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What Exactly is a BTU & How Does that Apply to My New Air Conditioner?

The heat from your stove and the warmth in your home are measured by units of heat known as the British Thermal Unit, commonly referred to as the BTU. This simple measurement is used to classify how much heat an appliance can generate. At its core, a BTU is the amount of energy required to raise one pound of water by one degree on the Fahrenheit scale.

When it comes to heaters, ovens, and other appliances that burn natural gas to generate heat, a BTU measurement is used to determine how much energy your appliances need to effectively heat/cool your home or cook your food. If you choose an appliance that has insufficient BTU to perform these tasks, your appliances will have difficulty performing what you ask of them. Conversely, if you choose a unit that is too powerful, you will find that you are simply wasting energy and draining money from your wallet each month to pay the utility bills. You can calculate your operating cost easily by multiplying the BTU calculation by .000293 which will give you the kWh (kilowatt hour) measurement.

Calculating BTU Requirements for Cooling and Heating

The most important measurement you will make when determining how many BTUs you need for an HVAC system is the square footage of your home. To obtain this number, you will need to measure the square footage of each room. Most importantly, you will want to make sure to calculate the square footage only of those rooms that are connected to your heating and cooling system. Thus, you don’t need to worry about unheated spaces, such as a garage, when making your calculation.

Generally speaking, you will require 20 BTU per square foot of area. Thus, if you have a 2,000 square foot home, you will need approximately 40,000 BTU per hour to keep that home comfortable. When making your calculation, you will also need to factor in your climate, the type and quantity of insulation within the home, and the lifestyle you maintain. Because these factors can have a considerable impact on the overall capacity you will require, it is best to seek the assistance of a qualified HVAC technician to confirm your calculation prior to making a purchasing decision.

Special Considerations for Air Conditioning

If you are buying a room air conditioner as opposed to a central air system, you only need to calculate the size of the room where the air conditioner is to be installed. As with heating systems, air conditioner capacity should be calculated by using the total square footage of the area to be cooled. Generally speaking, a 100 square foot room will require 5,000 BTU’s per hour to keep it comfortable. For a home that’s between 1,500 to 2,000 square feet, you will require approximately 30,000 BTU’s per hour.

Other factors you include in your calculation should include the amount of shade that you have around your home. If it’s heavily shaded, you can subtract 10% from your calculation. If there is no shade, you should add 10%. Further, if you have more than 2 people in the room to be cooled, you should add 600 BTU’s per hour to account for the additional heat a third person will generate. Similarly, you should add 4,000 BTU’s per hour for kitchens and laundry rooms.

Contact ACE Home Services Today with All of Your BTU Questions!

We invite you to contact ACE Home Services online or at 602-943-2000 for more information about air conditioning and heating systems. With more than 20 years of experience under our tool belts, we can help you select the right-sized system for your home’s cooling and heating needs.