Two common ways to cool a building are to use air conditioning or to use evaporative cooling. Air conditioning uses a refrigerant compressed by a motor to transfer heat from the inside of the building to the outside. Evaporative cooling uses a fan blowing air through a moist mesh or pad to transfer heat energy from the air to the water in the mesh, by way of evaporation. There are a number of advantages and disadvantages to each system. Does this Spark an idea?
Design
An evaporative cooler needs power for the fan and water pump, and a bit of water. The standard air conditioning unit needs two fans (one to cool the unit, and the other to blow air across the cooling coils), a compressor motor, and often an evaporator or pump (to remove water that condenses on the outside of the coils).
Running Cost
Basically, an evaporative cooler costs the same as having a fish tank and a desk fan. A standard air conditioner has at least three motors, maybe four, and the compressor needs a bit more power as it deals with higher pressure. All things considered, running an evaporative cooler is about a third the cost of running an air conditioner.
Maintenance
The evaporative cooler requires a bit more regular maintenance than a standard air conditioner, as it needs to be cleaned to prevent mold buildup, and its pad needs to be replaced. An air conditioner could benefit from a new filter on a regular basis as well, but this is optional. Should the evaporative cooler break, its parts are relatively cheap and the system is easy to fix, since all that can break are the fan and the water pump, or maybe a switch or two. An air conditioning unit will often require calling in a professional, and a costly replacement part.
Results
An evaporative cooler does not deliver a consistent supply of cool air. It works most effectively in warm, dry climates. On the driest day it may reduce the temperature by 30º F. Since it relies on the evaporation of water, areas and seasons with higher humidity will not allow for as much cooling. The evaporative cooler also increases the humidity of the building it is used in, which may be undesirable as it could attract insects such as mosquitoes, or shorten the life of electronics. An air conditioning unit will keep you cool anywhere, in any season, with the capacity of lowering the temperature in a house by 50º F, or even much more, depending on the unit quality and the house's insulation. However, it will also dry out the air entering a building, which can be hard on the body, and the same air is circulated through the system repeatedly.
Types
There are three basic types of evaporative coolers, while there is one basic kind of air conditioner. Evaporative coolers are direct, indirect, and direct-indirect. Direct is the simplest, but creates the most humidity. Indirect intakes air from the outside, cools it, and uses that air to cool the air on the inside of the house without making contact with it. It does not produce humidity, but it also doesn't cool as effectively. Direct-indirect uses direct cooling to further cool the air after the indirect cooling cools it, which still produces humidity, but not as much as the direct method does. The standard air conditioner uses compressed, then decompressed gas to cool the air.
Tags: evaporative cooler, conditioning unit, standard conditioner, conditioning unit will, transfer heat