About Evaporative Swamp Cooling FAQ - Swamp cooler Information
 
Q: What is evaporative cooling?

A: Nature's most efficient means of cooling is through the evaporation of water. Evaporative cooling works on the principle of heat absorption by moisture evaporation. The evaporative cooler draws exterior air into special pads soaked with water, where the air is cooled by evaporation, then circulated.

Q: What choices of evaporative cooling do I have?

A: The range of commercial and industrial evaporative coolers available today is extensive, varying from commercial mobile coolers to large and fully ducted systems designed for commercial

Q: Are evaporative coolers more suitable for specific climates?

A: Evaporative cooling is especially well suited where the air is hot and humidity is low. However, in higher humidity areas there are many proven cost effective uses for evaporative cooling that make it the right choice. For example, industrial plants, commercial kitchens, laundries, dry cleaners, greenhouses, spot cooling (loading docks, warehouses, factories, construction sites, athletic events, workshops, garages, and kennels) and confinement farming (poultry ranches, hog, and dairy)

Q: What advantages does evaporative cooling have compared to refrigerated cooling systems?

A: Evaporative cooling will provide substantial energy savings over refrigerated air units. The simplicity of the design allows low maintenance requirements. The evaporative cooler will provide fresh, filtered air. The outside air that has been cooled will blow the stale inside air out. With the substantial savings on energy and the air constantly changing, the industrial / commercial evaporative cooler is ideally suited for area cooling or spot cooling in factories, laundries, churches, schools, agri-businesses, restaurants and many other applications.

Q: What size evaporative cooler do I need?

A: Evaporative coolers are sized based on cubic feet per minute (CFM) of airflow. For sizing information on Industrial/Commercial coolers the formulas are located in the specification charts of the cooler being considered. When sizing an Industrial or Commercial cooler it is important to be job specific to include unusual heat loads and static pressure of the system design.

How do swamp coolers / evaporative coolers work?

Swamp coolers are an efficient and effective machine for cooling. As a direct placement for air conditioning in dry climates, it is an example of how we can work with nature. Being so much less expensive than air conditioning, it almost seems that we are getting something for nothing.

The way a swamp cooler operates is very simple. There is a low horsepower motor which pumps the water from the floor of the cooler to the top of the cooler, where it proceeds to fall down the sides, along porous filter pads. A second motor drives a fan which pulls air from the outside, through the cooler, and then pushes it into the hot room. The significant cooling action is the water evaporating as the air passes through it. (Incidentally, the water level is kept constant with the help of a floating sphere functioning similar to the one in the toilet bowl.) The hot air enters the cooler, where two small motors power nothing more than a fan and a pump, in order to send cool air into the hot room.

The way the air is cooled in the cooler is similar to the way evaporating sweat cools the human body.  When a substance is perceived at a certain energy heat level, measured in temperature; there is really a distribution of varying levels of temperature throughout the molecules of the substance. This assortment of temperatures average out to the measured value. Most of the molecules can be around the average, and the farther from the average, the less of them there are. For example, water at room temperature has most of its molecules at approximately that temperature. But it also contains molecules that are near the boiling point of water, and also near its freezing point; however small in quantity they are, they are an important presence. Because at the boiling point of water, there are molecules that are a gas and that are a liquid. The liquid molecules will absorb energy in the form of heat t o become a gas and escape the confines of its old form. As the molecules from the higher temperature evaporate, the remaining liquid averages less heat. But there will still be water at the higher temperatures because the remaining molecules redistribute themselves along the bell curve, which enables the next molecules to evaporate. Heat is siphoned off this way from the water. More importantly, heat is extracted from the air as the boiling point liquid water grabs the needed energy for its freedom into gas.

An evaporative cooler produces effective cooling by combining a natural process - water evaporation - with a simple, reliable air-moving system. Fresh outside air is pulled through moist pads where it is cooled by evaporation and circulated through a house or building by a large blower. As this happens, the temperature of the outside air can be lowered as much as 30 degrees.

Probably because evaporative coolers add moisture to the air and blow it around, they are sometimes knows as "swamp coolers." Evaporative coolers can work wonderfully well, provided the outside air they are drawing in is dry and desert-like. As the humidity increases, however, the ability for them to cool the air effectively decreases. Simply put, swamp coolers were not designed to work in swamp-like conditions.

Air conditioning, on the other hand, became popular because of its ability to cool the air, no matter what the humidity might be. Even on humid days, room and central air conditioners can lower the temperature to a thermostatically controlled temperature. They also use as much as four times as much electricity than swamp coolers do, and they are more expensive to install and maintain. Air conditioners can require ozone-damaging refrigerants, and they recirculate the same air over and over.

Fairly popular in desert areas, swamp coolers will work fine most of the time in California's more humid climates. Sacramento, for example, averages about 30 percent humidity on a typical hot summer afternoon, still dry enough for evaporative cooling to work effectively. Despite the potential, however,

want to know why evaporation lowers temperature?

The process of evaporation happens all the time. Our bodies, for example, perspire in hot weather; through evaporation the sweat dries and drops our body temperature.

Whenever dry air passes over water, some of the water will be absorbed by the air. That's why evaporative cooling naturally occurs near waterfalls, at rivers, lakes and oceans. The hotter and drier the air, the more water that can be absorbed. This happens because the temperature and the vapor pressure of the water and the air attempt to equalize. Liquid water molecules become gas in the dry air, a process that uses energy to change the physical state. Heat moves from the higher temperature of the air to the lower temperature of the water. As a result, the air is cooler. Eventually the air becomes saturated, unable to hold more water, and evaporation ceases.