Tom has come up with a very nice evaporative cooler for his RV. The cooler is effective, uses very little electrical power, and is inexpensive and relatively easy to build.
The cooler works very well with Tom's solar powered RV and allows him to camp without access to grid power.
Evaporative coolers work very well and are very efficient for hot and dry conditions, but are less efficient as humidity levels rise. This page has a chart that will give you an idea of how well an evaporative cooler will work in your area.
Thanks very much to Tom for working the cooler design out and sending it in!
Highlights
The system uses fans to blow outside air through a porous wet cooling pad. Evaporation of water in the cooling pad cools the air, dropping the temperature by as much as 25 F.
The compact unit contains a water reservoir, water pump, aspen cooling pad, and circulation fans as shown in the diagram.
It runs on 12 volt DC power and is powered by the RV's solar panel and battery -- pretty cool :)
The finished unit ready to mount in the RV window.
The same sort of design could be used for all sorts of cooling applications -- cooling a living space or shop or greenhouse with no grid power, cooling when the power grid goes down, ... For this size cooler, the fans and pump only use about 18 watts at 12 volts -- so a modest size PV panel could direct drive the cooler. The design could be scaled up for larger spaces.
