- Atmospheric conditions :
As evaporative air coolers works on the principle of evaporation, It works excellent will low humidity region.
RH of 60% and low is the best condition for use of evaporative air coolers
For Eg, Let us see ambient temperature condition of a New Delhi on a particular day.
Temperature is 36 deg C with 39% of humidity, With the use of Evaporative cooler temperature of room can be reduced to 26 Deg C.
This means total 10 Deg C of ambient temperature can be reduced by air Coolers, In this case use of evaporative air cooler is advisable.
- Cross Ventilation of Room :
Cross ventilation is important for operating evaporative cooler efficiently, if air is supplied from one end it should be exhausted from the other end, travelling maximum path in room. Air exit should be provided at height for better cross ventilation.
- 3. Design and Portability.
Evaporative coolers are designed for both indoor and outdoor duty, Outdoor evaporative coolers are best for air cooling and fresh air entry. Indoor evaporative coolers must be provided with wheels for movement.
- Air changes and size of evaporative cooler
Air changes is important for selection of air cooler as with higher air changes power consumption will increase while with lower air changes room will not be comfortable.
Air changes should be in range of (20-55) based on environmental conditions, where 20 air changes is recommended for good environment condition and higher air changes is recommended with the polluted air.
Eg if your room size is 3 mtr X 4 Mtr X 3 Mtr (Length, breadth, Height), Calculate room volume by multiplying ie 36 m3, Air changes required = 20 ,
fan capacity should be (volume of room X Air changes required) = 36X 20 = 720 m3/hr
- Cooling Pad.
Aspen and Honey comb pads are the most used cooling pads for evaporative condensers, While Aspen pad are cheap and needs frequent replacement, honey comb cooling pads are superior on durability, efficiency of honey comb pads are not dropped drastically as in case of Aspen pads over time of use.
- Water holding tank.
Water holding tank should be sufficient to hold water for at least 10-12 hours.
- Energy efficiency
Use of energy efficient motor in air cooler will save money in the power bill of house hold. While comparing different model of evaporative coolers energy efficiency can be calculated by dividing air delivered by power consumed.
Motor used in evaporative coolers should be inventor compatible for using it even at the time of power cut.
- Noise level
Noise level is important while considering evaporative cooler, Low noise evaporative coolers should be considered for human comfort.
- Water level indicator and controller.
Water level indicator and controller are very important feature for operation of evaporative cooler consistently, proper visibility and higher dial for water indicator is better.
Water level controller is good for automatic filling of water in evaporative coolers.
- Ease of Maintenance :
As evaporative coolers usages tap water and with the operation of cooler there is salt formation in the basin, it is recommended to clean coolers on weekly basis. Cleaning provision of cooler must be easy for quick and effective cleaning.