Keeping your house comfortably cool is directly linked to the size of the air conditioning unit. Size doesn’t refer to dimensions like weight or height but the amount of power needed to deliver reliable cooling throughout the home. Here is a guide on how to choose the right unit size for an air conditioner installation. 

Why It Matters

Air conditioners are rated by British Thermal Units or BTUs, which measure the amount of energy needed to raise the temperature of one pound of water by one degree Fahrenheit. Before an air conditioner installation, the technician will determine which unit with the proper BTUs will provide a comfortable environment.

If the unit is too small, it will operate continuously, not deliver consistent cooling, and work harder than needed, which can raise your monthly electric bill. 

If the unit is too big, there may be rapid cooling runs and stops. These repeated cycles will create unwanted heat in between each interval. When the unit constantly kicks on and off, it also strains the system and can significantly increase energy costs. 

How to Choose the Right Size

The right AC unit offers a complementary mix of proper cooling cycles and energy efficiency. To select the right size, take the total house’s square footage, multiply it by 30, divide that amount by 12,000, then subtract 1. This will give you the tonnage amount needed. In hotter and drier climates, you don’t need to subtract 1 at the end.

Also, note your home’s unique factors that will affect the right size, including whether your home is partially shaded by trees, if the property has a basement, and how hot it gets in the summer.

If you’re unsure about choosing the proper AC unit size, some HVAC contractors have state-of-the-art systems that will do the calculations for you to provide an exact BTU measurement. 

For more than 20 years, Air Conditioning Unlimited in Aiea, HI, has helped homeowners take the guesswork out of selecting the right size AC unit. Serving all of Oahu, the licensed and insured HVAC contractor provides expert air conditioner installations for all types of property configurations. To learn more about choosing the proper unit, call (808) 455-3128. Visit the website for their complete lineup of services.