Evaporative coolers have been used in warmer climates such as the USA, Australia and the Middle East for many years. As the effects of global warming are felt in cooler climates such as Europe the use of evaporative coolers is becoming more widespread.
On days when heat or humidity, or even excess pollen, causes discomfort, people often head off to lakes or the seaside in search of relief. Evaporative Air Cooling is, in many ways, simulating the cooler conditions so often found at or near large expanses of water. It makes it possible to effectively cool factories, warehouses, offices and many other areas.
As water is evaporated, energy is lost from the air reducing temperature. Two temperatures are important when dealing with evaporative cooling systems. The first is the dry bulb temperature. This is the temperature that we usually think of
as air temperature, measured by a regular thermometer exposed to the air stream. The second air temperature, important in evaporative cooling systems is the wet bulb temperature.
This is the lowest temperature that can be reached by the evaporation of water. The dry and wet bulb temperature can be used to calculate the relative humidity.
Evaporation will take place when the humidity is below 100% and the air begins to absorb water. Any given volume of air can hold a certain amount of water vapour and the degree of absorption will depend on the amount it is already holding. The term humidity describes how much water is already in the air; relative to the amount it is capable of holding. Air is saturated when it cannot hold any more water. Imagine it as a sponge, if the sponge held half as much water as it was capable of holding, it would be 50% saturated. In the case of air, we would describe the Relative Humidity as being
50%.
Energy is required to change water from liquid to vapour. This energy is obtained in an adiabatic process from the air itself. Air entering an evaporative air cooler gives up heat energy to evaporate water. During this process, the dry bulb temperature of the air passing through the cooler is lowered.
A cost effective solution
On a normal summers day temperatures in factories, warehouses and on particular mezzanine floors can rise well in excess of 30°C, resulting in unpleasant working conditions which can have an effect on morale, absenteeism, production and ultimately productivity.
For these types of applications conventional air conditioning systems are prohibitively expensive, leaving evaporative cooling as the only viable alternative.
The technologically advanced Breezair sets new standards evaporative air cooling
by providing improved air delivery and high cooling capacity. Environmentally friendly
the state-of-the-art Breezair provides the following benefits:
Introduces 100% fresh and filtered air
Doors and windows can stay open
Maintains some moisture in the air
Cooling capacity increases as the outdoor temperature rises
Low energy consumption. Up to 80% more economical than conventional air conditioning systems
In an evaporative cooler, such as Breezair, a pump circulates water from a reservoir tank to the top of absorbent cooling pads. The pads become saturated with water as the water descends by gravity back into the tank. Powerful centrifugal fans draw warm air from outside through the wet pads. As the air passes through the pads it is cooled by evaporation and the cooled air is then circulated around the building.
Evaporative air-cooling systems should not re-circulate air as this will result in hot and humid conditions. Air from an evaporative cooler should be used once only and should move from the cooler, into the air cooled area and then out of the building. Constant cool air movement pushes heat out along with stale air, smoke, odours and pollution.
Evaporative air-cooling systems should not re-circulate air as this will result in hot and humid conditions.
Air from an evaporative cooler should be used once only and should move from the cooler, into the air cooled area and then out of the building. Constant cool air movement pushes heat out along with stale air, smoke, odours and pollution.
Evaporative air-cooling is particular suitable for commercial and industrial applications, where compressor-type air conditioning is prohibitively expensive. Quick and easy to install, coolers are fitted to the exterior of the building, either on the roof, the sidewalls or at ground level. A system of ductwork and air diffusers is then used to channel the cool air to where it is needed. Rigid pre-fabricated metal ducts are the most common, but for some installation flexible ducts can be used. For spot cooling in factories and warehouses,vertical ducts with plenum boxes are also common.
Seely International is proud to announce that the Breezair Evaporative cooling system has been shortlisted for product of the year at The 2008 Building Services Awards.
