This was only the second summer I’ve lived in this house, and the second year I’ve ran the swamp cooler. I thought I was lucky to have a swamp cooler that sets on the ground instead of the roof. I expect to have some dirt get through the ducting, but i had quite a bit of it all summer long this year. I also found that the cooled air was making it out our under the concrete pad that the cooler is setting on. Summer is over, so i pulled off the swamp cooler to take a look. I found a huge mess.
The metal duct work is mostly rusted away. I would expect that the ducting would be incased in concrete, which it appears there was an attempt to do so. Except only 50% of the ducting had concrete surrounding it, the rest was up against dirt. Damp dirt, which led to the rusting and the mud which penetrated the ducting.
I pulled up the majority of rusted mess out. I allowed the pit to dry out then vacuumed up as much of the dirt with a shop vac as I could. I also found a layer of dirt in the 18 inch duct that leads to the main distribution center under the forced air heater. Thankfully that where the dirt stops.
I’ve got a huge mess to clean up. I’m going to need to talk to a HVAC contractor to see what can be done. Hopefully I can do most of it myself, but I will need some advice. I decided not to deal with it this fall, instead I sealed up the main 18 duct so the heated air wont get out this summer. I took a piece of foam and a piece of plywood, sized up to the wall where the inlet to the house is, and held them with some 2×4’s that I hammered into place.The foam compresses and seems to have a good seal. I filled any other holes with pieces of foam and some expanding foam.
If your interested in following the progress, you can view pictures at a flickr set.