Evaporative Cooler

Evaporative Cooler (also swamp cooler, desert cooler, & wet air cooler) is a tool that cools air through the simple evaporation of water. Evaporative cooler differs from air conditioning by refrigeration & absorptive refrigeration, which use vapor-compression or absorption refrigeration cycles. In the United States, the use of the term swamp cooler may be due to the odor of algae produced by early units. Air washers & wet cooling towers use the same principles as evaporative coolers, but are optimized for purposes other than air cooling.

Evaporative cooler is well suited for climates where the air is hot & humidity is low. For example, in the United States, the western/mountain states are lovely locations, with swamp coolers prevalent in cities like Denver, Salt Lake City, Albuquerque, El Paso, Tucson, & Fresno where sufficient water is available. Evaporative air conditioning is also popular & well suited to the southern (temperate) part of Australia. In dry, arid climates, the installation & operating cost of an evaporative cooler can be much lower than refrigerative air conditioning, often by 80% or so. However, evaporative cooler & vapor-compression air conditioning are sometimes used in combination to yield optimal cooling results. Some evaporative cooler may also serve as humidifiers in the heating season.

How Evaporative Cooler Works
An evaporative cooler is essentially a large fan with water-moistened pads in front of it. The fan draws warm outside air through the pads and blows the now-cooled air throughout the house.

Little distribution lines supply water to the top of the pads. Water soaks the pads and, thanks to gravity, trickles through them to collect in a sump at the bottom of the cooler. A little recirculating water pump sends the collected water back to the top of the pads.Since water is continually lost through evaporation, a float valve - much like the three that controls the water in a toilet tank - adds water to the sump when the level gets low. Under normal conditions, a swamp cooler can use between 3 to 15 gallons of water a day.

A large fan draws air through the pads, where evaporation drops the temperature approximately 20 degrees. The fan then blows this cooled air in to the house.Little units can be installed in a window, blowing cooled air directly in to a room. Larger units can blow air in to a central location, or the air can travel through ductwork to individual rooms.

Normal air conditioning is a closed method, taking air from inside a house and recycling it. For air conditioning to function properly, doors and windows should be closed. Evaporative cooler, however, takes air from outside the house. For evaporative cooler to work properly, the cooled outside air must be allowed to escape. By choosing which doors or windows in your home you leave open, you can to help direct the flow of cooled air to areas where it is needed.

Benefits of Evaporative Cooler

Benefits of Evaporative Cooler

• Thanks to a new awareness of energy efficiency, evaporative cooler are achieving a new popularity. Recall, swamp cooler use as much as 75 percent less electricity as air conditioning does. The Sacramento Municipal Utility District estimates the electricity savings at approximately $150 a year. For hotter desert climates, the savings can be much more.
• Evaporative cooler operate on 120-volt electricity, which means they don't need special high-amperage circuits like plenty of air conditioners do. A swamp cooler can be plugged in to a nearby outlet.
• Because the technology is simpler, an evaporative cooler costs about half as much as an air conditioner that will icy the same sized area. Some Texas utilities, such as PG&E, also offer rebates up to $300 to electricity customers who install whole-house evaporative systems. For point of view, a speedy check of the net in July 2001, found units capable of cooling 750 square feet that were priced as low as $275. Installation costs of swamp cooler are comparable to air conditioning units.
• Air conditioning works best when the windows are closed, since interior air is cooled and recirculated. Because swamp cooler icy outside air and blow it in to the house, however, to work effectively they need at least four window open. The cooled outside air vents through open windows or doors, pushing out hot inside air and any smoke, odors and pollution that may be present. With evaporative cooler, a complete air change in a home occurs every one-to-three minutes. This flow of fresh air means that evaporative cooler can be operated without using the water pump to replace warm stale air with cooler nighttime air, much like a whole house fan does. That is an added benefit.
• Plenty of people appreciate the fact that evaporative cooler adds moisture to the air, which helps to keep wood furniture and fabrics from drying out. The damp pads through which the outside air flows are also efficient air filters, trapping some dust and pollen. Since the pads are continually wetted, trapped particles are flushed out and trapped in the bottom of the cooler.
• Small evaporative cooler can be often placed in windows, much like a window air conditioner. This requires very small installation. Larger units usually need ducts to distribute the air, but these can be an existing forced air duct method in the house.
• For the most part, evaporative cooler doesn't need as much ductwork as air conditioning. For a newly installed method, a short duct can direct the cooled air to a central point in the house. From there, air can be directed through the various rooms by basically opening and closing doors and windows to permit the cooled air to flow.
  

Evaporative Cooler Tips

• Use a two-speed blower motor. A cooler operates in low speed (which is its more efficient mode) 60%Ð80% of the time.
• Use a low-voltage thermostat. High-voltage thermostats permit greater temperature swings, although they are better than no thermostat at all. Manual control wastes energy and can allow the house to get uncomfortably cold at night. (Many people trade in their evaporative cooler for air conditioners when all they really need is a $50 thermostat.)
• Provide a minimum of 3 feet of clearance on any side of the cooler that requires access for maintenance.
• Provide an easily accessible water shutoff for rooftop installations. If your cooler suddenly starts to leak, you donÕt want to have to run around looking for a ladder.
• Provide an electrical disconnect near the cooler to facilitate safe maintenance. This is particularly important for rooftop installations. When the disconnect isn't handy, it's a temptation to work on the live cooler. Better units now come with a disconnect.
• Be sure the cooler inlet is 10 feet away from, or 3 feet below, plumbing vents; gas flues; clothes dryer vents; or bathroom, kitchen, or laundry exhaust fan vents.