Here are some tips for buying and maintaining a portable evaporative cooler:
- Capacity: As in, how much water does that swamp cooler's tank hold? The larger the tank, the longer it can run, but more water means more weight to push from room to room.
- Cubic Feet: A swamp cooler's power is measured in cubic feet per minute. Follow a 4:1 ratio of CFM to square feet of space. For example, if you want to cool a 250-square-foot bedroom, you'll want a swamp cooler rated at 1,000 CFM minimum.
- Circulation: Even though they have built-in fans, swamp coolers work best when there's a steady flow of air in and out of the house. This is more important for larger portable units than for tabletop coolers.
- Connectivity: Sooner or later, your swamp cooler is going to run dry and you'll need to refill the tank. But some room-sized models have hoses that can be connected to an external water source.
- Cleaning: Swamp coolers need to be cleaned periodically to remove calcium buildup and to prevent mold growth, and filters must be replaced on a regular basis. Fiber-pad filters are most common and fairly cheap, but rigid-media pads are more durable (if pricier).