·
49 minute read
When Ross Trethewey calls heat pumps "magic boxes," he's not being hyperbolic. As the founder of TE2 Engineering and building engineer for PBS's This Old House, Ross has spent 15 years designing some of the most sophisticated HVAC systems in North America — from 7,000-square-foot custom homes to 45,000-square-foot compounds.
But here's what makes Ross's perspective invaluable: he's not just designing systems for unlimited budgets. He's proving what's possible when you get the fundamentals right.
The Foundation: Design Before Installation, Every Time
"You could have the best installed system on the planet, but if it's designed wrong or applied wrong, you have zero chance of success," Ross emphasizes. It's a principle that cuts across every project size and budget.
Ross's approach starts with proper Manual J, S, and D calculations — something he believes every HVAC contractor should master, not just mechanical engineers. "For any HVAC contractor, they should be well equipped to be able to provide that level of information and run those calculations."
Math isn't optional. Even for Ross's high-end projects that might take six months to design in full 3D CAD, the foundation is still a solid half-day to day-and-a-half of proper load calculations and system selection.
Heat Pumps: Magic That Actually Works
Ross's enthusiasm for heat pumps stems from their fundamental efficiency advantage. "I could put a dollar of energy into this thing and I can get $3 worth or $4 worth of heat energy out," he explains. "It almost feels like it defies the laws of physics."
But he's quick to add the crucial caveat that efficiency and cost aren't always the same thing. For homes with natural gas, you need to do your homework on the economics. For homes with propane, oil, or electric resistance heat? Heat pumps are almost always a win.
The real magic happens when you pair heat pumps with solar. Ross designs net-zero homes where the solar production offsets the heat pump energy consumption over the course of a year. "Why wouldn't we be doing that?" he asks. "It's a perfect synergistic relationship."
The Future is Air-to-Water
Of all heat pump technologies, Ross is betting big on air-to-water systems. "If I had to pick a horse in the race, 15 years from now, 20 years from now, I think it will be air-to-water."
His reasoning is compelling:
Future-proofing against refrigerant changes. As the industry moves from R-410A to R-32, 454B, and eventually to A3l refrigerants, air-to-water systems keep the refrigerant contained in the outdoor unit. "I can take the box that's outside my house, rip it off, put a new box in, reconnect the water pipes and off we go."
Incredible flexibility for distribution. With water as the heat transfer medium, you can use radiant floors, baseboard, high-wall units, or ducted air handlers. "Find me a heat pump that can deliver 500 BTUs on design day," Ross challenges. "You can't, but we can put in a hydronic system that can absolutely deliver 500 BTUs."
Superior dehumidification. In hot, humid climates, air-to-water systems can run 40-degree chilled water through coils at low air flows, wringing moisture out of the air while maintaining comfortable temperatures.
Built-in thermal storage. Air-to-water systems can store energy in buffer tanks, allowing homeowners to run heat pumps at night when electricity is cheap and use stored thermal energy during expensive peak hours.
Tackling Old Home Retrofits
Ross's approach to retrofitting older homes starts with a simple principle: reduce the building load first. For an 1850s Cambridge home with 15 ACH50 (extremely leaky), the first priority is air sealing and insulation where possible.
When full electrification isn't feasible due to poor building envelopes or electrical service limitations, Ross advocates for strategic hybrid systems. Rather than oversizing everything to meet heating loads, he'll design a smaller heat pump to handle cooling and shoulder season heating, with the existing boiler providing backup heat below 35-40°F.
"I would much prefer to go dual fuel, go with a two-ton heat pump and put a hot water coil in off of that boiler," he explains. This approach gives you 80-90% of the heat pump benefits while avoiding the exponential costs of multiple outdoor units and oversized ductwork.
What Separates the Top 5%
Ross works exclusively with what he calls "A-level contractors" — and the pattern is clear. The best HVAC contractors are family-owned businesses with multi-generational thinking, not private equity-owned companies focused on short-term returns.
These top-tier contractors:
- Invest heavily in training. Ross regularly gets out-of-office messages saying entire crews are at air-to-water heat pump training.
- Take a collaborative approach. They review designs, ask questions, and suggest improvements rather than just executing specs.
- Think long-term. They understand that cutting corners today damages their reputation for decades.
- Provide proper tools and support for their technicians.
"There's almost a sense of pride there," Ross notes. "I don't want to let my grandfather down. I don't want to let my father down."
The Path Forward
For HVAC contractors looking to differentiate themselves and prepare for the industry's electric future, Ross's advice is straightforward: start with manufacturer training on air-to-water systems. The technology is here today, and manufacturers are generating leads for contractors who can install these systems.
"All roads lead to this type of technology," Ross predicts. "It is a little bit at the end of the rainbow, but it is obtainable."
The fundamentals remain the same regardless of system type: proper design through Manual J, S, and D calculations, quality installation, and a long-term view of customer success. Get those right, and you're positioned to succeed whether you're working on a 45,000-square-foot compound or a modest retrofit.
Episode Timestamps:
[00:00] - Why heat pumps are “magic boxes”
[03:56] - Ross’s origin story: 5th-gen plumber to mechanical engineer to TV educator
[13:22] - Benefits of heat pumps vs. conventional systems
[18:48] - Challenges of going 100% heat pump in older homes (no fossil fuel backup)
[27:13] - Designing high-end heat pump systems when budget isn’t an issue
[32:06] - What’s coming with air-to-water heat pumps to get higher temperature output
[42:46] - Heat recovery and system optimization
[54:11] - What separates top 5% HVAC contractors from the rest
[59:49] - Ross’s top recommended resources and final advice to HVAC pros
Connect with Ross Trethewey:
Transcript
[00:00:00] Ross Trethewey: Who wouldn't love a heat pump? It's a magic box, typically, that sits outside, that heats your building, cools your building, may even provide some domestic hot water in the traditional sense. That is magic. Still, I'm amazed how they extract heat when it's -13 degrees outside and how they cool when it's 120 degrees outside. It's an unbelievable piece of technology. I think that people underestimate underutilized and almost don't believe it. Yeah. It's magic. Yeah, I love them.
[00:00:29] Ed Smith: Hey, everyone. Before we dive into today's episode, I want to take a minute to ask for your help with something really important. And please. Mission. We are hiring a senior iOS engineer, and I suspect the person we're looking for is somewhere in this collective network. Maybe it's you. Maybe it's someone you know. Maybe it's someone who knows someone you know. Here's what makes this role special. Amply mission is to help get more heat pump installed, and more importantly, to make sure those heat pumps are perfectly sized for each home. We're not just building software, we're helping solve. One of the biggest residential decarbonization challenges we have amply is an awesome place to be an engineer. Why? First off, I'm literally the only non engineer at the company. It is an engineering driven culture where everyone gets deep into technical details because that's what it takes to solve these complex problems. Second, we're super early stage, which means any engineer who joins us is not just writing code. They're wearing a product management hat. They're getting to know our customers. They're walking in our customer's shoes and then figuring out how best to solve their problems. There is zero bureaucracy here. We don't have a bunch of leadership and hierarchy and standing meetings. We are extremely flat as an organization. We make decisions fast. That can be super exciting if you thrive in that kind of environment. The other thing that's really exciting right now is that our product is catching on with customers. We're getting fantastic feedback, but what we keep hearing is we want more. We want this feature, fix this. Our customers are clear about what they need next, and we know exactly what we want to build. So you'd be joining at this perfect inflection point where product market fit is happening, and there's this clear roadmap ahead of super important stuff to build and rollout.
[00:02:11] Ed Smith: We're looking specifically for an iOS engineer with Swift and SwiftUI experience, someone who's built apps from concept to launch, and who loves creating beautiful, intuitive experiences. If you're listening, here's how you can help us. First, the job spec is the very first link in our show notes. Check it out. Share it. Second, if you're on LinkedIn, the job spec is my pinned post. It's also Eric's. Feel free to repost it or share it on Instagram, Facebook, whatever, wherever your network hangs out. But here's what I'd really like to ask you. If you're willing, take 20s right now to rack your brain. Think about your network. Not just the obvious connections, but the ones once or twice removed. Your cousin's boyfriend who's an iOS developer. Your neighbor's kid who graduated a couple of years ago with a CSS degree and seems whip smart. I am confident that the right person is in our collective network, and finding great people through referrals is our favorite way to hire. If someone comes to mind, send them the link. If you know someone who might know someone, share it with them too. This role is all about helping heat pump pros do their best work, which means more homes get electrified the right way, more happy homeowners. And honestly, that's how we all win. All right, that's it. Sorry that took so much time, but this is super important to us. Thanks for taking the time to think about it. Now let's get on to today's episode. Hi and welcome to the Heat Pump podcast. I'm Ed Smith.
[00:03:40] Eric Fitz: I'm Eric Fitz. We are co-founders of Amply Energy.
[00:03:44] Ed Smith: Today we've got Ross Trethewey. Ross is the founder and principal engineer at TE2 engineering. And he's also the building engineer for This Old House on PBS. Ross, thanks for joining us.
[00:03:56] Ross Trethewey: Thanks for having me, guys. Excited to talk to you. I saw you at the symposium. Nice to see you. We'll talk some more about heat pumps and all this good stuff.
[00:04:03] Ed Smith: Okay, so lots of folks know you, Ross. From you being on the scene, you making presentations and whatnot. I think places like the symposium, social media, This old House. But for those who don't know you give us a quick sense of T two. So they have a sense of like the work that you do. So who are your customers and how do you help them?
[00:04:22] Ross Trethewey: So yeah. TE2 engineering is the company I started back in 2010, as we've been doing about 15 years now, and our kind of main part of our business is providing consulting engineering services for primarily mechanical systems, but also electrical, plumbing and fire protection. So we do MFP, and our bread and butter project is a high end custom residential project. So this would be a single family dwelling that might be the size of a commercial building, so to speak, that has an architect and has a lot of different players. The stakes are pretty high, but the reason that we're involved and we like those projects is because we've got the budgets to be able to do some creative stuff, and we can basically try to provide the goals and expectations that the client is looking for. And we get these weird requests sometimes from clients. And so we're able to meet them with what their goals are, what their expectations are, and provide a mechanical plan or electrical plumbing fire protection plan that meets the needs of that building and what they're looking for. And a lot of times it takes us into geothermal ground source, heat pump design. It takes us into air to water, heat pump design and solar and net zero buildings. And we get into these kind of creative solutions and strategies. So it's exciting to work on those projects where we're not trying to fight every single dollar. And it's super budget conscious where these projects have a little bit of flexibility in terms of how they're conditioned, and we have the budgets to do those kind of creative systems. So that's where we want to play. That's where the majority of our business is. We also do more just traditional manual J, mainly manual designs for more traditional residential projects. And we also do some commercial projects. We do some multifamily development. We're just we're doing an event center right now. So we do commercial buildings as well. But those that's generally about 20 to 30% of our overall business.
[00:06:17] Ed Smith: Very cool. When you say these very large homes, what square footage are we talking about? That's typical. Or where it almost looks like a commercial site.
[00:06:27] Ross Trethewey: You want the real answer or do you want. No, it's.
[00:06:31] Ed Smith: I want both. Give me the real and the lie.
[00:06:33] Ross Trethewey: No. So these projects are big. So I would say some of the high end residential projects start off at maybe 7 or 8000 square foot homes.
[00:06:41] Ed Smith: Okay.
[00:06:41] Ross Trethewey: Yeah. And the largest one we've worked on is about 45,000ft². Of course, that's over multiple buildings. So it might have a main house, a pool house, a guest house, potentially a cabana, a game room. So some of these are for ultra high net worth individuals that want their compound on Nantucket or whatever. But so we do get pulled into those projects which are obviously high stakes and very interesting. But yeah, so we run that spectrum from call it 7000 all the way up to tens of thousands of square feet of space.
[00:07:15] Ed Smith: So this is great. How does Bob Kraft heat and cool his second home? No, I'm just kidding. That's helpful. I would love to get into some of the, like, creative solutions that you have, because I think there's a lot of interesting stuff there. But Eric, I'll give it to you for the next one.
[00:07:30] Eric Fitz: I'd love to hear more just about you. Tell us about your own personal path. I know you're a recovering mechanical engineer just like me, but how did you get into this and end up where you are today?
[00:07:40] Ross Trethewey: Yeah, I think it starts off on the fifth generation plumber. So my great grandfather came from over from England to Boston in 1902 and started Trethewey Brothers. That was when plumbing was new. Before that, they threw sanitary waste out into the street. So it was a very different time back then. But I think growing up and the basically fifth generation, all my uncles are plumbers. My dad's a plumber. My grandfather's a plumber. All I knew was plumbing. So guess what? Every summer was all about plumbing. Every discussion around the dinner table was about plumbing. So I probably soldered a pipe at whatever, 5 or 6 years old. So I had, I think, a really foundational understanding of plumbing systems from an early age. And so that was the starting point, I think. But from there, basically I was curious about the systems, more or less about the installation and more about why. And I think ultimately the curiosity is what kind of drove me to go into the more engineering path. So I was curious why PVC piping for drainage, why cast iron? Why? And then it evolved into heating and cooling systems. And then. And so my bachelor's degree was in mechanical engineering. My master's degree was in sustainable energy.
[00:08:51] Ross Trethewey: It was in solar. And so I didn't have a crystal ball. But I thought, hey, the future will probably involve some sort of renewable energy. I was full deep dive into solar, geothermal, heat pump design, etc. wind big into that and trying to figure out how these buildings in the future would be electrified, conditioned and powered. I also grew up on a sailboat every summer, and so it was the closest that my dad would say that we could go to going to the moon, where we would do a sailboat race, let's say from Newport, Rhode Island to Bermuda. And so my dad says we were hijacked. My brother and I, the kids were hijacked. We were stayed out of trouble. But we learned a lot of stuff about how buildings survive and how to live within your means in terms of what you have. And so we had a limited amount of water supply. We have a limited amount of electricity. We had solar panels. You have batteries. And so I think and also being able to be self-sufficient, you learn how to service those things and troubleshoot those things on the fly, because you're out in the middle of the Atlantic Ocean, you don't have anybody to call and figure out.
[00:09:53] Ross Trethewey: So I think some of the experience early on set me up for that kind of engineering pathway. And then basically from there worked for a HPC contracting business and HPC engineering business, a manufacturing business went to Europe and studied with them in their R&D plant in Germany, France and Spain. And so was able to get an experience from the European perspective. And at the time they were paying like $0.40 a kilowatt hour. So they were doing stuff that was obviously far superior to what we were doing here in the States, where energy was cheap. And so I got a really good perspective from that, and then obviously started the business in 2010 for my consulting business. And then in 2011 was the first time I was on this house. So that was the start of the TV show, and it was about the first segment I did with solar. So it was a pilot first segment on solar, and they didn't call for, what, five years? So I was like, oh man, I must have done a horrible job. They the phone did not ring after that, but 2016 became a full time cast member.
[00:10:54] Eric Fitz: Got it. And how much of your time? I'm just curious. Split between being part of the cast and doing all the production versus your role at TE2. What does that split look like?
[00:11:05] Ross Trethewey: Yeah, it kind of ebbs and flows when we're doing heavy shoot days. A lot of production meetings, a lot of shoots. Obviously that's going to be heavily going to be focused on the source and assets for us, but the majority of the time is spent at TE2 engineering. So I'd say it probably is maybe 8020 something like that in terms of my time. 80% with TE2. Obviously 20% with the TV side. So it's a good blend. I think of it as like almost like a side gig, like a side hobby where it's, hey, because I love teaching, I love talking about this stuff. And so it allows me to get immersed in the teaching side and out of the kind of office from the engineering, the hardcore engineering side. So I do like kind of the balance with both.
[00:11:44] Ed Smith: That's awesome. We were big fans of your flowchart and decision making around heat pumps. Where in the country are you heating and cooling down and flowing down there? So we have really enjoyed a bunch of the stuff you put out through that, through the show and through the show and a bunch of the sort of teaching stuff that you do. We get the sense that you're super into heat pumps, we get the sense that heat pumps have a special place in your heart, which is one of the reasons we invited you on why it sounds like you have experience with all sorts of stuff. Am I right and if so, why?
[00:12:14] Ross Trethewey: Yeah, you're definitely right. Who wouldn't love a heat pump? It's a magic box, typically, that sits outside, that heats your building, cools your building, may even provide some domestic hot water in the traditional sense. That is magic. It's still. I'm amazed how they extract heat when it's -13 degrees outside, and how they cool when it's 120 degrees outside. It's an unbelievable piece of technology. I think that people underestimate underutilized and almost don't believe it. Yeah, so it's magic. Yeah, I love them. Amen Yeah. But I would also add that you got to properly apply it, properly design it. And there's pros and cons to all the different popups that are out there. Right. And so we don't want to say there's a one size fit type approach for heat pumps because there's air to air water water to air, water to water. Right. There's all different versions of that. And you got to pick the right one and apply it appropriately and design it appropriately and get it controlled and installed. So it's there's a lot of stuff there.
[00:13:09] Eric Fitz: So yeah, we definitely feel the magic part of heat pumps. But from your perspective, what do you think are the main benefits for a homeowner for the occupants in the building by going with the heat pump versus conventional system?
[00:13:22] Ross Trethewey: Yeah. So right off the get go the heat pumps have this amazing efficiency to them. Right? I think people are always amazed by, hey, I could put a dollar of energy into this thing and I can get $3 worth or $4 worth of heat energy out like that. Like, how does that work? How does that pencil it doesn't make any sense whatsoever. And so like the refrigeration process and the heat pumps, that's the magic is the efficiency right. That is unbelievable. And there are very few mechanical systems that you can get more out than what you put into it. And so it almost feels like it defies the laws of physics. And so I think at the high level, okay, you have an amazingly efficient box that can heat and cool at these extreme conditions. And it's variable speed, right. So it can throttle up and down to meet these particle conditions much better than most of the traditional equipment can. It runs on electricity, so I don't need to have a propane or natural gas or oil fossil fuel source for it. It's got all these different options for indoor equipment. Like I can go wall mounts, I can go ducted, I can go. And these are really quiet systems right. And so you've got all of these advantages and all of these pros for heat pump technology compared to what's been available on the market for a long period of time. And so I think this is the next paradigm shift, right. But I also want to caution And that the efficiency and cost are not always the same. So three times more efficient or four times more efficient is fabulous. But if you're paying 3 to 4 times more for electricity, it might be a wash.
[00:14:52] Ross Trethewey: Or potentially we see this with natural gas systems. And so one of the kind of caution items I always say is that if you have a house that's maybe an older house that's naturally gas, it has natural gas and it's heated with that system. The horror stories that we hear sometimes that we don't want to hear is they ripped out the natural gas system. They went to heat pumps and their electric bills went up, and they went up more than what the natural gas cost them their previous winter. And we don't want them to hurt the homeowner's wallet, so to speak. By making this by switching to heat pumps when properly designed and applied, depending on where you are in the country, which has a big gap to it and why with their when you pull that all together, you try to figure out, okay, is the heat pump the right strategy for this house? And if you have propane Fossil fuel oil boilers or something like that, oil furnaces or electric resistance heat. It's pretty much going to be a win against any of those technologies to go to a heat pump. I almost don't even have to do the math out. It's almost always going to win in that situation. And plus it's going to give you some air conditioning and humidification. So that's that. But with natural gas you got to do your homework. And I mentioned this on the ask this house which system is right for you type of question and that you got to do your homework when you compare it to natural gas in the traditional sense, depending on where you are in the country.
[00:16:05] Eric Fitz: Yeah, totally. It's definitely a danger to sell this. The technology sell heat pumps based on financial savings only for those areas. Like you said, if you watch this ratio between dollars per therm and dollars per kilowatt hour, you certainly get parts of the country where your operating costs might go up. But there's all these other benefits of heat pumps like generally, comfort is much better, whether that's reduced sound like you're talking about or because of that variable capacity, you're able to match your load and to your what you're delivering so perfectly that you get this incredible comfort, increased runtimes, better air filtration because the equipment's actually operating. But yeah. So it's all great points about heat pumps.
[00:16:44] Ross Trethewey: Yes. Heat pumps win in almost every sense. You just when you compare it to natural gas. My only caveat is just compare that just to make sure that it's not hurting the wallet. That's the only caveat there. They're fabulous. And then now you take it one step further. You add solar to your roof. And people always ask me, all right, I'm building this new house, Ros. What system should I look at if I really want to futureproof my house, and I want to look at it over the next 30 years, or I want to be able to give this to my kids someday. What should I be doing? Immediately, we're talking about solar panels with some electric heat pump of some kind, because now we can offset the solar production, provides the offset energy that the heat pumps use. And now you can get to net zero, right? You can have that house produce as much energy as it uses over the course of a year. So we're designing houses that literally have no electric bill, no gas bill, no oil bill. No fossil fuel source whatsoever. No risk of back drafting. No risk of carbon monoxide poisoning. Yeah. All that, all the interior quality and other benefits that we haven't talked about yet, but all of that, and they have literally amortized the cost of that over a 30 year or 25 year rolled into the mortgage. And literally they have no extra bill for that. The only thing they may have is a water bill, water sewer bill, if they're connected to municipal water supply. That's it. And so that is where I think I would love to get to across the country and know it's going to take some time to get there, but why wouldn't we be doing that? It's a perfect synergistic relationship to have solar with heat pumps and then the rest is history.
[00:18:10] Ed Smith: Are you mostly doing new construction for residential or retrofits?
[00:18:14] Ross Trethewey: It's about 5050. Oh, okay. 50% of its new construction. About 50% of it is renovation. Typically major renovation like gut renovations. Typically, sometimes deep energy retrofits. But yeah, about 5050. Great.
[00:18:26] Ed Smith: So when you do new construction, you're starting with a blank sheet, and you can do a bunch of this stuff when you're doing a retrofit for a big old home that is, but is less budget sensitive anyway when you're doing one of those. The cost piece aside, what challenges do you encounter in a large home retrofit? When thinking about putting in a heat pump system.
[00:18:48] Ross Trethewey: There's a lot. Anytime I deal with any old house. We just dealt with the project in Cambridge, Massachusetts. It's a it was an 1840, I think 1850 home, very large. First thing was air leakage. The thing had 15 ACH 50. No, it was just leaky, right. Air sealing is not on the list of check boxes for an 1850s home. It's just not. And so it's poorly air sealed and not insulated, but really hardly insulated. So you've got plaster and lath walls. You've got either stucco or brick siding. It's an older home and super leaky. And so the first thing is to make a building comfortable. The first thing I always think about is getting the building load reduced. What can I do to reduce the load of that building? Because if I reduce the load of the building, I permanently provide, regardless of what heating and cooling system I choose for that building, I've forever reduced the load and what that system needs to provide to that building. So we always look in our office, we always say, all right, we can produce more energy or we can consume less. And there's going to be a balance point depending on the project for those. And so we're trying to figure out where that kind of pencils out.
[00:19:57] Ross Trethewey: And so in some cases it would be so cost prohibitive to rip apart the entire building to air seal it, insulate it, wrap it with exterior insulation, lose its character. A lot of these are in historic areas as well. So we can't even do that. That's not even on the discussion table whatsoever, because Historic won't allow it, because it would lose its charm and its look, etc. but the first thing is, what can we do to air seal this building? And what can we do to reduce the heating and cooling loads by insulating air sealing? So that's number one. Sometimes it's a gut renovation from the inside and we have the ability to aero seal or do some sort of air sealing detail from the inside, and we can tackle some insulation from the inside. And so if it's a gut renovation, that's great. And we can go that path without affecting the exterior in a significant way. But then once you get past that, the next part is trying to figure out the heating and cooling strategies. And a lot of these buildings have 100 or 200 amp electrical services. And so they may have a natural gas or oil boiler that's providing the heating and some of its steam heat still. And so we're trying to find a way like all right what's the best strategy here.
[00:21:01] Ross Trethewey: So sometimes where we are sizing the system to provide air conditioning and supplemental heating. But the predominant primary mode of heating is still going to be that fossil fuel source. In some cases, it's some sort of hybrid heat pump technology where we're doing the heat pump itself, say with a furnace or with a hot water cooler coming off a boiler system. So we have the ability to go do fuel that way. A lot of these projects, because of that update needs and they need a new electrical service, or they need some load management software, something that will have some hardware that has relays that will click on click off effectively to make sure you don't exceed that 200 amp electrical service or 100 amp electrical service, depending on the size of the building and what they have. But we have clients that want a fully electrify, and it's a hard conversation to have with them to say, this building's gonna be really challenging to electrify. And when we start to outline some of these costs to go to electrical service upgrades, induction cooktops, heat pump water heaters, heat pumps and fully go down that path, it gets expensive. Yep.
[00:22:00] Eric Fitz: For sure. So always great to improve the envelope beforehand. If you can't before you're thinking about the mechanical systems. Is there anything else when you're let's say you've got enough service, no issue around electrical service, and you're trying to go to 100% heat pump system, you're not going to use the existing steam or whatever system is there. What particular challenges do you have going that direction?
[00:22:26] Ross Trethewey: So you're saying remove the fossil fuel altogether? Remove the natural gas?
[00:22:30] Eric Fitz: Yes. Yeah. If that. If that's the goal of the. Your client.
[00:22:33] Ross Trethewey: Yep. And you're saying fully electrify that building heating and cooling. Yep. And meaning. And we have the ability to update the envelope or no.
[00:22:40] Eric Fitz: Either.
[00:22:40] Ross Trethewey: Way. So if you aren't going to be able to update the envelope we're putting in now new ductwork throughout that entire building, more or less that's going to be insulated, because a lot of times it's going to be traveling in a vented attic and potentially an unconditioned basement. And so we have very we have challenges with duct leakage. We have challenges with duct sealing. We have challenges with duct insulation. So again we that solved we are now putting in these systems with obviously it's going to be a lot of heat pumps, right. To be able to meet the load of that building depending on the size of the building. We might need five heat pumps. We might have five air in there systems. And so it's going to be pretty disruptive to the building. And to get all that ductwork in to get the air handlers in, we're going to have some usually some sort of electric resistance backup, at least to deal with defrost cycling and deal with the kind of what if condition. If the outdoor unit failed for whatever reason, or block with snow or something like that for the what if scenarios. But yeah, for poorly insulated envelope, it just magnifies the ductwork gets bigger, the loads get bigger, the airliners get bigger, the heat pumps get bigger. And I try to avoid that when we can, because we think that's not maybe the best approach to handling that building. I'd rather, for example, if I could handle the load of a building with a two ton unit for size and for the cooling demand with a two tone system, or if I have to fully electrify and go to a five ton system which to do the heating and the cooling, because let's say the heating load is five tons inside the cooling loads two times, just making up some round numbers just for the sake of this argument.
[00:24:09] Ross Trethewey: But the heat pump airflow goes up, the ductwork sizes go up, right. All of that goes up. Everything spatial goes up, amperage goes up, everything goes up. So I would much prefer in that situation to go dual fuel, go with a two ton heat pump and put a hot water coil in off of that boiler plant and reduce to get rid of the steam. Get rid of the steam radiators, get rid of all that stuff, but be able to use that boiler system. Maybe it's a gas condensing boiler and running at 120 degree water temperature. Or at least it condenses and has a high efficiency. It can, but at least that way the you get to me, it's a that would be a more strategic way of getting a heat pump into a building. The two ton unit can handle all of the cooling demands and can handle the marginal heating demands. And then we bring on that hot water coil in this example when we need to when it gets cold out. So maybe when it gets to 40 degrees outside or 35 degrees outside, whatever that balance point comes out, we then kick on that system. But for all the hours between 35 and 95, the heat pump runs it load matches its variable speed. And I put and that also allows me to downsize my ductwork and my registers and my air flows. So I think that's a much more in those older 1840s houses that have really poor envelopes. I think that's the best chance of success for most of those projects.
[00:25:28] Eric Fitz: Yeah, it makes sense. And you still you get 80 or 90% of the benefit by having that heat pump covering most of the hours of the year, both from a comfort standpoint, carbon reduction standpoint, and then you're not getting into all these, like exponential increases in cost and complexity of having to redo the ductwork, having many multiple outdoor units, potentially to try to serve that load. Makes sense.
[00:25:50] Ross Trethewey: Yeah. Yeah. And to think about the electrical and say each heat pump runs I don't know. Let's make up another 40 amps whatever the size of the heat pump is depending on. So now if you have a 200 amp service and you got five of those heat pumps, guess what. Five times 40 is 200. So you've got 200 amps eating up and your five ton heat pumps. In that example you got nothing left over for anything else. And that's your heating system that doesn't account for anything else. Like if you have electric duct heaters or you have refrigerators, induction cooktop. So that's going to almost going to require an electric service upgrade at that point.
[00:26:22] Ed Smith: I'm so biting my tongue because you have almost exactly described my house, which is 1898, in Brookline, and I just want to extract free consulting from you, but I will not. I wish the folks who got rented this had talked to you before they did. That's. We're not even going to publish this. I'm. This is just a ploy. So I could ask you some questions about my house as you were talking about this. I'm from two conflicting thoughts in my head. One is, oh, my God, this is spectacular and every home needs this. And I wish all HVAC installers like could do it. And versus like you are specifically focused on this segment of the market that can afford this sort of thing. What are the hours you're spending on a typical job to design? And I know you do all sorts of stuff, including fire and electric, but if you just focused on the HVAC heat pump side, like what is a what is the design? Take your you and your team in terms of hours.
[00:27:13] Ross Trethewey: Oh man, that's a loaded question. Yeah a lot. There's it depends on what we're doing. Manual J manual D manual S is that kind of the. Because that could be anywhere from a day to maybe a day and a half. Type of to do a proper manual J on a proper building, depending on what kind of information we have, is typically I was going to take at least half a day. It's going to take four hours to do that. If we have some piecemeal plans together, we got to figure out the window heights. We got to figure out inputting. If you want to do a detailed load calc to do it right. From my point of view, it's going to be half a day to do that. Plus, now you're getting into system selection with manual S and then duct design with manual D, right. Soft and other programs that we use make things move a lot faster than they used to. But we're still talking about a day to a day and a half for that level of work, depending on the size of the house. But if we're talking about the full CAD and Revit, we do stuff in Revit as well, which is 3D, BIM. We're designing out every single duct in three dimensions on a building that's going to be coordinated with the structure and the architecture and other MEP items.
[00:28:17] Ross Trethewey: So we do clash detection. We go through we're talking about months, literally talking about months of design time. Sometimes we have a six month design schedule. Sometimes we have an eight month design schedule. So I'd say minimum two months, maximum a year depending on the size and scope of the project. So yeah, it's significant. And then but it requires that if you want to do it right, you got to do the math. You got to do your homework, you got to dial it in. And we're talking about controls center locations. How is the bath fan controlled. How is the ERV controlled? Where are those fan switches live? Where is my humidification sensor? Where's my dehumidification sensors? Where is my. Obviously my air handlers duct systems. Is there a steam shower that requires another additional exhaust system? Is there an AV rack that needs cooling mechanical cooling to be provided? Oh, does that need mechanical cooling year round? Like all of those, there's a movie theater. There's some projector equipment. Okay, that requires some cooling. So there's this. There's these, like basically a domino effect. Like the building program dictates everything. And these programs get pretty sophisticated, pretty fast. The control strategies, the number of systems, the complexity they're ratchets up. And if we're doing everything in three dimensions, it's takes time.
[00:29:33] Ed Smith: I think that's so helpful because like for our who we're trying to reach with this podcast is heat pump entrepreneurs. And the vast majority of folks are not focused on the segment of the market you're focused on. But I think it's so interesting to hear how you handle that segment, because what does it look like if cost is not an issue? And so you paint this like Holy Land, right? What could be. And then the question is, all right, as you get more of a budget constraint, what do you have to do? But I think it's very helpful to hear your process and hear how detail it is, but then also have these stats of budgets not an issue. 8000ft² on average. Yeah. So thank you for that answer. I think it's super useful for folks to hear, no matter who or what type of customer they're serving.
[00:30:12] Ross Trethewey: And I think you could still do a manual J, a manual S, and a manual D on any project of any size at any scale, and it doesn't need to be done by a mechanical engineer like us, an HPC contractor. It should be well equipped to be able to provide that level of information and run those calculations. And so that's a thing that we teach and we talk about, and we want to make sure that every HPC contractor can do that, because that's how you know that the system is sized and designed. And I think a lot of the skilled trades in the HVAC industry, they're so focused on the installation, the rebates and moving on to the next project. In the sales process, they're less focused on the design and application of the systems. And where I always say you could have the best installed system on the planet, but if it's designed wrong or applied wrong, you have zero chance of success on that project. And so you've got to get the design and the application nailed down first, and then you have a fighting chance of getting the installation and success, basically a successful project at the end of the day.
[00:31:18] Ed Smith: That was awesome. You can't have a well-functioning system without both good install and good design like you absolutely need both. So two thumbs up on that one. Ross.
[00:31:25] Ross Trethewey: Yeah, yeah, we got to hit that one over the head as many times as we can.
[00:31:28] Eric Fitz: So I love to switch gears and dive a bit more into your experience specifically with air to water heat pumps. Obviously you're working in Massachusetts. You've got a lot of hydronic systems that are already in place. Air to water heat pumps are a great opportunity to be able to do some really interesting stuff in the house. And you mentioned with heat pumps in general, there's so much flexibility in terms of how you distribute and get that heating or cooling to a space, and with air to water, there's that much, there's that many more options. Can you just talk a bit more about kind of your experience? And also just what are we talking about when we describe when we say an air to water heat pump.
[00:32:06] Ross Trethewey: Yeah. So out of all the heat pumps that's my favorite. If I had to pick one, that if I was to pick a horse in the race to say 15 years, you have a crystal ball 15 years from now, 20 years from now. What do I think? The hip hop technology that will be the most adopted and respected heat pump. I think it will be air to water. I could be way wrong, but that's my kind of crystal ball. And the reason I love air to water and the reason there's so many things. So where do I start? So with air to water, we're typically talking about a monoblock system, which means that the refrigerant is self-contained in the outdoor unit. So just like you would buy a refrigerator for your house that comes hermetically sealed with its own refrigeration process built in. I don't have to hook up gauges. I don't have to get into trim charge. I don't have to get into any of that stuff. Oh, do you do triple evac? Did you braise with nitrogen? Did you get your flare torques done properly? All that goes away. All that goes away. Right. So we have a think of it like a refrigerator that you buy off the shelf. And now I can connect effectively water pipes. They are going to be antifreeze propylene glycol and water in a cold climate, of course. Like here in Massachusetts, they can have a little bit of antifreeze in it with water, and that's what's going to come into the building. And that water is either warm water, let's say 120 to 140 degrees with current technology, or 45 degrees, 40 to 45 degrees if we want chilled water.
[00:33:27] Ross Trethewey: So I can either cool the building with the chilled water, or I can heat the building with hot water. And so this is nothing new like this type of technology has been used commercially for people to call them chillers because they just produce chilled water. And those have been used for, I don't even know, maybe 100 years now at this point. So it's just like residential is usually last frontier for HVAC technology to get to, but it's already been used, so it's nothing new there. The other thing too, is that refrigerants are continuously changing and evolving. And so we used to be our 22 Freon. Then that was mandated by the EPA to be to not good for the environment obviously, because the global warming potential. So they vetoed that. And then it went to R4 ten A. So everybody went into 410 A as the next refrigerant that still has a GDP of 2000. That's still too high. So for China is now being replaced with are 32 and 454 B. And so that's got a GWP around 506 to 675 in that range. So we're getting to better environmentally friendly refrigerants over time. But each refrigerant change in cycle comes with new challenges. Because sometimes we can't use the existing line sets between the indoor unit and outer unit. We can't. There's the new systems are not compatible with the old systems.
[00:34:39] Ross Trethewey: Right. If you change out your air handler, you have to change out the outdoor unit as well. And sometimes you need to flush and clean or even put produce new line sets to connect it to. So the way I look at it is if I have water as my heat transfer medium in this building, I don't care about refrigerant changes in the future. I can take the box that's outside my house. I can rip it off the house and put a new box in, reconnect the water pipes and off we go. So I can literally just continue to change boxes as I need to. The piping inside the building. Guess what? It's plastic. It could be copper if you want it to be copper, but it's plastic. It's PEX or polypropylene. So all these issues with corrosion go away. We don't have formal corrosion with plastic piping. We don't have to worry about galvanic corrosion with plastic piping, PEX piping and polypropylene piping. That's stuff they want to keep out of landfills. The reason it's so good is because it's corrosion resistant to everything just about. So now I have these pipes inside the building. So the arteries sort of speak of the building are in place with a very high quality material from a heating and cooling perspective. And now guess what? If I want to add a wing to my house, if I want to add an addition, I just can cut into that pipe. I can add some new PEX lines off of it, just like I'm adding a new fixture in a bathroom, right? We don't care about oh wait, I gotta run a new line set.
[00:35:58] Ross Trethewey: I got to get it to the trim charge, right? I gotta run a I gotta figure out a new outdoor unit that can do that. I don't care about that at that point because I can just expand and it's basically future proofing built into that project. And so my concern is that we have these are 22 systems that went in. And then when 48 came around, we had to rip out line sets in many cases to put in new line sets with new indoor units, new outdoor units to make them adaptive for ten A, and I don't want to go through that with our 32 and 454 B, and then I don't want to do that again with the new refrigerants that come out after that. Right. So we're at 812 right now. We're going to go to A3. A3 are explosive. There are 290 is like propane and CO2 and all these other things. So that's already been approved in Europe. It's already being used in Europe. So again if I had a crystal ball I think we're going to go there just a matter of time when at R2 90 CO2 or some other similar type of refrigerant is approved, we now need to figure out how to adapt that to the house. And I don't think most people want propane pipes running through their building for refrigerant systems, I don't think and I don't think they're going to do it with CO2 that runs at 1000 psi pressure or higher.
[00:37:07] Ross Trethewey: So I think if I can keep the refrigerant outside in a self-contained box, it alleviates a lot of those concerns. And so that's my rant on air to water heat pumps from just the technology and future proofing. And the one thing I'll also add is that if you use an air to water technology appropriately with storage, you don't have to be affected by time of use rates. Because what I can effectively do is I can run my heat pump at night when electricity is cheap. Store that energy in a storage tank in the basement or wherever in this house, and then I can use it during the day when power is much more expensive so I don't have to run the compressor. I don't have to run the fans, I don't have to run that stuff. And so I can just pull off of that system. And then they have phase change material that can be used to make that be to battery. The thermal battery hold much more energy than just the volume of water that's in it. So like again, future proofs and sets us up for a successful kind of roll out strategy. And I'm just I'm sick of having these trim charges be done. A flare nut be wrong, leak refrigerant, and then the system consumes more electricity than it was supposed to. Then it cuts out on pressure and just something that I've just seen too many times. And I'd rather not do it.
[00:38:17] Eric Fitz: I don't want to call it like a air to water maximalist or optimist. I definitely agree that there's some really exciting things to think about down the road as this technology progresses, that it makes sense as an end state technology for all the reasons you described, and then you didn't even get into the benefits of how you distribute. So you've got the hydraulic system to get the thermal energy into the different spaces, but then you can use radiant baseboard, you can use radiant floor, you could put in a coil and for heating or for cooling in the space it can be a high wall unit. It could be a floor unit. It can you have all of these options for how you actually deliver that thermal energy or extract it from the space. And so it's just incredible flexibility. Can you speak to one of the big challenges right now, which is for most of the products that are out there, they max out at a temperature of around 140°F. Are you seeing products starting to come into the market where we can get to higher temps? Like a typical like my house here in Maine. The hydraulic system was designed for the emitters to be running at 180°F.
[00:39:21] Ross Trethewey: Yeah.
[00:39:22] Eric Fitz: Yeah. Yeah. Yeah. What's the latest on getting that higher temp air to water system?
[00:39:26] Ross Trethewey: Yeah. So the 410 air, two water units top out at about 125 130 degrees, give or take, unless you have EV technology, which is enhanced vapor injection. Then you get up to about 140. The R 32 and 454 B units are going to 140 degrees, and some of them actually push that a little bit higher can get into 145 147 even topping out close to 150. So the new refrigerant definitely gives us a little bit of a boost there and better efficiencies. The CO2 versions and the R 290 versions are going to be running up to about 170 Fahrenheit, some of them even 180 degree Fahrenheit. So the each kind of phase and version of the refrigerants and the new versions of technology continue to push those temperatures higher and higher. So if you get an enhanced vapor injection with one of those refrigerants, yeah, we could get to a point where we could replace your boiler system effectively with a, let's say, a CO2 or R2 90 air to water heat pump connected to those radiators. And you can get to 180 degrees on design day. We can do that. So yeah, a lot of that stuff's available in Europe. We have some other issues here. Like EPA has some limitations on the amount of R2 90. As an example, there's a volume limit inside the heat pump. So we need that to be relaxed. We also need Ashrae to get their regulations and standards and safety thresholds up to current standards on that front. We need the obviously the trainings for the installers and the tools to make sure that they know how to service and properly handle these refrigerants as well. So there's a road there, but I'm hoping that's going to come faster than expected. But yeah, it's going to be at least I would say at least a decade to get there.
[00:41:05] Ed Smith: So are you not are you using air to water systems today or. No, you're just excited about them.
[00:41:11] Ross Trethewey: You are. We start with air almost on every project. We start with air to water. Let me start by saying new construction. We start with air to water. In our discussion, air to water is our starting point. And we usually provide like a good, better, best strategy. And we talk about the pros and cons. We have a whole presentation we give to clients which system is right for you. And we talk about air to water. We talk about geothermal or ground source heat pumps. I call geothermal because everyone refers to geothermal thermal. But yeah, ground pumps. We talk about traditional mini splits and VCF technology, and we talk about your traditional kind of hybrid system, furnace heat pump, or what I call a heat pump. So those are the five systems that we basically explain pros and cons to. But we start with air to water. That's the one we start with. Unfortunately we've been able to do we probably have 50 Maybe north of 50 in terms of air to water projects that are been running. And so hydraulics was what I was taught early on. So I'm definitely a hydraulics guy. John is one of my mentors. I learned a lot from him, learned a lot from Robert Bean, my father. Just a bunch of people in the industry that are all hydraulic heads and we all kind of stick together, but we're trying to get the information out there to say, this stuff is not rocket science. It's we can do it. And so, yeah, air water is here to stay and we're doing it.
[00:42:21] Ed Smith: Do you ever use it in retrofit situations?
[00:42:23] Ross Trethewey: We do. Yeah. So like some of those older houses like we talked about in Boston, let's say, or in Brookline where let's say they have radiators and let's say they have a let's say oil boiler or a gas boiler that's providing the heat through a forced hot water system in that system, in that house. What we'll do is we can do air to water in parallel, running in parallel with the boiler system. So we have basically an outdoor reset curve that's established. And so the air the water basically runs the heat. That building where it's more milder out. And then the boiler kicks on when it gets colder out. And we basically adjust that reset curve so we can shift between the air to water heat pump and the boiler. And so we're doing that today. Yep. Yep. And then new construction. We do it a lot too. And then we pair it up sometimes with radiant floor heating. Like Eric was saying we'll pair it up with trench heaters that these like these flush mounted elements that sit into the floor. So they're super esthetically pleasing and provide that kind of gentle heat over a wall of glass. We've done the air to water with hot water buffer tanks with chilled water buffer tanks.
[00:43:23] Ross Trethewey: We can even do simultaneous heating and cooling. We do it for domestic pre-heat in many cases, because we're going to store that water in a buffer tank. Why not let it do our domestic hot water and our space heating? So we didn't even mention that the air to water can give us domestic hot water as well, which VFS units in many spots can't. The other thing too, that I think is better for the southern markets, which we don't get involved with as much, but I just want to mention is that when you have hot water and chilled water, let's say at 45 degrees and 120 degrees, I can also I don't have a risk of freezing up an evaporator coil. My indoor air handler coil. I don't have to worry about my. Oh, I need 350 if I'm a town or 400 cfm a ton. Otherwise I'm gonna ice up. And no, that all again goes out the window. I could run a system on 200 CFM atomic, 150 cfm a ton. So now when you get these micro loads in a house, let's say you have a new construction home with a bedroom that has a 500 BTU load on design day, or a 1000 BTU design load and design day, find me a heat pump that can deliver 500 BTUs on designed air, 1000 BTUs in Design Day.
[00:44:24] Ross Trethewey: You can't, but we can put in a hydraulic system that can absolutely deliver 500 BTUs. Because I can throttle the flow rate down, I can throttle the temperature down. I've got more leverage to play with on that one. And so then you can go in the southern market where not only do I have a small cooling load, but let's say I have a big moisture load, let's say my latent load is really high. I can put 40 degrees into that chilled water coil, and I can turn my air handler all the way down to its lowest speed, and my sensible heat ratio can go from 0.9 down to 0.4. And now I'm just letting all that dehumidification happen. All that moisture is dripping off that coil. The coil is saturated, soaking wet, draining away, and I'm having very little change in the temperature of the room, but all the moisture is being wrung out off that coil. So now I can do dehumidification, I can do reheat, I can do heating cooling, I can add humidity. It's God, this stuff is awesome.
[00:45:13] Eric Fitz: Totally. Amen. And you can. And I know there are systems folks are working on to do heat recovery as well. So if you're into the summer season, you got air conditioning loads. Instead of just dumping all of that, that energy outside, you can put that into your buffer tank. You can use that for domestic hot water. And so you like, you've got so many knobs and levers that you can pull to just truly optimize this system. And we know that homes are a system, and we want to be thinking about the comfort issues in the home. Maybe we're thinking about our electricity consumption and grid issues with all of these different knobs and levers that we can pull. We can optimize all of these different aspects and really have an amazing outcome.
[00:45:55] Ross Trethewey: Absolutely. Yeah. He Recovery chillers or Heat Recovery Water heat pumps are available commercially. I haven't seen a unit that does that residentially yet. Most of those off is going to be three phase larger tonnages. But I think that will happen. And so you're right. It's like a water to water heat pump that basically can move heat from that where you need cooling and push it into the hot water side or the heating side. And so when you have these larger houses that have simultaneous heating cooling loads, let's say you have AV racks running that need cooling, an elevated machine room that needs cooling, and then you need domestic hot water and space heating in the north side of the house. I can literally move heat effectively from the oven, machine room and the AV racks or the mechanical room that's overheating. I could run that heat, pull it out, strip it out and dump it into the hot water side and send that to the north side of the building, or to heat my domestic hot water. And now my cops go up to seven if I'm doing heat recovery. So I'm no longer in that 3 to 4 limitation. I'm now in the copies of six, seven, seven and a half that range. And so that's fabulous. No more defrost right there. What? A heat pump goes in to defrost. Who cares? Right. I got all that volume of water. I got the buffer tank. It's almost got those protections built in. So yeah, there's a lot of reasons to love it Russ.
[00:47:04] Ed Smith: Like, we've had a few conversations with folks who the air to water heat pumps in the US sound like the end of the rainbow. What's there. But you can never quite get there. Like it's always just a little bit ahead of you. So to hear you've got a bunch out there using both in new construction and retrofits, if someone out there wants is if there's a HVAC entrepreneur who's curious about getting into air to water heat pumps sooner rather than later, and they're operating in space where budgets are constrained. How would they do it? What advice would you have for.
[00:47:33] Ross Trethewey: First thing, you start with training, right? And so any of the manufacturers that sell air to water technology in the United States, most of them that I've seen have a robust training platform. So a lot of those they have, like on site locations with working equipment that people can go, touch, feel, see, get acquainted with. And then they have those designing application sessions and trainings to complement that. I would say for any HPC contractor, reach out to one of the local air to water manufacturers and partner up with them. They also are going to get leads inbound leads to them from homeowners that hear these podcasts and other things they're going to say, hey, I heard about this area, water stuff. It's really cool. Can I get a quote on it? Can you install it? And so it's a way to differentiate yourself if you're an HVAC contractor. And I think that the I think all roads lead to this type of technology. So it is a little bit at the end of the rainbow, but it is obtainable. It is here to stay and there are definitely a bunch of resources now. There's also different webinars. There's a bunch of YouTube areas and locations that have a tremendous amount of information, say, YouTube channels that have a tremendous amount of information.
[00:48:38] Ross Trethewey: John does a lot of training on this. We talk about it in our Billing Science Symposium group that travels around the country doing different two day stuff. We're going to be at Kansas City, Cincinnati and Philadelphia the rest of this year. Yeah, there's a bunch of outlets for people more than ever before. So I think it's a great thing that most HPC countries should consider. Now, I would also want to mention some of the cons, right. There's an upfront cost difference, right. So the technology is very new to the US. So that comes with. They don't have the economies of scale yet. So there's a upfront cost difference in delta there. And especially if a contract has never done it before. He's going to pad his number to make sure that he's covered. So that's another thing to be aware of. If he's never done it because he's venturing into unchartered territory, so to speak. So there's that. There's also because we're talking about chilled water, there's always a risk of condensation and sweating on that pipe. So we got to make sure that the piping and the valves etc.
[00:49:33] Ross Trethewey: and pumps are properly insulated continuously and sealed. So we call it vapor sealed and insulated across its entire length inside the building, because we don't want to have dripping pipe in an attic, sweating, so to speak. We do have antifreeze in the building, so it's going to be a mixture of typically of water and propylene glycol. Propylene glycol is in salad dressing. So it's usually not a huge ordeal. But I just want to make sure that people know that it's not pure water in these systems. In a cold climate, there's going to be some mixture, maybe 20% 30% propylene glycol, 70 to 80% water mixed together. And that glycol does break down over time. So usually every five years or so we need to do a pH test just to make sure that it hasn't turned into glycolic acid. And so that's just one of the maintenance items that needs to be checked. But the rest of it inside the building is no different than any other kind of hydronic and air handler system. It's ductwork with filters that need to be changed and stuff like that. But I just want to make sure we mentioned some of the potential cons that may come up.
[00:50:26] Eric Fitz: Just briefly. I wanted to circle back to something you touched on at the very beginning, your interest in solar in particular, and this beautiful match of having rooftop solar, onsite solar and a heat pump system. Can you just talk about your approach for doing integrated design between those two systems and how you handle that at your firm.
[00:50:45] Ross Trethewey: So we'll always have a load calculation on the building. So we'll have a mano J done. So we'll know the heating and cooling load of the building. And what we'll do is we'll actually simulate that on a building with a certain air to water heat pump or whatever technology. We have to see what the energy use and kilowatt hours are for heating and cooling over the course of a year. So now we know how much energy we need to heat this building. We know how much electrical energy we need to cool this building. So we have that as a starting point. And then we say, hey, Mr. Homeowner, we've modeled it. We expect the building to consume this much for heating, this much for cooling. Would you like us to consider or would you consider doing solar to offset the heating and cooling energy of that building and what that would look like? And most homeowners would say, yes, that would be tremendous. Let's take a look at that. Some homeowners say, no, I don't like the esthetics and I've heard it doesn't work and yada yada. Yeah. So there are some negatives or naysayers out there. But in general, most homeowners and architects are open to it. And then we usually do a couple of different system iterations. The first iteration is offsetting 100% of the heating and cooling energy for that building.
[00:51:45] Ross Trethewey: We look at a second iteration depending on roof orientation, shading, and what the site can accommodate, to see whether we can get to that building to be 75% or 100%, meaning offset. We take into account plug loads, so refrigerators and all that kind of stuff rolled into the model, and simulated lighting is rolled into the model. Domestic hot water is rolled into. So we can get to a point where we could size the solar for 100% of what the expected energy use of that building is going to be. And so depending on what the homeowner wants and what the budget is and what the roof can accommodate, that's usually some sort of solar usually lands on that project. Sometimes we get into the discussion about backup power. So sometimes that leads us to a battery solution with a lithium phosphate type of battery solution to offset the critical loads of the building. Sometimes it is a generator backup generator solution, and sometimes it's both. It's a battery solution with a backup generator depending on if we have a homeowner that has the Armageddon scenario where they want to be fully covered. So it really depends. But that's usually the kind of the outline of where those the kind of the system design process, how it unfolds on the electrical side of.
[00:52:52] Eric Fitz: Things makes sense. So just like any other system, it starts off with a design manual J, S and d I get those, get the loads figured out, get the right equipment, and then you can size the solar system depending on the homeowner's goals or what the performance of the equipment is.
[00:53:06] Ross Trethewey: That's right. In some cases we've also had ground mounted solar where we couldn't do it on the roof of the building because of tree lines, shading, or for visual, esthetic reasons or whatever it may be, or historic, because it's from the south side. Was the front facing part of the building so historic wouldn't even allow us to do it. So when we get into those situations, sometimes we do Granma. So if they have the landscape and let's say in the backyard to do it, that's sometimes what we do. So it's not what I start with, but it is another option. And then whether it's batteries or set up for future batteries, that's another one that we go to. So the infrastructure is in and ready to be accommodated with a battery solution, but the batteries are installed now. They're added at a later point in time. And yeah. So that that to me is a nice way to do it depending on budgets and goals and expectations.
[00:53:49] Ed Smith: Ross, this is an awesome. We'll get into our sort of final area of questioning. So in your role, it's a really interesting segment of the market to play in. So I imagine you just see spectacular contractors. So in your experience, what separates like the top 5% of HVAC installer from the rest of the playing field?
[00:54:11] Ross Trethewey: So you're right that the projects that we get involved with are obviously very complicated, very high stakes type projects. And so usually we are dealing with what I consider to be an A level contractor, both from the general contractor all the way down through HVAC, electrical, plumbing and everybody on that project. And so everybody has a similar interest to get the job done and get it done well. And I think there's also help knowing that there is an engineer on the project that's basically quarterbacking. So to speak. The project and the way that we always come to market is, look, here's our design. Here's the goals and expectations that we have. And but if you see anything that you think we should change, modify that you're concerned with, let's talk about it. And usually we have a meeting on site to say have you reviewed the drawings. Have you reviewed the building? What challenges, what questions do you have. And sometimes an HPC contract electrical plumbing contract. They bring some really good suggestions, and we'll actually modify the design so that we're all bought in to making sure that we have a successful outcome at the end of the day. In some cases, we get involved in a project and there's a suggestion that's made, and that's because they don't know what the goals and expectations were for the get go for that project. So it's just a drop in information. It's just that the communication path was dropped.
[00:55:28] Ross Trethewey: And so once we explain it to them, we designed it this way because of the whatever that may be. Then they go, oh now I get why you're making us do it that much more challenging way. And it's not because we want it to be more challenging. It's because there's a reason that was selected or that was chosen. Whatever system, whatever the constraint or concern was. So we're always trying to figure out how to get the right players on the team and how we all can work together to make sure we have that successful outcome. And I know that's not the norm in the industry, and I, but I do think that's a big part of why the projects that we've been a part of have been successful and why we've grown over the last 15 years of doing this is because of that. People know they trust us. We have a long term view, and the way we look at the house is, hey, if this were our own house with this style of budget, what would we want? If you apply that type of filter, you're going to have a much more successful outcome at the end of the day, especially if you have the goals and expectations from that homeowner. From the get go. So the contractors that we do work with, they are the A level contractors, and they are, I think, the best in the industry because they have also that long term view for their business and for what they want.
[00:56:36] Ross Trethewey: So if most of these companies are family run, they're not private equity owned. They're family run businesses that usually are multi-generational. Some of them are. The grandfather started it or the father started and the sons not running, etc. they have a vested interest to make sure that business succeeds. So they're not going to cut corners. They want to do it right. And so they also most of these companies reinvest into their company in terms of they provide their contractors and their employees with proper tools. They provide them with proper training. We get the Out-of-office message from a contractor saying our staff is at training for the next two days. Unfortunately, if you have an emergency issue, call this person, right? There's one person man in the back of the office, but everyone else is at training learning about air to water heat pump technology, right? And so they provide for one case for their employees. So there's a completely different viewpoint for a family run HVAC business that has a long term view versus a sales driven organization that has a short term view that's potentially owned by some conglomerate 3000 miles away. They're coming at it from completely different angles, and that's why we like to work with those type of A level players, and that's why they rise to the top in the marketplace.
[00:57:49] Ed Smith: I love that answer, and Eric and I are biased in that direction too, for how we run amply. We just raised from friends and family and grants and yeah, yeah, that's the kind of business we want to build personally. So fascinating to hear that. You see that as a differentiator for who you work with as well. Although not surprised if this generation plumber, your dad runs the business. That makes sense, but nice to hear anyway.
[00:58:10] Ross Trethewey: Yeah, there's almost a sense of pride there, right, for that. Like next generation taking over the business like, hey, I don't want to let my grandfather down. I want to let my father down. I want to make sure this thing continues to succeed. In most cases, we find that type of business especially. What's that stat about? Most businesses fail after or don't even make it through to the next generation, isn't it? I remember there's a crazy stat about how many businesses actually succeed to the next gen.
[00:58:31] Ed Smith: Yeah, most businesses don't last past two years, let alone to the next generation. It actually we get all these, we get hit up all the time. Most podcasts don't make it past episode eight. So I think like a lot of things just get left by the wayside. But yeah.
[00:58:45] Ross Trethewey: Yeah. So if you've got a business that's lasted through a generation and is potentially in the second generation or even third generation, you know that they've got a good there's a good system there, they've got some good ethics, they've got some good trainings, they've got some good pride in their business and what they do. And those are the companies we like to work with. And I will say that most of those companies that are aging, that have aging owners, that might not have, let's say, kids that are taking over don't have maybe a proper succession plan. A lot of them are getting inbound requests from private equity conglomerates and other types of businesses that want to purchase their business. And so there's a lot of consolidation happening that I'm seeing across the country in the mechanical, electrical, plumbing, contracting and vendor Industries?
[00:59:30] Eric Fitz: Sure. Yeah. Ross. This has been so fun. I would love to wrap things up with one more question. Any other specific resources, trainings, books that you'd recommend for HVAC contractors that are out there trying to do this stuff the right way? Trying to level up.
[00:59:49] Ross Trethewey: There's a bunch of resources, I think, of the HBC school, Brian, or doing a tremendous job down there has some great content. The AC service tech, Craig is doing a great job with that. Obviously, YouTube is a tremendous resource. You just got to make sure you're in the right channel, but you can go down the YouTube rabbit hole and you can get some unbelievable information nowadays that it's right at your fingertips there. It's like so that, you know, I can't count that out at all. There's obviously the traditional textbooks and stuff like that. Residential energy by John Krieger. There's modern hydraulics by John Signal. There's a bunch of those books that are sitting on a bookshelf right over there that have a tremendous amount of information in them. I know that most people aren't going to spend hundreds of dollars on these textbooks, and there's that. There's BPI certification, there's Nate certification. There is obviously the manufacturer trainings. As I mentioned previously, there's a lot of information that's out there. You just have to want to be curious and you have to have the initiative to go get it.
[01:00:45] Ed Smith: Samantha Ross, thank you so much for joining the Keep On podcast.
[01:00:49] Ross Trethewey: Thanks for having me. This is awesome, guys.
[01:00:51] Eric Fitz: That was fun Ross. Thank you. Thanks for listening to the Heat pump podcast. It is a production of Amply Energy, and just a reminder that the opinions voiced were those of our guests or us, depending on who was talking. If you like what you've heard and haven't subscribed, please subscribe on your favorite podcast platform. We'd love to hear from you, so feel free to reach out! You can reach us once again at hello@amply.energy thanks a lot.
