Ductless Heat Pump Tips for HVAC Pros to Master Zoning and Install Smarter with David Rames Part 1
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All right, guys, we got David Rames back. He's the one a few months ago that said it's not your grandpa's heat pump anymore, and really it isn't. But anyway, we're here to talk about

multi-zone ductless systems. Now they have a place and I'm going to bring up a, an actual phone call I had with a potential customer about multi-zone ductless and where the application really, really fits. If you don't have duct work and you've got multiple rooms that you have to heat or cool, multi-zone ductless is a fantastic solution actually. So part one and part two with David Rames, it's two-parter again, guys. So this is part one coming up. This is the HVAC Know It All podcast. I'm your host, Gary.

Gary McCready. This podcast is sponsored by Cintas, and if you're looking for blue-collar uniforms or anything that's an accessory to a blue-collar uniform, check out cintas.com forward slash HVAC Know It All for your blue-collar uniform needs. Welcome to the HVAC Know It All podcast, recorded from a basement somewhere in Toronto, Canada. Your host and HVAC tech, Gary McCready, will take you on a deep dive into the industry, discussing all things HVAC.

From storytelling to technical discussion. Enjoy the show. David, you're back, man. So I got to tell you, the last podcast we did and we were talking about it, it ain't your grandpa's heat pump anymore. I got a lot of really a lot of good feedback on that podcast, especially from some local people, even people that sell heat pumps like from a supplier level. They were like, yeah, man, that was a really cool podcast. So you and I, we're going to talk multi-zone.

And I'm going to bring up a story that just happened yesterday that is actually very fitting for a multi-zone application. And I'll tell you about that conversation I had in just two seconds. But I did promise a shout out. So I have to shout this out before we start. So Service Titan HVAC National Championship powered by Trane is basically a championship where they take a bunch of techs down to Florida and

and they compete in the competition. It's on live national TV, and these techs compete in this event. There's like $100,000 in prize money up for grabs and stuff like that. I have a link to a quiz. Actually, I can just...

Shout it out. It's HVACNationals.com. So if you go to HVACNationals.com and you do the quiz, it's almost like a prerequisite to go to the next round. It's got to be done by June 30th. And if you complete it and you pass it and you move on to the next round, you could actually go down to Florida, free trip.

and compete in this competition. So you were saying you saw the plumbing side of that, David. I did. And honestly, being in the trades for 20 plus years, it was super cool to see...

The trades guys get on TV and show how good they are. Show it was the plumbing side. And I think they were installing a heat pump water heater, but boy, they were dynamic and they were running packs and they were doing a lot of things and won a little bit of money too. I think, I think we could all use a little bit more money last time I checked. Yeah. Yeah. My, my man, Craig, that's been on the podcast has won the plumbing and HVAC side too.

two years running and he's come home with some stance, like a substantial chunk of money from, from doing so. So anyway, I think he's the one that won when I watched it and it appears as if he has been there before. Yeah. Yeah, for sure. So we'll move on from that. I don't want to take up time on too much time on that because we're here to talk about a multi-zone ductless. So the conversation I had yesterday, I'm driving in my truck to a job and I get a call and

And this guy's like, hey, I got your name from one of your former customers who's a friend of mine lives down the street. And he lives in a century home. And he's like, yeah, we got, I think he's got hydronic heating. He's got a couple window units. He said he's got one ductless split in one side of the house, but he's got pockets of

uncomfort around the home. Right. And I said, do you have duck work? Like he's like, no, no, no duck work in the house whatsoever. And he's like, I got like three rooms on the upper level and we need some heating, cooling there. I've got our, our bedroom that is hot, cold. And I'm like, you are a candidate for a multi-zone duct lister. Right. So that's, that's kind of funny. We had that conversation yesterday when you and I were supposed to talk today. So for the, the techs out there or the

The people out there in the industry that don't know what a multi-zone ductless is, let's define it first. Yeah, so a multi-zone ductless is exactly what it says. So you have one outdoor unit.

And then from that one outdoor unit, and I'll use our Midea Multi-Zone Ductless as an example, you can run between 18,000 BTUs and 60,000 BTUs anywhere between, you know, one to six indoor heads off of one outdoor unit. So custom comfort, individual zone control in each room.

Uh, people love it. The one thing that I would warn people, this is a heat pump, not heat recovery, right? So we can't simultaneously heat and cool. Uh, but I always say if one room is warmer and one room is colder and someone's complaining and it's summertime, uh,

Just turn that zone up a little bit and mother nature will heat that room up if you're too cold, free of charge. So we don't have to worry about that. Don't flip it to heat or don't flip it from to cool in a heat pump multi-zone. Mother nature will do it for you. Yeah, no, for sure. So like, let's say we have three rooms, three different people, three different opinions or comfort level on what

the room temperature should be. One person wants it at 75 degrees, one person wants it at 68, and someone wants it somewhere in the middle. If you're in cooling season, then you just set accordingly and everybody's got their own level of comfort within each room. And that's the beauty of a multi-zone system. It's basically...

what it is. It's multi zone and everybody's got their own control. I, you know, I kind of just simple it back a little bit. I kind of compare it to a dimmer switch on a light. Right. And so in a central unitary system, you sit, unless you're in a zone system, but you set the wall control and the entire house is at that temperature. But what happens if you're only in, you know, the, the master bedroom from, uh,

you know, 10 PM till 6 AM and everyone's downstairs for the rest of the day. Do you really need to keep that bedroom upstairs at the same temperature of the room everyone's in? The answer is no.

And so it gives us flexibility for independent zones, but everyone, some people like to sleep when it's colder. And when you go upstairs and it's bedtime, crank the thing down and you don't have to do that to the whole house. So again, flexibility is key for a multi-zone. And, you know, when we go to these trade shows, whether it's AHR or, you know, we saw each other up at the Toronto heat pump symposium, a lot of questions are being asked about multi-zone. And so it's, it's good to know the word's getting out. Yeah. So,

Let's talk, we have to talk about its operation because it's not VRF, but it's still got a modulating multi-speed compressor in it. Yes. Yeah. So let's maybe go through the operation of that. So let's say it's a three zone system just to keep it simplified and one zone wants cooling and the other two are completely off. That compressor is going to run, that's going to ramp up to a certain capacity, but it's not going to have to ramp up to a hundred percent capacity. Right? Right. Exactly. Exactly.

Uh, one of the important parts of it though, is even though, and this is sort of a, uh, misnomer in the variable speed industry is you still got to do load calculations on, on the home. Uh,

And we want to dial it in. I mean, if anything's going to work to its maximum efficiency, you want to dial it in. And it actually takes it a step further when you're doing a room by room. So you want to do individual bedrooms and living spaces. Then you have to do a room by room load calc as well to know for sure. But to the point you were making, we've got one outdoor unit. Let's say we've got three indoor rooms.

Uh, you've got three different connections and it will beg, borrow and steal refrigerant from wherever it needs to, in order to get, send the right amount of refrigerant to that zone based on your set point.

Uh, and the electronic expansion valve is on the outdoor unit and it just sends refrigerant where it needs it and it takes it from where it doesn't need it. Yeah. So I was at, uh, actually called you when I was there to, to, to get some additional information. I was at, so in Mississauga, that's close to me, there's a Madea showroom and it's actually quite nice in there. And then there's a training center in, in behind the showroom, like in the same building.

But I discovered that as well, that the expansion valves in the outdoor unit, because we ran one particular multi-zone. It had a floor mount, a wall mount, and a cassette attached to it. And the two lines coming out of the outdoor unit, both of them were cold. So I'm like, instantly, you know that the metering device is in the outdoor unit. So we should talk about that because...

Some people don't know that because it's not always the same. Sometimes the metering device is in the indoor head in some applications. Sometimes it's in the outdoor unit. So when are we going to find the metering device like in the outdoor unit? And that line that goes after the metering device, like downstream of it,

to the indoor head. What do we call that line back in the day? Like we called it like a vapor slash kind of liquid line almost because you're flashing refrigerant in there. So it is a, it is a liquid and it's still a vapor until we get that superheated vapor coming back to the compressor. Right. Yeah. So it, you know what, the way we kind of break it down is, uh, on let's just take a central unitary heat pump and air handler.

And so on that, we know on the indoor air handler, we've got an electronic expansion valve indoor. Uh, once we flip over to our multi-zone, everything inside just depends on the electronic expansion valve on, on the outside. And so, you know, the other thing we'll find is on the ductless side of things, uh,

We'll need both of those lines insulated by both, both the liquid and the suction line insulated. You see on the central unitary stuff, just one of those is insulated. So there's a couple of caveats to it, but it's not crazy difficult. We just know we're going to run with our system, run an individual refrigerant lines to each indoor unit. And then you're going to run a 14, four communication and, and power cable from the outdoor unit to each indoor unit.

and then you set it up that way and then you've got individual control on each indoor unit for each zone. Now, that line that leaves the unit after the metering device, is there a specific name that Medea calls that? Not specifically, no. No, not specifically? Yeah, because I mean, I've seen all kinds of

names like back in the day, like when we were installing, when I first started installing them, one of the techs I work with always called it a vapor line, but essentially it's got liquid and vapor in it. Exactly. Because you have that flash gas for the techs that are just learning flash gas is when

We have a full column of liquid in the liquid line. It moves through that metering device and it flashes off. And they've always taught us back in the day that a rule of thumb was you're still going to have 75% liquid, 25% vapor, and the rest of the liquid is going to boil off in the evaporator to absorb the heat from the room and

But who knows if it's actually 75 and 25%. It could be a different number. As long as it works, as we say, right? As long as it's removing heat from the space and rejecting it to outside, we know the air conditioning system. That's the go. Is working. Now, is there any specifics that someone should consider before putting in a multi-zone? And when I say specifics, it could be install.

It could be design. It could, could be service, anything like that, um, that comes to mind, David. If you're looking for HVAC parts, supplyhouse.com is a shortcut for part shopping. They have thousands of HVAC parts from all the leading brands and the orders get shipped and delivered in a day or two tops. Order parts the easy way and get them delivered right away.

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2025. Yeah, a couple things come to mind is just understand when we have one outdoor unit and multiple indoor units, we are going to have to run a separate line set from the outdoor unit to each indoor unit. So in a six zone, we've got to make sure that we've got, you know, either attic space, which is the easiest way of doing it, a crawl space, or some type of a chase where we can get those line sets in.

Uh, in a central ducted, you've got one outdoor unit, one indoor unit, you run the line set in, you connect to it, you're ready to go. So, so, uh, even though it's very possible to do this in a retrofit, you know, or, or an add on, uh, new construction, it's a piece of cake because everything's wide open and we're seeing a lot more of this in new construction. While there's no drywall, everything's open to both the HVAC guy and the plumber.

everything's open and ready to go. The other thing to look at is, and I got a lot of questions and it shows us the interest is growing in this, both at AHR and the International Builder Show. I spent a lot of time in our multi-zone area of our display.

But they said, hey, you only go up to six zones. But what if I need eight? And I walk them over to the slim duct. And I said, well, here's your buddy right here. Because with a high static slim duct, some of those rooms, whether it's a bathroom, you

You know, you can put air in, you don't return out of it, but you can put bathrooms, secondary rooms and things like that. And that slim duct only takes up one of your zones, but you can feed three rooms off of that slim duct while only taking up one of your refrigerant connections on the outdoor. So that's how we make this thing a little more flexible. And with the Midea unit, we can also team up with a central ducted air handler and then we can put two zones.

of our Evox central ducted air handlers in a multi-zone. So if you've got a two level house and you do have duct work up and down, there's no reason to have two outdoor units, have one outdoor unit, two air handlers, and then you can feed up and down. So the flexibility of the system is really, I think what's intriguing to a lot of people now. Yeah. I want to come back to what you said about each zone needs its own line set run. So it's basically a home run from outdoor unit to indoor unit type of thing.

unit times three, if you're doing three heads, if we keep to that example, and then it's three separate communication cables going to each head. And I know from doing VRF, it's different because, and those, those that haven't installed multi-zone have done VRF. VRF is more like one piping system and we're teeing off to the different branches as, as we go. And usually it's the communication, it's daisy chain from, from

from indoor head to indoor head to indoor head. It's not a separate full on communication wire like we're doing for multi-zone. So that's a point that I wanted to make too. One of the things...

that can happen with an installer if they're not paying attention and i want to bring this up because i know that the media product has some sort of way to temporarily or i don't know you you you're going to fill me in when i want to reveal what i'm saying to you so if you mess up you cross like the wiring for two zones or something like that and you totally get it wrong there's some sort of

way to do an auto correction correct in that can you can you explain that to us yeah so we call it synchro connect and so no one ever plans to do that we've got a six you know six zone multi-zone and the guys are really careful and they label everything both the communication and the power wire and the line sets coming in and next thing you know they fire it up and one's not acting right

And they go, uh-oh. And then they say, I think we've miswired or we've mispiped one of the zones and we can't figure it out. So on our outdoor unit, we've got what's called Synchro Connect. So you go outside. There's a button on the board. You push it. You hold it down. It goes through a system of checkpoints, both communication and refrigerant lines. And then we'll correct that for you.

and says, okay, I know where this needs to go, where this needs to go, where this needs to go. Now, technically, we want this to be a bandaid and not a fix. So if you're out there on a Friday afternoon, you're finishing up, you find this,

We want to correct the problem because what will happen is if there is an electrical reset for a certain amount of time, then that synchro connect will go away and you'll run back into the problem. But it will bide the installing contractor time to where the multi-zone will work correctly until you can take the time to trace down which wire is wrong or which line sets go into the wrong indoor unit. But it's a real life raft.

But in a time on a Friday afternoon when you got to get this house up and running and get some cooling in there, some heating in there, it saves a lot of time. Oh, yeah, for sure. And I mean, you said it's supposed to be a bandaid for that Friday afternoon job. And obviously you want to go in and fix the issue. But if you didn't, let's say you didn't go back. And I don't want to I don't want to promote not going back to fix it. But let's say you didn't.

Will it continue to operate or will it one day say, you know what, there's something just not right here and like flash an alarm so the tech actually has to come back and fix it right? It will continue to work. If you have, and off the top of my head, I can't remember the timing on it, but unfortunately if that home would lose power, so you have a winter storm or something and the power goes out for several hours, right?

After that power outage, when it comes back, it will come back in regular mode. And so that's just the system saying, hey, this is a temporary thing. We're firing back up. We're going to go to the way we're supposed to work. So, again, it's a great Band-Aid. And the other part that I think of is I think contractors need to be –

empathetic to maybe the guy that follows you. And so you may be the installer, maybe someone else will come out and service it, you know, at a later time. So if you do that, you miss wire, you miss pipe and use a synchro connect the poor guy that's going to follow you. If there's a service call, if they call someone else is going to be in trouble because he's going to see it.

He's going to have no idea how the pipes and wires are run because now the drywall is up and all that kind of stuff. That's exactly right. So, so use it to save yourself again as a lifeboat, but then go back and take some time to fix it and let's get it right. Perfect. Okay, cool. The other thing that I want to talk about too is the outdoor unit mounting. This can be super important for after the fact. Now these, the new technology in these machines, they're very quiet. There's not a lot of vibration.

But here's the thing that I want to bring up. If depending on the construction of the building, like if it's, if it's a concrete foundation or something like that, and you're, you can fasten your brackets to the concrete foundation. Sure. You can probably get away with brackets, but if it's like a house that has siding and you're going to go right into like a wood frame or something like that with a bracket, I would suggest not if, if you can't, if you can avoid it, take it away.

to put it on a stand at that point, because the concrete has less of a chance of vibrating through the home and causing that the micro vibration and annoying people. There are some people that get annoyed by the slightest little thing as, as you know, Hey, my unit's making this noise. Well, I can't stop the micro vibrations, but we can install it.

on a stand away from the home. If we have that type of construction, it's just what I've noticed in the past, talking to many techs, my own self included. If it's a concrete foundation and we're putting it on a fastened bracket of the concrete on rubber pads, usually it's not a problem. If it's a wood construction, uh,

support and we're going into that with a bracket, then sometimes we may have a bit of a, an issue if the person is sensitive to sound. You are exactly right. And, and if I'm a contractor and I screw this bracket two studs and we know it's going to reverberate, we know it's going to, they're super quiet, but there is a vibration there. Of course. There's always vibration.

And then you've got this thing mounted up a little bit. And then the homeowner says, hey, I'm getting some, you know, some vibration. I'm getting some sound. Next thing you know, you sized your line set for hanging this thing six foot up.

And now you got to put it on the ground. Oh, now I don't have enough line set right to, to bring this thing down and sit it on the ground. So I'm with you. If you're going to attach it to concrete, a okay with that. But if you're just going to run it through some siding and into, into a stud probably would think twice about that and put it up on some, a stand outside away from the house. And then that way you can head that thing off at the pass.