|
There is only one correctly sized air conditioner for your home. You don't need a unit that is too big, as it will turn on and off too frequently, and be inefficient in dehumidifying the home. On the flip side, a unit that is too small will run too often and too long. On the hottest days of the year it may not be able to cool the home sufficiently. You need just the right size. How do you determine which one is just right? There are several ways you might go about determining the correct air conditioning cooling capacity (or size) unit:
Determining the Size of Air Conditioner Required
1. Heat load or heat gain;
A building or room gains heat from many sources. Inside occupants, computers, copiers, machinery, and lighting all produce heat. Warm air from outside enters through open doors and windows, or as leakage though the structure. However the biggest source of heat is solar radiation from the sun, beating down on the roof and walls, and pouring through the windows, heating internal surfaces.
The sum of all these heat sources is know as the heat gain (or heat load) of the building, and is expressed either in BTU (British Thermal Units) or Kw (Kilowatts).
For an air conditioner to cool a room or building its output must be greater than the heat gain. It is important before purchasing an air conditioner that a heat load calculation is performed to ensure it is the proper sizing for the intended application.
2. Heat load calculation for any type of room or building.
The heat gain of a room or building depends on;
- The size of the area being cooled.
- The size and position of windows, and whether they have shading.
- The number of occupants.
- Heat generated by equipment and machinery.
- Heat generated by lighting .
By calculating the heat gain from each individual item and adding them together, an accurate heat load figure can be determined.
3. Sizing Chart
|
House Size
|
B.T.U.
|
TONNAGE
|
|
UP to 1400 sq. feet
|
18 000
|
1.5 TON
|
|
1400 to 1900 sq. feet
|
24 000
|
2.0 TON
|
|
1900 to 2400 sq. feet
|
30 000
|
2.5 TON
|
|
2400 to 2900 sq. feet
|
36 000
|
3.0 TON
|
|
2900 to 3400 sq. feet
|
42 000
|
3.5 TON
|
|
3400 to 3800 sq. feet
|
48 000
|
4.0 TON
|
|
3800 to 4800 sq. feet
|
60 000
|
5.0 TON
|
|
