How do they work so well?

Evaporative cooling is the completely natural way of producing fresh cool air

Nature's most efficient means of cooling is through the evaporation of water. A simple example is the cooling you feel when stepping out of the sea - the water evaporates quickly from your body, taking heat with it – making you feel cooler.

Our coolers do essentially the same thing by drawing hot air through wet pads using a fan or blower. As water evaporates from the pads, it takes heat from the air with it, resulting in up to 12 degrees C cooler air being discharged from the cooler.

This can reduce the temperature of the air by up to 15 degrees C in the UK climate.

How Good Are They?

An evaporative cooler will always deliver air cooler than 24 degrees C. and almost always cooler than ambient temperature.

In addition, the constant air movement created by an evaporative cooler lowers the temperature perceived by room occupants - called the "effective temperature" - by an additional 4 to 6 degrees below the "evaporative cooled temperatures".

Finally, an evaporative cooler works best in the hottest time of the day. This is because relative humidity drops quickly as temperature increases. For example, a morning relative humidity of 60% at 24 degrees C will drop to only 31% when the afternoon temperature reaches 35 degrees C.

Typical performance during a Hot Period

The performance of an evaporative cooler during a typical hot period in the UK is that it provides optimum cooling when the temperature is the hottest giving a 'smoothing' effect.

Typically it can give up to 45kW of cooling from a single unit which consumes merely 1kW of electricity.

A bit about relative humidity

The ability of air to absorb water increases as it get warmer, likewise when it gets colder, it’s ability decreases.

The laws of Physics state that it is not possible to compress water, so it’s volume is constant at any temperature between freezing Point 0 degrees C and boiling 100 degrees C.

Above and below these temperatures, it becomes ICE or STEAM, and is no longer considered as WATER.

Consider the diagram above. Note that the volume of water is constant. This represents the actual amount of water present in the air, let’s call it actual humidity.

If 20 degrees C is our starting point, you can see that when the air is warmed up, the water represents a smaller proportion of the space occupied by the air, therefore it is relatively less humid.

At 10 degrees C, the proportion is greater, therefore it is relatively more humid. The important thing to note is that the actual volume of water remains the same.

This is why a properly balanced ventilation system does not make the building damp.

Choose Quality, Choose Met Mann. Choose Factory Cooling. Call us today on 0845 057 3097