On Sun, 16 May 2010 17:50:54 -0700 (PDT), Mikepier
wrote:

On May 16, 8:28*pm, Gordon Shumway wrote:
I am nearing completion of a kitchen remodel. *I am wondering how you
have dealt with sealing the exhaust fan port to the ducting going to
the attic.

I was able to thoroughly seal the exhaust port to the top of the oven
with foil tape prior to mounting the microwave. *The microwave has to
be mounted before the duct can be attached to the exhaust port.
Unfortunately, because of the limited space around the cutout in the
cabinet, I can't seal the joint between duct and exhaust port with the
same foil tape.

Any ideas?

Gordon Shumway

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

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.

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
3-1/4x10 duct over the exhaust port (flange) it just fits over the
exhaust port somewhat loosely. It fits as snugly as can be expected
with no other components. There is a noticeable rush of air inside the
cabinet coming from that joint. I never noticed that type of air leak
with the old unit. However, the fan on this one seems to much more
powerful than the old one.

Gordon Shumway

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