How to Keep a Sunroom Cool in Summer
LESLIE: Joe in Georgia is on the line with a cooling situation. Tell us what’s going on at your Georgia home.
JOE: I purchased a 1,700-square-foot ranch.
JOE: And it has a 3-ton air conditioner now. The owners put on an additional sunroom about 220 square feet but really didn’t upgrade the air-conditioning unit.
TOM: OK. Hmm. Yeah.
JOE: So in the summer, when it comes time to air condition the whole house, that room never gets cool.
TOM: I bet. Yeah, not surprising.
JOE: It gets very warm out there.
JOE: There’s a lot of windows and our options are going to a bigger unit of 4½ tons to cool the whole house or some people have suggested to me that there is an individual unit that you can put out there with its own compressor.
LESLIE: Joe, do you have an actual wall or is everything all glass?
JOE: There’s a space on the bottom, under the window, and there’s a space above it. I’ve measured it and from what I can find online, I think the unit would just about fit on top of the window spot.
TOM: Well, here’s what you would do, Joe. I would definitely recommend that you use a separate system for the sun room and here’s why. If you get a 4½-ton unit, you’re going to have to run that unit all the time, whether you need the extra cooling power or not, and that’s going to really run up your electrical cost.
A 3-ton unit rule of thumb – and you’re in Georgia, so I would be on the extreme of this – is you would figure 600 to 800 square feet per ton. You’re in Georgia, so I would figure 600. That’s only 1,800 square feet. And believe me, there’s a lot of other things that calculate into this: how much insulation you have, how many windows you have facing south and so on.
TOM: So your system is right where it should be, at 3 tons.
TOM: If you were to make that bigger, it would be wasteful for the rest of the house. I would look at a product called a Mitsubishi Mr. Slim. This is a split ductless system, so there’s no ducts to install. You put the compressor outside, the refrigerant lines get run to the inside. They hook up with an air handler that essentially hangs or is mounted right to the wall. I would put it on the exterior wall of your house facing into the sunroom.
LESLIE: Mm-hmm. And they’re like, what, 18 inches by – no, 12 inches by 30 inches?
JOE: OK. OK.
LESLIE: They’re not gigantic.
TOM: I had to turn around and look at the one that’s hanging from my studio. That’s how quiet it is. Yeah, it’s probably 16 inches tall by maybe 2½ – yeah, 2½-foot wide.
LESLIE: Two or three feet.
TOM: And they’re great. They’re real efficient and …
TOM: You can get them in just the air-conditioning mode or you can get one in air conditioning and a heat pump. In case you want to use that space in the wintertime, you could just switch it into the heat mode.
LESLIE: And they heat super-fast.
JOE: That might be a good idea, because it does get – it does stay cooler and I guess that must be because of the large, expansive windows that are in that one room.
TOM: Absolutely. Yep.
JOE: So it probably stays cooler, so we do find that we don’t even use that space once it starts to drop. But the temperatures don’t get extremely cold in Savannah here but still …
LESLIE: But it gets chilly.
TOM: And it’s perfect for that, because it’ll really just sort of take the edge off. Go to the Mitsubishi Electric website and check out Mr. Slim.
TOM: That’s the product. It’s a good product; it works well. And I think it’s the perfect solution for your sunroom in Georgia.
JOE: I’d been leaning towards what you just said. I actually looked at another brand but if the Mitsubishi is good, I’ll pull that up online and kind of look into that one, also.
LESLIE: It’s the one that Tom and I both have personally in our homes and we’ve got one in the studio. And it just worked out that way, not for any reason sponsorship-wise or anything. And we both love them.
JOE: OK. Alright. Well, I’m going to do my homework on it and I appreciate all your help.
TOM: You’re very welcome. Thanks so much for calling us at 888-MONEY-PIT, 888-666-3974.