I’m going to install an over the range microwave that has three vent options: out the back or up to vent ourside, or I can forgo venting and recirculate in the kitchen using a charcoal filter. Installation will be on an outside wall and the house has vinyl siding so venting out the back through the wall would not be difficult. In addition, given my attic and roof configuration, venting up through the roof would be easy, too. Any thoughts on venting outside the house versus recirculating and venting out the back versus up through the roof will be appreciated.
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Listeners write in about haunted pipes and building-science tomes, and they ask questions about roof venting and roof leaks.
Featured Video
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
As long as it won't be extremely obvious, I prefer to vent it out the sidewall. I try to avoid cutting into the roof whenever possible. That said, I'd vent it out the roof, before I recirculated it into the room.
The shortest run (straight back) will work the best. That's what I did with mine and it works real well. The only complaint I have is that the fan is a bit noisy, but that's not related to which way it vents.
If I had to recirculate back into the room, I probably wouldn't even bother turning the fan on.
-Don
Vent it outside before recirculating.
gotta jump on board with the others--vent before recirc. and side wall before roof.
The filters only work if you keep them very clean and most HO won't be diligient enough to keep them working right.
Just a side note. Don't skimp on the wall fasteners and use what ever ness. to fill the holes indicated on the wall braket--Toggles work nicely when only one stud is in the area--
Mike
Adam Savage---Mythbusters
i've installed many of those units and vented them all three ways
through the wall works best, the run is the shortest and doesnt compromise the roof integrity
however most these days around my area anyway are not vented at all, the customer just doesnt want it vented outside
on another note, make sure that the back plate is really secure, lag screws into two studs is best and make sure that the cabinet above is well fastened to the wall
the cabinet above the mw should be 15 inches tall(at least in standard 30 inch cabinet hts)
caulking is not a piece of trim
shortest is usually best.
out the side if there's no clearance problems ... soffits/windows/etc.
out the roof is no big deal ... cutting a hole in the roof is no big deal if U actually flash it right.
"recirculating" isn't a real option ... same as turning the ceiling fan on high.
Jeff
Buck Construction
Artistry In Carpentry
Pittsburgh Pa
Recirculating hoods are useless. They have some utility at removing grease and smells from cooking as long as you replace the charcoal filter frequently. The way grandma cooked a filter would last about ten minutes. Vent unless there is absolutely, positively no other way. Builders put in recirculating hoods because they are cheap and, because they don't require ducts or vents, are quick to put in.
If you run a circuit for the microwave install at least a 30A circuit, #10. Eventually someone will want to install a high power unit even if the one you install now would run on a 15A or 20A circuit, #14 or #12. Labor is the greatest cost in running the circuit so go large on the wire. You can still install a 15A breaker, if that is what the manufacturer recommends, at the panel on the end of that #10 cable.
I'm not a big fan of overbuilding but in this case it makes sense. Have to take human nature into account.
I've never had a reason to use the fan on the combo nuker / fan over my range, which vents inside. Why? I've stopped frying fish like I used to do years ago. Plus it drowns out all conversation. I asked my Mom recently how often she uses her stove hood vent a few years after I had spent a dangerous day on her shaky, wooden ladder venting her hood to the outside. "Hardly ever," was her reply. I don't think that modern cooking really requires much outside venting, unless you have a commercial stove and are cooking for a hundred guests. How often does that happen? If I could afford a hundred guests, it'd be catered. I'm a good cook, but I also enjoy people. Damned if I'd ever be cooking something complicated that required outside venting while I was also trying to entertain guests. Too much work.
You think frying fish is a major issue? So you say you don't whip up a mess of chitterlings, chitlins in country lingo, very often. These may have been the actual origins of both outdoor cooking and the phrase: 'Get the hell down wind'.A good hood has a lot going for it. Oil and grease, especially if you cook with the 'holy trinity of southern cooking', salt, sugar and lard, can disperse widely throughout a house. It can speed clogging of the evaporator for AC units. Condenser coils on the refrigerator. Not to mention coating the paint and woodwork.Cooking generates heat and moisture that can interfere with indoor air quality and takes additional energy to remove. Of course if you prefer the 'nuclear option', slapping a frozen dish in the wave you could likely eliminate the hood.