How to Soften Hard Water in Evaporative Coolers

You may know your evaporative cooler as a swamp cooler, but the words refer to the same type of machine, one that reduces air temperature via water evaporation. These machines work by drawing hot, dry air through cool pads. The key to an efficient cooler is keeping those pads free of calcium buildup that happens if your water is hard. Softening the hard water in an evaporative cooler means less mineral buildup and less maintenance. You can use a commercial water softener product or attach a water-softening machine to the cooler.

When hot, dry air is directed through something wet, the water in the wet thing evaporates, causing the air to cool. The evaporative cooler improves this basic process with mechanical parts. Swamp coolers use water pumps to keep the cooling pads wet and fans to distribute the cool air around the home. This turns evaporation into a very efficient air-cooling device. These are extremely popular in dry desert areas. Although water is critical to the swamp cooler evaporation process, it can also damage the efficiency of the machine. Hard water in the cooler is the most important example of this.

Hard water refers to water that contains a high concentration of calcium and mineral deposits. Swamp cooler calcium buildup can damage the mechanical parts of a swamp cooler, dramatically reducing the efficiency of the cooler. You will see tell-tale spots, such as mold and marks on the cooling pads. Routine swamp cooler maintenance if you have hard water includes checking and changing the cooling pads.

To avoid the problems of hard water, you can use filtered water, which has been cleaned of excess calcium and mineral deposits. Or you can use distilled water — water that has been turned into steam and then cooled again to remove salts, calcium and other minerals. This is even better than filtered water for use in an evaporative cooler because of its total lack of hard-water minerals. Another option is to use a water softener for the evaporative cooler.

Consider using a purge pump, which will keep swamp cooler calcium buildup to a bare minimum. This device pumps a portion of the water in the pan out every six to eight hours and replaces it with fresh water. Purge pumps are inexpensive and can save you plenty in terms of money as well as time spent cleaning your cooler.

If you are not able to get reasonably priced filtered or distilled water for your swamp cooler, your only choice may be to soften the hard water you have. One option is to install a whole-house water softener. You can also purchase products that will reduce the hardness of your water. This type of evaporative cooler water treatment is added to the water reservoir in the cooler. It will reduce the hard-water deposits left behind on the cooling pads. Use the product according to package directions. Alternatively, you can buy and install a softening unit to the recirculating water line of your swamp cooler.