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What Are Tons And BTUs?

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When you buy a window air conditioner that you are going to use to cool your house, then you generally go by the square footage of the room and find the correct amount of BTUs for that size room, which is generally listed on the air conditioner boxes. However, it's not that easy when you look at getting a central air conditioner. They generally aren't rated by BTUs but by something called tons. 


BTUs are short for British thermal units. A single BTU measures the amount of energy it takes to raise one pound of water one degree in Fahrenheit. So, if you take one pound of water and heat it one degree Fahrenheit from 32 to 33, you used the energy that corresponds to one BTU. An air conditioner that is rated at 5000 BTU would use that amount of energy to cool the space that it is in. Generally, the larger the BTUs, the more square footage it can cool.


While the central air conditioners' cooling powered is still measured with BTUs, those BTUs have been combined into tons. In cooling terms, a ton, which is equal to 12,000 BTUs, is the amount of energy that it takes to melt one ton of ice in one 24 hour period. Using the ton measurement is easier than working with individual BTUs when it comes to handling all the equations that are necessary to finding the right size central air conditioner for your house. For example, if you need to use 3 tons in an equation, it's much easier to use that 3 than it would be to use 36,000, which is the equivalent BTU measurement. 

Right Size Air Conditioner

You may be wondering why it's important for you to know how the air conditioner is measured and the difference in tons and BTUs. It's important because knowing those things will help you to make the right choice when it comes to getting your air conditioner. While size may not matter in some places, it does in air conditioning. An air conditioner that is too big or too little won't cool your house correctly and will just waste energy and money. Knowing how your air conditioner is measured will help you understand why the installer says that your air conditioner needs to be a certain size. 

If you are going to install an air conditioner, it's important that you get the right one. Knowing how it's rated can help you with that. For more information and advice, talk with professional HVAC contractors, such as those at Smedley & Associates.