Reuben Saltzman

PODCAST: Air conditioners and myths about R-22 refrigerant

Bill, Tessa, and Reuben discuss how air conditioners function, why it’s extremely unusual to have an undersized air conditioner and the end of R-22 refrigerant. Older air conditioners that contain R-22 refrigerant are typically going to be cost-prohibitive to service, but it’s not illegal to do so.
We also mention a video compilation we assembled showing 60 home inspection defects in 3 minutes. One of those was an iced-up evaporator coil melting all over the place while the furnace ran.

To know if your air conditioner contains R-22 or the newer R410A refrigerant, check the label on the unit outside.

R22 vs R410A


The following is a transcription from an audio recording. Although the transcription is largely accurate, in some cases it may be slightly incomplete or contain minor inaccuracies due to inaudible passages or transcription errors.

Reuben Saltzman: Why do we call it an air conditioner? All it does is cool the air, why not just call it a cooler?


Tessa Murry: I feel like I’m gonna get this question wrong.




Bill Oelrich: It’s okay Tessa.


TM: Well, AC units remove heat from the air.


RS: Well, heat and…


TM: Moisture.


RS: Exactly.


BO: Welcome everybody, you’re listening to Structure Talk a Structure Tech presentation. My name is Bill Oelrich alongside Tessa Murry and Reuben Saltzman. We’re gonna dive in. Sorry, what happened?


RS: Thanks. I’m just interrupting, I wanted to say hi, I’m excited.


BO: Oh, all right. Well, very good. You’re excited Reuben, so why don’t I hand it off to you right now, and you just tell us everything we’re gonna talk about today.


RS: Oh, man, I figured we talk about air conditioners and the current state of affairs related to home inspections and COVID-19 protocols, and the governor’s end of the stay at home order, and all that stuff. We’ve got so much to talk about, this is gonna be a three-hour podcast.




BO: Well, we have 45 minutes to get this wrapped up, so talk fast.


RS: Yeah, we’ve been going longer and longer. We’ve eliminated our commercials, and we’ve been going like long-form now, and it just gets longer and longer. We gotta get back to a 20-minute podcast, I think. Let’s…


BO: Yeah. All right, well very good. So you’re excited about air conditioners, why exactly would that be?


RS: Well, it’s starting to warm up in Minnesota, I’ve actually heard people talking about turning on their air conditioners. Now, for me, I think it’s crazy. Tessa you and I have talked about this. Like, you probably already have your air conditioner on Tess, and Jay probably hates that.




RS: But I’m with him. I’ll turn on my AC when it gets to about 90 in my house or above, then okay, fine AC. But below that it’s like I’d rather walk around in shorts. I love the warm weather. But I know there’s a lot of people who don’t that I’ve already heard from people who are turning on their conditioners. And right when you first turn it on at the beginning of the year that’s when you might realize you got a problem. Maybe a bunch of refrigerant leaked out or something that went wrong, and you have an issue with it. And I already got our first call about that, trying to figure out what’s this whole deal with R22. And my heating contractor told me it’s illegal to recharge the air conditioner with this old refrigerant. So I thought this is a great topic for us to dig into. But before we do, let’s just talk some basics about refrigeration. And we’re not getting super technical and super geeky here, but Tessa, why don’t we call them air coolers? Why do we call it an air conditioner, if all it does is cool the air, why not just call it a cooler?


TM: I feel like I’m gonna get this question wrong. [chuckle]


BO: It’s okay, Tessa.


TM: AC units remove heat from the air. I don’t know why don’t they call it a cooler? I guess, just the absence of heat makes it cool.


RS: Well, heat, and…


TM: Moisture.


BO: Exactly.


TM: Thank you.


RS: Yes. That’s why we call it a conditioner, it removes heat and moisture not just heat. And that kind of brings us into the next part of the equation, which is why you don’t wanna oversize your air conditioner. I mean, the idea that the bigger, the better, we… In fact, Jim just… I was just talking to Jim yesterday, and his client really wanted to make sure it’s gonna get the house really cold, and will cool it down really quickly. And he wanted Jim to be able to guarantee him that during his inspection. And Jim was just like, “I don’t know how I could possibly know if this air conditioner is gonna satisfy your desires for a cool house.” We had one client many years ago. I remember this woman wanted to establish before we came out to do the inspection on the home that she was living in, she wanted to make it clear that she expected her air conditioner to keep it below 65 degrees in her house at all times. Or even at 62, I don’t remember, whatever it was, a ridiculously cold number. And her air conditioner wouldn’t do that, she wanted us to come out and inspect it, and make the person who put it in, fix it. And he’s like, “No.”


TM: Did we pass on that one?


RS: We most certainly did, we wanted nothing to do with that. I mean, number one, we’re not building officials, we can’t make anybody do anything. But number two, that’s unreasonably cold. Number three, we’re not getting involved in any of that. I mean, a properly designed air conditioner is not going to get your house cold very quickly. If you turn on your AC, and a half hour later your house is nice and comfortable, I guarantee you that system is oversized. I mean, I’m not an HVAC professional, but when I talk to the people who are, they tell me the vast majority of systems out there are oversized. Like, you know somewhere around 95% of air conditioners out there are larger than they should be.


TM: Would you say that that’s true for furnaces too Reuben, a lot of furnaces are oversized?


RS: Oh, for sure, oh for sure. Yeah, they go big or go home. I mean, whenever…


TM: Yeah.


RS: Clients are asking, “Is this gonna be big enough?” I could tell you, I don’t think I’ve ever found an air conditioner or a furnace where I was concerned about it not being big enough, that just doesn’t happen. I found a bazillion of them that were too big, and you know you think, “All right, well what’s the problem? It’s like with a car, have you ever had an engine that’s too big for the car? No, more horsepower is better.” But it doesn’t work the same way with an air conditioner. Because what happens is, you cool your house down really quickly, but it doesn’t give it enough time to remove that moisture from the air which is the other half of your air conditioner’s job, remove moisture. So when it simply cools it down really quickly, the only thing that’s controlling whether that air conditioner runs or not is your thermostat. And all your thermostat measures is temperature, so it’ll quickly satisfy your thermostat, and you’ll end up with a cool damp house. And what does that lead to, Bill?


BO: A cool damp house.


RS: Thank you.




TM: No, I know what you’re talking about Reuben.


BO: I was paying attention.


TM: Have you ever been in someone’s house in the summer, when you hear you know the AC kick on, you feel the cold air, it’s like a blast and it shuts off in a few minutes, and it just, you feel like clammy…


RS: Yeah.


TM: And kind of just… It’s just sticky.


RS: Yeah.


TM: Yeah.


RS: It’s very uncomfortable. And what I know you wanted to say Bill and you’re just hesitant to say the M-word is mold.




RS: It can lead to moldy conditions.


BO: Oh, interesting. Okay, so I have my hand in the air.


RS: All right.


BO: Teacher, I have a question. How long should your air conditioner run when properly sized on a hot day. And not only hot, but hot and muggy.


RS: As long as it needs to, and… Wait, no Tessa, I know you’ve got a one-word answer maybe two words. Go for it.


TM: It depends, it depends. [chuckle]




TM: How hot is it outside? What direction is the house facing? How many windows do you have? What temperature do the occupants like? I could go on and on. [laughter]


BO: 85%, 90% humidity, I have six windows, two face south, one is open, the others are closed with the shades closed.


RS: Hold on. I got my calculator. Carry the two…




RS: 96 minutes.




TM: You know what? There actually are programs out there, software programs, where you enter in all these inputs, and it calculates sizes of equipment that you need and heating and cooling loads. So there are equations. Whether or not those calculations are actually done during construction of a house, and they’re implemented, is questionable. And actually, I would say, like Reuben said, the majority of the time, improperly sized HVAC equipment because the people installing it, they don’t wanna have call-backs in the middle of winter, right? When someone’s cold and their furnaces isn’t keeping them warm. So it’s safer to put in a unit that’s a little bit larger so they don’t have those call-back issues. Same thing with the AC. Although people don’t understand that their ACs shouldn’t be running for a short period of time, leaving them all clammy and cold and wet. So a lot of people just don’t recognize that they have an oversized AC unit.


BO: Okay, so correct me if I’m wrong. On a furnace, we have our gas supply on the furnace unit itself, sometimes they’re variable, right? It delivers more or less gas, depending on how long the thermostat’s been running or the unit’s been running and not satisfying the thermostat.


RS: You’re talking about a dual stage furnace.


BO: Yeah, yeah, so…


RS: Really high-end. Have you ever heard triple-stage furnaces?


BO: Can’t we do that for air conditioners? And it feels like you can’t just be the HVAC contractor and buy a lot of the same thing. It feels like these units are independent, re-sized, and I know they’re not.


RS: That’s a great point, Bill. And for the traditional system that we have in… I don’t know. 99% of residential homes. It’s gonna be what we call a traditional split system. It’s where you take the furnace and then you put an evaporator coil on top of that and you rely on the furnaces blower fan to distribute household air over that system, and then you have air with heat and moisture removed distributed throughout the rest of the docks. I’m using a lot of hand gestures for this. It’s good pod. You have this condition are distributed throughout the rest of the house, and then you have a unit on the outside. That’s a traditional split system, where half of it sits inside, half of it sits outside.


RS: They’re connected to each other with these refrigerant lines. To the best of my knowledge, there is no such thing as a multi-stage split system. It’s all either you’re going full speed, or it’s up. There’s nothing in between. There’s no modulating like you’re referring to, it’s all or nothing. Now, when you get into other types of systems, the system is called a mini-split. Now, this is… You’ll see them in a lot of hotel rooms where you’ve got this unit sitting in your wall, and that’s gonna be capable of producing heat or cool in the room. And it’s usually gonna be connected to another unit somewhere somewhat remotely with small refrigerant lines. So technically, it can be a split system, but it’s a much smaller self-contained system where you don’t have ductwork system going throughout the home, or throughout the unit. It’s just all right there.


RS: That’s called a mini split. And someone smarter than me would have to explain this, but for some reason, we can modulate those where they can run at peak capacity and they can drop all the way down to, I don’t know, maybe 10-15% of full capacity. So those systems are actually much more efficient. And when those are oversized, it’s not a problem. Those, it’s okay, and those are wonderful. Love the idea of them but they’re pretty unusual to see in Minnesota homes.


BO: So why would they not be fully embraced if they are the best technology to keep your house as comfortable as you can have it in a summer time condition?


TM: Well a mini split system is good for a house that doesn’t have ductwork because it doesn’t need ductwork, and you just mount that head through the wall, and it cools the space. So if you’ve got… A lot of older houses here in the Twin Cities area had boilers to heat their house. If they don’t have ductwork to install a standard split system, you need ductwork, and so it can be a lot more expensive to install all of that just to get the forced air AC system. So much cheaper, easier way of getting AC in an older house, that is heated with a boiler, so just do a mini split system. But if you’ve got a forced air furnace and then it’s easy to just add a standard split system AC unit.


BO: So are you saying then the most comfortable way to live in Minnesota… I’m filling in a lot of blanks here. Is to have a boiler with mini splits in all the rooms?


TM: I wouldn’t be opposed to it. That would not prevent me from buying a house.


RS: My ideal heating system would be a boiler with mini splits throughout the home. And I wouldn’t have radiators, I’d have in-floor heat.


TM: I knew you were gonna say that. Yeah, that would be awesome.


RS: Well, you knew I was gonna say ’cause everybody knows there’s nothing better. I mean…


TM: Right.


RS: It’s scientifically proven.




TM: Yes.


BO: And all those dust bunnies would just… They won’t be kicked up by all the air moving, they would just settle down, and my house is gonna be cleaner.




RS: That would be a good way to go.


TM: So have some kind of ducted ventilation system, but that’s for a different podcast.


RS: Depending on the house. I mean, you get a super old drafty house, like what a lot of these are, the ducted ventilation system might not be all that important, right?


TM: Right, yeah, that’s true. I was thinking if we were building our own house, today, and it was a new construction.


RS: For sure. For sure.


TM: Yeah.


BO: Okay. So I gotta bring us back to the original conversation, though. Was talking about refrigerant. So what were you saying about a legal refrigerant or…


RS: Well, this started out with an email I got from a real estate agent who had attended some of the classes that Tess and I were teaching. And he’s like, “After you guys’ classes, I trust you guys, I gotta get your two cents on this. I just had someone out ’cause I was trying to run my AC, and it’s not cooled my house. I had the HVAC contractor come out and he said the problem is that it’s low on refrigerant. And I’ve got this old refrigerant, it’s called R22.”


RS: I think all R22 is Freon but I’m not positive. Somebody will write in and correct me if I’m wrong about this, I know it. But it’s R22, and that stuff is being phased out. Well, basically has been phased out, where they first started saying, “All right, you can’t make systems that are pretty charged with it anymore, or can’t import it, and you can’t do this and that, we can’t make it.” And they kept changing the restrictions year by year. And I don’t know the exact timeline, but the big change that happened recently, is that starting January 1st, 2020, this year, they said you can no longer import this, you can’t manufacture it, you can’t do anything. So the only way to actually get R22 now is either you have a stockpile of it or you reclaim it. Like, you go to somebody else’s limping along system, you suck all the R22 out of it, and then you sell it on the black market.


RS: Like, it is becoming very difficult to obtain R22, but this guy’s heating contractor told him it’s illegal to add R22 to a system. Now that’s one I hadn’t heard before. And I said, “Yeah, it doesn’t sound right to me, but let me talk to my HVAC guys.” So I called up three of the companies that I know and trust here in the Twin Cities, and all three of them said the exact same thing, “No, that’s not true at all. R22, you can still put it in systems, it’s not illegal to add. It’s just very expensive, and it’s hard to get a hold of, that’s all it is.” So what this means to homeowners that have a system that runs on R22 is that if you have a problem with the refrigerant, if it’s leaking refrigerant, it’s going to be very expensive to address. I mean, in most cases, it’s probably going to be cost-prohibitive. I mean, like I think somewhere in the neighborhood of $800 a pound, or something it’s going for. And when a typical system…


BO: Wow.


RS: That takes several pounds of this, most heating contractors are gonna say… And I keep saying heating what I mean is HVAC, heating, ventilation, air conditioning. Most of them are gonna say, “Look, I’m gonna come in, and you’re gonna have to spend a couple thousand dollars having a refrigerant added. You’d be better off just replacing your system.” I mean, it does get into the cost-prohibitive realm, but let’s be clear, it’s not illegal. Let’s just get these facts straight.


BO: If you have to replace the refrigerant, do you necessarily have to replace all components in that system or can you just suck out all of the 22 and put in whatever new way of cooling refrigerant you’re gonna use?


RS: I’ll get the details wrong on this, I’m sure. But what I know for certain is that you can’t simply swap out the refrigerant. I believe you need to swap out all the different seals, and you need to change out the oil in the system as well. So it’s a very involved process to change out refrigerant, and that process there is probably going to make it cost-prohibitive too.


BO: Okay.


RS: So for… I mean, at least for a residential system. I guess, in commercial systems it might be cost-effective to switch over to a different refrigerant, but in most residential systems, I heard it just doesn’t make financial sense.


BO: So is it fair to say now that we’re socially distant from humans, but if you own an R22 system, I’d hug that thing every day it’s working as tightly as possible.




RS: That sounds good, yeah. And we’ve been talking about this to our clients for many years. I mean, I think we started maybe in 2017 or something. We made it a requirement, every time we’re doing a home inspection we need to identify the refrigerant type. That’s just a line item on our inspection reports. And it’s not required by home inspection standards of practice to report on the type of refrigerant used in an air conditioner. Well, we thought this is such a big deal that’s coming that’s gonna affect so many homeowners. I mean, there’s so many things that we report on as home inspectors that people just don’t care about. I just wonder why is this even in our standard of practice, why do we need to describe these components?


RS: But we do it anyway, ’cause we gotta check this box. But this one reporting on the refrigerant type, this is a big difference, this really matters. I think that ought to be part of home inspection standards of practice. And it’s really simple to figure out, all you gotta do is look at the compressor on the outside of your home, and look at the tag, there’s gonna be a bunch of numbers and letters on there, but look for R22 or R410A. I mean, I know there’s other refrigerants besides those, these mythical refrigerants that I’ve heard about, I’ve never seen anything else in my life. It’s one of those two that’s stamped on the side of the unit.


TM: R410A is the newer kind, so that’s good, yeah.


RS: Thank you Tess.


BO: Okay, so then give me some history professor of when R22 started and when R410A started. So are there units out there with 410A that are getting close to the end of their life cycle at this point or not?


RS: Yeah, R410A, I don’t know when it first started coming around. I know that there’s… Well, we’d have to get a heating contractor out here, ’cause I’ve heard some stories about different manufacturers dragging their feet and doing almost unethical things to kind of skirt the issue of trying to get rid of R22. And you know just a little history on R22, the issue is that I think it puts holes in the ozone layer, it’s bad for the environment. So they’ve got this thing called the… What is it? The Montreal Protocol, and the US agreed to incrementally decrease the use of hydrofluorocarbons. I think the biggest one is R22. So we started phasing it out. And I believe we started in 2003, and by 2010 they said I’m just looking this up now. It says, “No production or import of R22 except for use in equipment manufactured before January 1st.” So if they made the equipment before January 1st, it could still use that, but after that they couldn’t make equipment that used it.


TM: What year was that?


BO: Can you… Yeah, repeat that year.


RS: January 1st of 2010. So they can’t make equipment that runs on R22 after January 1st, 2010.


TM: And what’s the average life expectancy for a standard AC like a split system AC unit?


RS: It depends on where you are in the country. I know on the South, they say maybe 10 to 15 years. Here in Minnesota where you know we shouldn’t be running it more than about 10 days a year.




RS: The systems last a lot longer. We might get somewhere around 15 to 25 years out of our systems here.


BO: Very good. So can you be testing an AC right now in, we’re talking to you in May, middle of May, and get any good information about whether or not it’s an effective unit properly sized. Will you feel that cold and clammy just on any day you test it or does it have to be just the right day to really nail this?


RS: That’s a tough question Bill. I mean, you can at least know that the system is operating. There’s still value in flipping the system on. And I know what you’re getting at. Your point Bill, is if it’s 70 degrees outside, and it’s 70 inside and you turn that system on, what’s it really gonna tell you? And it’s probably not gonna tell you a ton about how well it’s operating. I’ve had to really know if the system was operating right you gotta have a psychometric chart or something, and you gotta know all these different variables and we don’t do any of that as home inspectors. And you’re gonna check refrigerant levels which we’re not even licensed to do. There’s all this stuff you gotta do to really know. As home inspectors we’re doing a very, very cursory check on it. We’re basically, we’re flipping a switch and we’re making sure that the system turns on and that there’s a difference in temperature between the air coming in and the air coming out. We’re looking for that temperature to drop to tell us that it might be working, that’s about all we can do. And we use our thermometers and we take pictures of that to document it to show, yeah, it was doing something. But we don’t talk about efficiency as home inspectors.


BO: So we’re not psychometric? What did you… What was that word you used?


RS: Can’t repeat that word, Bill? I don’t know where that came from. I think I just made it up.


TM: Psychometrics, yeah.


RS: Did I use any word Tess?


TM: Yeah, you did.


RS: Oh, I don’t know how.




TM: We can’t really test AC units for the majority of the year here in Minnesota. There’s only a few months where it’s warm enough for us to test that. We have to wait till the temperature is above do we say 55 or 60 degrees for a few days, at least.


RS: Yeah, something like that. I think it’s like 60 to 65 degrees.


TM: Okay. So we’re not gonna test an AC unit if we’ve had weather that’s below 60 degrees. So a lot of people will ask us when we’re doing home inspections, “Hey, can you make sure the AC’s working?” And if it’s cooler outside or it’s been cold we can’t. We can’t flip that unit on we could damage it if we did.


RS: Let’s close the AC discussion with just a few tips for home owners. Before you turn your system on making sure that you’ve checked all the correct boxes. Number one, make sure that your circuit breaker’s on. I know that some people like to turn their circuit breakers off in the fall. I actually did a blog post about that last fall talking about whether you should or shouldn’t. All the pros and cons, and bottom line is, if you shut off the power to it, make sure you turn it back on. Remember that one. Another is if you use a cover, if you get it all covered up, make sure you take your cover off before you turn it on for the first time. Make sure you have unimpeded airflow all around the unit at the outside. And it means, if you got a bunch of stuff stored around it, if you got plants growing up around it, if you haven’t cleaned it in a long time, clean it off. I mean those things work by sucking air in on all sides and then it passes that air over the refrigerant to help cool it down and if you’ve got impeded airflow the thing ain’t gonna work right. So that’s a really short way of saying it. So make sure you got free airflow, make sure the outside is clean.


RS: And then, lastly, think about what it’s doing. It’s removing heat from the air but it’s also removing moisture. And where does all that moisture go? It collects down at the bottom of the unit in a condensate pan, and then it takes all that condensate and usually… Well, in Minnesota homes, it usually brings it out to a floor drain. And it’s typically got a hose or some type of tubing coming off of it. Check your hose, check your tubing whatever it is, check your condensate disposal line and make sure it’s actually directed to the floor drain. I’ve been involved in several situations where I turn on the AC for the first time of the year. I come downstairs and there’s condensate going all over the floor ’cause people wrap up their condensate holes or do something crazy like that in the winter time. So make sure your condensate is going to a good location.


TM: I was just gonna clarify too, Reuben you’re talking about the unit that’s sitting inside the A-coil over your furnace that has a condensate line.


RS: Oh yeah…


TM: It could before you were talking about. ‘Cause with a split system it’s a little confusing. There’s two parts, one sitting outside and one sitting inside above your furnace. So both of them need a little bit of maintenance here and there.


RS: Yes. Yes, exactly, thank you. So make sure you got that going. And remember, for most split systems in Minnesota it’s using the same air delivery method as your furnace. So make sure that your furnace filter is clean. You gotta change your furnace filter in the summer and the winter on most Minnesota homes.


TM: Real quick if you don’t we have a good story about what can happen if you don’t change your filter or if you have an oversized system. Reuben, do you remember that house we were inspecting back when I was in training where we had the AC going for a really long time and then we switched the heat on and all of a sudden, all this water started pouring out of the evaporator coil and just draining over top of this furnace.


RS: Oh my gosh, yes. I have that on our video compilation.


TM: Yeah.


RS: The whole unit iced up. It was like just a gigantic ice ball inside and we couldn’t see it. It wasn’t working right. But yeah, then we’d flip the furnace on, it melted all that ice and, oh my goodness, water was pouring out of that thing.


TM: Not a good situation.


RS: No. I will put that link on this podcast. It’s part of a video compilation. It’s like 60 home inspection defects in under three minutes or something and it’s just clip after clip. And one of those was that furnace melting.


TM: Awesome.


BO: The moral of that story is check the furnace before you check the AC. Like run the furnace and then heat up the house and then use the air conditioner to cool it back down.


RS: No, no. The moral is change your furnace filter.


BO: Okay, gotcha, all right. [laughter] Okay. Keep it simple, keep it simple. Well, all I can say is air conditioning is magic. It takes heat in your house that’s cooler than the outside temperature and it throws it into that hotter environment. It’s just pure magic.


RS: It is, it is.


BO: Thank you for air conditioning.


TM: Amen.


BO: Awesome. Well great information about air conditioners. Sorry, we’re not gonna get to the new COVID home attendance policy and home inspections at our company this week. We got a little long-winded about air conditioners so we’ll do that next time. And thanks for listening everybody, it’s been awesome. I can’t wait to actually turn on the air conditioner, see some sun, get hot, sweat. And yeah, we’ll catch you next time. You’ve been listening to Structure Talk, a Structure Tech presentation.

Author: Reuben SaltzmanStructure Tech Home Inspections

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6 responses to “PODCAST: Air conditioners and myths about R-22 refrigerant”

  1. Richard Andrews
    May 25, 2020, 1:36 pm

    You guys are awesome,as a mechanical contractor as well as a home inspector,I can help a little,there are 2 stage condensing units for split systems and they have been around for a while.I believe Lennox made the first.As far as R22,I just bought a skid,which is 144 30 pound bottles,it is not cheap but not as bad as everyone thinks.A bottle works out to be around 650.00 each when you buy quantity.I charge 75.00 a pound for it.I do not do residential work but there are replacement refrigerants that are available if they do not use mineral oil.If mineral oil is in the system then only R22 can be used.Hope I helped a little.Thanks Again.

  2. Reuben Saltzman
    May 26, 2020, 4:19 am

    Good to know, I don’t think I’ve ever seen one of those 2-stage split systems before. We’ll have to mention this in next week’s episode. Thank you!

  3. Ben Franske
    May 25, 2020, 3:02 pm

    They actually do make two stage A/C compressors! I have never seen one in Minnesota. I don’t know for sure but I suspect they are not cost efficient here because we don’t get the high temps seen in other parts of the country (and especially not for as sustained a duration).

    Since our primary need is heating it makes more sense to have two stage heating.

    You are probably more likely to find two-stage cooling in air heat pumps in Minnesota as those are a bit of a specialty high end product anyway and because the same compressor is being used for heating and cooling if you want two stage for one you’re going to get it for the other anyway.

  4. Ben Franske
    May 25, 2020, 3:12 pm

    Also, you probably haven’t seen a mini-split in a hotel. It’s really a “packaged terminal air conditioner” aka PTAC below the window. Similar to a mini-split but all in one package installed through the wall. This is what has been typical in the Motel 6/Super 8/Comfort Inn/Country Inn & Suites/etc. high-end hotels are more like commercial systems (more below).

    Ductless mini-splits can be located on interior walls because they are piped separately to the compressor/heat pump. You can also have multiple interior units on an exterior unit but that is a bit less common because the system complexity (and cost) goes up a good bit.

    Finally, higher end hotels (and even some lower end ones now, for energy efficiency) are more likely to be done like a commercial building with chiller and heating loops running to fan coil units in each room with a more typical looking wall thermostat. These are more efficient because of a larger central heating/cooling plant PLUS the systems can be remotely controlled and tweaked (including for occupancy sensing) by a central computer control. So even if you set your room thermostat to 60 when you leave in the morning it will probably not actually run all day if you leave. They can also enforce centralized limits (and lie to you on the thermostat), automatically change setpoints on arrival/departure, store your preferred temperature settings in your rewards account profile and automatically set for your preferences when they know you have a reservation coming, etc. Commercial HVAC (and electrical power load management) is light-years ahead of residential.

  5. Reuben Saltzman
    May 26, 2020, 4:21 am

    Good info, thank you, Ben! We’ll have to mention a few of these corrections in next week’s podcast.

  6. Reuben Saltzman
    May 26, 2020, 4:20 am

    Good to know, I wasn’t aware of the two-stage units. Thank you for the info.

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