Evaporative Water Coolers - Removing a roof-mounted evap cooler

I have a long-unused evaporative cooler on the roof that I would like to remove.

The installation has a sheetmetal duct rising through a roof jack to the cooler, a down-draft model. There doesn't seem to be a lot of clearance between the duct and the jack, although I haven't dismantled it far enough yet to be sure. It's a sloped roof, asphalt shingles, if that matters.

Other homes in the area that have had the swamp coolers removed seem to have the roof jack left in place and capped.

So, the question is, how is the roof jack and ducting normally capped? Does the duct get one cover and the jack another? Is anything special done to reduce heat leakage or control condensation during the humid parts of the year?

I'd appreciate any advise before taking this on.

Thanks,
John

I've never seen one close-up but just to give you an answer of some sort what I would do is have a sheet-metal shop bend up a cover for the outside portion with some nuts on the inside that you could use pieces of all-thread to secure it from the inside of the attic. Remove the duct from the attic, install strong-backs to hold the cap on top and close off the grille to the house (and properly insulate it.

Doing it this way allows you to go back to the swamp cooler or install a big attic / whole house fan in the future if you ever were to choose to do so.

furd,

Many thanks for the reply. I've finished the job as you described.

I found that the box that the cooler was blowing down into had rusted out at the bottom, leaving a hole about 2" x 12", partially plugged with debris but basically blowing hot/cold air into the crawl space. It's temporarily cleaned and patched, but the long-term plan is to replace the unit with a wye for the 16-14-14 flex duct that goes in/out.

Thanks again for the assist.

John