Heating systems are usually classified in BTUs (British thermal units). A BTU is the amount of heat required to raise the temperature of one pound of water (0.45 kg) in one degree Fahrenheit. Various factors, such as square meters, determine the size of a heating system is needed to heat a building. Determine how many BTUs are required to heat one square meter is a key point in the process of selecting appropriate heating devices.
BTU requirements depend on more than the volume to be heated and the temperature range. Other important factors include the rate of heat loss through the ceiling, windows, walls and doors. Air leakage and poor insulation BTU requirements increase, like normal ventilation. The good sun exposure and heat generated by other devices reduces BTU needs.
A BTU is enough to heat about 55 cubic feet (1.55 m2) of air by one degree Fahrenheit. To find out how many BTUs are needed to heat one square foot of surface, determine the cubic volume of the area to be heated and the maximum temperature required. Measure the length, width and height of each room that is to be heated in a building. Multiply the length by the width to find the square footage. Then, multiply the square footage by height of the environment to find the cubic volume. If you're heating more than one room, add the total square footage and total cubic volume of all rooms.
Estimate the maximum temperature needed to keep the area as hot as you want. Take the lowest temperature likely to have outdoors during the year and réstala for your desired temperature. If you do not know the minimum temperatures likely where you live, see the data provided by the National Climate Data Center. Finally, multiply the number of degrees of temperature change you need by the number of cubic feet and divide by 55. Then divide by the square footage to know the BTUs per square foot.
Mini Split AC in the USA 