Evaporative cooling is best suited to medium to large open space areas with good ventilation and air movement. This makes it ideal to cool factories, warehouses, large storage areas, agricultural buildings, machine rooms, printers, nightclubs, manufacturing plants, workshops, etc.. Evaporative coolers work with the windows and doors open and give a continuous flow of cool, fresh air during the hottest days.

A recent UK survey has shown that Evaporative Cooling is the fastest growing area of the HVAC industry. It has become the most widely used method of cooling large open spaces in factories, warehouses and workshops. Unlike conventional air conditioning, buildings do not have to be kept airtight. This means that windows, doors and loading bays can be left open.

[Link to Eva-Cool site.]

How does Evaporative Cooling work?

Evaporative coolers are cooling devices which use simple evaporation of water in to an air stream. This lowers the temperature of air by the effect of latent heat of evaporation. In this process warm dry air is changed to cool moist air.  There is then a secondary cooling effect that can known as wind chill. It can be illustrated by the effect is caused by the evaporation process of the water drying quickly from your body i.e. coming out of a swimming pool and feeling cold.

Water
Evaporative coolers require a constant supply of water to wet the evaporative pads. In hard water areas it may be necessary to install water softer to avoid mineral deposits on the evaporative pads.

Ventilation
We would recommend that you allow 2sq. ft. of unrestricted openings (i.e. doors, windows etc.) per 1000CFM capacity of the evaporator.

Advantages
Less expensive to operate Evaporative coolers use less than one-third the amount of electricity of conventional air conditioners. They do not use CFCs or other ozone-depleting compounds.

 Disadvantages
The greatest disadvantage of evaporative cooling equipment is there dependence on a constant supply of fresh air. Without it, the air in the room will become damp and the cooling effect will decrease.

Portable evaporative coolers should be positioned near to an open door or window. If this is not possible then fans must be installed to draw fresh air into the building.

Alternatively evaporative coolers can be installed outdoors using ducting to deliver the cooled air into the workplace.

 Always buy evaporative coolers with multiple fan speeds. This allows the unit to be turned down when less cooling is needed saving energy, and  increasing the level of comfort.

Never use an Evaporative Cooler at the same time an Air Conditioner. This will cause your units to work against each other, wasting money and energy without additional cooling benefits.

Evaporative coolers and air conditioners are different!
Evaporative cooling and air conditioning reduce the air temperature in different ways:

Air conditioning is best suited to cooling small to medium sealed spaces; because it works by continually recirculating and cooling the air inside the room. For maximum efficiency doors and windows must be kept closed.

Air conditioning is unaffected by outdoor conditions, it will circulate cold air continuously irrespective of the outdoor temperature and humidity level.

Evaporative cooling is best suited to medium to large open space areas with good ventilation and air movement. It can be used in small rooms and offices but adequate ventilation must be provided, either by opening doors and windows, or fitting mechanical supply fans.

The efficiency of evaporative cooling systems depend on the humidity of the incoming air. On muggy days, the cooling effect is reduced, and in very humid conditions, it can make the workplace more uncomfortable. Luckily such days are quite rare, but when they do occur, evaporative coolers should be operated without cooling to provide air movement.

The disadvantages of evaporative cooling equipment
The single biggest disadvantage of evaporative cooling equipment is its dependence on a constant supply of fresh air. Without it, the air in the room becomes damp, the cooling effect decreases and eventually stops completely.

Evaporative coolers should be positioned near to a convenient open door or window. Where this is not possible supply fans must be installed to deliver fresh air into the building.

Alternatively evaporative coolers can be installed outdoors (preferably in the shade), using flexible ducting to deliver the cooled air into the workplace.

The advantages of evaporative cooling equipment
Evaporative coolers work most efficiently when drawing fresh air from outdoors. This offers several major benefits over refrigerated air conditioners, which recirculate the same stale dry air over and over.

Constant cool air movement pushes heat out - along with stale air, smoke, odours and pollution.

Constant supply of fresh moist air. Evaporative cooling does not dry out the air like refrigerated air conditioning. Maintaining natural humidity levels prevents:

Flowers, furniture, fabrics and foodstuffs from drying out.
Static electricity from building up.
Complaints from workers about sore throats, dry eyes and running noses.

Legionnaire’s Disease
Evaporative coolers, like all equipment, require maintenance. In very rare cases, evaporative coolers that have not been well-maintained have been found to harbor Legionella bacteria or other harmful substances. It is important that evaporative coolers be properly installed and regularly maintained according to Tasaki’s recommendations.

Evaporative cooling is the most rapidly expanding sector of the UK commercial and industrial cooling market. Evaporative air coolers are being installed in buildings which were considered to big or expensive to cool by other means.