Dry Air and Moisture

• Swamp coolers work on the principle of a hot, dry summer day and cool water. Water, when placed on our own skin in the heat of summer can immediately cool the flesh. The water evaporates from the skin's surface, taking with it the heat that resides in our bodies.
  
  Swamp coolers operate in much the same fashion. Hot, dry air is passed through a membrane of flowing water. The resultant air is now filled with moisture. This water-drenched air is cooled due to the same evaporation effect. For this reason, swamp coolers typically work better in environments that have a low humidity, such as the desert southwest of the United States. Areas that have high humidity may not be able to take advantage of the swamp cooler.
  
  

The Water Cell and Fan

• Air is passed through a water cell or membrane to add moisture. This water cell is fed constantly by a pump that is placed at the bottom of the swamp cooler. The pump forces water from the collection pan up to a distribution trough. This trough has many holes in the bottom so it may trickle the water down and through the cardboard-like membrane. Outside air is pulled through the membrane and into the home through a large fan. This fan not only works to pull fresh air into the house, but also acts as a circulator to distribute the moisture-laden air throughout the rooms of the home. Windows may be open in strategic locations to exhaust the air from the rooms. In other words, the swamp cooler can be used to "push air" from the home back to the outside by forcing the moisture-laden air throughout the house and out the open windows. This creates a full circulation of air movement within the home.
  
  

Fresh Water

• Swamp coolers should always be fed by a constant source of "treated" fresh water. This is achieved by a float valve that allows fresh water to fill the lower collection pan whenever the level falls below a certain point. Since air is drawn from the outdoors through a wet environment as the membrane, certain bacteria can begin to grow in the wet cells or the collection pan if left untreated. Chlorinated water is the best source for treated water that is used in the swamp cooler. Chlorine is excellent for sanitizing materials and this also works for the water in a swamp cooler. Water that is used from a private water well may have to be treated periodically with chlorine to keep bacterial growth at bay. Water used from a municipal water source should be sufficient for keeping the growth down to a minimum. A periodic schedule should be maintained for the cleaning of a swamp cooler, as dirt and debris may build up from the incoming air and water supply.