Air Cooler Buying Guide

Air coolers are a cheaper option than air conditioner. They work well in dry areas, in humid climates they are not effective and hence can be avoided.

Air coolers need a lot of water to be filled, hence this can be a big disadvantage if you do not get enough water in summers.

WHAT IS AIR COOLER?

Air cooler works simply where water is put in the cooler. The air is circulated by the pump in the cooler as water is sprinkled on the pads of the cooler. This evaporates the heat and cool air is circulated in the room.

TYPES OF AIR COOLERS

Direct, Indirect and two-stage evaporative cooling

Direct evaporative coolers are the most common, used to lower the temperature of air by using latent heat of evaporation, changing water to vapor.

Indirect evaporative cooling uses some form of heat exchanger. The moist cooled air does not come in touch with the environment outside.

Two stage cooling goes through 2 stages. In the first stage the air is pre-cooled by heat exchanger. The pre-cooled air in second stage pass through water soaked pads. Since pre-cooled air goes through water soaked pads in the second stage, in this type of cooler the humidity will be less.

Difference between desert coolers and room coolers

Desert cooler is better and provides better cooling. However desert cooler requires more power, more space and more water. In a hot place this type of cooler should be preferred.
In a smaller room and less hot environment, room coolers should suffice.

Desert Evaporative Air Coolers

Personal Evaporative Air Coolers

Room Evaporative Air Coolers

Tower Evaporative Air Coolers

COMPARISON OF AIR COOLERS AND AIR CONDITIONERS

• Air coolers use less energy than an AC.
• Air coolers need less maintenance than an AC. Also does not need elaborate installation and hence this cost is almost negligible unless you have some special requirements.
• Air coolers have environmental benefits with no harmful Chlorofluorocarbons (CFC) or gases emissions and very low power consumption.
• Air conditioners are more effective in extreme temperatures and also in humid environments.
• Air conditioners can control temperature which an air cooler cannot do.
• Air coolers increase humidity which reduces evaporative functions of human organs.
• Air coolers require regular supply of water to wet the pads. In areas where water supply is not constant, this may not be a feasible option

CHOOSING AIR COOLER SIZE

Air coolers are rated by air delivery or the cubic feet per minute (cfm) of air that the cooler can blow into your home. You can use simple formula to identify the proper size of air cooler that you need.

(SQUARE FEET AREA X CEILING HEIGHT) / 2 = CFM OF AIRFLOW NEEDED. (this depends on the climatic condition of the place but general we can follow following thumb rule)

So if you have a room of 500 sq feet with ceilings of 8 feet high then

( 500 X 8 / 2 ) = 2000 cfm

Hence, you will need a cooler with minimum air flow of 2000 cfm.

*cfm =  cubic feet per minute of air

All air coolers will clearly define the air delivery.

AIR COOLER FEATURES

Cooling Media

Cooling media today is mostly honeycomb nowadays. It is made from specifically engineered cellulose paper that is chemically treated to resist deterioration.

Honeycomb cooling pads are designed to provide maximum cooling, low pressure drop and longevity.

Thickness of Pads/media

Pad thickness is essential to get air cooled well – pads should generally be at least 90 mm thick.

Variable Speed

Variable speed coolers are used to control the speed of the fan. Unlike 2 speed coolers in the past now the coolers give multiple speed options which can be controlled via regulator or remote, this help specially at night if the environment becomes cold

Automatic Control

Electronic thermostats can vary the fan speed automatically, and switch the pump and fan on and off.

Automatic Shutoff Dampers

There are periods when the cooler does not run specially when the summer ends. This necessitates covering the cooler.
The shutoff dampeners are flaps in discharge of fan or in duct which opens when fan starts and closes when the fan is put off. This reduces the loss of cooling from the cooler.

Automatic Water Level Controller

Air coolers come with automatic water level controllers which can maintain water in the cooler at pres`et levels. This prevents flooding.
A water inlet pipe is needed for this. The controllers automatically let or prevent water from the connection to flow into the tank.

Water Level Indicator

The water level indicator is useful to determine how much water is there in the water tank. This is an essential feature as otherwise you need to check on the water tank by opening the cooler. Whenever the indicator shows water levels as low you can fill the water tank.

Castors

Castors are wheels provided at the bottom of the air cooler so that it can be moved freely whenever needed.

Remote Control

Air coolers nowadays come with remote control for easy and convenient mode of operation. Setting up speed control is one of the important features which can be controlled by remote control.