Today’s air conditioners come in several different sizes, whether they are a central air conditioner, a stand alone air conditioner or a window air conditioner. To have your air conditioning in your home run at peak efficiency you should size it to the area you are trying to cool. In order to figure out the correct cooling area you will need to measure all areas you are trying to cool. This will give you a close estimate on what size air conditioner you will need to keep you cool. In order to calculate this you will need to multiply the length times the width of the rooms you will be cooling. Once you have that number you can multiply that total time 25 BTU. This will give you excellent cooling whether it’s a sunny hot day, humid day or a moist day. Here is an example of figuring out what BTU is appropriate for your cooling demands. If the room you are trying to cool is 14 feet wide by 16 feet long that would mean you have 224 square feet. So we will take the 224 and times it by 25 BTU per square foot.

So 224×25 = 5600 BTU’s. This is the minimum you would want to use to efficiently cool your room. So what would happen if you were to use an air conditioner that is to small or to large. An air conditioning unit that is rated for less BTU’s will want to continually run so it can keep up trying to meet the cooling needs required. This will make your electric bill go up and will not effectively cool the room. A larger air conditioning unit can be overkill. In the air conditioning business bigger is not better. An air conditioner that is too large for the area will cool more quickly, but that is not always best when trying to properly cool a room. When your air conditioner is on and cooling the room, it is also extracting moisture from the air. Moisture in the air is humidity which makes us feel hot and sticky. Even though the air will be cooler in a short amount of time, it does not give the air conditioning unit time to extract the moisture out of the air. So to properly calculate the size of the air conditioner you will require, measure the area to be cooled and take this information to an air conditioning company or an appliance store where they can make the proper recommendations on what size air conditioner will best suit you.

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. signs your ac unit going outAir conditioners that are too big use more electricity and leave the air in your house with excess humidity. level ac unitAir conditioners that are too small do not cool your home to a comfortable temperature. new air conditioner unit pricesChoosing 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 CorrectionPicking the right home air conditioner is very easy with the right information. Before buying an air conditioner, find out how many BTUs you need.  This means think of the size of the room, and what the room will be used for. Matching Btu requirements to room size is very important when you buying an air conditioner system. This air conditioner sizing tutorial will explain you how to choose the right air conditioner size. Choosing an air conditioner size that is too small (low BTU rating) for the intended room will leave you feeling hot and flustered! And buying an air conditioner that is too big for the room can have its problems too. So the main question is what does BTU mean? Btu – British Thermal Unit (Btu) is the international measure of energy.

A Btu is the amount of heat needed to raise 1 (one) pound of water by 1(one) degree Fahrenheit. In HVAC industry, Btu's measure the quantity of heat a conditioning unit can remove from a room per hours. One BTU per hour is equal to 0293 watts. As the Btu rating increases, so does the weight, size and cost of the air conditioner. To calculate how many BTU’s you need you can use this table. The following tables are estimates based on average room conditions in a moderate climate. Exceptions are Kitchens – add 4,000 BTU cooling capacity to the recommended size. High Ceilings/Unusual Floor Plans – increase BTU by 10%. Warmer Climates – may require 10-20% additional BTUs per room over regular amount. BTU size too large: A conditioner that has a bigger BTU rating than the room size needs will cycle off too quickly. The unit will not remove the humidity from the air properly. Air Conditioner size too small: A conditioner that has a smaller BTU rating than the room requires will run continuously.