Payson weather was getting too cold overnight, so after a week at our campsite, we decided to move to a lower altitude. The ladies went over to Cottonwood and I drove south to a spot just outside Rye, Arizona.
Rye is only 15 miles from Payson but 2000’ lower in altitude. I figured that some daytime temperatures would be quite warm but nothing very uncomfortable. It turns out that a few days have been up into the 80s, a perfect temperature as long as you can sit in the shade and enjoy a beverage. The inside of Minnie, however, becomes too warm as the sun beats down and cooks the walls. With that thought in mind, I wanted to document here the homemade air conditioner I built.
If you don’t want to hear about mechanical contraptions you can skip this part.
I can’t fully take credit for the design of my evaporative cooler but I have long had the idea way before I found out others had similar designs. I have a large box fan purchased this summer that I would place in the window and use a mister bottle to spray the air in front of me. This worked ok but was tedious and inefficient. I tried soaking towels and hanging them in front of the fan. I tried blowing the fan across a tray of water. Nothing worked very well. Then I got the idea of placing a cooler pad in front of the fan and dripping water through the pad and catching it in a tray below. When I looked on YouTube, it turned out a few others had the same idea and explained in detail how they built one.
My first design had the cooler pad in front of the fan. Placing the pad behind the fan draws more air than trying to push air through the fan but I was worried about moisture getting into the fan motor. I finally rationalized that box fans are so cheap that even if they only lasted a couple years it was worth the increased efficiency to pull air through the pad.
My final design (so far, I’m always tweaking it) uses a frame of pvc pipe with holes drilled along the top and a cooler pad held inside the frame. A small fountain pump circulates water up the pipe where it trickles down through the pad into a plastic tote. The whole frame and pad are attached to the fan and placed in the window. I cut the tote lid for shrouds to seal the unit to the window.
Evaporative cooling works well when the humidity is low. On very dry days I have seen the air temperature as much as 15 degrees lower than the outside temperatures. When the humidity gets above 25% or 30%, the cooler will only take a few degrees from the outside air.
My swamp cooler would not be possible without the new lithium ion battery I put in. I have to give credit to the extra power it produces to run a box fan and fountain pump for hours on end.
Once everything is set up and running, all I have to do is add water every couple hours. It’s amazing how much water will evaporate into the air. And I guess there is a benefit to health too. Studies show that a slight increase in humidity is better for us than very dry air.