Sealing microwave exhaust duct

Usually the microwave comes with a flange with the damper attached and that goes into the ductwork. I don't think you need to seal where the microwave meets the ductwork. I don't think its possible anyway since there is no room to seal it once the microwave is installed. From memory, I don't think my installation manual metions it.

Never heard of directly connecting a uwave to an exhaust. My experience is that the exhaust fan in a uwave isn't nearly strong enough to exhaust thru any reasonable duct length.

If it doesn't have an exhaust connected, where is the exhaust going to go? Back into the kitchen? That would be idiotic.

Mine exhausts fine.

Yes, mine had the flange with the damper. That's what I was calling the "exhaust port." I was able to seal the exhaust port to the exterior sheet metal of the oven with no problem. When I put the

Gordon Shumway

Our Constitution needs to be used less as a shield for the guilty and more as a sword for the victim.

All the microwave/fans I've seen has the flange attached to the unit with the fastening tabs. I don't recall any in which you seal the flange to the unit. Read the instructions that came with your unit and see what it says, but I'm pretty sure the flange stays on the unit with no sealing. Make sure your unit is configured to blow air out the top. Some units you have to re-orient the fan inside depending on whether you want to blow air out the top or side

That's how I do it. You can get that 1/2" by 1/2" foam that is sticky on one side.

All the countertop uwaves I have ever owned or seen do exhaust back into the room in which they are located.

Not a countertop, an over the stove. And if you look at the way the exhaust fan is setup on most of them you will see that it can be removed and reinserted such that it now exhausts straight up. If you have duct work installed above it you can vent it outside instead of just recirculating the air

This is obviously not a countertop uwave. The exhaust fan is for the stove under it.