On the market there are air conditioners of different power able to satisfy every type of need. Generally those with low power, i.e. up to 5 kW, are installed in single rooms. Power is the fundamental data to be evaluated at the time of purchase: but how do you establish if one size is more performing than the other? To define the most suitable size for specific needs, it is necessary to know the size of the rooms, the windowed area and their exposure.

An undersized machine could prove to be inconvenient as, in order to reach the desired temperature, it will be in continuous operation causing a high electrical consumption and a more rapid deterioration. Conversely, an oversized machine would be unable to dehumidify the environment as it would reach the set temperature in a short time, without eliminating all the humidity, with the result of perceiving that unpleasant sensation of damp cold on the skin.

But how do you calculate the required power?

The calculation described here is only a generic but indicative example of the "cold" and "heat" requirements of the room you want to air-condition (alternatively, there is our thermal dimensioner). The equation for calculating the heating or cooling capacity (expressed in kW) needed to condition a room is as follows: K x l1 x l2 x h = W. In detail, l1 and l2 represent the sides of the room, h represents the height while k is a constant, which can fluctuate by one, two or three units depending on the heat loss in the room. This coefficient should generally be considered equal to 25 for cold and equal to 35 for heat. The result obtained, although very likely, should be considered indicative: it is only an expert installer who, after carrying out a technical inspection, can determine the real cooling or heating requirement of an environment.

What is the difference between a well-insulated building and a non-insulated one? Here are 4 construction classifications:

- well-insulated construction (double walls, insulating material on the ceiling, walls and floor, double-glazed windows, insulated doors);
- fairly insulated construction (double walls, insulating material on the ceiling, few windows with single glazing);
- poorly insulated construction (simple walls with glazed parts and non-insulated roof);
- non-insulated construction (roof in wood, sheet metal or plastic material).