 So even though I know David pretty well, I did print out your little introduction to make sure I got everything correct. But David has transitioned his home a post and being farmhouse built in 1828 entirely off of fossil fuels and designed heat pump systems for hundreds of other households in Maine. He is a certified energy manager and lead accredited professional for building design and construction. He is joining college of the Atlantic as their new director of energy, starting in August. And I won't take it personally but he did not also include that David is the vice chair of policy for Sierra Club mains executive committee so I will pass it over to David. Thank you. Yeah, thanks Sarah. And actually, it seems like a small enough group. We could go around and do introductions. If you could each give your name, what town you live in, your pronouns, and what your current heat sources are in your house. So I'm David Gibson, I live in moral, I use he him pronouns, and my house is primarily heated with heat pumps with high humidity wood stove as backup and for beautiful ambience on cold winter nights. Sarah, if you want to give a quick intro and then we'll go around. Yeah, definitely. Sarah Lane as I mentioned chapter director for Sierra Club main. I'm in a rental right now until I find a permanent housing place. So my rental unfortunately is heated with oil and there's no alternative fuel heat source. And so I'm looking forward to my new home being more energy efficient and I'm in Searsport. And john deal. I'm in Belfast. I'm him. The house I live in is heated primarily by a chip boiler with backup wood stove and heat pump. Hi, I'm my in Bristol 1875 vintage house recently installed to heat pumps, which are doing a great job but I still have part of the house that I rely on a little brown. Not sure who that is. If you're if you're there and want to unmute yourself and introduce yourself. Jim child. Hello. Can you hear me. Yep. Okay, fantastic. I'm here with my wife Pam and we're in Bristol. Our house was built in 1829 and it's heated with an oil fired furnace. And what else did you need to know. Just what pronouns you use. Oh, well he and he and she and or us. David. Hi, I live in Reno, Nevada right now but I am moving to Portland, Maine, because my son lives there. And I know David quite well he was Vice Chair of the Toyabe chapter when I was chair. So looking forward to seeing him again. My son lives in a circa 1980 house in South Portland. It's heated by oil fire fired burner. So maybe there's something I can do about that. Awesome. Yeah. Sue inches. Oh hi David. I'm coming to you from North here. You can see the post and beams over my head here live in an 1828 Cape farmhouse myself. And we are mostly propane here we have heating clothes drying hot water and everything is propane with a big bulk tank in the back of the house and then we did put a heat pump in we have a shop in our basement and we put a heat pump in there. Right around March, which seems to be working really well. So but the rest of the houses. It's more of a challenge, eating wise. So that's what we've got here. Becky, if you want to introduce yourself we're just giving our name town pronouns and eating sources. Hi, I'm, I'm Becky Bartavix and I live in a, I live on North Haven Island in an 1867 farmhouse that we super insulated and it is I have a heat pump that I installed, I think, four years ago and a heat pump hot water heater and I have taken out the furnace and I have solar on my barn and so I have no oil or any fossil fuel in my house, and I am alive to tell you about it. I am, I do. I do have a wood stove. I'm reading a lot about wood stoves it's a highly efficient wood stove but of course I'm causing particulates. As a result of that. I do argue differently about, about the carbon footprint of wood stoves but I only it's a high it's a very heavy soapstone stove and so I only burn it after dark and my house is heated by the sun mostly when it's sunny out. So anyway, what else did you want. Oh, she hers and I live on Penobscot occupied territory. Thank you. Patricia. I'm here in Fort Kent with an oil boiler and a pellet stove in 1950s vintage house. And my parents are actually moving up here as well and they are going to be in a very new house with propane radiant floors. See if I can turn them over at all. Awesome. And who is on the iPhone. Thank you for the great introduction. And thanks everyone for joining us today. Hopefully none of you are using any of your heat sources in this beautiful weather. I haven't opened up windows yet but hopefully this afternoon it'll be warm enough to have some windows open. Three and a half years ago, my wife and I bought a new house our home here in moral. It's an old post and beam farmhouse that was built in 1828. This is the front of the barn that is visible from route three. If you're driving between Augusta and belt asks you have driven right by our house. This is just unrelated to heat pumps. I highly recommend changing all of your light bulbs to LEDs. This waste can on the left is all of the incandescent light bulbs that we took out of our basement attic, the house and the barn. We found some 150 watt incandescent light bulbs out in the barn. It's very expensive. If you have those types of light bulbs and you leave the lights on over a weekend or you know that sort of thing so it's well worth changing all your lights to LEDs. So we placed our shower heads with low flow fixtures that use a lot less water. And the primary savings there is the electricity or heating oil or propane that you're using to heat your water. So again, highly recommend lower flow shower heads to conserve water. When we bought a fridge and we made sure to get an energy star rated fridge and I encourage high efficiency appliances as well. We also put in a water that I don't picture up in this slideshow. But again just starting with efficiency and reducing energy consumption. So before we talk about installing heat pumps. It's essential to reduce the heat loss out of your home first home efficiency is a critical first step. It doesn't matter what you're heating with whether it's heating oil or propane or wood stove or heat pumps. If you have a leaky old farmhouse. You don't have energy heating the great outdoors rather than heating your home. And with heat pumps that becomes even more efficient because you want to have the system properly size. And I don't think it's possible to size a heat pump for a leaky farmhouse that the wind blows through on a cold winter day. So, air sealing and insulating is the first step. EPA or Department of Energy Graphics showing common sources of air leaks in the house. And, and then on the right is a blower door. And the blower door is the most important tool that a professional energy auditor will use. It helps to identify where air leaks are occurring in your home. And also quantifies the magnitude of the air leakage so you can get a before and after and understand how much you reduce the air leakage out of your house, which, which makes a big difference. And also can help you to identify if you missed some doing doing a test out after after doing air sealing. And sometimes you can do air sealing on your own if you if you know where there are leaks, like, like for instance this was next to the chimney in our house it's it's very common for there to be huge air leaks next around chimneys. And while you want the blue gases and all of that to go up and out the chimney you don't want a bunch of warm air leaking out of your house alongside it. The orange spray foam is is fire block or fire rated spray foam. But many other air leaks and other locations you can use can spray foam, or cock or other other types of materials that are common at any hardware store to seal up air leaks. If you want to do it yourself or hiring an energy auditor and the big benefit with the energy auditor is that often they'll use the blower door to guide where to seal and so helping to make sure that you're getting the biggest leaks and prioritizing and not wasting dozens of hours of time trying to chase down little tiny leaks and making sure that you're getting the most the most air leakage for for for your effort. And our crawl space, we have a basement under half the house and a crawl space under half. And the crawl space had fieldstone foundation walls. And so we put down a vapor barrier plastic layer to prevent ground moisture from getting into the house, and then spray foam the walls down there to fully seal and insulate the ground walls. I'm not really aware of any other way to seal and insulate a fieldstone foundation wall. I know many of us in the environmental community don't love spray foam. It is a product made from petrochemicals that is getting better. So the newer spray foam formulations have a greenhouse gas equivalent of CO2 versus older formulations that were 1400 times worse in terms of their global warming potential. So it is important to use the the newer HFO type spray foam. And again this is something that you're much better off have it hiring a contractor to do. I will do it yourself kids at Home Depot. And I have heard mixed reviews on those. So anyway, I highly recommend air sealing your home. And then the energy auditor will also use an infrared camera, which can help to identify places where there's insulation that's missing or other heat loss out of the house. And then blow in a whole bunch of insulation in your in your walls and attic. This is this is our attic with cellulose insulation. And it's really important to air seal before you add more insulation, because if there are air leaks, and especially an attic warm air rising in your home and then leaking out and then it compromises the value of the insulation if insulation works by trapping little pockets of air, and, and if there is air passing through it then it compromises that and so you're both losing the heat that is leaking out through the air leak as well as the heat that the insulation should be trapping. So I highly, again highly highly recommend having an energy audit and then air sealing and improving insulation, as much as possible, before transitioning to heat pumps for heating. And also installed window dressers in our windows. This is a great way to improve the efficiency of older windows. Thankfully the previous owners had put double pane windows in everywhere in our house, but the window dressers still make a significant difference. We've seen frost on the inside of our double pane windows on a cold winter morning. And with the window dressers it stays basically room temperature on that interior surface. So it feels a lot warmer in the in the room and helps to prevent both air leakage directly around the window. If it's not sealing properly and traps a layer of air to insulate the window space. And for, for those of you who aren't familiar window dressers is a nonprofit organization based in Rockland, and they have builds all around the state. And community members help to build the inserts, and they require everyone who is getting inserts to volunteer time, helping to build them. So it's a great community experience, as well as an awesome way to improve the efficiency of your system. And because it's all volunteer effort, it's very cost effective. I think it was like 500 bucks for window dressers for all of our windows in the house versus a single replacement window can be close to that by the time you pay a contractor to install it. So some things to think about before, before installing heat pumps or before replacing your heating system. What are your goals for the project. Are you intending it to be your primary heat system in the house, like like Becky are you trying to replace your, your furnace and and eliminate your heating oil system all together, or are you trying to supplement an existing system at which you can either, if you if you have a heat pump in the in the main portion of your house, it can offset maybe 70 or 80% of your, of your heating fuel and then using your other system for some of the peripheral areas, bedrooms and things like that. Or if there's cold rooms in your house. I've seen them installed just to improve comfort and a portion of the house that isn't being adequately heated. And, and then are you trying to reduce costs or improve comfort or, you know, just understanding what the goals are, so that you can convey what your goals for the system are to a contractor it's, it's kind of a different project if you're replacing your primary heat system versus adding, adding something supplemental heat pumps work very differently than most combustion heating appliances. Most combustion systems are designed whether whether that's a boiler or a furnace that most of them are designed to be able to reheat the entire space of the house very quickly. So that if you come in on a cold day and your heat system has been turned down you want to be able to bump up the thermostat and get it 70 degrees in your house within 15 minutes. And heat pumps do not work that way. They're meant to run continuously. So you generally don't want to set the temperature back when you leave or at night, you want to let it just run continuously and it maintains the temperature in the space. So some systems generally have a much lower heating capacity. They're, they're much more of a low and slow versus a hot and fast type of heat. And so they won't reheat your house quickly if you turn the temperature down five degrees it could take a few hours to reheat the space depending on what the outside temperature is. The heat pump also, while they do blow air around and they and they are fairly effective at distribution is more similar to a wood stove in terms of a central point of heating, versus baseboard heat or or ducks that are ducted into every room and providing heat in every, every room in the house. So, depending on what your existing heating system is, you'll, you'll find like you may find it to be very different from, from many of us in Maine that are used to having wood stoves. We understand that it's 500 degrees next to the wood stove and gets progressively colder the further away you are heat pumps do have a good fan unit and blow the heat out. So if you have doors closed for other obstructions, then the, that inhibits the distribution of heat from the from the heat pump unit. And then it's also important to think about what, what kind of backup heat you have during a power outage. And while most furnaces and boilers also have electric components and will also do, you'll lose heat from your boiler or furnace during an outage. So heat pumps, you, you definitely lose your, your source of heat because they're fully electric. And so, having a wood stove or a backup generator, or another source of energy to keep your house warm during power outages, which we all know how common those are in various areas around the state. Very, very simply heat pumps work by moving, moving heat from one area to another. Generally heat always moves from areas that are hot areas that are cold. And so a heat pump uses a refrigerant to be able to reverse that cycle and force the refrigerant to take on heat or release heat. So you don't want it to rather than just having the warm air leaking out of the house over time. And so typically heat pumps system will have an outdoor compressor, as well as an indoor head for distributing the heat inside. One of the systems today can be reversed. And so you can flip it to cooling mode in the summertime and they will cool and dehumidify your house in the summer, which is an incredible added benefit. That was one of the key things that my wife was looking for she grew up in Reno, and is used to the dry heat in in the summertime. And so having the humidity of Maine was not her favorite thing. So adding heat pumps and being able to cool and dehumidify our house in the summer has been an incredible bonus as well. And I could get into a much more technical detail of how heat pumps work, but I didn't think anyone would want that. The key thing here is that you need to have refrigerant lines and electrical that run between the indoor and outdoor unit. They need to be fairly close to each other. Most manufacturers you can have 50 or 60 feet of refrigerant line. The longer that is the more expensive the system is going to be the more complicated the installation. And so typically if you can have them on opposite sides of the same wall, that's, you know, that's going to be the simplest and most efficient installation. In terms of locating the compressor outside. There's some important considerations to keep in mind. In Maine, it should be at least 24 inches high, potentially higher off the ground up in the county where you get more snow. The key is that it's completely out of the snow in the wintertime. If, if it's mounted too low, then it can freeze and just freeze itself shut and stop working. And I've heard of that happening, particularly for heat pumps that were just mounted directly on the ground. The pump does run a defrost cycle in the wintertime. And so it doesn't pull heat from inside but it just reverses the flow of refrigerant for a few minutes to defrost the outdoor, the fan unit outside. And, and then any moisture that's frozen on will melt off. And so it needs to be up off the ground so that can run somewhere. And then my final note on here is you don't want it right next to a walkway because that water will refreeze and can create a slipping hazard. And so you generally don't want it right next to a walkway where the where you'll cause ice problems. I recommend putting the outdoor unit on a gable end, or if you have an asphalt roof with gutters where there's not going to be snow sliding off the roof for or constant water running off the roof. That's fine too. But, you know, it's a it's a fairly sophisticated unit and while they're designed to be outside and all weather. They're really designed to have 12 or 18 inches of snow slide off your roof on top of it. And then it's also recommended for them to be sheltered from the wind. And if, if you're on an island that's open and exposed to the ocean on one side, or if you were, you know, our house is in a giant open field until the wind break we planted two years ago grows up taller. And so, having it be sheltered from the wind will improve the efficiency of the unit in the wintertime. If the fan has to fight a 40 mile an hour wind that's going to that's going to cost efficiency for your system. And so for for our compressor, we actually have a sheltered area under the barn that's open to outside it needs to have full circulation around it for the outside air to exchange heat with. But it's sheltered with a rock wall on one side and a concrete wall on another side, and then it's under the barn so there's no risk of snow or ice sliding down onto it. And so our unit, you can see one of the brackets is hung on the concrete wall there to take down a little bit to have enough space underneath it. But that was the best space in our house, but often they'll just be mounted to the outside of the house they can either be mounted to a concrete foundation wall, or on a ground mounted stand with a concrete precast concrete pad and some metal brackets to get them up off the ground. Generally, they don't recommend mounting them to wooden stud walls, because the vibration from the outdoor unit can carry through inside and can be quite loud inside the house. And so generally we avoid mounting them to wooden stud walls and only to concrete foundations are just mounted on the ground. So some considerations for where to put your indoor unit. The biggest question is where do you want the heat. If there's, if there's a specific area of your house that's cooler that you're trying to add supplemental heat to then that would guide your decision. If you're trying to have more of a whole house heating system, having having a having an indoor unit centrally located, where it has good airflow and distribution throughout the house. This is more. You're, you're much better depending on the size and layout of your house, you're much better off having one to three indoor units, not trying to put one in every single room as a as a heat pump designer, working for revision energy for the last three years. We had a lot of customers that were like, oh we want one in every bedroom and we want one in the kitchen and we want one in the dining room. And no, you don't. You want them to be able to distribute the heat and blow air around, you know, and generally you don't want, you wouldn't want to mount one in a room that's smaller than about 10 by 10 or 12 by 12. A smaller bedroom is going to be too small. So they, they can have trouble maintaining the temperature if the space is too small. I've seen them put in hallways where where the owner thought that the heat would rise like it like facing into the stairwell, and it kind of just short circuits and it's pulling back in the heat. And so it thinks that it's heated the whole space. In reality, it hasn't distributed the heat very well and so the bigger and more open the space is the better off the system will be. And they and they really can distribute heat well in a house. But the key is that your, your exterior has to be well insulated and well sealed. You can't compensate for major air leaks in a room, and particularly with bedroom doors closed. You know, you'll lose a few degrees of temperature by having the bedroom door closed at night. And so you can regulate temperature either by adding a grill into the door to allow more airflow through or leaving doors open. It's pretty well to have a heat pump in a larger hallway upstairs and then it distributes into all the rooms when the doors are open. And anyway, generally it's not recommended to have them in every room. And like in our house are our house is about 80 feet long and 25 feet wide. It's broken up. It's, you know, poorly designed old farmhouse where it seems like they added rooms at different points. And we have three units in our house, a higher capacity unit in the middle of the house in the living room that heats the kitchen and two smaller bedrooms. And then we kind of have a master suite at one end that's pretty isolated otherwise and so that has its own heat pump in it. And then at the far end of the house. We have an incredibly oversized bathroom and entry area that has a heat pump that heats that end of the house to supplement. And if you want it for cooling, if you have a two story house, you're going to want to have one upstairs warm air rises and cool air tends to sink. So if you have a heat pump only downstairs and you're trying to cool the house, it's not going to be very effective for the upstairs area. Generally you want to mount the indoor unit on an exterior wall so that the refrigerant lines can go out through the wall and then and then run on the exterior of the house. This is where it works to, you know, build an interior chase or run them up in a down to the basement or up to the attic in a stairwell or that sort of thing. But usually, again, the more complicated the installation the more expensive the system is going to be. So, if you are trying to find a place to put them, it will cost you more upfront. I didn't realize I can scroll. And so they generally require a space depending on the exact type of indoor unit they generally the typical ones require about 12 inches of height and three feet of width to mount them on the wall. So if you need to be about six inches below the ceiling, most of the units will pull air from the room in from above and then blow it out below. And they can be a little depending on the manufacturer they can be a little bit closer to the ceiling, different manufacturers have slightly different size units. This is, this is kind of a typical one this this is a Mitsubishi heat pump system. Most of the manufacturers are similar sized. And we'll have, you know, some are a little bit wider a little bit taller or that sort of thing. There are other types of indoor units as well. The floor mounted ones that tend to be about two feet wide and 18 or 20 inches tall that that mounts on the floor, more like a monitor heater type of thing. And those can be effective, particularly if you if you don't have space higher on the wall. And for new construction, you can install ceiling cassettes that recess into the ceiling and then blow the air down more, more like modern air conditioning or that sort of thing. Most installers that I know don't like installing those into older homes because you run into all sorts of issues with access and with stud spacing. I've definitely encountered homes. I don't think I've ever been in an older house where the studs were actually spaced evenly 16 inches or 24 inches there. There's always some variation with that. And if you need a certain amount of space and you're an inch or two shy. You just cut a giant hole in your ceiling that now needs to be patched up. And so most installers don't like to install them in the ceilings of older homes but for new construction that's an option. As you can see, our cat loves it. We put a little cat stand, a little climbing tree for him. And in the winter in the morning he'll be sitting in front of it with the heat just blowing in his face. And generally the heat coming out of them is around 100 to 110 degrees is what I've observed. And if there is a little bit depending on the capacity of the unit and how much heat is being called for, but it's not a forced hot air coming off of a furnace that can be much warmer than that in some circumstances. It's a pretty comfortable heat. I don't know I get questions about that sometimes. And then the fan in the indoor unit has variable speeds as well so depending on the needs, the fan will you can set it to auto and it'll pick up as needed to distribute the heat more or it'll slow down. The lower fan speeds they're very quiet. And there can be a little bit more noise. I mean just like turning up a window fan or that sort of thing you set it on high and it's going to be louder than if it's on a low speed. You do make a little bit of noise in the in the winter time when they run a defrost cycle. You know, it's reversing the flow of refrigerant and so there's kind of some gurgling or bubbling type noises, usually, as that happens. But I can say that it's much quieter than baseboard heat. If you if you have old baseboards that expand and make pinging sounds and stuff like that. It's much quieter than that. Yeah, I've had a lot of customers ask questions about how loud they are, and it really depends on what your, your frame of reference is. So, efficiency main has some incredible rebates for heat pump systems. And they've actually changed some in the last six months so I won't go into a lot of detail but typically they have a larger rebate for the first indoor unit and a smaller rebate for the second indoor unit and no rebate for any additional units beyond that. And so the, the rebates are you often, I don't know, a quarter or fifth of the total cost of the system. And, and they also provide information for vendors here on the bottom left of this, this particular screen on their website. And the last I heard from Michael Stoddard who's the director of efficiency main, they have more than 500 heat pump vendors in the state that are in their system. And there's a lot of variation, just like anything there's a lot of variation between different contractors. I highly recommend working with a reputable contractor either, you know, talking to friends and finding out who they've worked with. If you're looking for revision energy, I can highly recommend them. But there's a lot of companies around the state, there's, there's some that are better than others. And I would say that often you get what you pay for. If you're spending more, or if someone has a higher offer that usually entails more labor time on site, and it is really important for them to do a triple evacuation of the refrigerant lines. So they pull a vacuum in the line and then pressurize it I think to 500 psi with with nitrogen, and then and then they evacuate the line again and that helps to flush out any air bubbles that may be in in a unit or in the in the lines and make them really clear, so that so that there's just refrigerant in the line. If, if it's not installed properly and there's bubbles of air in the line or that sort of thing it can really cost efficiency in the system, or, or cause, you know, if that air bubble gets to the wrong place within the system, it can stop functioning together. And so the installation is really important, and it's worth doing right because they're in theory if it's done right then it only has to be done once. So anyway, efficiency main does have a whole list of vendors you can see who works in your area, but it's also worth, you know, double checking on on the quality of those vendors. Again, also offers home energy loans. And so if you don't have the funds available to pay outright, they offer loans up to 15 grand at a pretty affordable interest rate, and they've been working to decrease their loan requirements. Sarah, am I allowed to talk about legislation in this call today. Yes, that's fine. Okay. Thanks for asking. I apologize later. I've been working hard on a bill LD 1659 that will create a statewide green bank, or statewide clean energy and sustainability accelerator to help improve financing options for efficiency clean energy and other climate solutions. So with the goal to make loans like this even more widely available, especially to lower interest lower income borrowers who don't have income necessary for for most loan programs, or who don't have credit to be able to qualify for for loans and so it's modeled after the green bank, which has been very successful in that area. And we had a good public hearing a couple weeks ago and it should have a work session on the bill, potentially this week. Yeah, there's some there's some great legislation moving forward and the Sierra Club has been very active in the legislature this year. So anyway, trying to improve the availability of loans for these types of projects. So anyway, I wanted to do a shorter presentation and allow time for questions. So I'm happy to take any, any questions that you might have specific to your house can be a little more complicated but I'll try. Thank you so much David so folks, we're small groups of folks just want to say it if they don't feel like comfortable saying it out loud you can put it in the chat and I can read it for you. And I guess, just until we have some questions, I will go first I have questions but I'll start with just one. I've been looking at a lot at a lot of house houses that, you know, varying ages, but that have forced air heat. And is it possible because the ductwork is all there already to do to swap that out for heat pump. Centralized heat pump. Is there an air source heat pump. No, with a ground source, I installed a ground source heat pump in our house and Reno which exchanges heat with the earth rather than heat with the outside air. And with that actually that's exactly what we did we put in a water to air heat exchanger that that then had a blower and blew into the ductwork. I would say that, for one, most ductwork is not worth reusing. Most of the time the ductwork has a ton of leaks in it and is uninsulated or very poorly insulated. And so in an older home ductwork can lose 25% of the heat that you're putting into your heating system. And then also, air source heat pumps are much less expensive than a ground source heat pump. So I wouldn't recommend putting in a ground source heat pump in almost any circumstance. So typically I would say no it's not worth trying to reuse your ductwork. Either hang on to that existing system as a backup, in case something happens to your heat pumps, or remove that ductwork and sell it to a scrap yard. Thank you. And Sue I saw you come off mute did you have something. Yeah, I did actually so. One of the trickiest things in an old house I think is trying to find a place to mount a heat pump that doesn't have a window in it or, you know it's just it's not easy to do and so I'm wondering about kind of innovative ways like has anyone installed them down low on a wall or has anyone stole installed them perpendicularly in a in a narrow space or you know just can you talk about sort of maybe some innovative ways to fit one in because as I look around my house, there's almost no place to actually put it mount literally mount a heat pump. Yeah. No, that's something that we run into quite a lot. The floor mounted units are a different shape they're usually about 18 or 20 inches high and two feet wide and so those can go low on the wall at the floor level or six inches above the floor. Usually they don't recommend installing the, the, the regular wall mounted units lower down, because they, the, the fan only comes up to horizontal and so it has pretty poor air distribution. So if it's mounted lower on the wall, the floor mounted units actually flow in the other direction so they pull in at the bottom and then blow out through the top of it to kind of arc it up and across the room. And I know that Mitsubishi offers floor mounted units and I think that probably to and I can do to but I can't say for sure. The major manufacturers have that as an option usually they're a little bit more expensive, but versus having no place to put it. And then people do get creative if you look over Becky's shoulder. You'll see that hers is mounted in a corner and has some custom cabinetry around it to pull it out from the wall and angle it across the room. So, so there are options for for getting, getting more creative with it in terms of locating it somewhere that isn't directly between two windows. I'm trying to think what else I've seen. I've seen some cases where the windows were far enough apart but the window trim was too close. And so we just added a board across behind it to pop it out so they can just kind of the the unit can go across over the window trim on either window on either side to just try to you know try to create a little bit of extra space clearly you don't want it to stick into the window itself, but you know, depending on your window trim, losing an inch or two of that being visible can be can be an option. Right, are the floor mounted units as effective as the high up ones. Yeah, they're they're pretty similar in terms of their capacity and and the efficiency of them usually that the efficient the primarily the efficiency of a heat pump is due to the compressor outside. And the actual unit inside has a much lower impact on the system efficiency. Go ahead, David. Yeah, yeah, my David my son's home is got a baseboard hot water heating. So, could that system be matched to a heat pump through a heat exchanger or something to at least provide supplemental. I know that there are a couple companies that have been working on air to water heat exchangers to be able to use an air source heat pump and go into either a radiant floor for a radiator system. Often those systems require a higher water temperature depending on the type of the distribution some of those require water temperature of 160 or 180 degrees which you wouldn't be able to achieve with the heat pump. And so usually I see that I've seen that with radiant flooring. But I haven't, I haven't worked on any of those systems directly because we, the company that I was working for we piloted a couple projects and found that they were a newer. They were a newer company and that we had some supply chain issues and when we had to send our crew to a site three or four different times to, you know, install pieces that arrived late. So it wasn't cost effective for us, and things might have improved since then or there might be other options, but really like there. It's a really straightforward design and and it's having having the indoor unit that's designed to run refrigerant outdoor unit that's matched is really the most effective way to do it just having a mini split and then leaving the existing system alone as a backup heating system. It's really hard to retrofit into old equipment and then you're dealing with, you know, questionable. There's a lot of questions with the distribution system and the quality of it and and that sort of thing so having just a standalone heat pump system is usually best. Any other questions? Jim, go ahead. This gym. Yep. This gym. All right, getting right back to the beginning. I quickly see that we, we were going to go heat pump. We have a lot of work to do on our house to seal it up. The house has an old fieldstone foundation, which I know is leaky 90% sure that none of the walls have any vapor barrier in them. The ceiling in the second floor, the floor of the attic doesn't have a vapor barrier. We've got up there fiberglass bats sort of thrown around. I was just wondering what the, what's the best approach to get going with sealing up the house. Oh, and the picture of the, of the, of the, I guess it was your basement with the spray foam on the walls and the vapor barrier on the floor. Can you walk on that vapor barrier? Yeah, you can. I mean, it's not intended to be walked on constantly. But you know, for the occasional use going down in the basement or the crawl space, yeah, you can walk on it or crawl around on it or that sort of thing. So again, I recommend efficiency main has a whole list of vendors on their website. You can see what companies work in your area. You may have a ton of efficiency vendors as well as heat pumps. You can select the type of project that you're trying to do heat pumps versus efficiency or that sort of thing. And you said you're in Bristol. Yes. I know that evergreen home performance is based in Rockland, and I'm pretty sure they do a lot of work down in that area. So evergreen home performance did the vapor barrier and spray foam in our crawl space. And so I can recommend them. But there's a there's a bunch of great companies around the state. And you may find that some of them have longer lead times and others. So in terms of getting it done before it's cold again. And this is a good time to get started on it because you have a few months to line up the contractor and get the work done before, you know, we're swinging back in a winter time. But yeah, the efficiency main website has a has a link to find a vendor, and their website is just efficiency main.com. They they're the best source and that efficiency main also has incredible rebates for air sealing and insulation and that sort of stuff. So I think it's $1,000 rebate for your attic $1,000 rebate for your walls $1,000 rebate for your basement or crawl space. And then I think there might be a $500 rebate for doing the energy audit and initial air sealing. So the the rebates certainly help and they can, they can, in addition to providing rebates they can also help direct you to a contractor. Thank you. Yeah, you're welcome, Becky. I just want to mention that I my basement was done by evergreen years ago and I don't have a plastic floor I have a rubber floor, because I use that space more so I walk on it's kind of got a honeycomb thing over top under beneath the the rubber on the floor so and then there are little trenches that we dug and put gravel in so that water can flow through and down to the sump well and then it goes out so you know it it works that way but I'll tell you I'd never imagined the benefit of sealing the basement and particularly the sill. I'd done energy efficiency work for years and years and years and I had always recommended installation in the attic and, but he rises and it sucks in cold along the floor and that is, you know, just it's an astounding impact if you do did nothing else it would make a big difference. So anyway, and I just want to introduce those two gyms to each other who live about a quarter of a mile from each other and are both friends of mine. John, do you have a question. Yeah, I'm looking at introducing people the idea of getting heat pumps in. I'm looking to see if you have sort of a rule of thumb, assuming that the space is well insulated. There's decent interior circulation. Is there approximate number of square feet that a single unit can cover so that someone can look at okay I'm going to need two pumps for my 2000 foot house, etc. Not exactly. There are some rules of thumb in terms of designing the capacity of the system. And so different heat pumps have different size capacity in terms of the heat output. So our larger unit is 15,000 BTUs an hour and our smaller units are 6000 BTUs an hour. And I know that there are other manufacturers there's other units that have 24 and I think 30,000 BTU an hour unit. So clearly the, the capacity of the heat pump system makes a big difference in terms of, you know how much heat you can get out of it. The number of units in the house is usually more determined by the lay out the floor layout of the house. You know, if there's two floors in the house typically having one upstairs and one downstairs if you want to be able to use it for cooling in the summertime. And so yeah, I found that it's usually more driven by the floor layout and an old farmhouse that's chopped up into 10 different rooms. You might find that you need more units just to be able to distribute the heat where you want it versus a newer house that you know has an open floor plan. You might be able to heat the entire house with one unit. Thanks. Yeah, you're welcome. Any other questions. I have an additional question that has been touched on servicing how frequently do you get them serviced that sort of thing. The information on that. Yeah, so the indoor units have filter that you're supposed to clean monthly or I find that even with our cat like I only need to clean it about twice a year. It's like you can look at it and see wow there's nothing on it or it's toted in dust. Cleaning the actual coils in the unit. They recommend doing that annually at least to start. And what I found is, again, our house is fairly clean. We like we just have one cat and although he's been shedding a lot lately. If, if there's if your filter is getting clogged up, it's probably pulling stuff through into the into the coils, and that dramatically reduces the efficiency of the system if it's trying to heat through a bunch of dust and fur and stuff like that. And so having the coils clean once a year. When the technician came out to do ours he was like you can have this done every three years like you're you're in good shape. And generally when they clean the coils on the indoor unit they'll clean the coils on the outdoor unit as well. And so yeah every every one to three years, and some manufacturers offer sorry some contractors some installers offer a maintenance plan where you know when you purchase the unit your you can also pay for 10 years of service or that sort of thing. But yeah cleaning cleaning the filters yourself and most of them you can wash off in the kitchen sink. Pretty, pretty simple and pop them back into place. Yeah, if you're, if you have a bunch of usually it's animal fur that's the worst, but, or if you're doing construction projects like turn the heat pump off or put a bag over it if you're doing drywalling or that sort of thing in your house. You definitely don't want to suck drywall dust or, you know those types of construction contamination into the unit or where you'll want to make sure to have it cleaned shortly after. It will similarly affect the efficiency of the coils and the distribution of heat. We did a program on heat pumps a while ago and one of the concerns people expressed was how cold it can get before their heat flows can be useless. Do you have any opinion on that. We've heated entirely with our heat pumps for the last three winters, and I live, I live in moral about 10 miles from Belfast a little bit inland from you john. But I mean I've seen temperatures minus 12 minus 13 outside and our heat pumps were still keeping at 6465 degrees inside and our usual set point is around 68 or 70 so usually what happens is you start to lose capacity. Particularly, you know, if, if your house isn't as well insulated as it could be, you know, that's it can't keep up with the amount of heat being lost by the house. So usually what you'll see is a decline in temperature inside versus, like by a few degrees versus having no heat at all. I think that there's a certain point where the heat pump will shut off. I think with this, the Mitsubishi units that we have it's minus 18 or minus 20. And there are different manufacturers that have different compressors with with different capacities and so generally that's a rating that the, that's based on the capacity of the compressor outside. I think there are systems that are rated for minus 30. But I couldn't tell you which manufacturers have, you know, the best compressors for really cold temperatures like up in, up in the county, you want something, you probably want something with a greater capacity. Thanks. So, or the alternative is, you know, if you have propane or oil system to let that come on and, you know, it's how many days a year is it that cold out, you know, maybe in Fort Kent and Fort Kent is probably more than in Belfast. You know, but if you if you need to burn a couple gallons of heating oil to get through that really cold spell, you know, as well worthwhile if you're saving 500 or 800 gallons through the rest of the winter by using the heat pump system. So we, we generally recommend keeping the existing heating system, even if you're not going to be depending on it. But clearly there's homes like Becky's that work well without that. I also helped my brother lives down in top some and he removed their oil boiler entirely and they have one heat pump upstairs and one heat pump downstairs. And I was built in the 1980s that they, I helped them re-insulate the attic and they also they put new siding on and added an inch of rigid foam under the siding for, you know, continuous insulation in the walls. But, you know, yeah, heat pumps can can be effective straight through the winter and in most of Maine I think if you get up further north in Maine or in the mountains, you'd want to have something to supplement just because it gets colder in those areas but for the you know in most of the state they can be 100% of our heating, as long as we keep the power on. Maybe we'll make we have so many heat pumps will actually start having a cold winter. Again, which would be nice. So I so I my heat pump is in the, this is the kitchen, which heats. I have to stairwell so I don't have anything upstairs. And it, you know, so it does the whole main part of the house and then I have a wood stove in the attached barn edition that heats my living room and bedrooms upstairs from there but I don't have to heat that so I've I've been very lucky and I'm in a pretty windy site so yeah it I'm doing fine. And I really appreciate the, the, the maintenance that I've gotten out of revision. And this is one of the things that I've heard from, at least one or two of the other contractors want to make sure that they're willing to come out and, or for me it's coming out onto a ferry to, you know, to get out here to maintenance so being sure they'll make it is, you know, an interesting challenge for some people. And I know it's one o'clock now any other questions. All right. Seeing none. Thank you David for so much for coming and for giving us your insight on the heat pumps. As I mentioned at the beginning. This is our last community conversation until the fall. But we have some already lined up so keep an eye on our website and if you get a newsletter will be sharing information on those. But thank you, everyone.