evaporative-coolinghvac
This is my first experience with an evaporative cooler because we just moved into our house. I have no idea how long these pads have been it he cooler. We never noticed any smells come from the cooler and the cooler seemed pretty cool to us. How do I know when the pads should be replaced? My understanding is that these cardboard type ones last longer than the fiber based ones.
Stick closed-cell backer rod into the larger gaps. Then caulk over everything (small gaps as well as the backer rod) with a good exterior-grade caulk that looks good color-wise when connecting them.
At minimum, you should drill weep holes in the cans to allow standing water to drain. If you are ambitious, remove them. The globs of tar you see at the lower edges were used to waterproof the fasteners that attach it to the roof. Scrape off the tar and remove the fasteners. Patch the fastener holes with roof tar. Remove the entire flashing, tuck the up-slope edge of the flashing under a course of asphalt shingle, apply roof tar under the flashing at the fastener hole locations. Fasten down then tar over the fastener heads again.
A manufactured version of the same style of mount is pictured below, note the weep hole.
Best Answer
You're going to be up there at least twice a year, to put on and remove the jacket, so check the state of the pads each time.
You won't need to replace them every year, but treat them like any filter - if it looks dirty or clogged, it probably needs replacing.
The pads in your photo don't look bad - I'd leave them for now, and check again in Spring.