This week, we welcome a guest who truly needs no introduction: Alex Meaney, founder of MeanHVAC. For many in the industry, Alex has taught us much of what we know about Manuals J, S, D, Zr, and more.
In this episode, we dive straight into the intricacies of Manuals J and S, especially their application to heat pumps. Unlike traditional HVAC systems, heat pumps—capable of both heating and cooling—are far more sensitive to mistakes in system design. With Alex’s expertise, we explore why this is, and how to address these challenges.
Throughout the episode, Alex drops invaluable insights, including:
If you’ve ever wanted to geek out on how heat pumps are reshaping the fundamentals of HVAC system design, this episode is a must-listen!
[00:00:00] Alex Meaney: when you're talking about manual J and even, manual S and D, the difficulty is almost never, in heating, Like it's a weird brag on my part, but if you gave me a pencil and some paper, I can doa heat loss calculation off the top of my head, There's very few sort of catch 22s in there. Cooling is where everything gets complicated,
[00:00:27] Ed Smith:Welcome to the heat pump podcast. Our goal is to make sure the transition to heat pumps goes well for everyone, homeowners, contractors, and the planet. We cover all topics related to heat pumps. The science, the technology, the business, and the policy. Today we have Alex Meaney, founder of Mean HVAC and a man who needs no introduction in the HVAC and building science worlds. For many of us, Alex taught us everything we know about manuals, J, S, D, Zr, and probably more. We wanted to interview Alex and get deep into the nuances of manuals J and S, as they relate specifically to heat pumps. Heat pumps are an amazing technology, but they are exponentially more sensitive to errors in sizing than other forms of HVAC hardware. Manuals J and S are critical to making sure the transition to heat pumps goes well. We taped a lot with Alex too much for one episode. So this is Alex Meaney part one. We introduce manual J and manual S at a high level, and we just start to scratch the surface of how to think about them for heat pumps in particular. We leave you with a bit of a cliffhanger at the end. So if you enjoy this episode, be sure to tune in for Alex Meaney part two, when we release that. Enjoy the show.
[00:01:41] Ed Smith: Alex, let's start off with Mean HVAC, because you're an entrepreneur in the HVAC space and you're doing super interesting stuff. What is it? What do you do when you work directly with contractors? What services do you provide? Tell us about it. Awesome.
[00:01:55] Alex Meaney: the primary goal of, my company is to teach people how to properly design HVAC systems whether it's teaching live classes or, my, design course that's,on demand, uh, pre recorded stuff, but not, it's basically me teaching a class to a camera.
So it's got some production value and doesn't have that, like "we recorded a class" kind of vibe where you can't hear people asking questions, but also since I've been teaching classes like this for about 20 years, as though you were in the room following along. So it doesn't have that super rapid pace. One of the reasons I left my corporate overlords was they wanted me to do things like explain manual J in five minute chunks. Uh, because that's the industry standard for training videos. It's like, if it's over five minutes, they won't watch. Well, one, have some more respect for your customers. And two, it's not possible to explain some of this stuff in five minutes, guys. andI branched out on my own to do that and create all the stuff that I wanted to create to provide high caliber, high quality, training material. but I also do consulting work. People want to bring me in to do one on one work with them, or we do a lot of like zoom stuff,reviewing plans, that kind of thing. I dabble in design work, but I really don't, I mostly refer that stuff out. I take it on if the business is slow or,I have something I need to pay for, which sounds like a boat payment or something, but it's more paying my friend's kid to develop an app. I'm going to be releasing in a week or two. Uh,It's all more or less in service to the industry's kind of stuff. mostly the focus is on training, awareness, consulting, that kind of thing.
Where I have a lot of passion, a little less demand, but the discretionary,time and effort often goes to, teaching people about the intersection of, building science and HVAC, uh, because they are incredibly tangled up.
It's, I don't think one, I don't think you can disentangle one from the other. I don't think there's anything that is strictly HVAC or strictly building science. Like it all goes together. Maybe some of the building science stuff where it deals with like bulk water and, Okay. roofing materials blowing off and stuff like that.
But from the HVAC side, you just can't divorce it from that. And so trying to shine light on that and, getting people to even just start looking at it. I don't need to be the resource that teaches you everything, but maybe the catalyst that gets you, learning more of that stuff. is a goal of mine.
[00:04:28] Ed Smith: awesome.
You hit Eric and I in the heartstrings there. That intersection is where we like to operate as well. And it's one of the reasons we're excited about what we're building at Amply. But,that was very well said.
[00:04:39] Eric Fitz: I want to hear more about the man, Alex Meaney.who the heck are you? How did you get into HVAC? Just tell us your backstory.
[00:04:47] Alex Meaney: I wanted to be a teacher when I quote unquote, grew up. I was a horrible student, uh, in high school and beyond. And,had a, had an English teacher, pull me aside and.told me you're just bored. Aren't you? And I, yeah, kind of here.let's move you up into the top classes, which is a bold move. and I was like, Oh, school can be fun. Cool. And I, I did really well, like the last two years of high school and went on to college. And my goal was to go be an English teacher because that person changed my life. And, in my, at the college I went to,former North Adams state college, now MCLA, they put you in classrooms right away if you're going to take the education track, like first semester. So it turns out I hate children, and washed out of the education program immediately. Like I didn't last more than two or three weeks. Um,In fairness to me, they put me with, behavioral problems, seventh graders and the most burnt out teacher alive. so I don't think anybody's coming out of that. I think. hindsight being 2020,the career of teaching is at least at the time, maybe it wasn't as bad as it felt, stories I have from teachers these days. I think I dodged a bullet. Uh, But I cast around, not knowing what to do.
What I settled on was a career in media and radio. and they didn't tell you what people in radio make for money. Uh, I was actually offered a job at a local NPR station. out of college. Uh, and I'm not so old that making 14, 000 a year isn't the most ridiculous thing you've ever heard. Um, You mean public radio doesn't pay well? I'm so surprised you know, I wasn't expecting to make a lot of money, but, paying rent would have been
[00:06:31] Ed Smith: I agree. $14K is egregious.
[00:06:33] Alex Meaney: I don't think I had a year where I didn't have at least two W2s at the end of the year, and then I quit a job without having another one lined up, which I had not done before. but it was a really bad situation. Salary work, 70 hours a week, I did the math. I was making less than minimum wage. uh,I went in and quit and,didn't know what the heck to do and showed up at this job interview. That I thought was a normal job interview. It turns out it was a temp job. at Wright Soft, they wanted somebody to make a phone calls to their customers and, give them a quick survey, to find out like what the next thing they should develop is. and, I liked the environment there.
So I would give him a survey and then I would tell him, Hey, you don't own this thing. We make a thing that does this. And you don't have to buy it.
Just wanted to tell you about it. And at the time the big thing was, operating cost comparison tool, right? So this is about 20 years ago. This was before systems didn't really pay for themselves. Um, at the time you could sell a 15 seer system, and it, and the ROI over a 10 seer was big enough that it like literally paid for itself, uh, within a pretty short period of time.
It was a very easy way to do HVAC sales for a brief window there. so I sold a bunch of software and went to Bill Wright, I think, like two weeks after I started there, I'm like, will you hire me? I made more money than I cost. And he's slow, slow down, maybe. Um,but eventually he did hire me and he used me to, clean up his, house a little bit. Um, My, my trick is, you only have to tell me once, maybe twice. and I can more or less figure it out. And He would move me into a department either right after or right before he fired somebody. I replaced somebody in sales. I replaced somebody in marketing. I replaced somebody in tech support. and then they, put me on the road with the trainer and the trainer quit. They ironically weren't planning on getting rid of him, but, I think he may, maybe saw it as a sign. So I walked into work on a Monday, as the head of tech support at the time. And they were like, Alex, we bought you a plane ticket.
You're going to South Carolina. You got to teach class. Uh, considering I walked into my office with the president of the company and the head of human resources standing there,five minutes late for work, I was, a shocking moment, but not quite as shocking as I thought it was going to be. Uh, so from that point forward, I was teaching people how to use.
[00:08:48] Ed Smith: Wright Soft
[00:08:49] Alex Meaney: and I was very nervous about doing it and talk to Bill about it. He assured me that my job was to teach them the software. that it was their responsibility to learn the manual J or they should know the manual J and all that stuff you're here to teach them how to use the software. None of the questions were about the software, none of them. Like, how am I supposed to know how much insulation's in this? I started making connections with people who can answer those kinds of questions. spent close to 20 years in relative obscurity. racking up, over this shoulder over here, that, that little thing that's my million miler status with Delta. that's actual miles flown, not the bonus miles. Like just literally, spending close to 40 weeks on the road or more than 40 weeks, going around teaching people how to do this and making it a point to try to answer their questions. and the. If one of my superpowers is, you only have to tell me a couple of times. The other superpower is I have no problem saying, I don't know. Like We were having a conversation before this, podcast started, by the way. whoever's listening, watching, whatever, these two guys come prepared. I was getting slideshows emailed to me and questions and here's how we're going to do like these. A lot of work goes into this folks. Just FYI, normally I just show up and sling it, because it's the same stuff all the time. But, had a whole conversation and I was like, geez, I don't, I'm not sure the answer to that question. And we started looking things up in books and it was really riveting.
I'm probably be very glad that they didn't record this for you.I, when they asked me a question, I didn't know that was my answer. I don't know, actually, let's take a look. And it's amazing how far those two things will get you. Frankly, not being able to remember it after the second or third time isn't required.
If you just say, I don't know, and look it up, it's a superpower. and so I, I spent 20 years of doing that. then writes off got bought by a mega corporation, Berkshire Hathaway owns MiTek. They make most of their money, working with big production builders in, Some way, shape or form,
There's a lot of different ways they make money, but it's mostly with the, top 10, 20 builders out there. and they kept pushing me into roles that had nothing to do with HVAC contractors and everything to do with builders and that really, I think I spent 20 years working very closely with HVAC contractors. There's a, there is very much a tribe. And they were taking me away from my people and, um, COVID hit and they just ended all training and gave me a totally new job And it was clear that I was never going to go back to teaching. So I quit, and I started this and went back to basically the thing I was doing for them before, except doing it for myself and working with distributors, contractors, trade groups, et cetera, to, to do this stuff. So yeah, fell ass backwards into it. And,and self taught, but self taught from some of the most. Um, knowledgeable, kindest, just awesome experts in the field. I've just been very lucky, putting in those many years to meet the people who can answer those questions that people have for me. and I can regurgitate what they said. that's basically been my whole job. Yeah.
[00:11:52] Ed Smith: It's awesome for the industry. You did take the plunge for me and HVAC. It would have been a real loss if you were not doing what you do. I don't even know how many conferences I've been to in the last 12 months, but you have been on stage teaching people, this stuff, literally every single one of them,
[00:12:09] Alex Meaney: Yeah, I get around. It's fun.
[00:12:12] Ed Smith: you have fun on stage, which we can tell.
But I wanted to ask, how was the leap? Into entrepreneurship. Were you hesitant? Or were you like, no, I'm ready. This is what I should do.
[00:12:25] Alex Meaney: Even when it was Wright Soft and I loved the people I was working for, working with like Bill Wright, a father figure to me. being on the road 40 weeks a year. Get you thinking about the backup plan.it's, that's a lot of travel, like a lot.
I had a business model in mind, and then when COVID hit and they took me away from the HVAC world. the business model was very clear to me that, One, that pre recorded high quality online training,can work when what you're training is how to use the computer, If I'm going to sit in front of a zoom screen and try to learn how to, diagnose an air conditioner.
That's there's a lot of flaws in that. there are whole companies trying to solve that gap andthey're closing the gap, but there's still a pretty big gap there. but teaching people how to use the computer in front of the computer. That's a little bit of a different animal. you've got all the tools in your hands that you would need.and so it was, surprisingly successful. There's a lot to learn about HVAC design and everything is dependent on itself, right? That the number one problem of my job is manual J without manual S is useless and J and S without manual D is useless. If You don't get all three, It's not right, period, So it's not something I can just be like, Oh, let me teach you this part and then set you loose in the world and have you, do better and succeed, you have to know all the components. And So we would try to compress all that information into two days. And I still do because people can't show up to three day classes.
It's too much time out of work. and the, Phrase most often, was it's like drinking from a fire hose, It needs this class needs to be longer and,doing it online. Even if it was just live, we were spreading it out over two weeks or something. You could tell,evaluations are great, but the best evaluation, an instructor who's paying attention gets is the type of questions, feedback, and follow up questions that you get after the class.And there were still things that people were missing that were, tricky and people always missed. Uh, but the, it seemed to be that it was registering better just cause we were spreading it out over, over a longer period of time.
So now when I do the two day classes, everybody gets,a short couple of months of free access to the recorded version.
So they can go back, they could retake the whole class if they want to. Um, and, the other thing it taught me is everybody hates online training. I literally think that maybe, aside from the entertainment factor of being in the room,and frankly, my, the videos are almost as entertaining.
My editor makes fun of me all the time when I make a mistake. Um, but,so other than the locked in the room part, the online training is probably superior in maybe literally every way.
[00:15:09] Ed Smith: Hmm.
[00:15:10] Alex Meaney: But everybody would rather go to the class. And I think it's the lock me in a room thing. I've had a few like doubters, email me back.
They're like, yeah, you were right. I'm glad I didn't go to that in person. This was a better way to do it. Uh, but it does take a certain amount of self discipline. but I don't think it's ever going to go away.
[00:15:26] Eric Fitz: it's like anything there's, if you go to the extremes, like it's not going to be great. There, there's benefits of both. it's really great to be in person. It's an opportunity to meet other people in your field and, hear questions other people are asking that spur you to ask more questions and learn something. But
[00:15:42] Alex Meaney: so I accidentally blended them together. I was trying to replace the travel. That was, I would like to say that it was my goal the whole time of this hybrid thing that I was building and, you know, no, I was trying to get off the road.
Um, and it didn't work out that way, but what came out of it, it was a much better experience, in terms of, learning this stuff.
[00:16:00] Eric Fitz: Nice. Alex,you teed up sort of next set of questions we were wanting to dive into. Mention manual J. You mentioned manual S. Let's start with manual J. Just give us the kind of top level. I know you can't explain it all in five minutes, but like
[00:16:17] Alex Meaney: I mean, I've spiel for you.
[00:16:18] Eric Fitz: everybody listening should know what manual J is, but let's remind folks if they haven't thought about a little while and why it matters so much for design,
[00:16:25] Alex Meaney: A manual J calculation. and if anybody's wondering the J and manual J stands for joule, unit of heat that nobody uses. Uh, andit's a heat loss and heat gain calculation, That's what they're called. He lost, he gained. some people just call them heat loss. the heat gain is implied and it is a complex method.
The interconnected nature of how heat transfers from point A to point B is bonkers, if you're talking about doing like the actual physics of it, the formulas would scare anybody off. and so they break it down into kind of three components, you're high school math, convection, conduction, and, and radiance, split them apart and calculate things that way. Um, and what it does is it, describes the buildings needs. Basically, that, on a cold day, you're going to lose this much heat. so this is what you'd have to replace it with on a hot day. You're going to gain this much heat and this is, how much you're going to need to remove to keep it.
and then of course, moisture as well as a separate component of that calculation, tell you what you would need to do or need to have Um, in order to be comfortable, what it doesn't tell you specifically or exactly is. What nominal size system you need, It tells you how many BTUs the building gains, how many BTUs the building loses. that's what it tells you. It's about the building, not the system, Once you know about the building, you can start solving the building's problems. And that's where you get into manual S Manual S we've identified the problems. Manual S is the solutions. S does not stand for solutions, but I do like to use it. Yousay that it does right. Manual J is the problem. Manual S is the solution. And manual D is the execution. Manual D is how you get it there. if you're using mini splits, which I know is a big focus for you guys, you do get to take manual D out of the equation a bit, at least for the wall hangers and the, ceiling cartridges that aren't ducted in the floor units and those kinds of things. but as soon as you start introducing duct work, how do I get from point A to point B, how do I get the air that I need to the places that I need, that's manual D.
[00:18:33] Eric Fitz: so J is about what the building needs. Sis figuring out like, selecting the right equipment. What's the right solution
[00:18:39] Alex Meaney: finding the solution to the problem?
[00:18:42] Eric Fitz: And I love that. I haven't heard that before. that D is about execution. that
[00:18:46] Alex Meaney: nicely. yeah,
[00:18:47] Ed Smith: just for the record, we love ducted heat pumps too. We're, this is the Heat Pump Podcast. we don't discriminate between ductless versus ducted. they each have their time and place. for how to solve the homeowner's problems in a cost effective way.
[00:18:59] Alex Meaney: Absolutely.
[00:19:00] Eric Fitz: Generally speaking, you know, manual J, manual S and you'll D for that matter. It's not about whether it's heat pumps or something else. It's any kind of HVAC. It's a, it's a building and it's HVAC equipment that we're getting into.
[00:19:13] Alex Meaney: calculations for, uh, wood burning boilers and things like that buried in these books.
Like it definitely does not just have to be heat pumps.
[00:19:27] Eric Fitz: our audience, we were kind of curious to drill into, you what are the special considerations if you're primarily installing heat pumps that you should be thinking about for manual J and manual S. One topic that we've come across is, Adequate exposure diversity and,curious if you could explain what the heck is AD AEDwhy we should care about it just at a high level,
[00:19:50] Alex Meaney: I like to say that, the AED formulas and charts, tell you what any idiot that spent three days in the HVAC industry probably already knows. If you've got a lot of West facing glass, it gets hot in the afternoon. Oh my God. If you've got a lot of East facing glass, it might get hot in the morning. That's where the sun is guys, oh my God. but what the AED procedure and peak and diversity and all this stuff do is try to sort out, what the best solution would be without overreacting, when you're talking about manual J and even, manual S and D, the difficulty is almost never, in heating, Like it's a weird brag on my part, but if you gave me a pencil and some paper, I can doa heat loss calculation off the top of my head, Like give methe formulas aren't complicated. The process isn't complicated. there's very few sort of catch 22s in there. Cooling is where everything gets complicated,
You get some heat from a window in the winter. Hey, bonus. but we can ignore it, Because we're going to have to eat the place when the sun goes down. we've got heat coming in windows in the summer and sometimes it's here and sometimes it's there and it's not happening at the same time. And everything gets more complicated. Um, and so manual J has a way of looking at the building or the zone or the, whatever, to try to capture that. sometimes it's hot, sometimes it's cold process and have a methodology of dealing with that. Um, and that's root of AED, the way I like to explain it is if you had the world's simplest building Just two rooms, one with a giant East facing piece of glass, one with a giant West facing piece of glass, if we just thought of, the East facing piece of glass, having a load. In the morning. Cause 10 AM sun's up shining on the window. We say that there's, a thousand BTUs, a heat coming in through the window. Okay. in the afternoon at 4 PM or 5 PM, there might be a thousand BTUs coming in the West facing window and maybe at 10 AM, the.west side is 500, maybe at 4 PM, 5 PM. The east side is 500 because the sun's not on that window anymore. So if you look at the load of that building at any time of the day, the load is going to be like 15, if we're just talking the windows, like 1500 BTUs. when it's a thousand over here, it's 500 over there.
When it's a thousand over there, it's 500 over here. But if you looked at the load of the two rooms separately, you would probably conclude that each of them is a thousand. BTU because at it's worst part of the day, you're gonna hit a thousand over here and the worst part of the day you're gonna hit a thousand over there. If you size a system for that, the sun isn't in, the west and the east at the same time. We don't have two suns in the sky. So you wouldn't size off of 2000 BTUs, you'd use 1500. It's the highest it gets at any given time. But if you wanted to figure out how much airflow to give. The East side or the West side, you might want to consider it's worst part of the day, especially if you had something to control that airflow, like a zone system, et cetera, et cetera. Right. And so even if we don't talk about like peaks and diversities and we're going to talk about it, but if you just threw that away and just looked at, you what the load numbers are and you added time as a factor, you realize that these load numbers aren't going to add up. and believe it or not, like previous methods like the manual J seven, which is 20 years ago, it would put two suns in the sky. Absolutely. Like the math you would, if you follow the math, you were doubling down on a lot of those, uh, boosted loads.I don't think at any point the difference in the code procedures, changed more than when they went from manual J seven to manual J,they went from something you could do by hand to something that you needed a computer for. a major motivating factor was having a better way to calculate the needs of individual zones versus the total building.
[00:23:47] Eric Fitz: Just a reminder for folks who are just listening, we're going to post a couple of diagrams and some examples here just to bring some of this to life a little bit more, for folks that like visuals. But if you're watching on the video, we've got, just to recap what,what Alex just covered, at a super high level and correct me if I'm wrong here. When someone asks, does this room or does the zone have adequate exposure diversity? Typically that space, if it has a diverse set of, walls that are exposed in a diverse set of directions with lots of windows, that has adequate exposure diversity. And that was a result in a relatively smooth looking curve that you started to describe versus what you said also at the beginning. If You don't have adequate exposure diversity if you've got a room that just has a whole bunch of glass, say, just on the east face of that room.
[00:24:36] Alex Meaney: yeah, I suppose I didn't exactly answer the question asked, adequate exposure diversity is the description of the space zone, home, whatever as to whether or not it has a relatively even temperature throughout the day or whether one time of day dominates it. It's called adequate exposure diversity. Because at one time for a hot second, for like maybe a year, there were unique calculations for West facing walls, East facing walls, South facing walls, North facing walls. They actually opaque surfaces, sunlight on them, at one point, I don't know if this is still true, but like at one point in Arizona. You bought a plot of land, if it fronted North South, it was a more valuable piece of land than if it fronted East West, because of the effects it would have,on the energy bills and the comfort of the home. and so there is a heat factor for walls. And so at one point. It wasn't just windows that they were looking at, It was literally the exposures of the building.they threw that away for reasons of everybody decided it was overly complicated and, they chickened out in my opinion. Manual J was supposed to be the, we're going to do this with computers method. and then. People complained that they couldn't do it by hand. And instead of saying, did you read the first paragraph where it said, this is the one we're going to use computers.they made some changes to the methods and they took out that distinction between, North facing walls for opaque surfaces, and the way it faces. Adequate glazing diversity or adequate window diversity might be a better name for this, but it used to be adequate exposure diversity because we're looking at other things and the name just stuck.
[00:26:26] Eric Fitz: that's fascinating. I did not know that.
[00:26:29] Alex Meaney: Yeah,20 years doing something. You become like a historian.
[00:26:32] Eric Fitz: that was great. That was a bit of a dive into important manual J consideration. But what about manual S there's supposedly a new version of manual S out there. What are special considerations, Particularly for manual s that applies to cold weather heat pumps.
[00:26:48] Alex Meaney: Heat pumps are a technology that's been around forever and ever. they generally weren't capable of doing much heating, back in the day. And so the industry regarded them, as this thing that could chip in to do some heat if you were in like Miami. then, we started developing technology that, made, uh, heat pumps a really viable source of heat. And by the way, if you go back far enough,there might be some really smart people listening to this who are screaming about, ground source heat pumps and water sourcing pumps that, that stuff has been around since like forever. and has always been capable of doing, some pretty good heating. that's absolutely true, but, whether it's fair or not, it was still considered a niche, once upon a time, when we started looking at air source, heat pumps as a viable source. of of heating.we started to, realize we might have trouble, on the cooling side of things with oversizing, it starts to become really difficult up North to, size a heat pump.
That isn't just destroying your cooling load. And the idea that, Oh, it's variable. It'll be fine. Is a, just a really false one. it's hard to screw up heating. It really is the reason that drives most of the decision in the industry is is my homeowner going to call the complaint. The answer is not for a couple of years when you oversize, on heating. but in the short term, it doesn't tend to generate too many. complaints. Cooling is the one where everything can go wrong really suddenly. And it's because, uh, our cooling systems have two jobs and.they use the same mechanism for both jobs, which means if you don't design things in a way that checks both boxes, we have comfort issues and indoor air quality issues and all kinds of other issues.Heating needs to be enough and in the right ballpark, Cooling needs to be pretty precise to work the way air conditioning has always sort of worked. to keep people comfortable. Add to that the chase for seer rating. efficiency very largely has to do with something called compression ratio, which I'm not an expert on, my friends are. Um, but it frankly has to do, if you want to think of it in simple terms with how cold the indoor part gets and how hot the outdoor park gets.
If you can keep the indoor part a little warmer than you might've otherwise done it. And you can do that by making things bigger and forcing more air across them and offsetting the fact that things are a little warmer. you can reduce the usage of the most, uh, expensive energy hog in the system, which is the compressor. And use more of the cheaper components, like the fan to get the same amount of capacity. But what that does is it makes the indoor part warmer. And if you think about condensation, which is like the most important, no, maybe not the most important to everybody, but should be the most important, If it's a little warm in your house, you're uncomfortable.
If it gets humid enough, you'll get sick, Like you, it's bad. It's really bad for indoor air quality. Plus you will be uncomfortable, It's all the problems of the other one, plus a bunch of other problems. and not only Are we overshooting our marks, which, makes it difficult to do that humidity control. we are also just baseline worse at doing that moisture removal than we were.it was less efficient, but when you ran the heck out of that compressor and ran the fan a little less water pours out of the system.rather than trickles out of the system. And so our need for getting it just right is increasing and there's pressure on the market to, be like blow past it. Cause we want to do it for heating, as well. And it creates a sense, or a set of perverse incentives. and so the new manual S. takes a look at, expanding the way we look at heat pumps and what could be considered acceptable in terms of, being able to be a little over on that top cooling number mark. But, are you going to have to do that? the most significant, set of rules that, you encounter are if you're in a dry climate, so you don't have a moisture removal requirement, things get a little easier. and if you. quote unquote decouple, the, cooling and the dehumidification,
If you have,the capabilities to deal with the sort of, consequences of being maybe not completely oversized by the definition of oversized, but like identifying the issue of this might not be able to control the humidity. So we're going to call in reinforcements and do that. It lays out some guidelines about how you could go about that. The trouble is you want to hit this heating number with as much of this higher efficiency, unit as you can. you're tempted to cover more of that heating load with the higher efficiency system, potentially the, sacrifice or to the detriment of, comfort indoor air quality in the summertime, it's a rock and a hard place kind of situation.
[00:32:30] Eric Fitz: I feel like I remember seeing an older engineering submittals. The rate of condensate removal for, lower SEER units was like, it was typically measured like gallons per hour now on
[00:32:42] Alex Meaney: could be.
[00:32:43] Eric Fitz: you're seeing like pints per hour is typically a unit, that you're seeing are definitely fractions of gallons.
That seems right, like the latent capacity of these, this newer equipment, it tends to be lower. you've got higher sensible heat ratios. The amount of total cooling that they can provide, there's a lower and lower amount of actual latent that's in there. yeah, that could be a challenge.
[00:33:05] Alex Meaney: Yeah, there are outliers in studies like that. One of the things that, can be a bit of a dead, giveaway. of something that's, potentially going to be an issue, is, units that have, high EER numbers.EER numbers are the full blast momentary.
How efficient is this thing? Not over an entire season. But on the hot day, when it's running for the full hour, all the way out, the ones that tend to have really high EER numbers that are air to air systems are some of the worst at removing humidity because they are optimized for efficiency as a friend of mine would say,rather than optimized for comfort.
SEER in the case of variable capacity, systems, which the types of heat pumps we're talking about here, the cold weather heat pumps are generally a variable capacity. The incredibly high SEER numbers means that not only does this thing have more trouble pound for pound, removing humidity on a hot day. But that when you see this giant leap from the EER number to this SEER number, there's like double the EER number, that can tell you it's not one to one. It's not a perfect system. Just look up the damn performance numbers and then you'll know. But that's a clue that the thing is going to immediately ignore all moisture removal needs whatsoever, and just run as efficiently as possible.
And as much fan as possible, as little compressor as possible. For a lot of these systems, I've had some access to expanded performance data for a couple of manufacturers that, is not available to the public. That's super fun. Right? That shows what the, performance is at various stages of, compressor speed, and a couple of them. once they pass 85 percent and lower, it's zero moisture. Like literally none in in own testing.
Gets that high SEER rating though, moves it off the shelf.
Yeah. So it's an, it's a minefield. In cooling, your needles and adding the heating component to the same system makes it even more of a balancing act. Right? Imagine you had a scale,where the fulcrum wasn't in the middle. So you had to find, figure out how much weight you had to put on each side to get it to level out. Well, now imagine you've got a single point and a triangular configuration where you have three places. You have to put weight on each corner of the triangle and you can't see where the point is under the middle. how do you balance that? that's what we're doing here. we used to have two things we had to balance. Wasn't super easy, but a ll right. We're balancing two things. Now I have to balance three. the iterations you might need and the ways that can play out and the ways that can go wrong has increased literally exponentially.
[00:36:21] Eric Fitz: And just to clarify those three points, the triangle are energy efficiency, sensible capacity and latent capacity. Do you, are those the
[00:36:28] Alex Meaney: Now I'm throwing energy efficiency out the window just heating, cooling and latent.
Temperature control in the winter, temperature control in the summer and your humidity control, in the summer.
Forget efficiency, I have to be comfortable.
Efficiency has nothing to do with comfort. They correlate, they're not causal,
[00:36:43] Alex Meaney: The BTUs I add and remove are the things that I need to do. And the more. jobs I'm putting in the same box, same system, the the harder it is to find that balance of being able to do now, instead of two jobs, three jobs with the same unit, even if we toss energy efficiency, which I'm not suggesting we do just. But for the moment to discuss the difficulty of the job, as soon as we decide to go this route, it becomes a more difficult balancing act,
[00:37:14] Eric Fitz: And so manual S is about providing some guidance and some constraints saying, Hey,
[00:37:21] Alex Meaney: If you do this, it's going to be
[00:37:23] Eric Fitz: yeah, we gotta manage all these things. And you can't go too far outside that triangle. or you're gonna lose multiple points in that triangle and that's gonna be a real problem.
[00:37:30] Alex Meaney: the things I'm saying about like difficulties in one season, you can be further past your heating numbers than you can your cooling numbers. Heating there's a good amount of wiggle room there.
But backup heating is a thing, right? Cause it literally, it's just one type of BTU, it's all just heat. Like make fire, make heat, Or, electric resistance, make heat like it's not super complicated. And so if you miss your mark on the short side, on, Heating, there are often ways to pick up some of that slack. Whereas if you don't have it on the cooling side, no homeowner is going to add window units to their home as part of their comfort system and be happy with that. And if our goal is energy efficiency, that's, you know, kind of a bad idea to begin with. I'm a little curious to see how some of these, Split window units, actually perform the trick would be getting it actually sealed into the window. Of course, that's the, that's where all the energy actually goes.
[00:38:27] Eric Fitz: Totally.
[00:38:28] Alex Meaney: but I don't know, maybe one day, cause right now it's a pretty tricky problem, is finding where to sit on that, cooling side of things, then again, needing supplemental cooling usually isn't the problem it's usually being. Too far past the, the, the cooling side. so I don't think that's a major solution to most things.
Um, but yeah,don't want to say, you don't have to worry about heating, heating is obviously a, very important, but you're going to hit all the, stupid obstacles and hurdles on the cooling side. Generally,
I'm trying, trying to balance that out is the hard part.
[00:39:00] Ed Smith: So that's it for Alex Meaney part one, if you feel like we were just getting started. You're right. Join us when we released the second half of our episode with Alex, where we get really deep on manual J manual S and heat pumps. Thanks for listening to the heat pump podcast. It's a production of Amply Energy. Just as a reminder, the opinions voiced where those of our guests or us, depending on who was talking, if you like what you've heard and haven't subscribed, please subscribe in your favorite podcast platform. also love to hear from you.
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