Single Zone Ductless Systems for Heating and Cooling an Individual Room

Many homeowners choose to add a single zone ductless system to heat and cool an addition to their home. Mike Cappuccio, owner of N.E.T.R., Inc. discusses how best to install a new ductless system. Listen or read more to find out about single zone ductless heating and cooling systems.

John Maher: Hi, I’m John Maher. I’m here today with Mike Cappuccio, owner of N.E.T.R., Inc., heating and cooling company in Massachusetts with a focus on Mitsubishi ductless heating and cooling products. Today we’re talking about single zone ductless systems for heating and cooling an individual room. Welcome, Mike.

Mike Cappuccio: Hi John. How are you?

John: Good. So, Mike, in what situations might I choose to install a single zone ductless system?

Mike:  Okay, single zone ductless systems. Great question. The single zone system is really being used now. It was very, very popular years ago. And when I look back, I’ve been doing ductless heating and cooling now for, with Mitsubishi Electric for over 20 years now.

John: Wow.

Mike:  And when we first got involved in it, it was the single zone. It was the single zone that you sold all the time. It doesn’t happen as much anymore, but I’m going to tell you where we do see it get done a lot. It’s the addition on the home. It’s when people put an addition on a home. I was just out at a job site yesterday where a little addition got put off to the side of the home and it’s being used as kind of like a small TV room or something like that that they’re putting off on the back of the home, and the current heating and cooling system won’t get into that area.

Or, they think that they going to get that in there, but they can’t really zone that out at that point. They’re trying to either add additional duct work or have the plumber come in and put a loop of hot water in there for the heating. But then there’s no air conditioning. So, our systems are really great for that particular addition that you’re putting on there. I mean, we go in there, we put in a nice single zone, hyper heat unit, one-on-one, one outdoor, one indoor and tie the two together. And it’s great when the room’s being built too, because we can put all the refrigerant lines and electrical inside the walls so you don’t have to have the line height on the outside of the house.

Ideal Installation Time

John: So, when you do it at the same time as building the addition is really helpful.

Mike:  Yeah, mm-hmm (affirmative). Yeah. And a lot of times they go in what’s called a frog and people are like, “Okay, well, what’s a frog?” And it’s a terminology of a family room over a garage.

John: Oh, okay. Family room over garage. Yeah.

Mike:  A lot of people like, “Okay, I need a unit from my frog, from my frog room.” And I’m like, “Okay, well what’s the frog?” I’ve learned what the frog room is now. It’s the family room over the garage. And they might have an air conditioning system in the home and it’s taking care of the rest of the home. But that family room over the garage is always warm. So that’s where we would go in and put a one-on-one. Master bedrooms, family rooms. Sometimes people just want the kitchen area done. So, we do the kitchen area.

But a lot of times it’s additions. Sun rooms. People put sun rooms on the back of their homes and they put one indoor, one outdoor and away they go. Because the rest of the house is already done at that point.

John: Right. So, is it cost efficient to install a single zone, a system like that? Or should I really push to install a multi-zone system now and do my whole house if I could afford that?

Mike:  Well again, it’s when we go into the home and we’re looking at . . . the homeowner might think that they just want to do this one addition on the home and that’s it. And we start to ask some probing questions about, “Okay, well, what is it that you don’t like about your current system now? Is there anything that you just don’t like about it?”

And most times you find out there’s a hot spot or a cold spot in the house that they’re just not happy with. And you go to put in a dual zone. Sometimes those single zones we end up putting in more than one zone into the home with that. We don’t just put in one unit. We ask them probing questions, find out if there’s additional problems, and you do go to the dual zone unit.

What you can’t do is take a dual zone unit, what I mean by that is an outdoor unit that can control two indoor units, and just put one on it now to run. You can take a three-zone outdoor unit and put two indoor units on it and leave one additional port off if you wanted to do something at a later date and time. You could add an indoor unit to that particular condenser. But, it’s either, if you’re going to do two, you have to do two at the same time.

And a lot of times that does what happened. That does end up happening in the house.

John: Okay. Would it again be a sort of a similar situation that maybe you would have an addition and so you’re adding in the indoor unit into the addition, but then you’re also doing, say, the kitchen on the house or something along those lines?

Mike:  Yes. Yeah, that sometimes is what happens. You go in, you end up doing the kitchen and the addition on the home, or a basement area, family room, video room in the basement or something like that can get done. Or sometimes the gym down there or something like that that we end up doing what that. Because from a cost efficiency standpoint, you’re not buying another condensing unit for the outside. You’re only buying an additional indoor unit. If we were to go back and do that later on, you say, “Okay, well I want to just buy one now.” I buy one indoor and one outdoor and I do the addition. Well, when I come back to do that additional spot, if we do come back, which a lot of times we do end up going back, it’s kind of crazy. Once we put one —

John: People like it so much —

Mike:  Yeah. We put one in someone house, they —

John: They say, “Ah, I want one of these in this other part of my house.”

Benefits of Installing a Two-Zone System

Mike:  Yeah. They want another one and that happens frequently and they’re like, “Well I want to put another indoor unit on my outdoor unit.” “Well, remember we discussed that you can’t do that now?” So, we either end up changing the outdoor unit to a multi-zone outdoor unit, which isn’t cost effective because you’ve already paid for the outdoor unit at that time at one time.

John: Now you’re replacing it.

Mike:  Now you’re just replacing it and you’ve got to pay again. So, you’re better off to put the two zone in in the beginning right now, because you’re only buying one condensing unit, so your pricing from that perspective is maybe 20 or 30% more to buy the additional outdoor unit to put that on. So, it’s definitely more cost effective to buy a multi-zone in the beginning if that’s the direction you’re thinking of going.

John: Right. If I did want just use a single zone system, can I use that to cool two different rooms in my house? Or is that really not advisable?

Mike:  Well you can, okay, because they do make the single zone unit now that you can put the little SEZ ducted unit on it. So, we could put that in the attic and run two small pieces of duct work and do a single zone system to do two areas.

John: Like two bedrooms or something like that.

Mike:  Two bedrooms, yeah. We could do two bedrooms with that small little ducted unit. We’ve put wall mount units in one bedroom and tried to cool the opposite bedroom with some type of an AirShare fan or something like that. It’s okay. I’m not going to say it’s perfect because it might be good for like a guest room situation where someone maybe only stays in there a couple times a year. We can put what’s called a transfer fan in the wall to take some of the cold air from the one bedroom that actually has the unit in it and move it over into the other bedroom. Or a lot of times we do that with master bathrooms or a small bathroom off of a bedroom to get some air into a bathroom. But you don’t really have a cooling coil in the space per se.

John: Right. You’re just trying to take some of the cool air from one room and just below it over into the other room.

Mike:  Yeah. With the little ducted system, we put a return in each room and we’re pulling that heat out of that room and bringing it up across the cold coil and actually removing the heat from both spaces with one thermostat. You’re going to get the same temperature in both rooms with that. So, we’d run that off the return air sensor and we wouldn’t put the thermostat in one room and make one room colder than the other.

John: All right. That’s really great information, Mike. Thanks again for speaking with me today.

Mike:  Thanks, John. Have a good day.

John: And for more information, visit the N.E.T.R., Inc. website at, or call (781) 933-NETR. That’s (781) 933-6387.

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