Choose the right size air conditioner to cool your home. Buying the right size of air conditioner is in your best interest; only the right size of unit or system will efficiently and effectively keep you and your family comfortable. Air conditioners that are too big use more electricity and leave the air in your house with excess humidity. Air conditioners that are too small do not cool your home to a comfortable temperature. Choosing the right size air conditioner requires some basic math and just a few minutes of your time. Measure the square footage of the room that you'll air condition. Use a tape measure to measure the length and width of the room. Write these measurements on your paper. If the room is not square or rectangular, divide the room into sections composed of squares and triangles and take those measurements. Calculate the square footage of the room. For a square or rectangular room, multiply the length by the width. If your room is some other shape, find the square footage of the triangular sections by multiplying 0.5 x length x width and sum each of the square and triangular sections to determine the total square footage of the room.

Determine the square footage of each room of your home if you are purchasing a central air conditioning system. Reviewing your property tax statement or contacting your county auditor's office is another way to find out the total square footage of your home. Don't include areas, like the basement, that won't be cooled. Determine the cooling capacity needed for the room or your home. Cooling capacity for room air conditioners and central air conditioning systems is measured in British Thermal Units (BTUs) per hour. The United States Department of Energy Energy Star website offers these guidelines for BTUs per square footage: 100 up to 300 sq. feet: 5,000 to 7,000 BTU 300 up to 550 sq. feet: 8,000 to 12,000 BTU 550 up to 1,000 sq. feet: 14,000 to 18,000 BTU 1,000 up to 1,200 sq. feet: 21,000 to 24,000 BTU 1,500 up to 2,000 sq. feet: 30,000 BTU 2,000 up to 2,500 sq. feet: 34,000 BTU Things You Will Need Steel measuring tape Paper Pencil Tip References Energy Star: Properly Sized Room Air Conditioners Photo Credits Jupiterimages/Comstock/Getty Images Suggest a Correction

The sizing chart below is useful to help you determine your approximate central air conditioner size requirements. If you still need help, don't worry! Chat with or call one of our factory trained advisors to help get you the answers you need. As an alternative to the sizing chart below we offer MANUAL J - a professional load calculation based on your floor plan, location, and all variables. Please follow the link below for pricing. The turnaround for this service is 1-2 days. MANUAL J Residential Load Calculation Air Conditioning Square Footage Range by Climate Zone In order to scientifically calculate the right central air conditioner size, you can perform a Residential Load Calculation. Another way to size air conditioners is to determine the system size that is currently in place. The manufacturers do not list the air conditioner size on the unit. The system capacity will be coded into the model number of the outdoor unit. For example, model CKL24-1 is a 2 ton unit.

There are 12,000 Btu's per ton. The number 24 in the model number indicates the unit is 24,000 Btu's, divided by 12,000 Btu's per ton, equals 2 tons. 24,000 Btu's/12,000 Btu's per ton = 2 tons Use the following conversion information to determine your existing system size (use the system model number NOT the serial number) 18 = 1.5 tons 24 = 2 tons 30 = 2.5 tons 36 = 3 tons 42 = 3.5 tons 48 = 4 tons 60 = 5 tonsair conditioning units size calculation When sizing air conditioners, be careful not to make the mistake of getting one that is too large. air conditioner outside unit iced upIf the system you install is too large for the space, it will short cycle. cost of new carrier ac unit

In other words, the compressor will not run long enough to dehumidify the space and will limit your comfort. In addition, it will cycle on and off more frequently, increasing operating costs and reducing the system life. Proper air conditioner sizing is critical to optimize performance. If you're still unsure which system size is right for you, or if you're having difficulty downloading the Air Conditioner Size Calculator , please e-mail us or call us toll free number at 1-855-634-5588. Sizing air conditioners by phone is difficult but we can provide you with the tools to get you started. Heating Square Footage Range by Climate Zone Use the lower of the two numbers if your home is well insulated and the higher number if it is older or poorly insulated. (Hint: Use the larger of the two numbers above if you're unsure of your home's insulation) Simply multiply the appropriate factor above by your home's total heated square footage to arrive at your approximate required heating capacity.

For example, if you live in the yellow zone, your home is well insulated, and you have 2000 heated square feet, the equation will look like this: X .40 heating factor (from the chart above) 80,000 Btu actual output Then, to calculate the output on a gas furnace, multiply its efficiency rating by its listed input rating for the actual Btu output of heat. For example, if a furnace has a listed input rating of 100,000 Btu's and an efficiency rating of 80%, it will produce If the same 100,000 Btu furnace has an efficiency rating of 93% it will produce: 93,000 Btu actual output For this example, using an 80% efficient furnace, the 2000 square foot home above would require a 100,000 Btu input furnace which will produce the necessary 80,000 Btu's output of heat. If you're still unsure which system size is right for you, please e-mail us or call our toll free number at 1-855-634-5588. An experienced design technician will be happy to assist you. Variables such as your insulation, type and number of windows, number of stories, construction type, etc. will greatly affect the required Btu's per square for both heating and cooling.