Through-the-wall Kitchen exhaust fan

[carloco]

The kitchen has the original through-the-wall exhaust fan.  The fan works well but the outside damper and hood are rusting etc...   It lets cold air into the house.  I tried a to tape a bag around the vent but I still could feel air coming through.  Today I took the outside hood off and tried to caulk around the vent pipe but then I couldn't put the hood back on.  Anyway I stuffed the exhaust pipe and tied a plastic bag on the outside hoping to make it to the spring. 
Are there any good exhaust vent caps that provide a good seal when not in use?  We don't use the thing that much because the previous owner built an enclosed porch that includes that area.

[Greg]

The best thing would probably be to find a new version of what you have currently.  They don't last forever.   You might end up replacing the fan too, sometimes parts cost more than complete assemblies.

What size is the vent?  Round or rectangular?

With vent dampers it's always a balance between preventing backdrafts and ease of operation with the fan on.  Usually in favor of the latter.  If the fan is strong enough, maybe you can create a flap using magnetic strips like a pet door?

[carloco]

That's true.  I have been looking online for a while without success.  All of the through-the-wall vents are designed for bathroom or dryer exhausts.   Maybe I can use one of those.  The fan blows air through a 7.25" diameter pipe.  I think most dryer vents are 4 or 5 inches.
Maybe someone heard where they sell this type of exhaust fans  and vents.

[carloco]

I found this cap on Amazon

[phred]

Why not remove the fan altogether?  Cut a circle of sheetrock or whatever with beveled edges and mud it into the hole after you stuffed in some insulation & a vapor shield.  Do something similar on the exterior.  Sand & paint.

[carloco]

good idea, but the exterior is brick.  I always wonder if I can make a little round window there.

[phred]

out of plexiglass?  Still, if you can find matching brick, should be able to mortar some into there

[Exflyboy]

out of plexiglass?  Still, if you can find matching brick, should be able to mortar some into there

+1

If you can find the same brick simply drill out the mortar around the remaining partial brinks around the opening (assuming a round hole has been cut in the brick wall) then insert the full (or half) bricks into the holes and it will look like there was never a hole there.

You can stuff the new mortar into the gaps using a lollipop stick etc.

Frank

[Spork]

I love the 50's look of this.   I'm going to go opposite of everyone and say "google around for parts".  There are all sorts of vintage appliance forums out there.  And it doesn't have to be "exhaust fan related".  The stove people would love it.

[Greg]

I meant take the old hood to the local HVAC supply house and see if they can replace it.  Home Depot probably won't have it.

[carloco]

I decided in the spirit of keeping the same old look and reducing the amount of waste to add this little damper I found on the amazon
I hope it is easy to add.
 

[Greg]

That is meant to take the place of the pipe through the wall, or can be added to either end.  I had one in my studio where I used essentially the same fan as you but for an updraft situation.  The fan sure was loud.  The damper ended up making all sorts of noise when it was windy, so I removed the flaps and depended just on the roof jack vent hood flap.  Hopefully yours doesn't have this problem!

[PantsOnFire]

The best thing would probably be to find a new version of what you have currently. 

I wholeheartedly DISagree with this.  The new through-wall fans are crap.  All of them.  The ones from the '50s and earlier are quite good and many of them are still going strong. 

When our 1949 "Power-Vent" started giving us trouble, I took it apart and refurbished it in an afternoon.  We had to replace the pull chain ($5 worth of stainless ball chain from the hardware store), degrease the housing, fan, and motor, lube the hinges and the on/off lever, and replace the door spring and weatherstripping.  All told, I spent maybe $20 including some nice silver enamel for the front grille.  Considering all the horrible reviews I found when I was shopping for a replacement fan, I'm quite satisfied with the refurb option.  And that fan draws more air than any of the ducted versions I've ever encountered (aside from lab hoods and commercial stuff). 

Don't give up on the old stuff just yet--in many cases the quality of durable goods has gone WAY downhill (planned obsolescence), and IMO these fans are a prime example.