How to Right-Size Your AC System

When it comes to your air conditioning system, there’s no such thing as “one size fits all.” Getting the right system for your house is not only vital to keeping your family cool and comfortable, but it can also translate into big savings.

Air conditioners that are too big use more electricity. They will cool the air too quickly and shut off too soon – before the building structure has a chance to cool down as well. This allows heat and humidity to sneak back in, meaning that your AC will kick on again and the cycle repeats. This frequent off and on uses a lot of energy. On the other hand, air conditioners that are too small may run continuously but fail to keep your home at a comfortable temperature.

Determining the perfect size for your home isn’t rocket science. Start with the square footage of all the rooms you need to be cooled. You can either measure each room yourself or go with the total estimate on your property tax statement.

Air conditioners vary by cooling capacity, which is measured in British Thermal Units (BTUs) per hour. The BTU rating essentially tells you how quickly a unit can cool a room, and it generally ranges from 5,000 to over 20,000 BTUs. Choosing the right BTU ensures that you’ll get the most energy-efficient cooling system for your home.

To determine the right BTU for the square footage of your space, you also need to take into consideration factors like your home’s ceiling height, insulation, and your preferred temperature. Here’s a handy calculator that can help.

There are a few other best practices to keep in mind. In general, for rooms that are shaded, reduce BTU capacity by 10%. Likewise, for those that are full-sun, increase it by 10%. Remember that people give off heat, so add 600 BTU per person in your household. If you’re cooling the kitchen, add an extra 4,000 BTUs than what is typically needed for the room size.

Are you looking to replace or supplement your current system? Depending on the size of your space and your individualized needs, you’ll have several options to consider. All of these types of air conditioning units come in different sizes and efficiency ratings.

Window unit air conditioners

• Popular because they are affordable and easy to install.
• Professional installation can ensure safety and prevent leaks.

Freestanding air conditioners 

• Popular for cooling only certain parts of the home (kitchen, bedroom, etc.) and can be moved between rooms.
• Most have reservoirs that need to be emptied periodically.
• They can be heavy and are less efficient but provide flexibility.

Built-in air conditioners

• Installed in areas of the house that may not be connected to a central AC system (garage, basement, etc.).
• Require a hole in an exterior wall but don’t take up window space.
• Professional installation is generally recommended.

Centralized air conditioning system

• Definitely the most effective and efficient but a greater initial investment.

Your air conditioning system can contribute to over half of your electricity bill during warm weather months, so finding the right AC unit for your home and needs can save you money for years to come. Contact a professional who can recommend the best options for you!