Air Coolers in comparison to Air Conditioners.
Advantages
Disadvantages
Performance
Performance
මේ ටික ගත්තේ Wikipedia එකෙන්. ඒකට අනුව relative humidity එක වැඩි නම් air cooler එකෙන් දැනෙන සීතල අඩුයි. Cololmbo වල relative humidity එක 60%-80% වගේ නේද? එතකොට මේකෙන් දැනෙන සිතල අඩුයිලු.
Advantages
- Less expensive to install
- Estimated cost for installation is about half that of central refrigerated air conditioning.
- Less expensive to operate
- Estimated cost of operation is 1/8 that of refrigerated air.
- Power consumption is limited to the fan and water pump. Because the water vapor is not recycled, there is no compressor that consumes most of the power in closed-cycle refrigeration.
- The refrigerant is water. No special refrigerants, such as ammonia, sulfur dioxide or CFCs, are used that could be toxic, expensive to replace, contribute to ozone depletion and/or be subject to stringent licensing and environmental regulations.
- Ease of maintenance
- The only two mechanical parts in most basic evaporative coolers are the fan motor and the water pump, both of which can be repaired at low cost and often by a mechanically inclined homeowner.
- Ventilation air
- The constant and high volumetric flow rate of air through the building reduces the "age-of-air" in the building dramatically.
- Evaporative cooling increases humidity. In dry climates, this may improve comfort and decrease static electricity problems.
- The pad itself acts as a rather effective air filter when properly maintained; it is capable of removing a variety of contaminants in air, including urban ozone caused by pollution, regardless of very dry weather. Refrigeration-based cooling systems lose this ability whenever there is not enough humidity in the air to keep the evaporator wet while providing a constant trickle of condensate that washes out dissolved impurities removed from the air.
Disadvantages
Performance
- High dewpoint (humidity) conditions decrease the cooling capability of the evaporative cooler.
- No dehumidification. Traditional air conditioners remove moisture from the air, except in very dry locations where recirculation can lead to a buildup of humidity. Evaporative cooling adds moisture, and in humid climates, dryness may improve thermal comfort at higher temperatures.
- The air supplied by the evaporative cooler is typically 80–90% relative humidity; very humid air reduces the evaporation rate of moisture from the skin, nose, lungs, and eyes.
- High humidity in air accelerates corrosion, particularly in the presence of dust. This can considerably shorten the life of electronic and other equipment.
- High humidity in air may cause condensation of water. This can be a problem for some situations (e.g., electrical equipment, computers, paper, books, old wood).
- Water Evaporative coolers require a constant supply of water to wet the pads.
- Water high in mineral content will leave mineral deposits on the pads and interior of the cooler. Depending on the type and concentration of minerals, possible safety hazards during the replacement and waste removal of the pads could be present. Bleed-off and refill (purge pump) systems may reduce this problem.
- The water supply line may need protection against freeze bursting during off-season, winter temperatures. The cooler itself needs to be drained too, as well as cleaned periodically and the pads replaced.
Performance
- Evaporative cooling performance is variable due to changes in external temperature and humidity level. A residential cooler should be able to cool air to within 3–4 °C of the corresponding wet-bulb temperature.
Example - At 32 °C (90 °F) and 15% relative humidity, air may be cooled to nearly 16 °C (61 °F). The dew point for these conditions is 2 °C (36 °F).
- At 32 °C (90 °F) and 50% relative humidity, air may be cooled to about 24 °C (75 °F). The dew point for these conditions is 20 °C (68 °F).
- At 40 °C (104 °F) and 15% relative humidity, air may be cooled to nearly 21 °C (70 °F). The dew point for these conditions is 8 °C (46 °F).
මේ ටික ගත්තේ Wikipedia එකෙන්. ඒකට අනුව relative humidity එක වැඩි නම් air cooler එකෙන් දැනෙන සීතල අඩුයි. Cololmbo වල relative humidity එක 60%-80% වගේ නේද? එතකොට මේකෙන් දැනෙන සිතල අඩුයිලු.
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