if not it would appear that some of the underlying assumptions here for casting and so forth are not based on the Sound Foundation. So I'm looking at the right hand side of this and I'm looking at the EUIP which by the way of the whole building EUIs we're not comparing the just the heating and cooling system EUIs. So if I go back to February on a high performance building on a net zero building the way you broke it out was that 5.3 kilowatt hours per square foot per year of that 25 you've got 24.9 but that's same more or less. 5.3 of that which is you know about a quarter sorry about about 20 percent is apparently what would be dedicated to the load that is attributed to the heating and cooling. So I go across to the center to the to the the air source heat pump column and that EUI rises from 24.9 to 31.4 it's the same building. The only difference as I understand it is that there is an air source heat pump heating and cooling system not a ground source. So we attribute the difference of 6.4 or so of the EUI to the air source heat pump over the ground source heat pump. So that means that the to my analysis that means that the assumptions related to coefficient of performance of the ground source heat pump are over twice as high as the air source. Now my general understanding is that you'll get a coefficient of performance in the low twos for an air source heat pump and the high threes for a ground source heat pump. So that suggests there's about a two-thirds differential not 120 percent. So it's so in that that 31.4 really should be 28 and then all of the computations of PV that are required to carry the difference would be different and a lot of the numbers in the following charts would be different. So am I wrong? Why is it that the coefficient of performances are so widely different? Have you assumed that the coefficient of the performance of the ground source heat pump is what I would say unreasonably high? Or have you assumed that the coefficient of performance of the air source heat pump is unreasonably low? It just doesn't make sense to me. I would like you to address that now if you could and I won't ask any more of the questions because none of the other questions I have is to me even half as consequential as this one. Bruce definitely I can take that address that question and you know if we need to dig a little bit deeper again we can have another conversation. So we did take a look at the spreadsheet you sent us so what we did is we kind of compared our analysis or our inputs. So you're spot on in terms of COP again we're talking about average coefficient of performance the annual coefficient of performance not the rated conditions. So yes the one more thing added to this mix is it's not purely the difference is not purely from COP alone it's also coming a little bit from the the distribution system as well how the air source heat pumps are delivering the heating and cooling. So there's a little bit of that so that kind of reduces that gap that you're seeing in terms of the difference between COP for GSHP and ASHP. So you're comparing the device COP and you're saying that my numbers are more accurate so far as the device COP is concerned and you're saying but of course we need to address the system COP and you're saying if we address the systems COPs the variance is greater between air source heat pump and ground source heat pump because the air source heat pump systems demand more as well as their ability to connect and draw heat from the air. Do I understand that's what you're telling me? That's correct okay. When we actually we went back in the model and kind of extracted the data because we run these analysis on hourly basis so for each hour depending on how the if it is ground source heat pump it will look at what is the incoming temperature of the water and how much load you have and it calculates COP on hourly basis so when we ran the average COP for the year we were close to four on the geothermal system and then two COP for the air source heat pump system so it is roughly I'm talking about and I'm not giving you the any decimals so so that is that is the first part and the second part was the PV difference right in the same one I remember you're calculating the PV difference yes I did a math error there as you can tell it was not 109 it was 199 so not four times but eight times but again predicated on my understanding of your thing here yeah so once we adjusted for that there you know it kind of comes to the same number we came up with and again we actually included some additional 50 percent capacity additional capacity for the PV system yeah you know accounting for system degradation that we'll adjust Steven from solar design associate CCR we can chime in more since that presentation or since that numbers were put out he had some thoughts on system degradation which we'll address later on but also gives us a little bit of buffer in case the usage moves up and down a little bit here and there yes yeah that makes sense sorry I just wanted to add when look at your spreadsheet and your method is correct but there was one tiny mistake that you times the you divided the cell piece should times it and that's where the majority of differences from but once we adjust that and and your number is very very close to ours I I think we need to talk about that but we don't need to do it here but anyway that that at least gets me to the point where I'm I'm reassured thank you thank you I'm reassured that what I first thought was incomprehensible is not comprehensible and I also appreciate that this is very early and really what I was digging into was a was whether there was some oversight of some sort and I know these will get refined and things will change or well refined and so forth so I think that has is clear enough for me now the other question that I had which is only one to I note that on the very last page the the the the we're looking at the if you if you can go to the last page of the I can do it here actually the cost savings and comparisons and or it maybe it's the second last page I beg you pardon I think it's oh hold on where am I oh no it is the last page sorry I wasn't scrolling down that's it yes um very interesting to see the the the the cost of electricity moving forward and I understand the reasons why you say it and so forth but the then down the bottom you say the electricity cost savings estimated at 90% of consumption and I guess that's a rule of some thing and it seemed to me that that was predicated on an almost complete use of the PV as generated going straight to the loads and therefore there would be very little purchase from the very little of the of the PV production fed into the utility and and and not so much complementarily being purchased back so that this is the demand charges and all of those things for that purchased electricity which seems very small to me and and I I thought oh well that's probably because this is almost all daylight our operation so I guess the question is if and as if this building were to shift to have more functionality in non daylight hours which for example could be the a greater level of community use which one could promise as a way of selling this building to the community as a whole I guess I would understand that that's those electricity costs the marginal costs that you've got there which are between seven and nine thousand dollars would increase if the if the after hours use of this building increased you are correct Bruce that if the hours of use assumptions that we had an earlier slide were to change it it would affect the energy performance and and yes the savings are predicated on an exchange of you know producing power and getting credit for it when the building is not occupied in that again yeah getting energy from the grid when you're not producing as much and it all working out to be close to zero yeah and and I I commend Shelley's thought process about the the bigger picture being the important picture on this although it'll be hard for us to keep that constantly in mind because the immediate costs are the ones that we're probably going to have to defend but the extent that we can shift the conversation to the bigger picture and do so with sound data and confidence and unilaterally one mindset amongst the committee and people like me who are supporting the committee in town then I think it's a it's a good a good piece of counsel Shelley I appreciate that I think that's that's that's it for me thank you very much thank you thank you um okay Chris Riddle I'm bringing you in and I've brought you in so once you see something you can unmute and talk you're with us you can hear me yes um first I want to call everybody's attention to the words energy budget in the uh zero energy bylaw um we are required by that bylaw to develop an energy budget um early in the process and then to keep it updated throughout the process I we sort of have an energy budget and that we have a 25 ui target but the intent there was that there would be maybe after the product of a of a run of the of an energy model would produce a fairly detailed target that we would use as a as a as a as a target to guide our guide our work and see how we're doing relative to that that energy budget so just please look up the word energy budget in the zero energy bylaw and give me a sense for where we stand on that are we going to just rely on just so the 25 ui or we're going to try to come up with a fairly detailed um energy budget for the project secondly um under I'm just repeating somewhat about Bruce said that the schedule does not show any nighttime use and I thought that we were going to add nighttime use back into that schedule based on an earlier discussion um on under hvac options um is am I right to say that energy recovery ventilation is only provided where it's indicated on that chart and is that uh and so that the the the large users the the gym and the cafeteria and those kinds of things do not get energy recovery ventilation am I reading that correctly or not um what is the difference between ducted fcu for fan coil units and ahu I'm not understanding what that distinction is I'd like to understand what ducted fcu fcu and ahu mean um our rooftop hvac units contemplated I hope they aren't but I would like to know with an answer to that um under kitchen why is electric heat only in the air source heat pump option not in the ground source heat pump option why is that um does does ducted fcu equal a vrf system that's my question do we are we distributing we're we're we're distributing free out refrigerant to those units um let's see what is ahu served by a shp I guess I understand that I guess that means that we are doing it with a hydronic system it is heated and cooled by the air horse air source heat pump am I right to say that everything is going to be um uh hydronic except for those things that are called ducted fcu that's a question let me guess I thought we established that that wasn't right um why is chill beam only in the ground source heat pump option the question I thought that's not the life cycle cost I think it would be good for the life cycle cost to show a similar life cycle cost profile for a oil or gas system so we can show that that the boilers wear out too and we have to replace them too and and all that sort of stuff I mean you sort of do that but I think it would be good to see that over time and no that's it thank you um we can respond to those I will I will respond to the last part first that was mentioned earlier that uh there was a desire for a baseline um which would be a fossil fuel burning so we could compare costs and saving so uh we will effort that and I will hand it over to samoon to talk about spaces that sort of by the r u and the components of the fan club first can we just start damn sure okay I'll I'll see if I can remember all the list of questions that Chris has presented I try to write down the best I can so let me know if I missed anything one of the first question was uh is erv only in the chill beam area or not actually energy code dictates what areas I need to have a erv so like uh most recent IED IE uh conservation uh code 2018 requires that even the handling unit depending on size and duration its operates that does require partial energy recovery system for the ventilation portion so that will be complied with uh and second question was uh what is why are we using ducted fan code unit versus in the drf option versus chill beam which is inside of building there's two reasons uh one is that pill beam is much quieter so you can clean the space and still meet the modern standard of a learning environment acoustical requirements and second reason is that most times when you do air sourcing pump system we use a ductless in ductless units and that's pretty good for like residents where you have a plenty of a dead space where draft doesn't really sort of bother people but in the case of classroom where it's highly densely occupied you don't have any dead space where you could throw this air and if you have a set in front of a wall unit pretty drafty where then the summer or winter time is constantly blowing right in front of it so that's the second reason uh third was uh do we have any rooftop handling units right now conceptually we are thinking about ERUs and handling units to be on the roof mounted um we have done buildings where everything is inside but that of course adds cost to the project so that's something that the design team has to evaluate kitchen exhaust kitchen system has electric heating coral not because of any other reason but uh limitation of air source heat pump system air source heat pump system cannot tolerate any air that's cold within 24 degrees it actually crafts out so I have to heat it up to 24 degrees before I could utilize air source heat pump system for further heating and reason I don't have electric heating on other parts is because modern-day air source heat pump system is rated to operate down to minus 13 degrees outside uh in previous less than 10 years ago when we were designing system we always had a backup electric heating coral because below zero degrees it used to just not be able to perform at all uh when it comes to ducted vrf is the same as fan core unit yes indoor unit for the vrf portion we are proposing ducted fan core unit and it gets its energy distributed by refrigerant piping uh I think next one was uh is geothermal thermal system all hydronic yes it distributes at the geothermal plant it produces chill water and hot water and distributes throughout the building uh only difference in geothermal system is that it cannot produce hot water that's hotter than 10 to 25 degrees so the heating coils and the system has designed such that you could utilize the low temperature water why is chill beam in ground source heat pump option only air source heat pump system is kind of limited and what you could do they give you you have outdoor unit and when it comes to distribution system you have a fan core units or duct less fan core unit which has a certain amount of noise generation so I can't really utilize without ducted system and they don't have a chill beam option for the vrf system and when it comes to geothermal system we do have a lot of options when it comes to distribution system whether we use chill beam system or vav system and all that but we have found so far we have found that a chill beam system made to be a most maintenance low maintenance and quiet and trouble free did I miss anything Chris I think that's good I'm sorry Simone did you mention the kitchen yes sorry thanks thanks Simone I think that's I think you said everything I'm not sure but obviously I can watch it now we can watch the recording one thing that I think uh we didn't talk about though was the um the the daily weekly yearly kind of schedule um Tim could you bring that up just for a second um so I know that Denisco worked with the the school to kind of establish that and maybe we should just quickly look at it again um and and maybe note you know I think this is probably based around kind of typical uh daily and weekly use and not necessarily that there wouldn't be a special events that might be outside of these hours at times but um you know if if if changes to this were needed we would need to identify those very quickly because these these are guiding a lot of uh the uh the decisions that are or the calculations that are being done at the moment and so there there is some evening use but there isn't what I might call uh you know late evening use uh past the 5 36 o'clock kind of uh threshold on a regular basis correct and and we can I guess circle circle back or or actually Rupert's on so maybe Rupert wants to weigh in Rupert sure um uh we do rent out spaces in various school buildings to talent athletic groups uh gyms particularly uh throughout the year and I would need to do have a little time to sort of give a sense of what our current uh rental um frequency is but um certainly usable gyms can be uh quite sought after in the town by various athletic groups up until nine o'clock at night um uh so uh if it would be helpful I can try to dredge up some information uh for the team that would be really helpful yeah sorry Jonathan and and then just to point out as well um you know for summer use and right now maybe you know it's that your existing buildings are being utilized in one way rather than when you have spaces that can accommodate air conditioning etc so what we have identified is that not only the core spaces such as the admin who's there year-round maybe even some of the the cafeteria or the gym which might be used for summer school summer fun programs or whatever we're also identifying in the summer that the classrooms are going to be utilized as well from 7 33 p 3 p.m. daily and are you going to use all of them um maybe not maybe it's going to be the first floor maybe you only need 10 uh 10 classrooms instead of the 30 classrooms but um if if we we appreciate this comment about use because it it's not only about you know when each space is being used but the other component that we've had to make an assumption on is the plug load and for us this is our biggest area of unknown and a little bit of our concern and in that we don't want to underestimate the plug load and the use of the school because that's going to inform you know the energy model but then we're coming back and measuring it to see how well we did afterwards as part of your bylaws so I don't know Rupert you know thinking about plug load thinking about you know the impacts now that everyone's on laptops maybe we don't charge them all day like we've been trying to figure out how we can reduce the plug load in the schools but we don't want to underestimate now because we want to make sure that we have the capacity to support the school going forward so it's so a little bit of a conundrum right now we want to get it down as low as we can but we don't want to underestimate some of these so maybe maybe Rupert um we can maybe have a separate conversation with you that that would be and maybe Mike or someone who's going to say no you know that we're all doing something one way we can have a more informed decision on that I don't know Rupert and Kathy both have their hands up sorry I was babbling away muted Rupert did you want to follow up on that or should I go to Kathy first I'll just say briefly yes I'd be happy to talk about plug loads I think that probably the biggest variable that's going to affect how close we meet the models is going to depend on occupant behavior particularly around windows and ventilation and I don't know how to figure that out Kathy um yeah I just when when you have the conversation with Donna and Rupert noting what you've done for the summer hours you've got all parts of the building being used all summer so it'd be good to you may have done a very generous estimate for after hours already but just to try to make that clear what's underneath that um because the buildings are not used right now that way um all summer long so uh we may have underestimated the evening hours during the school year and overestimated the summer hours so just getting some kind of balance between those before we say we need a lot more solar panels because the building is going to be used all the time and I understand this is all in a future looking way um because one can imagine a cafeteria with a stage will be used in a way that a cafeteria without a stage is not used now but you've got the cafeteria being used um all summer long every day of the week during weekdays so I just think just just getting some sort of balance when you look at those um and I have no idea how to do that so that was just an observation no that's helpful and I think um we will circle back this was I think um superintendent Morris's best guess on on usage and then you know Rupert you can speak more to this but I don't believe that they have assemblies that they utilize the cafeteria all the time those are sort of one-offs so maybe we can generally state certain things like 10 times out of the year or once a month or twice a month the cafeteria will be utilized by the school in the evening whatever um and and then we can talk more about if you have summer programs even if they're camps or whatever that utilize the building I think that's what was kind of accounted for here but Rupert if you're you're amenable and Kath probably would love to listen in why don't we see if we can schedule something with superintendent Morris to to fine tune these based on your observations and then what he's aware of that would be really helpful and I see that both Chris and Shelley have their hands up and I don't know which one was first so I'll I'll go with Shelley and then Mr. Riddle. Thanks so first just a quick comment about user behavior um really feedback loops is what it's all about so we got to you know make sure that there's mechanisms that the users in the building can see where their usage is at and have signals that trigger them to act in this way versus that way so like on the opening windows for example one thing I've seen in schools is you have a little green light that's next to the windows and when it's okay to open the windows the green lights on and when it's not you don't right literally you need things that that make it that clear so that's just a comment on that front but the other thing that I saw in one of the public comments was asking about how to deal with COVID and ventilation and recirculating air and classrooms so I just want to put that out there for discussion as well and wonder a little bit about his um their display displacement ventilation been considered for the delivery system and I think you can do that with either geothermal or with air source heat pump but just curious if that's been looked at um Simone uh if if we got to the the questions that were submitted ahead of time I was going to have Simone speak to that one because it's a general rather than design specific and that's one that we could answer at this stage but Simone can you speak to that for a bit yes when it comes to COVID concerns both with the niscoe associates uh the niscoe design we have consulted with the many school districts about this COVID concerns uh there are two viable options we have available which is HEPA filtration and the UVC spectrum lights uh we have used both of them and we also I see that Amherst has adopted portable HEPA filter system which is very very effective various system have a lot of different options all HEPA system has some component of recirculation system and some of them has more flexibility when it comes to doing the measures for example if it's an air handling unit you could put good robust MIRV 13 filters which is about 50% effective against virus-laden particulates uh you could also put a UVC light which is 99% effective of destroying all the viruses when you with the smaller units for example fan coil units they do sell MIRV 13 filters but it's not really uh they don't last for long they get their ratings because they put a lot of static electricity charge there so after a few days it just becomes MIRV 10 or 11 so I don't know if you want to invest too much money on that and you can't use the UVC light on fan coil units because UV light degrades the internal insulation system so it just falls apart after a while uh chill beam system you cannot put any filter system at all so you would have to use a portable filter system and one kind of sorry one more item is that there was one more question about ERV system uh whether it is based on heat wheel or dual core reactivation system they do have a small amount of cross contamination in order to address that we would we could use a UVC light to make sure that uh any contaminants will be destroyed just one follow-up comment about um air displacement ventilation is the delivery system is the difference between that it's it's the air is being delivered really slow high volume across the floor and then rising up and being returned high and so the theory is that any germs coming off of people are then allowed to go through the event through whatever filtration system that you have before returning back to people as opposed to when you're mixing in the room and then basically if you're relying on mixing within the room to get to your temperature set points then everyone's breathing everyone else's air that's my understanding of the difference between those two and so it it matters which which it is to see if your your filtration system is actually going to be effective yeah i've been doing this hvc engineering for like 43 years too long probably but only um directional and controllable airflow system is in the class 100 clean room where slam enough flow conditions where it's unidirectional and uh hospital operating rooms every place else it just mixes all over the place you may see presentation graphic presentation nice arrow going one direction but it's not true as a matter of fact first reported case where they said hvc system may have caused us spread of the covid was actually because it was in asia it was a walled up plus unit and the um infected person was sitting right below the air conditioning unit and he was pushing all the air across the other rooms so it was nice way to spread it in the case of a beautiful displacement ventilation air does go across the room so if you happen to have an infected person sitting right in front of the displacement diffuser everybody else again so what i'm saying is uh in practicality hvc system when somebody tells you this system is better because of an air circulation pattern it's not believable it's impractical so kathy in the interest of keeping track of time and make sure we can cover as much territory as we can yeah there are two more people wanting to come in so yeah jonathan so should i move to the next person then yes but i want to say one quick thing first which is i know that tim has given some consideration to some of the the uh questions that are are uh addressable at this time that came in ahead of time and i don't want to miss that and so um i'm hoping that maybe we could it's about uh 225 now maybe at about quarter till or so we could uh kind of give tim that opportunity just to address some of those questions as well um yeah thank you for that i will say that many of them have been covered especially with that last uh conversation that covered a lot and obviously uh getting comments from the public is very important but it maybe we'll say we'll call it 250 then just to just to stop and pause to make sure that if there's some some important ones that we haven't surfaced and talked about that we do that okay thank you so yeah we're just coming in so jonathan just keep so i'm so that's a request that each the next people try to be really focused as well yeah hi can you hear me rude rude harkins uh 42 cherry lane and amherst um maybe it's the lawyer in me um sometimes likes to get things explained piece by piece so um thank you for answering so many of the questions i my list is very short now um but i did want to come back to my top question about 108,000 uh gross square foot figure for the reno ad i still have not really heard um a satisfactory explanation for why that reno ad auction can't be the same gross square footage approximately of 105 750 that you're using for the the new building um partly because it would give us an apples apple comparison partly because that's what the space summary uses so i don't know how we could go outside that maybe there's leeway i don't know um and partly because obviously if we make bigger building we generally increase construction costs and operating costs so i don't want to see for those reasons i i think whatever you can do to give us a 105 750 um reno ad match that we can compare so very helpful you know except to the committee whether they want you to spend that time doing that but um the things i would want to be sure you had looked at would be changing the dimensions of the interior courtyard in the reno portion um changing the dimensions of what portion of the the old building you actually preserved in the reno um selecting making the new addition smaller uh to keep it at about the same size and if needs be moving room types around between the reno portion and the ad portion or some combination of those to try to get to a reno ad model that was more equivalent um and there may be things that i just can't imagine that you guys have hit in the old building that with you know a few diagrams of the layout of the building and where you can make cuts in the building where you can't um might explain it but uh at some point i think it would be very helpful to have that because obviously the 108 thousand figure ripples through all of your your estimates on energy usage at least it seems to you've got it you know when you'd be doing that multiplication times whatever your e y to get your energy usage and your pv needed so um when we're trying to shave off a percentage here and a percentage there it seems like a worthwhile exercise to me but so that's that's uh one that i i don't really feel has been adequately answered yet um you've um sort of touched on why the gsp gshp h fact number is um higher than the as hp number for just the h fact portion i was a little puzzled by that and i wondered if the chilled beam distribution was being included in that or some other costs that were pushing the gshp option up beyond its just its um the wells cost and that's on slide seven on slide eight i thought i heard you today confirm that maintenance cost equals neutral means there's about the same maintenance cost between the as hp system and the gshp system and i wondered if that's what you were saying and if you've looked at the likely maintenance staff hours that would be used for each of the systems and how much you'd have to farm out to professional contract heating contractors for the maintenance and what the comparison is maybe it does come out neutral i don't know i thought before you had said that it was different um that i i'm also interested in just how many servicing companies are in the area if we went with a gshp system uh that was always a problem with my manage the management people i worked with they always thought you know we weren't taking into account the maintenance costs over the long haul with certain more highfalutin systems we put in and i'm wondered whether there's adequate servicing on both the 24 seven basis and just generally in the area to service both types of systems um and let's see i i was confused by the co2 emissions figure but maybe i'll clear that out up and later iterations of your um your slides and explain that how much co2 we're saving in the admissions and then i think you've covered most of the sort of arcana about ventilation systems which i really appreciate because um i heard a talk by an air hygienist after covid broke out who was saying we looked at building systems for water and municipal systems for water purification and filtration after cholera outbreaks and we basically got our systems good now but we haven't done the same for air and i appreciate that you're going to be looking at airborne virus mitigation and how to set up the the filtration and the different systems i think we really need to pay attention to that now and i appreciate that so um anyway i think you basically touched on all my other previous questions unless there were some that tim had an answer for that i didn't thank you thanks rudy um we can start to answer these and and actually that this will get to most of them but uh starting with the 108 gross 108,000 gross square feet for renovation addition um the sort of exercises that you've described you know truly evaluating um which rooms get saved which rooms go away um the size of the addition as it relates to the existing building are all things that we're going to study in detail going forward um that we have you know started to look at but we haven't gotten to the level of detail that would give us the certainty to say that we can get to 105 750 and we might not be able to get to 105 750 there are some inefficiencies inherent in using different shaped rooms in a different arrangement as part of your building than what you would do if you would start from scratch um we may be able to get below um 108 but that inefficiency is is part of reusing a building um and and we will do everything we can to make it as efficient as possible but that is that is part of the issue of using it and you are correct if there are 3,000 more square feet of building there are 3,000 more square feet two heat cool and keep the lights on so all of this uh you know will have in our minds as we move forward and set the options um Tim another thing you've just that occurs to me on that topic is that while there's some inefficiency you also don't want to necessarily compromise the the the programmable space to to make up for that that you're not going to you want to take it out of the classrooms to be blunt about it you know if absolutely you've got a big u-shaped corridor for example yeah we are not going to yeah yeah cut a quarter of a classroom route to hit that square footage target that's you know we're going to build the school that serves the students uh the you know the way it has to uh and sometimes the price you pay is a little extra space um just can I just add one thing there that I think helped make it clear to to the public is that a lot of that inefficiency is in the circulation space and so what you're talking about is reducing programmable space in exchange to have the inefficient circulation space and it's more than what people might normally assume and I think that generally people wouldn't think about unless you know but in our case for a long time and dealing with these things so just to kind of add another little comment there could I just touch on that maintenance cost differential the vrf system is a lighter duty construction it's probably like light commercial duty and based on my talk with all the users it does have higher maintenance but when I started looking for the actual documentations studies I couldn't find anything so as a default value I recommend that that we just for now uh because of lack of information that we just keep maintenance costs for both same when it comes to how many uh what's that a qualified contracts there are around here I feel pretty good because you have a benefit of having so many higher education buildings around here so I would think it is true but I haven't done any survey to find out how many there are okay you know I just I would just add to that both UMass and Amherst college have ground source yeast bumps in them so we do we don't just have higher education but we have higher education that have included these systems in their systems and we have some other buildings so unless we're assuming that none of them are being maintained that we're generating a market is the other way I would think about if there isn't a good contractor here there ought to be a good one because there's a lot of business for them so so should I bring the next person and Jonathan I'm just looking at your and Rudy did we get the big ones yeah I think so I just um if you do change this the space of the building aren't aren't we going to have to reassign space to the different program needs and that that's a that's a discussion I don't want to go through again but um if you're in the ad reno and you've got extra room space who's getting it anyway for down the line yeah um sorry Kathy go ahead no I just want just Shelley was adding so I think that's a topic for a different yeah and here but what Shelley was saying is you still have to have hallways so if we're keeping part of the old building we still have to have a hallway in it we have to have doors that come in and out so there's a limit to how much we can massage that we have we're putting the same classrooms in it but that's that extra 50 percent where does it come from um for you know so I think we should just leave that for a separate discussion don't know because yeah yeah I think it'll be all much clearer with floor when you have your first pass at floor plans I think this topic will be easier to discuss and yeah I just I just just from from a programming perspective the renovation addition or new construction will meet the educational program no more and no less and so again as Shelley and Kathy both have said it really just becomes efficiencies in the layouts as as we are working with an existing building so the program components are all going to be there and we're not going to make them larger just because there's extra space but as Jonathan said we're working with um school department actively to make sure that we understand completely what the adjacencies of the programs need to be and then and then we can lay it out as efficiently as possible while maintaining daylighting and all of that other stuff with the existing building so those will be forthcoming at a building committee meeting shortly thanks Kathy let's see if we can bring in the last person who's got questions so um Maria um I think I have brought you in yes great so um I had a couple of questions about the assumptions that were listed in the the um packet for today um and I believe I heard you say that three stories is not a done deal so I think that and that's two stories is also going to be studied for new construction so I think that that should probably come out of the assumptions and I think that is a good thing to understand the difference between two and three stories not only from uh this the building but specifically for net zero and for pbm that kind of stuff so uh a request to do that another uh bunch of the assumptions was about the envelope and you had some r values of 25 for wall and 40 for roof and I'm wondering why you chose those um in the fort river feasibility study when we were looking at doing an e i u 30 um uh uh ui sorry 30 uh building we looked at an r rating of 35 for the wall so 10 higher and 60 for the roof so 20 higher there with 15 at the slab uh as opposed to the um ui for a an ui 50 building we were using something more akin to what these envelope values were 25 and 30 so if you could explain that that would be helpful um and I did have a question about uh for spaces that have uh tall ceilings so the gym and possibly the cafeteria have you considered um uh and I'm curious about floor radiant heating um and just why that would be good or not good or is it not being considered I'm curious about that thank you um I'll take the first part and then distribute um two stories for new is not off the table uh the assumptions in the presentation is what was used to generate uh the costs and operating costs for what has been presented and and moving forward working with the district to figure out what is the best in terms of education and all other things being considered uh I'll just leave it at that two stories that's certainly still on the table um and then I will start the uh r value of the envelope and then hand off to bombsheet but these are assemblies that we have used and they perform to get to our e y targets but there is certainly more installation that can be added uh but you get to the point where the cost of that extra installation does not improve uh performance of the effect that it's worth it uh and I'll let bombsheet follow up on that um yeah I mean there are diminishing returns to be on a certain point for sure um and uh I do agree that you know we haven't done the optimization that exercise is going to follow up later on uh right now what we are looking at is comparison of the systems but as Tim has mentioned you know the 25 uh value in the walls you know that may be bumped up on other zero net energy schools that we are working on we are looking anywhere from 25 to 30 again the roof depends on you know the final massing option where we get if it's three stories where there's two stories and how the massing is finally developed that can change because if we want to um see you how much surface area we have of the roof and what is the optimum level so we work on that piece it's a really great question but we will get there for the placeholders yeah I also want to add uh it is because we have such high efficient energy uh it's efficient uh systems that uh our heating and cooling is already very low right now it's uh for our geos uh ground source heat pumps versus another case it's only 5.3 ui for heating and cooling which is about 20% of the total ui so if we improve on that um it's going to be uh may more and we see uh diminishing retros as i mentioned i want to mention just a second comment on this is for everyone's comfort level these love these insulation levels are consistent with the ashray advanced energy designed by kp-12 schools so as a starting point it's completely reasonable could i address that radiant floor issue okay uh oh what's that unlike uh residential uh buildings we need to comply with the ventilation system so you have to have an air system of some kind for the gyms and part of our job is to make the system uh best value as possible uh and radiant heating means i would have to have a radiant heating system plus the air system so it would increase the first cost uh anyway and uh probably another item is that uh modern day wood floor system in the gym is pretty sensitive so i'm not really sure if i could get uh good performance of a wood floor with the radiant floor in the commercial applications that's something maybe tim could address a little better um that would require a little more detail and research than i'm comfortable saying right now i mean i know the issues uh there are issues of humidity warping all sorts of things that can affect um the quality performance of the gym floor which we wouldn't want to interfere with by including introducing the radiant heat below it but the the reasons that samoon mentioned are are the driving factors here i appreciate those answers that was very helpful thank you i think i think that is um it for let me just double check there are no other hands up uh jonathan that concludes public tim were did were there any kind of last things that that that you all had had an answer for that we didn't touch on i don't think so but i don't i don't think so either i mean i have a list here and all of my highlight isn't items have been touched directly or indirectly so i mean we will also keep a record of the questions that were asked so in addition to the recordings of the meetings there's a written record of what was asked and answered so as we can come back to it and refer to it if needed or to ask it again but um so with that in mind i think we have covered everything that we could hope to do today great just looking at my agenda for the day we do not need to take a vote that which would be the next item um we have no items not anticipated 48 hours before the meeting um and so unless there are thought last thoughts questions concerns on the part of the committee um i would welcome a motion to adjourn oh i see rupert's hand well i just have to take advantage of of this uh august group of uh experiences in minds uh with i just had a quick question about um the uh displaced ventilation system i've read about it i've never experienced it i worry that it um about comfort levels uh with the cooling air being introduced down low um and i just wonder if anybody has any comments thank you yeah we what we are asked on almost every school system to evaluate it and i spent a lot of time with uh lunch and learn visiting looking at design documents and it's too delicate for my liking is that if you look at it you're supposed to introduce uh luke cool air in the ground level sweep it across and as it hits the a person which is creates thermal plume which takes a little while to uh was it uh create and i'm not really sure how successful you are to get asked a 10 year old to stand in one spot enough so that it's a little form it's too delicate i like to stay with the system that's been proven for quite a while so moon with that is is there any energy savings is it is it more efficient than and you know an active chill beam or is it less efficient i mean if we want to look at it in the context of this group it's something that i think van sheet should should answer okay yeah um yeah um i i don't see a lot of energy benefit from it um definitely there is benefit when you have high volume spaces where displacement ventilation um really works well is because of the de stratification so you're supplying cooler air closer to the occupants rather than conditioning the whole volume and in classrooms we don't have that high volume of space so you don't get that benefit of the de stratification using displacement ventilation so from energy performance perspective it's pretty much neutral so so jonathan i'm ready to adjourn i just want to say a big thanks i mean i i appreciate the answers and i appreciate the willingness to take very detailed technical questions from people who are in total support of this project so it's it's an effort to both learn more and understand thinking i i just found this to be an excellent session so thank you all very much and we look forward to seeing you again whenever is the right time for you to to get a recommendation as we think about the information that we've got so thank you donna did you have a yeah i was just i was just going to say we too kathy sincerely appreciate everyone's input into this wonderful project that is going to be the first net zero building in in the town of amherst and your thoughtful comments really help us think through everything and make sure we're not missing anything i wish we could have all the answers today but you know the design process is iterative so unfortunately we can't but we really appreciate your patience and as we work through these along with the program along with the site along with right so we will hope to be before you sooner rather than later although we need to do a little work in the design phase to be able to respond to some of the questions but we don't have an enormous amount of time left right june is going to be here sooner than well hopefully sooner because it still feels like it's winter but sooner sooner than then then you know we want from a work perspective but this has been very helpful rupert we're gonna we're gonna get with you we have to work on plug loads we've got a whole bunch of other things that we can be working on while we're trying to refine the design so thank you all welcome so kathy we should probably do the the proper thing and i'll ask again for a motion to adjourn i make a motion to adjourn and with that uh i will adjourn the meeting thank you have a good afternoon everyone