What is Evaporative Cooling?

A natural, low energy (low cost) alternative to air-conditioning

Evaporative cooling is a natural low-energy alternative to air-conditioning that uses up to 90% LESS ENERGY. Instead of using refrigerants and lots of energy to cool air and produce moisture which has to be drained, Evaporative cooling uses the latent heat already in the surrounding air to evaporate water held in special filter pads contained within the unit. As the evaporation process takes the heat out of the air, the air is, consequently, cooler.

We offer a range of evaporative air cooling solutions including internal, external and portable units and a range of distribution options. See our product pages for more details or combine with our Infrared Products for a complete HVAC solution.

Characteristics of Evaporative Coolers

The cooling effect created is dependent on the outside air temperature and its relative humidity (RH). Where the ambient air is already saturated (i.e. high relative humidity), the cooling effect is lowered. However, when relative humidity is low, the cooling effect is greater and improves proportionally to any increases in external temperature. Consequently in summer months when temperatures are high and RH is relatively low, the cooling effect is maximised.

Eco air chilling Vs Refrigerated Air-Conditioning

Air conditioning accounts for 15% of total American energy use, predominantly being a domestic must-have, consuming 261 billion kWh annually. (US aircon demand equates to the same amount of fossil fuel as Africa consumes for its entire energy needs.) Its use in the UK is much less - accounting for 1% of the UK's annual Carbon Dioxide emissions, and is mainly oriented around business use. However according to the Chartered Insitute of Building Services Engineers, its use will grow by 50% over the next 20 years. (See "Cold Comfort" by Rob Sharp, The Independent, Tuesday 3 August 2010). There is therefore considerable potential in the new or replacement air conditioning market to consider eco cooling.

The following comparison between Evaporative Heating and Air conditioning also places the two alternatives into context:

Are there any issues of dampness with Evaporative Air Cooling?

The implication of Evaporative cooling on the space being cooled is to increase the relative humidity of the air. This leads to some common questions about it:

• Doesn't the increased humidity counteract the effect of the cooling? No: at air temperatures below 25°C, relative humidity has a negligible effect on temperature. Evaporative cooling systems cool the air temperature to well below 25° C;
• If you are cooling air which is damp, does condensation occur? It can do, which is why it is important that the installation observes the following important points:
  • Cooled air must also be extracted either by mechanical extraction or apprpriate vents;
  • "Ventilation" mode is supplied with our units to continue the process of air extraction after cooling ceases;
  • Buildings that already have condensation problems may experience cpndensation problems with Eco Cooling during Spring and Autumn, when RH in the atmosphere is typically higher;
  • We can model your dew-point temperatures inside your buildings before installation, to evaluate and deal with any likely condensation issues in your building;
• Are evaporative coolers prone to legionnaires disease? Statistically, there has never been a documented case of Legionella in the 20 million coolers in the Western world. To safeguard our own systems, we ensure the following:
  • There are no areas in our systems where stagnant water can form;
  • Water temperature in our systems does not exceed 20°C. Legionella is generally accepted not to be a risk where water temperatures are below this.
  • All water contact surfaces in our equipment are plastic. Corrosion from metals which can create salts and airborne contaminants does not occur.
  • As water evaporates, any salts present are left behind. Our systems monitor all salt concentrations and automatically empty and replenish with fresh water, therefore eliminating these salts from becoming contaminants;
  • Our systems ensure emission of water droplets in the cooled air is not possible, removing the mechanism for transmission of bacteria such as legionella.