Home air-conditioning. Once a sure sign of plush living, has today become a way of life for practically everybody. The tonne rating doesn’t refer to the weight of the equipment, but to its cooling power. A one tonne unit will produce the same amount of Cooling as one ton of ice melting in 24 hours.

Engineers sometimes describe cooling capacity in BTUs-British Thermal Units-per hour.

One tonne = 12,000 BTUs, so a one-tonne air-conditioning unit can remove 288,000 BTU’s of heat in 24 hours.

A two tonne unit can remove twice this amount and so on. Deciding on the right size unit for your home is the easiest thing to go wrong. Many things affect the air-conditioning load-the size of the house, how much Wall faces the afternoon Sun, the insulation, the amount of shade, roof over-insulation, the amount of shade, roof overhang, windows, even house and roof color. Air-conditioning companies frequently use an estimating form that takes a number of such factors into account.