what is the formula used to determine how many btu's I need to buy for a window air conditioner?
Answers:
Here is a general room size charts for window and portable air conditioners. The second link below has window air conditioners.
Hope it helps.
Size of Room and BTU
Portable air conditioner units are rated in BTU (British Thermal Units). This measures how much heat is removed by the hour. Bear in mind that portable air conditioning units require more BTU than window AC units to cool a room of comparable size. Err on the high side for particularly sunny rooms. The chart below offers a rough estimate of the number of BTU needed for your room size, even though the manufacturer rating may be higher.
7,500 BTU-150 square feet
9,000 BTU-200 square feet
10,000 BTU-250 square feet
12,000 BTU-350 square feet
How portable air conditioners work
Unlike window units that pull air from the outdoors to cool your room, portable air conditioning units use indoor air. The portable air cooler dehumidifies the air and the collected water is called the condensate. The condensate is removed from the air conditioner using two main methods. First, a bucket or tray inside the unit collects water and the collected water must be emptied frequently. The second method evaporates the water and exhausts it through the main venting hose. Portable air conditioners must also vent the resulting hot air through an exhaust hose that extends outside a window, door or air vent.
Although you don't have to hoist portable air conditioners into a window every year for installation, there is some temporary installation each time a unit is moved from room to room. With a portable air conditioner, the exhaust air blows out a hose. One end is attached to the back of the unit and the other end must be vented outside. Each portable air conditioner comes with a window adapter kit that keeps the hose firmly in place and provides foam rubber to insulate the partially open window. Additional hoses may be attached for the purpose of draining the condensation that accumulates during operation.
Other answers:
I would think you would find the cubic foot of the room you want to cool, or the space you want to cool. There may be a conversion chart on the side of the air conditioning box or perhaps someone at the store can take the cubic ft. and tell you how many BTU's you need. That is how you figure heat.
I would think you would find the cubic foot of the room you want to cool, or the space you want to cool. There may be a conversion chart on the side of the air conditioning box or perhaps someone at the store can take the cubic ft. and tell you how many BTU's you need. That is how you figure heat.