In this episode of the Heat Pump Podcast, we have the privilege of speaking with Nate Adams, known as the "House Whisperer," about his extensive experience in building science and optimizing HVAC systems for better home comfort. Nate is widely recognized for his work in the electrification of residential heating and cooling, as well as his unique approach to sizing HVAC systems for optimal performance.
Nate's journey into the world of HVAC and building science began with a mechanical upbringing that encouraged observation and problem-solving. Over the years, he has worked on countless projects that involve understanding how HVAC systems operate in real-world settings and how to size them for maximum effectiveness.
A key topic of this episode is the importance of correctly sizing HVAC systems. Many HVAC systems are oversized, which can lead to inefficiencies and uncomfortable living conditions. Nate advocates for a more aggressive approach when it comes to sizing, suggesting that systems should be sized smaller than traditional recommendations, especially when using heat pumps. Smaller systems allow for better runtime and more even, continuous distribution of air, resulting in a more comfortable and energy-efficient home.
Manual J calculations are commonly used to determine the size of HVAC systems, but Nate points out that these calculations often lead to oversized systems. The problem lies in the input data, which is frequently inaccurate or incomplete or “conservative”, with contractors building in their own “factors of safety”. Nate explains that the key to proper system sizing is using accurate data, being aggressive in the sizing process, and using feedback loops to monitor performance and constantly improve your sizing. He also touches on the importance of including energy use and other “check figures” to get a more accurate picture of a home's needs.
For those in the HVAC industry or anyone interested in improving their home's comfort and energy efficiency, Nate's expertise offers practical advice and innovative ideas for the future.
[00:00] - Introduction to Nate Adams
[03:34] - The House Whisperer's Approach
[06:14] - Nate's HVAC Career Path
[12:46] - Electrification and Heat Pumps
[17:57] - The Debate on Heat Pumps and Furnaces
[21:34] - The Misconception of Manual J
[24:53] - Understanding Manual J Calculations
[32:23] - Feedback Loops for Better Comfort
[36:34] - Aggressive Sizing for Comfort
[45:28] - The Challenge of Scaling HVAC Solutions
[57:00] - Closing Thoughts
[00:00:00] Guest: Nate Adams: We are providing the single biggest piece for human comfort, which is we're washing all of the materials in the house with slightly warmed or slightly cooled air. So we're getting all the surfaces in the house to be even. It's called mean radiant temperature. Robert Beam taught this to me years ago. It's dead freaking nuts. Like when you start experiencing it, you're just like, this is amazing. This shouldn't be. But it is. It just is. And so 60% of human comfort is radiant based. We have about 150 or 150,000 temperature sensors in our bodies, mostly in our extremities, hands, face, feet. And if those are happy, we're pretty much comfortable.
[00:00:45] Host: Ed Smith: Hey, everyone. Two quick announcements before we start. First, I'm a bit embarrassed to say this. For the last couple months, we've been trying to hire a new senior iOS engineer. Last episode, we announced that we had hired someone. He was here for three weeks. He was awesome. And then some flashy new venture capital and private equity backed startup with no product and no customers offered him a giant increase over what we were paying him, and he left, which that's just a huge gut punch. We offer very competitive market rate stuff, but, you know, irrational behavior like that, like we just couldn't compete with we're trying to build a business that is just built on solid fundamentals. I say this because so much of this podcast is, frankly, Eric and I learning alongside you all about how to build a great business. So many of the tips that we get are just about business in general, and I know that for many of you, hiring is your single biggest struggle. So I give you that unvarnished update because we feel lucky. So many of our guests have shared so much with us, and so it's the least we can do to do the same. We're asking for help again. If you all had a referral that you didn't send in or you think of anyone else who would come to mind. We'd love those referrals. We're looking for a killer senior iOS engineer. The job spec is in the show notes. Sorry to take your time with this again. Thank you for understanding and thank you for your help.
Okay, on to happier news. The US Heat Pump Summit is coming up. If you like this podcast, you're going to love the US Heat Pump Summit. And frankly, so many of the people who have been on this podcast are going to be at or presenting at the US Heat Pump Summit. Eric and I went last year and it was an awesome event. The caliber of attendees in the caliber of speakers was through the roof. If you're focused on building a big and successful heat pump business that does right by homeowners, you're going to find your people at this event. It's in Worcester, Massachusetts in November. The link is also in the show notes. So go to it and we've got a discount code. So if you go you buy a ticket. Use discount code: AMPLY. A-M-P-L-Y all caps to get a discount on your tickets and we hope to see you there. All right. Thanks so much for listening, on to the episode.
[00:02:22] Host: Ed Smith: Hi and welcome to the Heat Pump podcast. I'm Ed Smith.
[00:02:25] Host: Eric Fitz: And I'm Eric Fitz. We are co-founders of Amply Energy.
[00:02:28] Host: Ed Smith: So today we have the one and only Nate Adams, widely known as the House Whisperer. Nate, welcome back. But this time as a solo guest.
[00:02:35] Guest: Nate Adams: Yeah, I'm not going to be arguing with Alex Meaney this time around, but that was a lot of fun. I'm glad we did that.
[00:02:40] Host: Ed Smith: Yeah, that was an awesome one. Nate, you're a man of passion. Mission, heat pumps electrification. But you're not a traditional HVAC installer. Like, tons of people know you, but tell us a little bit about your backstory, where your interest expertise comes from and what you do day to day.
[00:02:57] Guest: Nate Adams: Okay, I think I'm going to take it back quite a ways. To having an extremely mechanical father. Like. Obnoxiously so. I'm like Michael Jordan's untalented son. When I compare myself to my dad mechanically, like he was just a savant. Like, I've met a lot of mechanical savants at this point in my life, and he still stands out, like, as special because he could look at almost anything. Tell you how it was made. Tell you what the defects were. He was unbelievable. The wildest thing he ever did was he restored in 1911. Mercedes that had a carburetor that no longer existed. So he had carburetors from two other cars of the same year. So that was a 90 horse one. And he had ones from 50 and 70. And he had a pencil drawing from a brochure for this car. By the way, this car was so expensive that the Kaiser of Germany bought the step down. This was a really expensive car when it was new. And so he figured out he'd never made a carburetor before, and he figured out how to make it and machine it. And it turned out there was one in the Indianapolis Motor Speedway Museum. So he and I drove out to Indy.
[00:04:01] Guest: Nate Adams: The mechanic there pulled the thing off. He measured it and photographed it. He was within eight hours of machining after 200 something hours of machining to create this thing, of having it perfect. So that gives you an idea of where I come from. But one of the things that he talked about a lot was, if you're struggling with something, observe it. If you can't figure something out, just keep staring at it and turning it around in your mind. And I think of making a 3D model of things in my mind, and so I can spin it and then I can begin to pull things apart. So I fundamentally that's a feedback loop. And so if you're having trouble understanding something, you want to just study it and look for feedback loops and just try and peel things apart. And so while personally he was incredibly hard to deal with, that part of him was amazing. And he taught that to me. And I've brought that into my work here. So like I look back and I just see that again and again. So like, I get into so many freaking fights, it seems like I'm always in a fight. And fundamentally it's usually.
[00:04:59] Host: Ed Smith: On social media.
[00:04:59] Guest: Nate Adams: Yeah, exactly. Yeah. Not physical fights. It's not really my style. Usually it comes down to I have watched something and watched it operate and tried to study it and understand it, and I've measured things that few people have done and I've come to different conclusions. And then oftentimes I'm arguing with people over. I call it arguments over specification sheets. The specification sheet says that it should do this. And I'm like, I ran it and it did this instead. So therefore I win because I actually watched the thing operate and I understand what it's doing. So that kind of just background is really important. So as far as professionally, things fell apart with my dad I was working for, my dad fell apart, and I went to work for a fiberglass distributor that sold fiberglass insulation to contractors that were building new homes and insulating them. And I started learning building science at that point. The housing crash came. My job disappeared two weeks later, my wife's job disappeared in user experience and graphic design. So I started a retrofit installation company. I was planning on doing it anyway. I was miserable at the company that I was at. It was like office space. I had five bosses, so somebody was always mad at me, but they never talked to each other. And I'm like, look, I'll do whatever you want, but you got to talk amongst each other and decide what you want me to aim at, and I'll do that. So it was just miserable, so I was ready to jump anyway, lost the job.
[00:06:17] Guest: Nate Adams: And in doing the retrofit work, I've always been someone who seeks excellence. And what's the best way that we can do things within reason. So not necessarily perfection, but excellence. There's a difference between the two. And all too often I was hearing back from clients that when I was insulating, things were getting worse. And what it all this together in my head, I also met my old partner, Ted Kid, who fundamentally taught me a house whispering. And I was then miserable doing the insulation contracting because I was working 80 hours a week trying to keep my crew working 30 because the job size was too small. Fundamentally, it was what the challenge was. My average ticket was 2500 bucks. I was turned out to be was I was reducing the heat load of the house. So the equipment was running even less so like particularly it was additions that come to mind. So additions like they almost always get hacked in as far as the ductwork goes. So they just get taken off an existing trunk that already all the airflow was already spoken for. So if the equipment runs even less, that room gets colder still because it already needed more flow than it was getting. And as I started pulling working too hard to try and get to work, because insulation as an idea is usually worth somewhere between 1 and $3000 to most homeowners. That's about it because it's just an idea. They don't really feel the difference when you get into true home performance and solving problems at their root.
[00:07:35] Guest: Nate Adams: All of a sudden, it's not insulation. It's improving comfort. It's improving health. It's making the house a better place to live. And now like ten grand's oftentimes where it starts. And at the time, my average was $28,600 for a job doing a doing house whispering, which doesn't sound like much today, but this is 2018. That was a fortune. So the average ticket for HVAC was like nine grand. So I was doing forex that plus and but in doing all of that, it was really interesting to learn what was possible and would move the needle and what wouldn't and try because that's still that's not like 100 or $200,000 budget or $1 million budget for some of the deep retrofits that you see sometimes, which those are never going to go anywhere. And honestly, even the milder ones I don't think are going anywhere. I think this is we have to deal with things from an HVAC perspective for the most part, for better or for worse, just being pragmatic years later, but something that ended up frustrating me with the house whispering, you'll hear me constantly being frustrated. I'm always like looking for whatever the next thing is. I do something for a few years and I get bored and I want to figure out what the next piece is. And yeah, I can do these really cool projects. And my closing ratio was really high. It was 92% from plan to project and about 70% from lead to project. So pretty good. Above average. But I can only do 10 or 20 of them are bad, but those are unusual.
[00:08:55] Guest: Nate Adams: And remember this was a lot of content marketing on my part. My little website was getting 30,000 hits a month talking about like ventilated attic ventilation and various things like that. It was shell focus because that's where I come from. And but the HVAC is absolutely critical to providing comfortable, healthy homes. And what I wanted to see was anyone who wants one can get a truly comfortable and healthy home. That has really been my thrust for years and years. I've tried multiple paths to get there. None of them have worked, but to a degree like you said, the one and only. I'm well known in the space at this point, but it hasn't been financially successful and it hasn't moved the needle nearly as much as I'd like to see yet. And so that's what I continue to strive for. So as I move out of creating a contractor or business model. Moving back to consumer education because, like most consumers don't know what a good system or a good install is. So I'm going to be working on teaching that. So anyway, it's fiberglass insulation to insulation contractor to house whispering to trying to figure out an HVAC business model. And now back to consumer education. And then I also do Airbnbs with my wife. Very cool themed all electric. So of our five houses now I've pulled gas meters on three of them and I own a crap ton of heat pumps and dehumidifiers. So I think we we own 12 dehumidifiers now. That's a lot for one person.
[00:10:28] Host: Ed Smith: Yeah.
[00:10:29] Guest: Nate Adams: But yeah, it's been an interesting path forward. And then through all of that we were talking about by text like to me, one conclusion that came to was one way air conditioner. So here's a reversing valve for a heat pump, so this turns an air conditioner into a heat pump. Like, why do you want a piece of equipment that can only do half of what it's capable of? And in northern climates, where we only do 4 or 5 months a year of cooling, you're not even getting 50% use out of that piece of equipment. When for 150 bucks in parts, you can get full use out of it. So like that, that had been scratching the back of my mind for a long time. I finally figured out a way to put it that was useful in 2021, and did a Twitter thread on where I thought that the manufacturer should get paid to stop making air conditioners and only make heat pumps moving forward. Because it's such a small change, it's a very low cost thing to do. And that turned into a paper, and then it's actually turned into two Senate bills after that one called the Heater Act, the other called the Cooler Act because air heat pumps are cooler than air conditioners, which cracked me up. Uh. But those are not going to go anywhere in today's political economy. But I'm glad that those at least made that. But back to my thrust of creating comfortable, healthy homes for everyone. That's part of that because the right system will do that for people, or it will help a great deal, because houses can still be too leaky to actually really deal with. But even if you take a really crappy house and you put a good system in it, it'll be decent if not good.
[00:12:02] Host: Ed Smith: Awesome overview. And one thing that you didn't hit on in there? Comfortable, healthy homes for everyone. You seem based on your social media presence, and we're talking to you like electrification is a key aspect of that for you. Like like where and why does the focus on heat pumps tie into this?
[00:12:23] Guest: Nate Adams: That's a good question. It's funny, it goes back to an inconvenient truth. Al Gore convinced me years ago, or yeah, I still don't like him. I think he's hypocritical. I find him highly annoying, but I can still respect some of his thoughts and arguments, even if I have trouble with the rest of them. And one thing that really hit me through that too, was from a conservative perspective. Stewardship really hits me hard. Let's leave things well for the next generation. Let's not use up too much of what we have. So that was a key thing. And then the other thing was just looking at the economics of clean energy. It clean energy now is the cheapest form of energy in human history and it's still getting cheaper. This is where we're going. Cheapest and most available resource wins. Last I checked, pretty much all of us have power lines to our houses, so it's available and it is the cheapest. If we can not have the utilities be stupid, which is out for debate at the moment, but it's just it's where we're going to go and then the experiences of it are better. So a heat pump done well is a far better experience. An induction cooktop is better than gas in almost every way. It's nice to see the flame to see get a visual indicator of what's going on. So that's one thing that yeah, I'll grant you, but induction is nice.
[00:13:49] Guest: Nate Adams: It's easy to clean, it's easy to adjust. It's instantaneous. Like it's a lovely thing. Electric cars. I'm a car guy. And it's funny you start getting these arguments of but it doesn't make noise. But like when it comes to being a car guy, it's usually about speed. There's nothing faster than EVs right now. The Tesla model S plaid with A19 0 to 60, and I don't even remember what the quarter mile is 8 or 9 seconds. It's just obscene that you can get a four door sedan to do things that, like Ferrari and Lambo, can't match. So the electric products are just fundamentally better than the fossil fueled ones in general. So yeah, there's some exceptions and there's some use case challenges. Like I drive a pickup truck, I don't want to drive a pickup truck, but I tow 20,000 miles a year. I got to drive a pickup truck. It just is. And like, electric trucks don't make sense for that use case yet. Just. That's a bad use case for them. So you have to recognize where things are good and where they're not. But yeah, electrification it's I view it as both a green thing economically rather than a green thing environmentally. It's the environmental things is nice, but it's good for outdoor air quality. It's good for indoor air quality. So if we're talking about clean air and clean water, it's really good for that.
[00:15:01] Guest: Nate Adams: There's all of these things where it's like when you step back and you first principles everything of where we're going and what's the best path is it's just electric. Like it's this is not it. It shouldn't have been a political thing. The political stuff drives me bonkers. My my pin tweet for years was be careful politicizing heat pumps and electrification. We have now done that. So we're seeing the results of that everywhere. The UK there's a huge backlash. Germany there's a huge backlash in the US, there's a huge backlash and it's because we're using the wrong freaking language. Don't act like you're selling CrossFit or veganism or a religion or something like that. That is the wrong way to come at the mass market. But that is a lot of how the tactics have been in the last few years. Sadly, as far as like it, decarbonization within our lifetimes, we probably blown that shot at this point, which is a bummer because if the Heater act had gone through with the IRA, that would have changed everything from an air conditioner to a heat pump in 2050 would have been on the table. So like, it wouldn't be a sure thing, but say 1 in 10, but now it's 1 in 1,000,000,000, so I don't see any daylight for getting there by 2050, which is a bummer because it's where we should go. Just from a pragmatic thing.
[00:16:18] Host: Eric Fitz: Ed was jumping in and saying, there's so many different topics you raised there. When thinking about the political, how politics and have come in to kind of influence heat pumps, that it definitely is a complicated issue. When I step back and look at the market. Forget what is happening in politics. The market has spoken, and for the last two years, more heat pumps have been shipped than conventional furnaces. And that trend continues. And I think that's really about when you look at just the product and the solutions that heat pumps can offer, they're just they're more comfortable. They can solve a whole range of problems for homeowners. And so that's promising from my perspective that there is definitely progress. And yeah, there's certainly some questions about if you are thinking about the decarbonization side and the targets that are very important for us to hit. There are definitely some challenges there about hitting certain timelines, but I'm still from talking to various folks and who are installing these systems, talking to homeowners who have them. There's a lot of great stories out there too, and progress is being made, but not as fast as we'd like.
[00:17:32] Guest: Nate Adams: So I'll push back on that because the heat pumps versus furnaces thing. I honestly hate it because it feels like you're looking at two things that are dissimilar. It's what if people who argue with causation and correlation all die like? I think a lot of that bump is because many splits have gotten more popular. But a lot of mini splits are installed and cooling only uses. And that's I wish we could see deeper into the numbers, but I can't afford to buy the numbers from Hardy and see what's actually going on. And the slope of that line is not particularly fast. It's 6%, but I can't see that slope continuing because we're going to be getting to the Midwest, which has cheap gas and one way air conditioners, basic single stage stuff like, I don't think we're going to tear into that. The Midwest is the one to break. That's the hard one to do. Now, there are some contractors out there doing it, and I do love seeing the positive things being said about heat pumps now, because when I first started arguing on HVAC school back in 2017. Holy cow! The pylons that happened. What? You're an idiot. Like that's at least moving. And that's good. But there's still a lot of. No, I don't want one of those because the liberals want the heat pumps. And it's. My background leans politically right a little bit. It was a lot. And I've moved just pretty much dead center at this point. But like we're arguing over reverse gear in a car. I don't want reverse in my car because the liberals want that. Like what? It's a technology. It's reverse gear. Like what? You're going to push your car out of the parking spot every time you have to use a pull through. There's no way around it.
[00:19:06] Guest: Nate Adams: This is dumb. Why are we arguing over this? Like we are the only market in the world that doesn't run basically all heat pumps, because it's such a small change between them. I mean, like, you can still buy a mini split heat pump for 600 bucks. The whole freaking system at Home Depot or Lowe's right now, or like a mr. cool, God forbid. We don't want to dive into that. But anyway, it's like, why is this politicized? It's like reverse gear in a car. It is so dumb. And then when you look at the feedback loop of if you actually watch runtime in a house, which is what I've done for years, I think I shared the presentation to you. I presented to the local Acca group in Cleveland in 2016 about watching a runtime like watch, seeing when things slid, and looking at the output curves of the heat pump and seeing what the actual load was and like, okay, that's really close to what we predicted, or that's too high or that's too low. Whatever it is, when you start looking at what houses actually need, you're going to find that furnaces are stupid. For most homes, it's the wrong piece of equipment. It's like needing to drive a trim nail and getting the sledgehammer. It's the wrong tool. So like, why is this? Just go freaking measure. Just go watch. And like, when everybody who does comes back up. Yeah, I see what you're seeing. Is it every house? No. Know if it's a leaky house? Yeah, you're going to need more. But then you keep seeing a load calc. So we'll come around to manual J. Now, like, I get given a manual J and I'm like, dang it, that's at least double what reality is.
[00:20:41] Host: Ed Smith: Good this way to bring it around. I was about to do that so we could go down preaching to the choir on this podcast, at least on on the value of people so that we could come into some of these interesting political topics in a second. Let's go into this manual J thing a bit. So let me just teed up. There's been a lot of stuff on social media lately about manual J and without naming names, my interpretation of a bunch of it was I've seen x number of manual JS. It didn't seem like a big number three five, and they were way too big. And I've got a rule of thumb methodology that I like and it seems better. We should throw out manual J which was then sparked like a flurry of back and forth. And Nate, one of the reasons we love you is like you do just you watch stuff, you practice stuff, you share your experience. And it's one of the reasons we love having our software in your hands. You tell us what you like and what you don't like, and you don't hold. You don't pull punches and it's always valuable. Whether we agree with it or not, it's always valuable. We'd love your perspective. I'd love to dialog, frankly, about this sort of the manual. Jay questions. Okay, so you were just saying you've seen a bunch of manual JS and they're always too high. Tell us more about that in your read on where we need to go.
[00:22:00] Guest: Nate Adams: Wonderful. So I should start off with amply has shifted my thinking much more than I thought it might have. Thank you for that, because my assumption with seeing things be so wrong so often, like twice as high as. That's where I see things. That's like the median, if you will. So sometimes I see where it's only 50. Yeah. Like 50% or 75% is high. I've seen some where it's two and a half or three times too high. And you're just like, what is going on here? And I've used a bunch of tools. I've used energy gauge, I've used B, I've used treat, I've used basically every manual J tool out there. And they all seem to overstate heat load between 40 and 100% every single one until you tru it to reality. And the best reality is usually energy use. I'd like to know blower door energy use and thermostat set points because sometimes, like I had one client, his gas use was low and I'm like, where do you keep it set out in winter 55 degrees. All of a sudden 800/3 was a ton. Where before it wasn't that much. So like something you need to know what the outliers are. But in general, most people sit between 65 and 75. And so you have an idea of what's going on. Uh, but my goal in local is to be within about a half ton of what actual heat load is, and heat load is almost always higher than cooling load, although it's not as much higher as I thought it would be like. I keep watching houses and finding it might only be 25% more than cooling. It might be the same as cooling. Occasionally it's less than cooling.
[00:23:33] Guest: Nate Adams: One of our houses here, it's less than cooling because we painted it a dark color. It's brown, so when it gets to be 85 degrees, the shell of that house gets hot and that air conditioner runs his brains out for six hours. And that surprised me because I was literally standing in the house watching the equipment operate and feeling like the warm spots in the house. And this is how you learn. You have to inform your intuition constantly, but I want to be within a half ton because any closer than that's dumb, you can't buy equipment less than that. And that usually my biggest decision is going to be a two ton or a three. That's almost always my decision because it's shocking how many houses are there. And the other piece of it is so let's not talk rules of thumbs. Let's talk heuristics gets a better word for it. So I just recently got a manual Jay in the Chicago area. It's for a brand new house. It's ICF Foundation two inch foam board under the slab house R 49 spray foam on the roof, 1700 square feet. Got a 45,000 BTU heat load. So my check figure in my mind is for a tight new home in climate zone five. We should be around 1000ft² a ton, give or take, as a heuristic. So it's a check figure. I'm not saying that's how you should size, but when you see 400 square foot a ton or 300 square foot a ton, you're like, wait a minute, let's we need to go look at what these numbers are and try and figure out what's going on. And so the slab, Nate.
[00:25:03] Host: Eric Fitz: Just just to jump in for a second, I just at this point is so important that this these heuristics, these rules of thumb, whatever you want to call these gut checks, these sanity checks are really useful when applied correctly, when they're used as this sanity check as this. What? This is weird. I need to dig into this more kind of thing.
[00:25:23] Guest: Nate Adams: Yes. Yeah. Don't size with this. I'm not saying size 1000 square foot a ton. I'm saying have check figures in your mind. So, like retrofits in Cleveland, I usually found that I was sizing at 600, 800 square foot a ton. That's just where it came out. Is that always what it is? No. And I want to check the math. So if when you're sizing aggressively, you need to know your math. You need to reduce your risk so you don't get callbacks. But here's a key thing to ask you. So I've been I pulled my first client gas meter in 2014. The most aggressive one that I did was I put a three ton carrier green speed in a house that had a legitimate 50,000 BTU load, and I ended up doing it was a baker's dozen of electrification. Guess how many times when we were as much as 25 degrees below design temperature in Cleveland, any of my clients houses slid unless they slid when they didn't want it to.
[00:26:16] Host: Eric Fitz: That their thermostat dropped by slid. You mean thermostat went below?
[00:26:20] Guest: Nate Adams: Exactly. Yeah. The thermostat wouldn't hold that point. Yep.
[00:26:23] Host: Eric Fitz: My guess is knowing you that maybe know times that in this scenario.
[00:26:27] Guest: Nate Adams: Zero zero. So they may have used a lot of resistance. Ali sure did. Whew. But but she also told me that is the only house that she has ever had where she had to either check her phone to see what the temperature was outside, or step outside to understand what the outdoor weather was. That is a comfortable home and that was a mid 60s 3000 square foot split level that we did reasonable air ceiling job on. Nothing super exotic, but it's all feedback.
[00:26:57] Host: Ed Smith: That you did have electric strip back up on it that could have jumped in when the heat pump couldn't keep up. Yeah.
[00:27:04] Guest: Nate Adams: Yeah okay. It honestly I it resistance is not futile is my joke for anybody who likes Star Trek. Uh I always have resistance. If it is an option, if it's a ductless mini split is not an option, but if you have a ducted system and there's a slot, put three kW or five kW in there because guess what? Someday the compressor is going to fail. I hope it's 25 years from now, but someday it's going to fail. And now it's an annoyance, not a crisis. And that's also something we should talk about with like versus furnaces when the furnace goes out. Do you have backup? Nope. When the heat pump goes out, when the compressor dies and you have resistance backup. Do you have backup? Yep. Like, yeah, it costs 2 or 3 times as much to heat the house. But your house is warm. And at the end of the day, it hot showers and cold beer. Like Amory Lovins says, that's what people want. So it's just critical to do that. But the reason that I, undersized so badly, by the way, was so that the equipment was running 100% of the time. So this is where I think we need to shift the conversation. Equipment should never, ever shut off if we can. It's actually pretty much technically impossible because we have so many hours where we're like below 3000 BTUs a load and like there there is no equipment that's good at that. Like most climates in the US have 2 or 3 months where we're talking near zero.
[00:28:23] Guest: Nate Adams: Heating and cooling load is what it is. But if we can at least get to 50 or 60% runtime, which requires being very aggressively sized like that can be, you have to put a two ton heat pump on a house with a three ton load to even get to 60 or 70% runtime, but when we do that, what we're doing is we are providing the single biggest piece for human comfort, which is we're washing all of the materials in the house with slightly warmed or slightly cooled air. So we're getting all the surfaces in the house to be even. It's called mean radiant temperature. Robert Beam taught this to me years ago. It's dead freaking nuts. Like when you start experiencing it, you're just like, this is amazing. This shouldn't be. But it is. It just is. And so 60% of human comfort is radiant based. We have about 150 or 150,000 temperature sensors in our bodies, mostly in our extremities, hands, face, feet. And if those are happy, we're pretty much comfortable. Right now my knees are cold because I've got crappy windows and I've got my window cracked and it's a little bit cool outside, and it's starting to hit me because I'm wearing shorts right now. I can be very aware of where my physical comfort is, and if we can get the equipment that runs all the time, we will have really comfortable clients, even in crummy houses, even with crummy ductwork.
[00:29:44] Guest: Nate Adams: And to run 100% of the time, we have to size it as aggressively as we possibly dare and then probably go another size smaller. So that's why I am so anal retentive about how small can we possibly make the equipment I'm chasing comfort. Like I said, my goal has been for anyone who wants one. I want them to be able to have a truly comfortable and healthy home. Small equipment is the single biggest factor in providing that small and variable speed and fully communicating. I put a Boche in this house. I'm about to rip it out and put a carrier green speed in. That should say something. I have a four year old heat pump that I dislike enough. I'm going to remove it, and I don't even know if I'm going to reuse it in the near term. I think it's going to go sit in a shed, because it won't dial down as much as I want and it won't dehumidifier. And then like in heating mode, it basically acts like a single stage piece of equipment, and my house is not as comfortable as I would like it to be. Like, I know what's possible and I'm missing the mark. And initially when we did this, I didn't think this house was going to be where we'd live. So I'm like, yeah, it'll be an experiment. Now we live here and I don't want that piece of equipment because it won't load match.
[00:30:56] Host: Ed Smith: Nate, let me jump in because you have taken us on a remarkable journey in so many points. We started with manual J, and it was tends to be high. It tends to be high. And you want to be within a half a ton. You took us to heuristics. Rules of thumb. Things that you sense, check numbers that come out of a complicated model is basically what that is. The importance of those guys. Your philosophy on sizing, which is undersized, put in a heat pump that's undersized, back it up with electric strip heat. But there's like all these trailheads I want to go back down because that house you started with in Cleveland or Chicago and they used it was 55,000 BTUs, and you put in a three ton. But I don't think your point was that's actually the load was I think your point was you put in an undersized system and you had electric KW. So I'm not sure you knew exactly where that difference was. But talk about feedback loops. Talk about like why doing a load, putting in system, observing it. Like what about that is is so critical for you that you think more HVAC contractors should be doing and maybe even the powers that be observing as well to inform. Stuff like manual J.
[00:32:11] Guest: Nate Adams: Yeah. Sorry. You're I've been hitting broadly trying to sketch out like all of the thought processes that are behind this. Like when I say something, there's probably a great deal many hours of thought behind it to come to those conclusions. So that's hopefully that's coming through to a degree, which also makes it hard to be on point.
[00:32:28] Host: Ed Smith: You know, the it's not the ravings of a madman, it's the ravings of a man who cares deeply and has experimented countless times. And this is a topic that is near and dear to your heart. That's how it that's how it comes across.
[00:32:40] Guest: Nate Adams: There you go. Yeah, it's the mad scientist, but the mad scientist? Who cares? Yes. And also is trying to figure out how to think about scale at the same time, which is a challenge. But back to your question. When you watch equipment run, you will see that you have oversize pretty much 100% of the time. I've seen a couple of houses like old leaky houses, and brick houses can be really challenging. Brick houses have a bunch of thermal mass, so they're awesome until they genuinely go cold. And then the only solution to them is a crap ton of BTUs. It just is. They're weird to watch. They break all the models. Our models don't take thermal mass into account well enough, but in general, you're going to watch houses and be like, you gonna put a 70 K furnace in that? But it looks like my actual loads two and a half, three tons, maybe three and a half, maybe two, and you'll start getting more comfortable with downsizing. But this is also where hybrids end up being a really nice thing because great, put the 60 K furnace in whatever. I don't care because if you put a three ton heat pump on top of it, like a three ton heat pump and a 60 K mod furnace, that system will work in 80 or 90% of American homes right now, and it'll do a pretty good job.
[00:33:54] Guest: Nate Adams: I'd prefer to do a two ton or not even have the furnace, but my preferences don't come into play here. But if you watch houses And you watch the equipment run. You're going to get much more comfortable with sizing smaller. And if you can get a heat pump, particularly in your own home, I don't think you've had Jim Bergmann on yet, have you? Oh. Did you. Oh that's right. Yeah. Because yeah, he was saying like, we need to talk about like when we're wrong, we need to talk about it even more loudly than when we're right. And his point was basically me busting his chops for years until he put a Bosch heat pump in his last house, and it was so funny. We had lunch one day and he's like, Nate, that stupid heat pump cost me 20 bucks more last month than it did if I'd run the furnace, but he just told me like the furnace would wake him up almost every night when it kicked on and the heat pump never shut off.
[00:34:47] Guest: Nate Adams: So he was okay with it. And my basement has never, ever been warm since I've had this house for 15 years now. The basement's warm and I'm like, Jim, we're sitting at lunch. We just spent 20 bucks a person and you're whining to me about 20 bucks for the month. Shut up. And so we've become good friends. He's so funny and in his new place that he just bought. He just put a hybrid in there too. And the conditions weren't right for him to put a or to start the heat pump up. It was too cold. So he just ran the furnace and one day it hit 65 degrees. So he went out and he started up the heat pump. And he's. I wanted to call you and tell you that you were right. Which is why to get from Jim. But he's my this. I can't believe how much more comfortable this house is with this heat pump than it was with the furnace. It's just it's unbelievable to me. And like, I've seen that again and again personally. And until you experience it, you just don't believe it. We're all doubting Thomases.
[00:35:44] Host: Eric Fitz: I want to unpack this very specific point about getting more comfortable. I'll call it rightsizing or downsizing or being more aggressive with your load calculations. I think that's what you're trying to say. And that word aggressive is, I think is very important. I actually want to quote Manuel Jay itself. This is in the very beginning of the latest version of Manuel J. It's actually page 23 for those keeping track. Manuel J says be honest and aggressive. Manuel J is an engineering tool that has an inherent and appropriate factor of safety. Any attempt to add other safety factors or to manipulate the procedure may result in unacceptable performance, especially in part load. And Daniel J is super clear about this. And so let's talk about what do we mean by being aggressive. What when you're doing a manual J what does that mean.
[00:36:43] Guest: Nate Adams: Well so let me give you an example that just sticks in my mind like crazy. It's actually it's in my book, The Home Comfort Book, the third chapter of it. It's HVAC 102 about sizing. There was one of my first projects I put an ecobee thermostat in. We kept the existing HVAC, which was a two stage 60 K and a three ton air conditioner. And I got to watch what happened. And one of the things that started with that, one of the pain points that he had was hurricane Sandy had come through just a little bit before that power went out, and the house dropped 20 degrees in eight hours. And it took it days to come back because my friend Stu, who'd put that, frankly, like borderline undersized furnace into that house, it took it two days to come back up to temperature because it was sized about right for where that house was shell wise at that point. So we fixed the shell and he left to go on vacation, and it took 26 hours to fall eight degrees. So we really change things around a lot on it. And so when I watch the runtime chart on that, we also experienced the coldest February in Cleveland history right after that job a couple of months later. And so we got to 20 below design temperatures, five in Cleveland. So we were 25 below design and that furnace didn't kick high stage. So low stage was 38 K. That furnace didn't kick high stage until it was like -15. And it was really because he fiddled with the thermostat that made it kick, but it shut off at design temperature. So if I mean by definition, if a system shuts off a design temperature, is it oversize?
[00:38:25] Host: Eric Fitz: Yes.
[00:38:27] Guest: Nate Adams: So that was 38,000 BTU shutting off. So the actual load on that house was around 30. By looking at it, that was a 2300 square foot 1957 built one and a half story house in Cleveland, Ohio. That's not what you would expect. Now, we did a reasonable job on the shell, like it was reasonable, but it wasn't that tight because there was a limit to what we could do with the budget that we had. But the coming back to the heat load, the model that we had, which we were using treat at the time, which is a New York based program for their efficiency programs.
[00:38:59] Host: Ed Smith: But it's not manual, Jay.
[00:39:00] Guest: Nate Adams: No, it's not right, but it's similar. It's actually slightly more conservative. It's supposed to be. So the that was 67,000 was what the heat load showed on that. But then that had a bunch of fudge factors packed in. And you could take the fudge factors out. And I think it was like 43 for that house. But when I watched it and the actual load was I 2830. It's tough when you're looking at that to be exactly sure where it is, but that's again within half a ton. We're talking two and a half ton load is what that was designed, and the load calques were coming in more than double that. And that was a load that we had Trude to energy use that particular tool. But if you ran like that's a common number is the key thing. So I see lots of heat loads that come in between 60 and 80,000 BTUs. And so let's use the 67. So when you get a 67,000 BTU heat load, what are most contractors going to put in? They're going to do a 60 or 80.
[00:40:04] Host: Eric Fitz: They're going to go they're going to size it up.
[00:40:05] Guest: Nate Adams: They're going to do an 80. But I just 100. Yeah. Or even 100. Yeah. Let's just be sure. Yeah. But the reality was 30. Now that isn't something that I should hammer on, like super hard. Because you're not going to have shells like that in a lot of houses. But let's say that the load was 45. Putting an ad in is a disservice to that client. That house should get a 60. That's the challenge. But the reality was a three ton heat pump was the right piece of equipment for that house. You never would have expected that. But from an engineering perspective, that was the right answer. So we are using the wrong answer so often. And a lot of that. Like that's what that that post from Eric Reinhart, I believe it was on LinkedIn that just went wild. He said the load calques are a significant problem there. We're never going to electrify with the numbers that we're getting. And he was criticizing loads that he was getting. Which is what I'm doing. So like the one in Chicago that was 45,000. We ran our own and we got 21 using Quick model. And so I was back to what we were originally talking about, like where you guys have helped me adjust my thinking. I thought the formulas were just wrong. I still think they're probably too conservative, but I don't know that there is conservative as I thought. And then the other challenge is to get within half a ton. We have to. How can you leave out air leakage? Air leakage is between like 20 and 70% of the heat load. Depending on which house you're looking at, it might even be as low as ten. So if we don't have that number, how can we be accurate? How can we be proper? And that's a really hard question.
[00:41:46] Host: Ed Smith: It's a great quote.
[00:41:48] Host: Eric Fitz: Yeah. What I think I'm hearing from you, and I want you to correct me if I'm misinterpreting. What you're saying is that the manual J math generally is pretty solid, but it's the inputs into the model are what really matter. And so if you've got bad inputs, if you aren't taking into account what the actual insulation is in the attic or in the walls, or that you've got whatever type of windows, or you are taking a total guess at how tight the home is. That's where you get into trouble, and that's where folks end up inadvertently putting in really over sizing. In general, they end up putting in their own factors of safety, essentially into manual J. Is that what I'm hearing?
[00:42:32] Guest: Nate Adams: Yes, for the most part, I think that's what it is. I still think the formulas are probably a little too conservative, but I don't think there is conservative. As I thought before I started playing with your tool, because this 45,000 BTU Chicago house, I was mentioning 1700 square feet with the 40. Yeah, with the 45 that we came up with. 21. The slab that they put in for that 45 was just four foot of foam board around the outside. The whole house had had foam board underneath it. So that came out with a 14,000 BTU load there where the windows, doors and attic all together were like 12. And I'm like, so there's a check number that you know is wrong. One unit shouldn't be more than like the other three main heat loss factors combined. And the duct loss was too high because it was modeled outside the envelope. But it was a spray foamed house. Spray foamed rough, so it can't be outside the envelope. By definition, the mechanical ventilation load was too high. The infiltration load was too high. And like all of these things add up. And we knocked out a little over half what the load was. So yeah, those are input challenges to be sure. And I think that probably is the biggest thing. And that's where my thinking has really shifted, to be frank. And I'm sure Wes Davis will be glad to hear this. But still, how do we do it Without some kind of check, figure on what the air leakage is. And past energy use to me is a really good check figure to get an idea of. Is the house really leaky or not? Are we always going to have it? Heck no. We need a model answer because we aren't going to have all the data that we want in many cases. But if we're going to say proper manual J, if we don't have either a past energy use or a blower door check number because that's like half of the equation, I don't think we can call it proper. So we need the inputs and then we need that check figure. Whatever it is.
[00:44:25] Host: Ed Smith: There's a bunch of stuff you've hit on on this feedback loop. Like you put in a piece of equipment and then you have monitoring in place to see how it runs. For most of the industry, the feedback loop is did I get a callback? And if that's your feedback loop, then bigger is better because I didn't get a callback when it was -20 out. The second thing that that on that Eric on the post on LinkedIn from Eric Reinhart. It was basically, I've seen a bunch of manual JS and they all seem wrong. So manual J is wrong. And Eric Fitz here will tell you it's the heating is designed to be what, like 20% a bit oversize. That's the factor of safety. But if you're going in there and you're laying in I don't know what the insulation is. I'm going to go R 13 and instead of R whatever that's higher. I'm going to assume these are the windows, I'm going to do this and this. And one of the things that we've had fun talking to you about is like you scan one of your Airbnbs and you put in a bunch and you send us your manual J.
[00:45:18] Host: Ed Smith: And we look at it and we have a conversation like, what about this? And you're like, oh, and you tweak it and then it gets it gets nailed down. But like most folks don't have that. And a lot of the ways manual J is being used is like you walk into a house and you already have a number from all the other jobs you've done. You like it houses the size they typically put in an 80,000 BTU furnace. So that's the number I got to get to. So what do I need to put into this thing to get that number back out. So I think there's just the industry has changed and heat pumps have changed it because they operate the way. You've explained six different ways on this. If you size it a little bit lower, it's going to run better. So you want that razor's edge or even a little bit undersized system with the appropriate electric backup. It's a complete mindset shift from how folks have been designing for, what, 100 years?
[00:46:04] Guest: Nate Adams: Yeah, that's one of the biggest challenges.
[00:46:06] Host: Eric Fitz: I think there's an important nuance here, too. Is that all right? I just want to talk for a second about what factors of safety these are things that have been in place. It is an engineering practice. They are a very good thing. Back in the turn of the century, when we were first building using metal railroad bridges and the sort of civil engineering practice was starting to come together. Factors of safety weren't being used. People talked about riding on a train going across some of these bridge. It was like it was terrifying. Like bridges were failing all the time. And so there were a lot of great practices had been put in place for when you are modeling or designing something, and you cannot. It is impossible to fully model 100% of the real world. It's extremely expensive to do that. So in any model there are based on engineering principles. There are usually some form of factors of safety and manual J has factors of safety. From what I have done from my own research, looking at other large sample size research studies. On the heating side, it's somewhere between 20 and 30% factor of safety for the heat calculations. That does vary depending on your climate zone. There's other there's a lot of different variables that are going into how large that that factor of safety could be. And that factor of safety is there because we assume in a home, like if you do some verification of like how much insulation is in the walls, we generally assume, okay, you've got that continuous that insulation is present in the entire building, but in practice.
[00:47:44] Host: Eric Fitz: If you open up walls at various points, for whatever reason, maybe you're blowing in dense pack cellulose and in multiple bays could have been missed for whatever reason or during construction. An entire yeah, entire section of a ceiling may have never had the fiberglass batts laid down for whatever reason. And so those factors of safety are in there to just protect us a little bit for those things that we just can't see in the walls and that we can't easily verify. And they're really good. And so Daniel J in particular is providing this guidance to be aggressive, because it already is putting in these protections for us to make sure that we're not getting having a surprise when we do manual J. And then the other piece that I wanted to say that's very important is to separate manual J from manual S. Manual J is about the home and manual S is about the. What's the right solution? What's the equipment that is appropriate given Manuel J. And there's very specific guidance and protocols on the manual s side that help us also think about, okay, what are the loads and therefore what should we be thinking about from a equipment performance perspective, given my climate zone, given my altitude, other things we need to keep in mind. So I just want to make sure we're not mixing the manual S and manual J concerns too much.
[00:49:08] Guest: Nate Adams: I think that's that's fine. I should talk about manual S in a second, but one bit of pushback on the safety factors is no one's going to die. The worst case scenario is instead of the setpoint holding 70, it slides to 65 or maybe 62. No, like death is not something we're not talking a train falling into a crevasse. It is.
[00:49:33] Host: Eric Fitz: But they're in there because heating and cooling systems actually legally are considered a health and safety piece of equipment. There are a lot of places like their renter protections. You know, if you have got a medical issue, it's and that's why they are built in because they actually view it as a health and safety. Yeah.
[00:49:50] Guest: Nate Adams: No. And that part's correct. I guess it's a question of what it is. I'm also thinking, I remember reading that the Brooklyn Bridge was supposed to be six times stronger than was actually needed, but then they found out afterwards that the steel was half as strong as they thought. So they're still okay. There's still three x, but it's good to put some extra in there. But that's to me it's a little bit different anyway. So and then on the same subject talking about resistance backup, which I don't think people think about how many BTUs is 15 kW, it's 51,000, give or take. What's 17 kW per five, 17,000 BTUs per five kW. That is a lot of backup, considering that a shocking number of houses probably have heat loads under 50,000 BTUs. I'd like, I'd argue basically anything built since 1980. So like in Cleveland, that's when we went to R 11 in the walls and R 30 in the attic and modern platform construction with plywood. So basically construction hasn't markedly changed since 1980. That's 45 years ago now almost 50 years old. Our quote unquote modern building practices. And those houses I find are usually relatively tight. We're not going to say great, but like I think in a ratio on blower door of CFM 50 to above ground square footage. So like we had a cool old 1835 house that was 2200ft² above ground. It had a 3800 blower door. So that's as close to a 2 to 1 ratio. 3800 to 2200. Or I mean like a 2000 square foot house with a 2000 blower door. That's a 1 to 1. I find that a little modern building construction is usually somewhere 2 to 1 and it under oftentimes close to the 1 to 1.
[00:51:38] Guest: Nate Adams: The 1 to 1 came up in my mind years ago for building science reasons. Because 0.35 ACH natural, which is where you need to introduce mechanical ventilation in BPI standards. Like I kept watching the auditor reports and it was really close to square footage, 1500 square foot house, 1400 or that it would be a 1400 blower door would work out to 0.35, something like that. It was. Is it dead on? No. But again, check figures. That was my check. Figure in my mind is 1 to 1. And then in doing the house whispering when I got a house to 1 to 1, it was very controllable with HVAC where when it was well above that it wasn't. And so from 1982, today, a lot of these houses are good enough that we can do a huge service to customers by putting the right piece of equipment in. That runs a lot that's right sized, and we can solve all kinds of problems with HVAC alone, which messes with my mind because I come from the shell side. I want to fix the shell first. Everybody should air seal and insulate, but realistically, no one's going to. I've come to that conclusion after years of beating my head against the wall. So in sizing stuff, we we still just aren't sizing aggressively enough. So how do we get people to realize that they can size much more aggressively? And the feedback loops are the biggest answer. Watch your put echo BS in. If it's single or two stage equipment, put in a couple of energy monitors. Do your own house.
[00:53:02] Guest: Nate Adams: I'd say everyone should start with their own house because if you screw it up, you can fix it and then know that 15 kW is 51,000 BTUs. Ten kW is like 33 or 32. So the my favorite backup strip is a carrier, which is a three stage. It's 369 kW. That is like perfect for so many systems because I really like reheat dehumidifier, which we can do another episode, but three kW is less than a ton of output. So you can the system can match that really nicely and run at 50% capacity and just suck the moisture out of the air and get a nice long runtime so that it does a good job on that, like the systems that I use. They don't use a whole lot of power for reheat at the end of the day, where if you try to do that with a single stage piece of equipment, like it can be an utter trainwreck like resistance. Backup is just something we should use a lot, and that also fits in 100 amp panel. Like, there's all of these pieces where when you start watching, you start seeing, here's what the sweetness is like. A two ton heat pump with a three, six, nine backup is an incredibly useful piece of equipment. Well, it fit every house, no, but probably hit 40 or 50%. That's a big slice. That's 50 million homes in the US, where a two ton with that backup is probably the right piece of equipment. But if you aren't being careful with the manual Jay and it comes back at 50, 60, 70,000 heat loads, You're sure as hell not putting a two ton in.
[00:54:33] Host: Ed Smith: Nate. We're coming to the point where we should probably wrap up a bit, but I want to summarize because we've hit a bunch of stuff. First of all, you're awesome. Thank you for joining us. I appreciate that. Second feedback loops right. Don't just take gospel. Go put stuff in and see how it runs. And it's more than just did I get a callback or not see how it's actually running. Put in a ecobee, put in a Emporia Energy monitor, whatever it is, to see how it's actually holding up based on what you thought. Second manual J. The math isn't wrong. It's often like misused or misunderstood. There are these factors of safety in there, and so folks are layering in more factors of safety. If they're being not aggressive but conservative, you're going to get a massively oversize system. And you said this a few times. Like that's a disservice to a homeowner. Be aggressive. Came out multiple times. Be aggressive with your manual. Jay. Be aggressive with the equipment you're putting in, especially on the heat pump side, but not so aggressive with the with the electric stripped back up right. Like a 1015 kW. That's going to provide a ton of BTUs. And that provides the peace of mind for the homeowner. Rules of thumbs are useful checks, but they should not be used for sizing. Just a ton of awesome points. Eric, anything that came to mind for you that we should mention too because we hit on a bunch of stuff?
[00:56:03] Host: Eric Fitz: Yeah, I think it's worth just on the on this point of being aggressive and like what that means. Manual Jay itself actually gets into this a little bit more detail to clarify what they mean by that language. So when you're putting in your inputs like that's really what you need to be really watching carefully for manual. Jay, there's software out there that does the math for you. It's the inputs that matter. And so on the cooling side, the example that Manuel J. Provides is you're in the home and you're noticing they have drapes on the windows. We assume that those drapes are actually going to be used at least half closed or even fully closed. Most normal people at design conditions, when it's wicked hot out, they're going to they're going to close their drapes. So between the two of assuming they're going to not use their drapes at all, or if they are going to use their drapes or blinds, like assume they're going to use their blinds on their windows for your calculations. That's an example of being aggressive. Same thing on the heating side. If you're hopefully with every project, you are poking your head up in the attic and you're at least taking a quick look to see what you've got going on for insulation up there. Same thing you're opening. You're like taking off an outlet cover in a wall. You're putting in something nonmetallic just to double check, is there? Can I pull out some fiberglass hairs? You're verifying like there is any insulation at all. And if you see that there's some there, use the assumption that's like slightly more aggressive. So if you're not sure if it's our 21 or our 30. Go for our 30. That's the more aggressive assumption to use.
[00:57:33] Host: Ed Smith: That's a great example.
[00:57:34] Host: Eric Fitz: You will end up with a properly sized, correctly done manual J.
[00:57:40] Guest: Nate Adams: If you have that check figure though. I'll push back on that. I still think we need for proper. You need to know something about past energy use or air leakage, or at least make a somewhat aggressive. How about this? Make an aggressive assumption on that. Like 1980 to today, you can probably be more more aggressive although. So let me give one key piece here. My my strong climate bias, which is hard to kick, is climate zone five. So I'm used to a cold climate with hot, humid summers and all the ductwork inside. As soon as you get down south and you get leaky ductwork outside, yeah, you better know what you're doing. But the good news is, most of that stuff is easy to do. If it's a flex duct system. Seal your boots, seal your joints. There's not that many of them. If you're replacing the system, at least take a quick look at them. It doesn't have to be that hard. You can seal boots in a couple hours in most houses. Seal the freaking boots, but know where your biases are and try and fight them and be aware of them. But we really need some other check figure, with infiltration being 20 to 70% of the load. If we have no idea what that number is. We're going to be too conservative. So I would generally lean more aggressive on that. Down south, you're going to have to pay attention to duck leakage, but you can visually get an idea oftentimes of whether that's a problem or not. But I firmly if we're going to say proper because I have to say every time I hear that word proper, there's a in the on the climate side with electrification, I always hear bold and aggressive. And I'm just like that.
[00:59:11] Guest: Nate Adams: Every time I hear that, I want to reach out and strangle someone because they're just it's just wrong. No, you're not going to do anything you're going to do for projects and be like, yay, team, you didn't move anything. This is stupid. And so when I hear proper every time, I'm just like, hey, I've come to really dislike that word. Because if you don't know infiltration, I don't think that it's proper. And that's really hard because also scaling up lower doors, I've just tried I don't know that we're going to do that, but that's why we've been talking for years. How many times have I mentioned look at past energy use? Like damn near every conversation because it gives you an idea, like I noticed in Cleveland that every 300 or so translated to about a ton of heat load. So 300 terms of heating usage, which is easy to figure out like most gas water heaters use like ten terms a month. So you got 500 terms a year of usage, and you subtract out 120 terms for water heat. That's 380 terms. That's probably a ton and a half or two ton house. So if you have that as a check figure and it's going to vary where you are, like that's going to vary by climate zone and like equipment, like a whole bunch of other pieces. But that's a reasonable check figure. That is much easier to get than a blower door. So that's why I'm suggesting that is. That I think that should be a layer like a check layer, because for the most part, we're not going to have that. I recognize that I'm a reasonable person, but we need some kind of a check layer if we're going to call it proper. Is that fair?
[01:00:45] Host: Eric Fitz: Yeah, yeah, I think that's when I hear people say proper. When I say proper, it's just looking at like from the book perspective, it's being aggressive is the idea of being proper. So if you're not, if you're if you didn't verify how much insulation is in the attic, don't assume that there's zero insulation or a tiny bit that's the proper is. First off, verify. Do something to just double check what you get, what you're working with, and then if there's a little bit uncertainty, Be a little bit more aggressive. That's what I mean by proper in terms of like how you're selecting your inputs. I love the secondary layer of do some have some kind of gut check, have some kind of heuristic. Every maybe one out of ten homes do a blower door to like you get those feedback loops to yeah yeah. Or get their fuel usage. Absolutely. But because that's definitely going to be better than guessing at the numbers.
[01:01:50] Guest: Nate Adams: Yeah. Try not to guess. All right I'm going to drive you nuts. There's one last piece that I want to hit. All right, so we were. You touched on manual S? I'm going to mess with your mind. You know how many times I've run a manual S?
[01:02:02] Host: Ed Smith: Zero.
[01:02:03] Host: Eric Fitz: Man, I'm worried about that.
[01:02:04] Guest: Nate Adams: Ever. No, I've never done it. So for if you're talking single stage equipment, you better be paying attention to your manual S. But because I've run pretty much exclusively carrier infinity Systems through my practice because they had, hands down by far the best cold climate performance of anything on the market for years and years until, I don't know, like 19 or 20 when we started getting the mini split based units here. But those have such wide airflow flexibility capabilities that you can run it like it's a dry climate, you can run it like it's a humid climate, you can run it like your high elevation, you can run it like your low elevation. And all of a sudden, like as long as your air handler is kind of close, you can make it work. So that that is a huge argument to me for truly. So there's there's communicating and then there's truly communicating like it's obnoxious. I feel like, what was that movie? Oh dang it. What we have here is a failure to communicate. Cool hand Luke.
[01:03:10] Host: Eric Fitz: Cool hand Luke.
[01:03:10] Guest: Nate Adams: And so like, I'll be nice in not name the manufacturer, but it is a mini split manufacturer that says that it's communicating. But what I want to see in truly communicating equipment is where, yes, the compressor can vary down to a very low degree, like 2,025% capacity, but you have to be able to match the airflow from the air handler to that. That's my problem here on this system. This Bosch won't get the coil freaking cold enough, and there's nothing I can do about it. So I'm going to rip the damn thing out. I'm going to let a $6,000 piece of equipment sit somewhere. I'm very annoyed by this now. It was an experiment to see if I liked this equipment or not. And the answer is no for this application, to be fair. So I'm not saying across the board, but truly communicating, you have to be able to run a cold coil at minimum capacity. That to me is how I define it. You don't have to do that technically with communicating, but I haven't seen it done without it, and only a few systems do that.
[01:04:09] Guest: Nate Adams: Now, one system that gives me a great deal of hope in this is that I can fit a system, so I will call that one out. I've got two of them in our Airbnb, so I'll put two little one and a half tunnels in. And those will do a good job with dehumidifier down to about 75 degree day. If it's a sunny 75 degree day, the surfaces get warm enough in the house that there's enough sensible load that it will do the latent work, which is cool to see. So like I'm impressed with that system. Below that you have to have a dehumidifier, which is why I like reheat dehumidifier on because it variable speed equipment covers a lot of sins and reheat covers a bunch more. Is it perfect? No, but it does a lot. But if you've got a good system, particularly in humid climates, which is 80% of the US, and you can run a cold coil at minimum capacity like the manual s, almost doesn't matter. And then like you got stripped heat manual.
[01:05:07] Host: Eric Fitz: But but manual is the tools that just help you evaluate. Do you have a great piece of equipment like a carrier? Your green speed. There's nothing wrong. The manual is the. It's there. It's actually relatively simple. It's so that, in fact, professional can look at a bunch of different bands, a bunch of different piece of equipment and decide, oh, this is going to work great or it's not.
[01:05:24] Host: Ed Smith: I would carry a green speed so well because it's a simple calc. You're doing the manual in your head, you know it's going to do the job for heating, cooling and sensible and latent. So I think that that is one of the benefits of getting to know a certain manufacturer, having go to equipment that in a climate zone where you operate all the time, like some of this stuff does become ingrained.
[01:05:47] Host: Eric Fitz: So you are getting those feedback loops from you're doing the whole process.
[01:05:54] Host: Eric Fitz: You're seeing yeah, you're seeing how it's operating. And you're like, man, this is working beautifully.
[01:05:58] Guest: Nate Adams: So yeah, that's who.
[01:06:00] Guest: Nate Adams: And what other one other last piece on that. One of the reasons I like hybrids is you can have that safety blanket for the higher capacity, but size it to cooling and see what happens. Because sizing the cooling like I'm seeing the number 80% on hybrids come again and again, which is how much gas use was reduced, or oil or propane or whatever, 80% reductions by putting in a heat pump that was sized to cooling in climates on five. And like I've seen 90 with a couple of my systems. But yeah, being able to size aggressively is key. And that's part of why I say use your strip as your backup. Like this winter here was an incredibly cold winter. We were way below design here. Basically, it was like I moved back to Cleveland because we moved a couple hundred miles south. We used, I think, 800 kilowatt hours of resistance. Chill out. Like this was expensive here because I've got time of use and it actually bit me in the butt. But let's say that's $0.20 a kilowatt hour for and let's call it a thousand. That's $200 that the resistance would have cost me. Going out to it cost 100 bucks now. Come on. Like the fear levels that we are feeling over $200. If $200 is going to break your household budget, you should probably be renting and not owning because you really shouldn't. You should be able to take that kind of a hit, and the fear factor around it drives me bonkers. So you can size a half ton smaller than you think you can, and you're going to be talking about 50 or $100 or $200 a year extra in resistance. And that was we were 20 degrees below design a couple times, and it was weeks of below design temperatures.
[01:07:46] Host: Ed Smith: Awesome.
[01:07:47] Host: Ed Smith: All right, Nate, on that note, I'm sure there's 20 more points you could make.
[01:07:53] Guest: Nate Adams: Keep going.
[01:07:54] Host: Ed Smith: And you want to talk to you about. We'll have to have you back. Thank you so much for joining the Heat Pump podcast.
[01:08:01] Guest: Nate Adams: Thank you, gents, for having me. Thank you for building a nice tool for real. It's a nice tool.
[01:08:06] Host: Ed Smith: Thank you. Thanks for giving us a feedback loop and beating the heck out of it.
[01:08:09] Host: Eric Fitz: Yeah, we'll really appreciate it.
[01:08:10] Guest: Nate Adams: Thank you for touching my ears.
[01:08:14] Host: Eric Fitz: You're welcome. We're you know, it's always fun to talk with you. I always learn something new. It's always interesting. So. Yeah, again, I really appreciate you coming on again. And we look to look forward to continuing the conversation.
[01:08:27] Guest: Nate Adams: Sounds like a plan, gents. Enjoy the rest of your day and your weekend.
[01:08:30] Host: Ed Smith: You too. You too.
[01:08:35] Host: Eric Fitz: 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.
[01:09:01] Host: Eric Fitz: Thanks a lot.