Preparing The Evaporative Cooler Duct For Winter

I’m still not done renovating the interface from the evaporative cooler to the underground duct work. I’m getting close but I need to get it sealed up for winter before I finish it this year.

The typical set up for cooling and heating in New Mexico involves separate evaporative cooling units from heating units. Dampers are installed that block air from entering one unit when the other is running. The damper is almost always a flimsy piece of metal that slides into the duct without any kind of insulation or air barrier around it.


This is fine when blocking the cooler air from entering the heater in the summer but it’s not fine when blocking the heated air from entering the cooler in the winter. I’ve been looking at automatic barometric dampers, they open and close based on which way the air is moving. Some automatic dampers look like they might seal the air penetrations when closed but they are not insulated. I’m thinking of designing my own insulated automatic barometric dampener but for now I’m going to have to seal the duct manually.


I started by cutting a piece of polyethylene foam I had from some shipping materials slight larger than the 18 x 18 inch opening. I placed it over the flimsy metal dampener. I sealed it up with some self adhesive foil covered foam pipe wrap.


I covered the lower portion of the duct that is under the dampener with more polyethylene foam and covered it with the foil pipe wrap.


It should be well sealed and airtight for this winter and easy to remove the foam when I finish it up next summer. I still have a number of issues to deal with.

I had Steamatic come out and clean the duct work. They tried cleaning the main duct from the cooler to the manifold the distributes the air to the rest of the house. The dirt was too caked on to get it all. The Steamatic guys suggested I pull a flexible duct through to seal it up.

It’s a great idea and something I will try next year. I also need to finish sealing the main interface with cement and sealing it with a moisture barrier.

It’s still hard to believe that the previous residence of my house was a HVAC contractor considering all the problems I have had with the evaporative cooler. I haven’t started writing about the super crappy heating system.

One Reply to “Preparing The Evaporative Cooler Duct For Winter”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s