Installing Kitchen Ventilation
LESLIE: Kendra in Maryland has a kitchen question. How can we help?
KENDRA: My husband and I are renovating our kitchen. And we bought a microwave that goes over the stove so it has a ventilation hood built in.
LESLIE: Yeah, except it ventilates it right back into the kitchen, doesn’t it?
KENDRA: Well, there’s an option that you can ventilate it to the outside, which my husband feels strongly about using because we have a gas stove.
KENDRA: But we have plaster and lath walls. It’s sort of an old house.
KENDRA: And so, other than having exposed duct work, we were trying to think of other options that we could use to ventilate it to the outside. And I was also wondering how important is it to ventilate it outside.
TOM: Well, your real question is, here, is whether your husband is right or not?
KENDRA: Yeah. (laughing)
TOM: Well, Kendra, I would say that it probably is a good idea to ventilate to the outside because the recirculating types of kitchen exhaust fans, frankly, don’t do that much. They don’t do a very good job of taking odor, taking steam …
LESLIE: No, it takes the odor and sends it to the rest of the house …
LESLIE: … because it’s forcefully, now sending it back into the kitchen.
KENDRA: (overlapping voices) Right. (laughing) Right.
TOM: That’s right. As if there wasn’t enough air pressure behind it …
LESLIE: (overlapping voices) It’s like and wait until you cook seafood. It’s like excellent.
TOM: (overlapping voices) Oh, yeah.
KENDRA: (overlapping voices) Right.
TOM: No, I do think it’s a good idea to vent it to the outside. And I don’t … I’m not sure what your hesitation is for cutting the hole in the wall. It’s not that bad. Houses are designed to have holes cut in them all the time. If it’s done properly, it shouldn’t be an issue. Even though you have plaster walls …
TOM: … those walls can be successfully cut through. It can be framed out properly. It can be ducted properly to get that passageway right through to the outside.
TOM: The fans, today, have dampers on them so when the dampers close, it shouldn’t even have drafts that come back into the house.
KENDRA: Oh, great. Okay. So you’re saying that it’s okay for us to just cut through the plaster and lath the three inches or whatever to put the ducts in there.
TOM: Yeah. It absolutely is.
TOM: Now, the only thing you have to watch out for is whatever happens to be in that wall.
TOM: When you open it up, it would be bad if there was a stud in the middle because that makes it a little more complicated and you’d have to frame around that.
KENDRA: Okay. Okay.
TOM: If there was electrical wiring running through there, you know. All of the normal cautions apply that you would have if you cut into a wall for any reason.
TOM: So, presuming you can get all that stuff out of the way …
TOM: … I would also tell you to make sure that you’re ducting through that. So you don’t want to leave like a wood hole through there. You want to make sure that there’s a metal duct that goes through that section and the reason for that is because you don’t want grease to get into the wall cavity. That could be a fire hazard.
LESLIE: Well, also, then the walls would absorb all of the odor.
LESLIE: At least in metal, it contains everything.