Insulating Kitchen Exhaust Hood Ducting

icesailor

What kind of termination are you going to be using? Round or square? Where I used to work, unless it was a Jenn-Aire, they were always square with a brow over the opening to protect it. With a square one, at least you can go and jamb some foam insulation into it in the winter and stop the cold.

Keep a record of how often you actually use the exhaust fan to clear odors from burning toast and frying food. Even if you have a large, expensive residential/commercial gas stove, you won't be running the hood when you boil water or sauté food on the cook top. This is the kind of thing that nickel and dimes the cost of a new home or renovation into a second mortgage. Money better spent on a quality water closet (Toilet) that you and your wife will use multiple times a day. Spend it on one of those "Comfort Height" ones like a Kohler Cimarron. If you and/or your wife have been jogging. running, and working out since you were children, when you hit 50+, your hips and knees are shot and need to be replaced. Those "Comfort Height" toilets will give you far more satisfaction than the exhausted fan hood will when you walk into the kitchen and its cold. The older you are before you get the bionic joints, the longer they last. And once you start getting new parts, you'll be wanting the Cimarron toilets.

I had a neighbor. He built this fantastic house as his dream get-away house. The kitchen looked like The Kitchen House blew up on it. I did some repairs one day. There was this huge squirrel cage blower wheel in the garage under a laundry sink. Looked like an oil burner fan motor. I asked him where it came from. He told me that the stove hood fan wasn't big enough so they put a bigger fan and motor in it. Now it works.

So I showed him how with the fan running, it would suck the cellar door closed. Or the door into the garage. I decided right them that I had discovered another third world/shade tree Mechanic test instrument. If an inside fan/appliance is running. and it will suck a door closed. you're going to have an air infiltration problem.

Bob Bona_4

I like the comfort height terlets. Toto though. Just saying.

icesailor

Pick any brand that is "Comfort" Height. I just installed far more Kohlers than Toto's. And the special parts for Toto Repair was always a bummer. I once waited over a year for a replacement for a broken tank handle in a common white color. Then, you better get the right flapper or,,,,,,,,,

JustinS

I am using a Broan 643 Wall Cap...

And we already took your advice on the Comfort Height toilets - those are great...

icesailor

My older and Geriatric Customers just love them.

JustinS

Bob Bona said:

You can stuff a bale of insulation in that cavity and all it would do is slow down the enevitable cold transfer. Unless you did this: The end of the cavity abutting the interior space is open to that space so that conditioned air is IN the cavity. Like a closet tipped on its side. The framing of the cavity is insulated like an exterior wall and wrapped in drywall.

I'm not sure what you mean by this, particularly the last part...

Bob Bona said:

Then, as I said before, before sleeving the pipe with R8 (which would be unnessary if that fantasy scenario above existed) seal the pipe joints with mastic or Hardcast tape. Even the Pittsburgh seams on the straight pipe and the adjustable seams on the 90s. Stop any infiltration into the pipe. That includes the weatherstrip of at least the exterior damper.



Make sense?

I'll have to check more closely but I believe that the ductwork is already sealed with Mastic - at least, the sections I've examined have the joints covered...

RobG

No offense intended to anyone in this post, but 49 posts on an exhaust hood? ! Just insulate the soffit as best you can and put on the best exterior damper you can find. Tape a nickel to the damper to help it stay closed. If a nickel is to heavy try a penny, if a nickel did work, try a quarter and so on, and so on......


Rob

JustinS

RobG said:

No offense intended to anyone in this post, but 49 posts on an exhaust hood? ! Just insulate the soffit as best you can and put on the best exterior damper you can find. Tape a nickel to the damper to help it stay closed. If a nickel is to heavy try a penny, if a nickel did work, try a quarter and so on, and so on......

Rob

May seem like a lot but there's been a variety of responses - some say insulate, others say why bother it won't do anything...

Also, tried weighing down the damper last year - have a bunch of rare earth magnets on either side of the damper, helped some but it still flaps in the wind a lot... I want to explore extending the wall cap down to maybe prevent the wind from having such access to the damper flap... probably won't make a difference but maybe...

icesailor

"" I want to explore extending the wall cap down to maybe prevent the wind from having such access to the damper flap... probably won't make a difference but maybe... ""

If it flaps in the wind, you have air infiltration into the conditioned space. Flowing air (wind) has a lower pressure than still air in the house. That's what is called "Draft". If the damper flaps, it's because the inside higher warmer pressurized air is trying to get out. In some high wind coastal locations, you could usually tell when the wind gusted over 60 MPH. The fireplace dampers would rattle and try to flip open. At 80+, they usually did.

The damper rattling is part of the equation. Denied totally by the energy "Experts".

Canucker

Rich said:

You will accomplish nothing except to stay out of your wife's crosshairs for a couple hours by doing any of this .

Do not underestimate the importance of this statement.

don_9

You still have a few option.broan makes a motorized damper for exhaust hoods.Your other option would be to vent the exhaust thru a charcoal filter n dump the exhaust back in to the envelope.

icesailor

Which is what I always did for myself.

I bought and paid for that overpriced energy to heat my home. I'll be danned if I will be sending it outside to heat the Earth.

JustinS

don said:

You still have a few option.broan makes a motorized damper for exhaust hoods.Your other option would be to vent the exhaust thru a charcoal filter n dump the exhaust back in to the envelope.

Yeah, we'll see how it goes... it may come to one of those two options...