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37 minute read
In this episode of The Heat Pump Podcast, hosts Ed Smith and Eric Fitz sit down with HVAC experts Alex Meaney and Nate Adams to discuss the building science, heat pump sizing, HVAC design, dehumidification, rebates, manufacturer data, the challenges of industry regulations, and a whole lot more.
Alex and Nate are two of the most experienced and brilliant folks in building performance, home retrofits, and HVAC system design. Alex and Nate come at things from different perspectives, and what unfolds is a fascinating discussion at the bleeding edge of building science., Alex and Nate share valuable knowledge on load calculations, heat pump rebates, efficiency metrics, and the real world challenges of transitioning to all electric homes. They also discuss common mistakes in heat pump installations, the role of data in HVAC advancements, and the limitations of current efficiency standards. Whether you're an HVAC contractor, energy consultant, or homeowner interested in heat pumps, this episode provides thought provoking discussions and actionable insights for navigating the evolving world of heating and cooling.
Key Takeaways:
- Why proper heat pump sizing is crucial and how incorrect sizing impacts heating, cooling, and dehumidification.
- The challenges of balancing latent (moisture removal), sensible (cooling), and heating loads in heat pump systems.
- How outdated efficiency metrics like SEER (Seasonal Energy Efficiency Ratio) fail to account for real-world performance.
- How rebates can lead to perverse incentives and outcomes.
- Why the lack of manufacturer performance data is a real risk to homeowner comfort.
- Why over-reliance on computer models can lead to poor HVAC design decisions and how field data should drive future improvements.
- Exciting trends on the horizon for HVAC design.
Episode Breakdown with Timestamps:
[02:34] - Introduction and Guest Overview
[03:09] - Guest Introductions and Backgrounds
[04:20] - Areas of Agreement in HVAC Design
[06:55] - Communicating Equipment and Dehumidification
[10:19] - Problems with Efficiency Ratings (SEER, EER, and Latent Performance)
[18:18] - Temperature vs. Humidity for Comfort
[22:59] - The Debate: Sizing for Heating vs. Cooling
[30:18] - The Impact of Building Infiltration on HVAC Performance
[42:22] - The Future of HVAC System Design
[51:33] - Closing Thoughts and Advice for HVAC Contractors
Connect with the Guests:
- Alex Meaney
- Nate Adams
Transcript:
[00:00:00] Alex Meaney: That depends is the most common answer to any question in building science. But yeah, I don't have the answer here. I definitely don't claim to. These are questions I'm asking, not answers I'm providing when we're seeing the same things over and over again and our reaction is, that's impossible. That's stupid because it's happening. So it's possible. Why is it happening? And oftentimes it's for a sneaky reason. It's the sneaky invisible stuff, man. That's the thing. Like a lot of this stuff unfortunately, is incredibly interesting but not actionable. I can't tell Joe HVAC contractor like you should try doing this. It might work. They're out there trying to sell solutions, and they need something that's a little more concrete, something that's easier and safer to stand behind. And where does that bring us?
[00:00:51] Ed Smith: Before we begin. We've been getting a ton of feedback on the pod, and a common request has been to share our top learnings. So we did that with our first book, where we packaged up the top ten Sales Lessons to Grow Your Business. Hear from our guests experienced heat pump entrepreneurs on how they built world class sales teams that consistently win in the market. Click the link in the show notes and you'll have it in your inbox in seconds. Enjoy the show! Welcome to the Heat Pump podcast. We have a super fun episode today. A conversation with Alex Meaney aka the Red soft Guy and Nate Adams, aka the House Whisperer. And that opening clip from Alex sums the podcast up well. We talk about a lot. We get really deep. We have different perspectives on the nuances of HVAC design, specifically focused on building envelopes and heat pumps. I worry a little that more questions are posed than answers are given, but I actually think that's a great thing. Alex and Nate are both brilliant. They know their stuff and they come at things from different angles. Sometimes those differing angles land on the same answer and sometimes they don't. But to me, it felt like this conversation pulled me to the bleeding edge of some of the most fun and interesting topics in building science and HVAC. We talk about heat pumps, load calculations, rebates, and what's wrong with them and what we think the future of HVAC design holds. If you are interested in the conversation around building science and heat pumps, that is equal parts analytical and philosophical, then this episode today is for you. Enjoy the show! Welcome to the Heat Pump podcast. I'm Ed Smith.
[00:02:38] Eric Fitz: And I'm Eric Fitz. We are co-founders of AMP energy.
[00:02:41] Ed Smith: So we have a fun one today. We have Alex Meaney and Nate Adams with us. If you're listening to this episode, you probably listen to the podcast. You'll know that we recently did an episode with Alex, which was great. And Nate listened and sent us a bunch of really interesting thoughts, questions, reactions. And so we brought Alex into the email chain and said, you know, we should discuss. And we realized we should take a part of it. Nate, since you're the newer one to the pod, do you want to start?
[00:03:13] Nate Adams: I'm Nate Adams, often known as Nate the house Whisperer, and, uh, been doing kind of wild retrofits for over a decade now, and then also trying to figure out is there a way to insert home performance into HVAC contracting. And I threw in the towel on that, for better or for worse. Uh, but moving to consumer education first, because one of the things that kind of drives me nuts is I hear a lot of people saying, if clients actually asked me for the right stuff, I'd do that. So I'm going to try and help the clients actually ask for the right stuff.
[00:03:44] Alex Meaney: And I'm Alex Meaney, owner, founder, or whatever of mean HVAC. Once upon a time was the right soft trainer, today still the right soft trainer, but get my dirty little hands everywhere I can to try to help educate. Mostly people in the HVAC contracting space, how to do sizing and determining loads and sizing ductwork and that kind of thing. I'm all over that.
[00:04:09] Ed Smith: Nate. So you and Alex have been texting to kind of like tee up a few things. We've got some topics we'd love to dig into, but I think on the start there was a whole bunch of stuff that you very much agreed on. Do you want to kick off and highlight a few of the things where you had violent agreement on?
[00:04:27] Nate Adams: I love that line of violent agreement. It's hilarious. Alex, you, as usual, summed it up well because I have to say, in sitting in Alex's classes, you don't expect to laugh at a load calc class, but you end up laughing. Um, and then he sneaks things in. But one of the things that you talked about, which I violently agree with, this is why I've been talking about reheat dehumidification for years is we need to now balance three different things when sizing equipment like namely heat pumps. So heat pump sizing is really tricky because you've got your latent load, the dehumidification, you have your sensible load, the actual cooling, and then you also need to heat now too. And then your heat loads generally going to be more than your cooling load, although not as much as I expected. Trying to size and keep those three things in mind. The conclusion I keep coming to when I came to years ago, because my my partner is like, we're going to run a carrier green speed. And I'm like, what's a carrier green speed? I have no idea what the heck I was doing, but we put it in and that was the best product for cold temperature performance until 18, 1920. Somewhere in that range when the mini split started hitting the market. So the carrier green speed is good for about 80 to 85% of its nominal output at five degrees.
[00:05:47] Nate Adams: So if it's a three ton unit, you're getting 85% of three tons. So have a pretty wild client. That first guy, he's. He's fun, but he didn't like cooling the house that much, so he'd only keep it at 80 degrees. And one day he's like, well, I kind of like to see what it does. I'm like, great, we'll set it to 72. Let's see what happens. It never ramped, but the relative humidity fell faster than the temperature did. So that thing ran an icy coil and started sucking the moisture out of the air. That's not efficient, but that's exactly what you want it to do. And it did a wonderful job at that. I'm like, Holy crap, this is amazing. I watch things operate and I learn how they're programed by seeing what they do. So I reverse engineer stuff. But we still had a problem with that because you get into the weather that as we're recording, I presume you guys have similar weather to it's 65 degrees outside, 70 degrees outside, and the night time low wasn't that much lower. So it's humid, but there's no cooling load at all right now. So my house is pegging 6,065% relative because I have a Bosch, which I now hate. Uh, I can't get the coil to run cold if my load is too low. It needs to be a higher load house to use this product.
[00:06:55] Alex Meaney: So are you on the five ton version of it?
[00:06:59] Nate Adams: No, it's a 2 or 3. Mm. Um, but my cooling load is only about a ton here. Our design temperature here is 83 for cooling. We're in the mountains, but it granted we had a lot of 90 degree days this year, and it wasn't humid. So my dehumidifier didn't run as much this year. But last year, every cooling month, my dehumidifier used more power than the heat pump did for doing the cooling. And it's like, good thing it's efficient so I can use twice as much electricity to get the job done. I just assumed I'd have a cold coil. But anyway, back to the green speed that will vary the the coil temperature inside, and it has good cold temperature performance. That to me is a sweet spot of what we want. It's technically possible without communicating equipment, but I haven't seen anybody actually do it. So for me right now I'm at a it's communicator bust when it comes to equipment selection, which is challenging because that's not cheap.
[00:07:54] Eric Fitz: And crucially, the communicating equipment allows for the you can have independent fan speed for whether it's a ductless unit or ducted from the what the compressor is doing. So you can get you can drop the coil temperature, you can drop the fan speed potentially, which also enhances latent capacity and vary those independently. That's the real benefit you get from communicating.
[00:08:16] Nate Adams: Exactly. And you can add reheat in there too.
[00:08:19] Alex Meaney: There are houses that go back a real long time that have nothing but electric baseboard. I'm not sure it's so much people worrying about the access to capacity as access to efficient capacity when you need it. I am of two minds on the reheat. I want to see some efficiency studies, and I haven't seen much of anything that puts them head to head. I know you have some small scale data. Yeah, I'm very interested in that, and I do think it's an excellent solution, but it is very limited in the marketplace. I am not necessarily of the opinion that the environment in a residential building needs to, 100% of the time, be within that magic 45 to 55% relative humidity range. I think momentary spikes are inevitable unless you expand the budget of the of the customer much higher than you know what most people are expecting to spend on a comfort system. I also don't think it's that big a deal. I think a lot of the studies that show that sweet spot humidity ranges is important. The time span, I think, is not like a day. I think they're making time measurements over a much longer period of time. Um, I'm starting to back away from the idea that you have to control whatever the level of humidity is that's coming in the house instantaneously. Like in that moment, the residential marketplace is typically full of building materials that create humidity buffers. If over a longer period of time you have the capacity to remove the moisture it can sustain, you'll see very short spikes that are flattened out by moisture absorption of the elements of the building, and then you hopefully can get ahead of it and draw that back out and create a much longer than an hour cycle when it comes to dehumidification. But this time of year, it's almost impossible to avoid.
[00:10:19] Eric Fitz: And Nate, just to bring it back around Nate, you started off talking about it is hard to balance these three things latent capacity, sensible capacity and the heating for for the equipment. We got to pay attention to sensible heat ratios which is essentially the this ratio between your latent capacity and the total cooling capacity of a piece of equipment.
[00:10:39] Alex Meaney: Sorry. Technically the term is sensible heat factor. Now sensible heat Sensibly ratio is for the building.
[00:10:44] Eric Fitz: The building really factors for the equipment ratios for the building. That's right. Yeah.
[00:10:48] Alex Meaney: It's in an effort. There's a lot of confusion over sensible heat ratio because the term applies to the load and the system. And it's very easy to trip up. And oh I got it. It was actually the brainchild of Kimberly Llewellyn over at Mitsubishi. And we just have a different term for the other side of the fence. I try not to be too pedantic too often, because when your job is expertise, it's really easy to fall in that hole. But this vocabulary is important. Thing is a big thing for me. So yeah, it's sensible heat factor when you talk about equipment, sensible heat ratio and talk about loads just to help people follow along in the conversation.
[00:11:31] Nate Adams: So there's our actually for the episode.
[00:11:33] Alex Meaney: Sorry Eric.
[00:11:33] Eric Fitz: What is great and John from ACA has a good little post on the sensible heat ratio versus sensible heat factor and in some of that backstory you talked about, which is great. Yeah. So what I was going to say is that. What are some of the things that that lead to challenges or changes in equipment? So in the sensible heat factor in particular as it pertains to C ratings over the years, and what I guess I'd love to hear your thoughts about how we focus on or not focus on sear as an important performance characteristic versus these other three things. We've been talking about.
[00:12:08] Alex Meaney: Lack of data.
[00:12:10] Nate Adams: That's there's some of.
[00:12:11] Alex Meaney: That and end of list. We don't require manufacturers to publish latent performance. It's not a it's not a rule. I don't I can get my equipment R rated. There's no latent performance factor, number characteristic anything. And we're allowed to slap these things in. I'm not one to brand bash, but there are multiple mini split manufacturers who have absolutely no Zero. Performance data for latent capacity. And the ones that do like the good ones have it when it's 95 degrees outside, right? They have it at peak load conditions, and it's not when it's 95 degrees outside, it's when it's at full capacity. Right. So not literally because you could take that literally and I would be very wrong. But when it's at 100% capacity is where we get that latent. And that's not where they pinch the pennies. They tend to do that as you ramp down. Um, and so since the vast majority of hours are not going to be at that highest demand, it's running in such a way that we don't know what it does like. It's the most frustrating thing in the world. I'm teaching classes and people are like, how do I know which one to pick? And I tell them, you don't. You? They don't tell you. None of them do. I can't even just say, well, just sell this one brand. It tells you you.
[00:13:40] Nate Adams: Have to buy it and find out. That's literally what I've been doing. And that's part of why I like that carrier equipment, because I've watched it run enough that I trust that it will do what it needs to do when it needs to do it. But I put two Daikin fits in two of our Airbnbs here as an experiment. One house is built in 52, no wall insulation, two inches in the attic, and the one next to it both have one and a half ton Daikin fits that were recommended to me by Roman Borg, who, like, there isn't a bigger Daikin fan out there. That system does a good job at partial load dehumidification, and the fit is a really inexpensive product compared to the other variable speed stuff, but it doesn't have reheat. Like if we have a 75 degree sunny day or more, it would hang on for dehumidification there was enough sensible load to have it do its work because that at full capacity can run 65% dehumidification or 0.35 CHF, which now apparently I need to be paying attention to. Not an SR. And so I've been really impressed with that little piece of equipment, but I didn't know how low the airflow would go on the air handler that's not published. And I asked, and they're like, that's proprietary. It's 234, by the way, is what the screen says and the what's the partial load? Sensible? I don't know for sure, but it has four different dehumidification settings that you can put it on and how it runs. And I picked one and it seems to be working pretty well. But the only way to actually figure this out is literally to buy and install it.
[00:15:12] Nate Adams: That's it.
[00:15:13] Alex Meaney: And what's noteworthy about the Daikin fit when it comes to efficiency, it's just below the line for most rebates.
[00:15:26] Alex Meaney: It they can't quite because there is a trade off. Yeah. As soon as we chase that really high number. And when it comes to a lot of these programs, the seer is a thing that they put in there, I think, to make it look like we're trying to save the homeowner money. There are several aspects about the goals of these programs that 1,000% save every homeowner money. That's the nature of a lot of these programs. But I've never seen a system that could pass the air test that couldn't pass the Seer test. I don't think it exists.
[00:16:08] Nate Adams: Could you define that, by the way?
[00:16:10] Eric Fitz: Because let's back.
[00:16:11] Eric Fitz: Up.
[00:16:11] Alex Meaney: Air is the energy efficiency rating. Seer is the seasonal energy efficiency rating. Air is at full demand. This is how much it costs to move a BTU, and Seer is over the runtime of the unit. In these simulated conditions, they have a standard set of conditions they run it through to simulate the seasonal effects and impacts of. For those of you listening, I keep moving my hand in a rainbow sort of shape here that over the arc of different temperatures as it rises, those temperatures rise and fall, and you rate the performance that way. And particularly with variable capacity systems, you can get really huge discrepancies between air and sea for a handful of units out there, like we have a 30 year heat pump. Yeah. Congratulations. It probably does absolutely zero moisture removal unless it's 105 degrees outside, because there's more than one way to save a to save a dollar cooling a home. But the easiest way is to decrease the compression ratio. In other words have the indoor unit run a lot warmer. Use the compressor less because it uses the most electricity. Use the fan more to blow more air across that coil so that you're squeezing more BTUs out. And it's got that rating and it's you put it in the Re lab and off we go. And it's got 30 seer. But if you actually ran it that way in a climate with any humidity it would likely be a nightmare.
[00:17:43] Nate Adams: So another way to look at it is we are all in just about everything in our lives, looking for one key metric to judge things by yay or nay. I haven't tried this analogy before, so let's see how it goes. But imagine you've got two piles of crap and one of them is a sensible pile. Yeah, and the other one is a latent pile. What seer does is pretends like the latent pile doesn't exist, and it does a really good job of cleaning up the sensible pile of crap. But the fact of the matter is, you're still left with a pile of crap and that work needs to get done.
[00:18:18] Alex Meaney: people do not like to make the choice between temperature and humidity, but if you gave them two rooms that they could go hang out in for an hour, and one of them was 75 degrees and 80% humidity, and the other one was 80 degrees and a 50% humidity. They're going to go stand in the 80 degree room, or it is more important to the average human's level of comfort, and we do nothing to rate it whatsoever. Yeah. It's nuts.
[00:18:48] Nate Adams: That's routinely when you walk into a house that has a 65 to 68 degree set point, what they're trying to do is reduce the humidity. But the bad part is then you're routinely getting the surfaces below the dew point, so you get condensation on them. And if there's dirt on them, which there always is, you get mold. You really shouldn't cool a house to below what the outdoor dew point is in general.
[00:19:10] Eric Fitz: People are running outside, potentially setting their thermostat at, say, 68 or 67, well below, potentially below dew point, because that's the only way that they can get their unit to run long enough before it satisfies the sensible, which is your thermostat and actually have a chance at Dehumidifying dehumidifying and getting some of that moisture out of the air.
[00:19:32] Alex Meaney: And it depends a little bit on the unit, like that story of somebody turning their thermostat way down to control humidity was a more likely occurrence 20 years ago, because when you had a ten Seer unit, it took two steps forward on humidity and one step forward on temperature. The net result was a drop in relative humidity because, as most people listening would know, and you drop the temperature of the space of the air if you don't remove any moisture along with it. If the literal molecules of water in the air doesn't change, relative humidity is going up. Relative humidity is relative to the temperature. And so when you use a low thermostat setting to control humidity, it has to be cooling in the right proportions to even do that. So the lower the temperature to be dry is something that occurs, although we're getting less and less of that as being an effective means of doing it and or achieving that level of humidity that we might want. And so instead, there's an occurrence that some journalists coined women's winter, which is summer.
[00:20:47] Nate Adams: It's a funny video, by the way.
[00:20:49] Alex Meaney: I haven't even. Oh is it, do they have like a.
[00:20:50] Nate Adams: There's a video.
[00:20:52] Alex Meaney: So what you end up what you end up having is men tend to have more body mass. On playing the averages here. We definitely tend to have denser body mass. We're better insulated as a result. We also tend to have a higher body temperature, and we tend to sweat more like our sweat reflex kicks in faster than it does for most women. And so what you get is a guy turning the thermostat down not until he gets to 50% relative humidity, but until it gets so cold, there's no sweat on their skin. And that might be 68 degrees, but I am well enough insulated that can be comfortable in that cold temperature, whereas I've blown way past the temperature where an average woman might be comfortable and they weren't having that sweating problem back when it was up at 75 degrees. There's where that giant disconnect is. It's like, why the hell do you have to make it so cold? And not many people can give you the answer because it's just because I'm uncomfortable and it's uncomfortable and it's summertime. What do you do? You hit the down arrow. That's how that works. And so they just hit the down arrow until they're comfortable. When you don't control humidity. If the only needle you can move is temperature, you can create an environment very easily where you cannot create an indoor environment where your average woman and your average man will be comfortable at the same time, somebody's going to lose on it. This happens in homes every day. If your thermostat.
[00:22:28] Nate Adams: Wars.
[00:22:29] Alex Meaney: Life if.
[00:22:29] Nate Adams: It's a classic. I have it.
[00:22:32] Alex Meaney: With your husband. This is where a lot of it comes from. This is like the physiology behind it, but it's so pronounced that it's women's winter because in the office it's like this. Because our commercial systems are oversize to degrees that make me very mad.
[00:22:48] Ed Smith: So guys, this is the question that was on my mind as we've been talking about this. Our target audience for this are are contractors who are looking to build heat pump focused businesses. Right. What should they do?
[00:22:59] Alex Meaney: So it's not like it's better with an air conditioner. The only reason that heat pumps make this more difficult is the desire to upsize the heat pump. When your climate is such that you would need more capacity in the winter than you would in the summer, which is frequently the case, particularly in the retrofit market. You need more muscle in the winter time than you do in the summer, and this is where our incentive programs get a little annoying to me because partial measures are not being rewarded anymore. Baby steps are not good enough, and so it has to be all the way in on electric. You have to be pulling the gas meter. That's a wonderful goal. But not everybody does have the means. And we're pumping money into the marketplace in areas where only the people with the means can afford to do it. We're being strongly encouraged by the marketplace and the artificial influences on that marketplace to make these decisions based on heating load alone, and just throwing that balance of cooling and dehumidification out the window because quote unquote, it's variable and we'll figure it out. I hate.
[00:24:12] Nate Adams: That line.
[00:24:13] Alex Meaney: I know right.
[00:24:14] Nate Adams: I hate that line. Variable will not save you. It will not. They don't dial down low enough in running some numbers years ago, if you put in a three ton full variable speed heat pump into a house, and I just modeled a three ton heat and a two ton cool, that couldn't match the load 50% of the year. So you're still missing half, and that's being able to dial down to three quarters of a ton. If you make that a two ton and you can dial down to half a ton, that would cover you 60% of the year. But there's still 40% of the hours in Cleveland that you couldn't cover with the true load match. Now, it doesn't matter as much in that temperature range. That's when the dehumidification matters more. But if you put a five ton in, it's wrong for that house. I don't know, 80% of the year, something like that, maybe 90% of the year. It doesn't save you. What I do is I try to size between heating and cooling, and I make up for whatever heating I can't do with strip heat and usually staged strip heat. And one thing people don't realize.
[00:25:14] Alex Meaney: Is that you can't do for dehumidification with the same strip.
[00:25:18] Nate Adams: What's the same strip exactly? When the heat pump can't keep up? If you have a good control, it doesn't shut the heat pump off and flip the strip. That's not how it works. It uses especially if you have multiple states. Another thing that I love about the carrier, they have a three stage backup heat strip and it's a three, six, nine. And that is a wonderful piece of equipment because nine kW is basically 30,000 BTUs. I'm sure I'm off by 500 or whatever, but it's pretty darn close. Um, and that's a really nice level of backup. Also, that will fit on a 100 amp panel most of the time.
[00:25:50] Eric Fitz: And this is what manuals says that we should be doing for heat pumps, even if they're modulating inverter based heat pumps, we should be looking generally at cooling, making sure that the equipment has the capacity to meet latent and sensible cooling. And then if that means you have to undersize the unit from a heating perspective, that's where you need some kind of backup heat strips.
[00:26:13] Eric Fitz: Uh, so to both of your points, I feel like. So there's a lot of different equipment out there, so I would. Recommendation is to like know the equipment that you're installing if you haven't tried to. Find this data. If you're not aware, if the data exists try to find it. Hopefully it's available. And if it's not, you should go talk to your distributor. Hopefully you can maybe reach the OEM and ask for it, because it's crazy that if we're being asked to do things like manuals, we're trying to do things like actually create comfort in people's homes. We need to know this basic performance characteristic. What is the latent capacity of this equipment at these different speeds in order to do the right thing? There are new models coming out all the time. I was just looking at a ductless unit that has a 4000 BTU nominal capacity. Ooh.
[00:27:03] Nate Adams: That's nice and low.
[00:27:04] Eric Fitz: It's really small unit and it's turndown ratio is like 8 to 1. So it can vary from 2000 1500 BTUs way up. And so there's ducted equipment and there's ductless equipment that's coming out that that have these incredible ranges through. It's continuously variable. That helps address some of these challenges. But every piece of equipment is different. There's some interesting nuances with the 4 or 5 stage.
[00:27:33] Nate Adams: And I want to push back to.
[00:27:34] Nate Adams: Those.
[00:27:35] Nate Adams: Of us who.
[00:27:36] Alex Meaney: Might still be oversize for your average small bedroom.
[00:27:39] Nate Adams: Sure.
[00:27:39] Alex Meaney: In a cold climate. Right. Like still not low enough.
[00:27:44] Nate Adams: exactly.
[00:27:45] Alex Meaney: You're still not putting it in every bedroom with that. That's just not. Yeah, yeah, not quite there.
[00:27:50] Nate Adams: But what really concerns me here is we learned in the 70s when we tightened houses up, we have less natural airflow and we don't control moisture very well. We get sick building syndrome. Um, we are very quickly headed for redux of sick building syndrome. There's a number of lawsuits brewing in the South with new homes where they're sizing the heat pumps for heating, but they actually need to dehumidification. But it's a single stage unit so it doesn't dehumidify. Plus we're moving to 15 here now. Equipment, which means sensible heat ratios are getting in the 0.85. Sensible heat factors. Excuse me are getting to the 0.85 range. So like everything we're doing is running towards making homeowners sick and making buildings rot. And I hate that.
[00:28:36] Alex Meaney: I wouldn't say it's a problem of tight buildings, because that's the thing about being in the South, right? That's the whole Joe Seabrook versus every other human on the ashtray 52 committee, by the way. Team Seabrook over here saying that we've gone from build a tight and ventilate it right. To build a tight and over ventilate it. Right. You reach a point somewhere around the Mason-Dixon line where you're letting outside air in, at least on the East Coast and South Coast, and that would be worse. The internal sources of humidity are less than the external sources of humidity. Yeah. So I think it has more to do with the equipment and its regulations. Man, they they fight last year's war.
[00:29:14] Nate Adams: That's a good way to put it. I haven't heard it that way.
[00:29:16] Alex Meaney: I'm actually butchering a quote that I can't quite remember.
[00:29:20] Nate Adams: No, but that's not wrong, because here's what we learned last year. So we're going to adjust to that. But actually what we're adjusting is now wrong. We just don't know it until next year when we'll try to readjust.
[00:29:30] Alex Meaney: Between that and the law of unintended consequences, you get the mess that we're in. We're going to start putting these things in. It's quote unquote the fault of the equipment. But it's a big ball of tangled mess like it is misused application. They did tell us what the capacity of that system was. And we decided we wanted to oversize it. Right. Oversizing is at the heart of a lot of these examples as being the big problem, right? A little plug to the actual goal of Amps mission here is to make sure that you do size that thing right, and chasing heating loads is probably a bad idea 100% of manual J loads for heating, not for cooling, for heating. 100% of manual J loads basically doesn't happen.
[00:30:19] Ed Smith: We're doing more trainings and we're starting more and more conversations with the question, what do you worry about more heating or cooling? And overwhelmingly it's not just due to the rebate programs. The answer is heating. No one's tracking humidity except for folks like us. And they don't know like us 6570. Like that's uncomfortable and it shouldn't be that way. But, um, if you're cold in the winter, that's not right. It's just simple. And then they're avoiding the callbacks.
[00:30:47] Alex Meaney: A lot of this conversation was tripped because on the last podcast, I said heating is easy. There are complications in heating. When you have a bad building envelope, you will always, in this industry, have a moment where it's like, oh, I thought I understood that. Shoot, let me read and find out how little I actually understood it and find out how complicated it really is. I'm not deep enough on that process. I think on infiltration and ventilation that Seabrook is hits is like elections. All infiltration is local. If you have an infiltration point in your living room is uncomfortable, and if that's the room that you live in, then that's a problem. I don't care if you have enough capacity within the home. If it's not being delivered to the place it needs to be, that becomes a problem. Hvac already has too much stuff that everybody needs to know to be good at their job. To lump the entire industry of building science on top of that is difficult. If you take a home that is poorly insulated, 68 degrees is uncomfortable. It's that Robert Bean MRT right in radiant temperature.
[00:32:01] Alex Meaney: Sometimes being able to maintain 68 degrees is a callback. Not being able to pinpoint why it's a callback is not surprising. And so lots of people have had lots of complaints in cold climates.
[00:32:15] Nate Adams: Let me throw something out here. So in doing the energy audits that I did for years, I would get energy bills from people. And one thing that I noticed was we'd have a cold winter and I would oftentimes get multiple years. People would come out with a big folder because I generally got engineers as clients. I'd look back two, three, two years, three years, sometimes ten years. Some of these people, Holy cow, how many, how much paper they have still sitting there. But I noticed that on houses that had reasonable shells and reasonable shells basically just means 1980 and later, because basically our building practices haven't changed much since 1980, at least in Cleveland, where I've seen a ton of houses because I've been through 1500 ish houses, something like that. And I noticed that the tighter houses saw a 15% increase in gas use, and the loose houses saw a 40% increase in, in usage. And I'm like, all right, this is not a straight line thing. So the challenge with infiltration is when you get stack effect really rolling, where the house acts like a giant smoke stack, your load goes vertical. Now, I don't think it's fully vertical. I don't even know that it's a square, but I bet it's like to a one and a half power is the slope of it, but it's no longer linear anymore.
[00:33:23] Nate Adams: And what I also noticed was 300 therms per year of heating was roughly equal to a ton of heating in Cleveland. Yeah, it was interesting to find that. And so I figured out how to disaggregate quickly, pull out the heating from like the water heat usage and you could get reasonably close. And that helps give you confidence. In fact, in some ways it gives me more confidence than the blower door, as long as I have some idea of what their set points are. Because I had one client that was like, oh, I only use 800 therms like, that's not bad. Like, where do you keep it in winter? 55 degrees? And I'm like, oh, that's not low anymore. And I went and ran it and sure enough, it has a crazy load. The first visit and the second visit ended up having six months in between. So it was an 80 degree day when I was there. I turned his air conditioner down three degrees. It was only 80 or 82 degrees outside. The temperature never budged. It didn't actually cool because the house was too leaky.
[00:34:21] Alex Meaney: Again, Joe Seabrook, but he's where I found the information. References decay test studies like CO2 decay. When we do blower door analysis, we're applying pressure to the building. Yeah. And the further you get from where things were calibrated, the less accurate your data becomes. The gap between the poor construction and the good construction with blower door test looks this big. And I'm spreading my hands wide here, obviously. And the gap in the decay test, percentage wise is much smaller in terms of performance, because on a daily basis, the pressurization isn't at 50 pascals. It's going to it's going to perform differently. I do think infiltration is a very big and very important part of the load, and it's the no brainer of no brainers in a cold climate to stop air infiltration.
[00:35:20] Nate Adams: Although it's good luck finding the contractor to do it is the problem. Every time I've recommended someone, I've gotten bit, with one exception, and Gary stays so busy that I can't hardly recommend him. But to your point, um, I agree. What I find is like a manual j calc when I run one is actually not that far off from reality on these leaky homes, but on a tighter home. Reality is about half when I actually watch runtime on the equipment. I guess I have a big question on this, which is is if there is a manual J version nine, is there some way to put. I don't even know exactly what the calculations would look like, but I look at energy use.
[00:36:03] Alex Meaney: I do some work for ACA. I don't work for ACA, and I'm not able to represent them in any way on this subject. But if Manuel Jay does come up for a big revision, I think there needs to be two paths. There needs to be a retrofit path and a new construction path. It is a little climate dependent. The problem is you need you need to study it and have a standard. And that means collecting piles of data. I've been very vocal about begging power companies whenever I can get my hands on somebody who works in that world to just buy a butt ton of thermostats that contain data loggers and instead of the incentive program being will give you free stuff. If you let us shut off your air conditioner on the hottest day of the year, which very few people want to take them up on, and the ones that do often don't realize they've done that.
[00:36:57] Nate Adams: And then they howl when they do it.
[00:36:58] Alex Meaney: Instead, trade it because they're not that expensive. Trade it for the data. Data trumps everything. Field data like the actual field data. Yeah. Not this computer model BS. Right. Like an actual. We. We lived in this house. We had data loggers. This is what happened. I'm starting to be more and more confident that the problem with a lot of these homes is zonal pressure.
[00:37:26] Nate Adams: You have a bedroom that's getting pressurized by the HVAC. Something like that.
[00:37:29] Alex Meaney: Well, bedrooms, the entire second floor. Right. The return is in the hallway. We close the doors and go to bed. Right. And it's just pumping all the air out of the house and sucking all that air back in. Right. Because I'm betting those decay tests done in the 60s or on older homes in cold climates. I'm betting a lot of them had radiant style heat, baseboard, radiator style heat where those pressurization problems were not present. Exacerbated test.
[00:37:58] Nate Adams: That's what my old partner Ted Kidd noticed in doing tons and tons of audits and looking at bills. He's like the radiant houses and the houses with variable speed furnaces, the modulating furnaces, those would have energy usage that was way lower than it seemed like it should be.
[00:38:14] Alex Meaney: not so much an energy perspective, but an HVAC perspective. We've never really cared that much about being that precise on heat and the source of the problem and the because the solution to the problem is more heat generally.
[00:38:28] Alex Meaney: Easy solution. And it's a cheap solution, relatively speaking, especially when you're talking about the equipment side of things. And so hundreds.
[00:38:36] Alex Meaney: Year big discrepancies in manual J between field tested data and what the calculations say it should need. Thermal mass is not something that we are accounting for. But I had an engineer take me to task and. All right, let's do the math. And we did. And it could account for maybe 10 to 20% of it, tops, and.
[00:39:00] Nate Adams: Might be more in a brick house. Brick houses were totally screw you. Oh yeah.
[00:39:05] Alex Meaney: Or like a concrete and not concrete. A stone farmhouse or something.
[00:39:08] Nate Adams: sure. Once they go cold, you're screwed. But yeah. Regular stick. Yeah. Not really.
[00:39:13] Alex Meaney: And when I say 10 to 20%, I should actually be more accurate than that. Like, it would predict that J might be off by 10 to 20%, but the numbers that a lot of people are showing are like 30, 40, even 50%. So there's a huge gap between the physics say it should be doing this and it's not. And thermal mass may have something to do with it, but it's not. It can't account for the entire discrepancy.
[00:39:42] Nate Adams: So Alex, I'll push back a little bit on the zonal. I think that's definitely a piece of the puzzle. I think that's going to be primarily a housing type problem. So I think about in like old houses in Cleveland. They would run supplies but not returns. And those were the rooms that you would see would get pressurized in the south. You'll see central returns and not returns in bedrooms. Pretty often in old homes you'll see supplies but not returns, and then a central return, which oftentimes looks like the basement stairs. And yeah, I could see some issues coming there. But the real problems for heating are the cold climates. And I think that's primarily stack effect driven now cooling. Yeah, it can be a problem. There's definitely a zonal piece, but I think it's usually a secondary thing to the blower door usually. Not always. And it's going to depend on exactly which house we're looking at. Yeah.
[00:40:33] Alex Meaney: that depends is the most common answer to any question in building science. But yeah, I don't have the answer here. I definitely don't claim to. These are questions I'm asking, not answers I'm providing when we're seeing the same things over and over again and our reaction is, that's impossible. That's stupid, right? Because it's happening. So it's possible. Why is it happening? And oftentimes it's for a sneaky reason. I have sent this study to so many people. I keep it in a I have a quick link to it in a cloud drive. I did a study that shows oversize and cooling equipment doesn't increase energy bills. In fact, they have a scenario where they oversize a system and it decreased the energy bill. That's true.
[00:41:20] Nate Adams: Psc motor?
[00:41:21] Alex Meaney: Nope. It was the. It's the sneaky invisible stuff, man. It was duct leakage. Oh, yeah. Duct leakage and pressurization of the. There was a lot more supply duct than there was. Return ducted. Pressurize the envelope. Pumped a bunch of hot air into the space and energy bills went up. So there's a lot of, like, sneaky, invisible things that happen. And that's the that's the thing. Like a lot of this stuff unfortunately, is incredibly interesting but not actionable. I can't tell Joe. Hvac contractor like you should try doing this. It might work. They're out there trying to sell solutions, and they need something that's a little more concrete. Something that's easier and safer to stand behind. And where does that bring us? It brings us blower door testing and ducklings.
[00:42:06] Alex Meaney: For sure.
[00:42:08] Ed Smith: We've had this interesting arc. We started talking about sear ratings and equipment today and how you actually do sizing today. And we're ending with a bunch of questions that feel like they're on the bleeding edge of HVAC system design. So I got a question. I'd love each of you to weigh in on. What do you guys think the future of HVAC system design looks like?
[00:42:28] Alex Meaney: Ooh! Data. Data. Data. Data. Data. Right, I don't think I think the future is going to be bumpy and ugly. And we're going to have a lot of misspent money and ineffective programs if we don't test the freaking houses. We have so much of what we work with is based on computer models that aren't able to capture the sneaky things that happen when you change this thing, and the confidence with which our policymakers will refer to a modeled outcome and treat it as though it can't possibly be anything than what that data says. And my other hope is that we finally come up with a required metric for humidity control in our cooling systems. And I think if we could broaden the scope of the things we look at and look at larger outcomes, we could probably or hopefully make some better policy decisions.
[00:43:31] Nate Adams: All right. So I'll start off with violent agreement. Yeah. So the efficiency standards I think have actually made equipment significantly worse at this point. We've gone too far with the efficiency standards. Not that efficiency is bad. I think we're riding the ragged edge of where anything further doesn't make sense. We need to look at the system for one. I actually like the steps in ACA. So you figure out what your loads are. You figure out what equipment you can use to do that. You figure out what size ducts you need, and then you figure out what the terminals are. Sometimes I don't know that many people that actually do manual T if you do, but it's not common when it comes to manual S, like I've never actually done the whole series ever, because I'm usually just replacing the system and then making some adjustments. I'm dealing with the newer equipment ductwork, but I'm very seldom running a new system. So when it comes to manual s, I just need to know is it two tons or three? And am I using the VNA for the VNA eight? That's my equipment selection. And what's unique about those systems is they will work in literally any climate. I don't really pay that much attention to the equipment selection, aside from being somewhere between heating and cooling. And then the duct design is usually informed by the cooling, usually because that's oftentimes the higher air flow. And then I go from there. But I like the process of it. So I think that's a solid process.
[00:44:52] Alex Meaney: So it ain't broke.
[00:44:54] Nate Adams: No. But what's broke is manual J for heating. Unfortunately I find useless for cooling. It's fine. It's close enough on cooling. No problems, but for heating it's too far out. One of my early projects was an electrification at all. It was just a shell project. Um, but the heat load was done with treat, which is a New York based program, but it came in at 67,000 BTUs, is what it was. I watched that system run, and the actual load on a design day was about 28, 28,060 7000 are really different, really different, more than 100% apart from each other. And I watched that happen again and again. And what's the problem there is if you get a 67,000 BTU load, are you going to select a heat pump? Hell no. You're going to be scared. But the reality is a three ton heat pump for that 1959 2300 square foot house in University Heights, Ohio. Outside of Cleveland, a three ton heat pump was the right piece of equipment for that house. But until the calculations start showing that we're not going to move to full heat pumps and we're going to be stuck on hybrids. And hybrids aren't the end of the world, but I find them inelegant, frankly, from an engineering perspective. Like, why have two fuels when we really only need one? Can we move to where the equipment selection is not nearly so challenging for one, because they have these wide ranges and the die can fit in particular. Gives me a lot of hope on that. If that is like you mentioned, Alex, can it actually get over some of the efficiency lines that we're looking for?
[00:46:29] Eric Fitz: Nate, for that example where you had 60,000 BTU design load with, you weren't actually using manual J. That was actually this. The other tool, the treat tool.
[00:46:39] Nate Adams: That was treat. Yes.
[00:46:40] Eric Fitz: Okay. I'm just curious.
[00:46:42] Alex Meaney: You did that with manual J. Like, uh. Um, who who did the study? Cadmus. I don't know who they are, but they did a study and published it. Yeah, but yeah, it's. And so it was.
[00:46:55] Nate Adams: With.
[00:46:56] Eric Fitz: Blower door test data. I guess my question is.
[00:46:58] Alex Meaney: Eventually did do blower door test. Yeah. The they did their own loads. They had contractors do loads. Funny enough, the contractors were more aggressive in sizing overall. Yeah. So nice job there. But but it still ended up showing significant significantly less energy use than expected based on those loads. And this is no surprise, we've been doing freaking operating cost estimates for decades and just throwing in a 0.7 multiplier to true. The answer that was it was literally an Ansi standard at one point. So take your heating load, but take it easy there. Take 70% of it, because there's this mystery stuff that we don't know anything about. And it's because the consequences were not there. Now we're experiencing consequences. We should freaking try to do something about it. The problem is, I don't think we know what the problem is. I think we need to measure. I think we need to test. I think we need to study and base our answers on that. But I do think a nice short term bridge is using power consumption data for sure. Expandable equipment. Okay, we'll start here and we'll add some electric strip as needed. The the other thing I always this isn't a thing to say at the end of the podcast, I apologize. But like we talk about a lot of this stuff, one of the things we often don't talk about is affordability. And I know economies of scale go a long way for some of that, but we often get so laser focused on our metrics that we lose sight of the big picture. Maybe. And maybe you're right. Maybe we don't need to increase our efficiency, because by the time we do, we need to add so much dehumidification that it it defeats the point. Um, maybe not right up north. That's not true. Shoot. Alabama. Their electric grid spikes in the winter. Yeah, like heat strips. Yeah.
[00:48:51] Nate Adams: All of the South is winter.
[00:48:53] Alex Meaney: Dominated electric grid. Taking that into account, you might be able to tolerate a little more increase in efficiency, I think, by the way, and this is not my idea at all. If we are going to continue to chase efficiency, we're going to see small scale chillers, because the only way we're getting to these higher efficiency ranges are with chemicals that are way worse than a wells. And so you'll need to keep them outside the house and use a media of some kind to transfer that heat. And we have that technology. They're called trilogy. You pump water and keep everything outside or.
[00:49:28] Nate Adams: Air to water heat pumps. Yeah. That's where I think we're going. We're going to go to monoblock next time because we'll be running propane and carbon dioxide.
[00:49:34] Alex Meaney: We're gonna we're going to be using chemicals that are that need to stay outside. And that is probably a general direction. But I don't care what the solution is. I don't claim to have it. I just want us to study the real problem in the actual world. Ah, that's really all I hope for. And then let the smart people figure it out. But let's look at the bigger picture and collect more data than your little study needs would be awful nice, especially when it's cheap and easy to do. For any nerds out there, want to ruin their day about the state of science in the world, read a book called Bernoulli's Fallacy. It's incredibly technical at times and gets way into math and statistics, which is a branch of math that is notorious for being hard to follow. It turns out, by the way, that the reason for that is it's as arbitrary as it feels when you're learning statistics, your brain doesn't want to grab a hold of these concepts because it's. But why? But how? Isn't this math? Aren't you supposed to explain it to me? It's. No, it makes this shape always does it, though. No, we're going to pretend it does. There is a reproducibility crisis, mostly in the soft sciences, but they are not by any means the only place we see it. We develop a study because we know what answer we want to see. We narrow our focus of the study to control the costs, and we aren't interested in finding counterfactuals from the bad results we create. We just tailor it to what we want our results to be. And I it's.
[00:51:16] Alex Meaney: doom and gloom and bummer. And yeah, sorry I kicked this topic off, but it I think it really points to the biggest overlap between your point of view and mine, Nate, is that we're not looking at this at the right way. Whatever it is.
[00:51:33] Eric Fitz: I want to throw a.
[00:51:34] Eric Fitz: Couple ideas out there. So I totally agree. We need some more data. We need to study this more carefully. There's ways that we can improve existing standards like manual J, manual S that are grounded in field studies and especially as it pertains to this newer equipment in the near term. Knowing that and manual J talks about this specifically that there is a safety factor already built into it. You should be aggressive. That is the guidance. So if you are unable to completely verify a particular assumption, be more aggressive. Go for the higher amount of insulation. If you're not 100% sure between the two values that you're guessing about, and if you are more aggressive, you're less likely to end up in a situation where you're over sizing, whether that's in the heating season or the cooling season. And also, I just this brings up a lot of Bruce Harley, who is a national, really a global expert on heat pumps specifically. And a lot of these different topics were discussing. I'm hoping at some point we can get him on the podcast. He's been doing some incredible work with the Department of Energy, with Canada on actually developing new standards for testing heat pump equipment that much more closely matches real world conditions, both in the cooling season and in the heating season, to hopefully get some better data about the actual performance of this equipment and improve the rating systems. And I think that's a whole other topic for a whole other podcast that we can get into.
[00:52:58] Alex Meaney: I all right. That could be yeah.
[00:53:03] Ed Smith: On that, Alex took us to a point that felt a little pessimistic, but it's nice to end on an upswing. And Alex this was awesome. Cool. Thank you guys for joining the Heat Pump podcast.
[00:53:15] Alex Meaney: Awesome. It was.
[00:53:17] Nate Adams: A pleasure. Guys thank you.
[00:53:21] Eric Fitz: Thanks for listening to the Hip Hop podcast. It is a production of Ampli 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 at Complete Energy Now.com just dot energy. Thanks a lot. Thanks for listening to the Hip Hop podcast. It is a production of Ampli energy, and just a reminder that the opinions voiced were those of our guests or us, depending on who was talking. If you like what you've heard and haven't subscribed, please subscribe on your favorite podcast platform. We'd love to hear from you, so feel free to reach out! You can reach us once again at hello@amply.energy. Thanks a lot.
