Cool Off With Evaporative Coolers
You may have noticed how the air feels cooler when you walk by a lawn sprinkler on a really hot day? That cooling temperature change is caused by evaporative cooling. Basically, this is how evaporative coolers or swamp coolers work. Evaporative coolers are more cost efficient because they use less energy than traditional air conditioners. These units do not contain harmful refrigerants that may harm the atmosphere. There are two types of evaporative coolers: direct and indirect or called two-stage evaporative coolers.
Direct Evaporative Coolers:
Most direct evaporative coolers have a blower that makes air go through a penetrable, pad saturated with water. When the air goes through the pad, it is not only cooled, humidified and filtered before it is emitted into the room.
Indirect – also called 2 Stage Evaporative Coolers:
Indirect evaporative coolers do not add as much humidity to the air. These coolers have a heat exchanger that prevents humidity from being added to air. First the air is pre-cooled then it flows through a water-soaked pad, where it is cooled again, and finally enters the house. Because the air is pre-cooled before it enters the second cooling stage, less humidity is added to the room. In other words, indirect evaporative coolers have 2 stages of cooling the air before the cooled air enters the room. The humidity of this cool air is usually between 50 and 70 percent, depending on where you live. A conventional direct cooling system produces about 80 percent more humidity. Two stage coolers cost more than direct coolers but are a fraction of the costs of traditional air conditioning systems
In some areas, swamp coolers can be used as the primary cooling system for a home. Conventional air conditioners must not be used at the same time as direct evaporative coolers, because the two systems will work in opposition; one adding humidity and the other removing it. Swamp coolers are sized based on cubic feet per minute (cfm) of airflow. These coolers typically have higher airflow than traditional air conditioning systems. In hot desert climates, 2 to 3 cfm per square foot or 3 to 4 cfm per square foot is needed. It is important to select the correct size because water and energy will be wasted if you don’t. Also, the incorrect size may produce excess humidity.
Evaporative coolers use about half as much electricity than traditional air conditioners systems. They also add humidity to the air which can be soothing in very dry climates. These coolers are environment friendly, energy efficient and cost less than central air conditioning systems. Evaporative coolers just might be the right way to provide cooling comfort this summer.