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What size of air condtioning unit do I need?

What size of air condtioning unit do I need?

At Home Depot we love keeping Americans safe and secure in their homes.  With a We Are Coupons Home Depot Money Off Coupon you can save money on just about evert aspect of maintaining and improving your home. One area of home improvement many American homes consider is that of air conditioning.  We all love our aircons but when installing one for the first time where do we start?  Just what size of aircon is needed for your home?

Know your Ratings

In choosing the right sized aircon for your home you first need to understand how aircon units are rated. Air conditioners are typically rated in two ways: cooling capacity and energy efficiency. All equipment is measured using either BTUh (British Thermal Unit per Hour) and BTU (British Thermal Unit). BTUh (British Thermal Unit per hour) is a measurement of an air conditioner’s cooling ability in an hour, also known as “tons”. One ton of air conditioning removes 12,000 BTUs of heat each hour.BTU (British Thermal Unit) is the amount of energy that is required to increase the temperature of a pound of water by one degree Fahrenheit.

Next, you will need to understand the energy efficiency of the ait conditioning unit. This is called the SEER rating or Seasonal Energy Efficiency Ratio and measures total amount of energy used during a cooling season.  Some units also use the energy star rating that most people are familiar with.


There are many variables to consider when choosing your new air conditioning system. There is no one size fits all and evert home in every location is slightly different. The variables you will need to consider are:


Warmer regions will need an appliance that runs for more than just the summer and better energy rating will be needed.

Home Exterior

The type of home, the materials it is built from and how much heat is absorbed or reflected makes a difference to the air conditioning unit you will require.

Shade and Sun Exposure

Sun and shade, the direction you house faces can make your property hotter or cooler. This will impact the size of air conditioning unit you need.


Insulation doesn’t just keep a house warm it keeps it cool in summer. How much insulation you have and how effective it is will play a major role in determining the size of the air conditioning unit you need.


Windows can be sources of energy loss or can make sunlight hotter. How many windows you have and their shade covering plays a role in determining the size of air con you need or what is needed for each room.

Higher and larger rooms are often more difficult to cool down and you will need more BTUs in a home with higher ceilings.

Heat Generating Appliances

Kitchens and laundry rooms have appliances that generate heat. These rooms will require more BTUs to cool down.

Calculating Size

Overall a lot of factors are taken into consideration when choosing a new air conditioning system for your home Once you have taken much into consideration you need a simple calculation to work out the size of air con unit you need. To calculate the size of the unit you will need, you will need to know the square footage of the room or house. To find the square footage, multiply the length times the width of the rooms in your home, then add them together. Once you have the square footage, multiply it by 25 to get the BTUhs needed to cool your space

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