Most Phoenix techs will say, “Well, it just depends on the size of the room.”
Yes, this is technically correct. But square footage isn’t the only factor to consider when sizing your ductless AC.
To determine what size ductless AC you need, a handful of other factors should be considered, including:
We know—that seems pretty complex. Don’t worry, though, we’ll break it all down for you by explaining:
Need a professional to size your ductless AC? We can do that, just contact us.
Ductless AC units are sized in BTUs (British Thermal Units)—a measurement of heat. The more BTUs a ductless unit has/is rated for, the more heat it can remove from the room in an hour.
For context, one BTU is equivalent to the amount of heat produced by burning through one match. Residential ductless AC units can range anywhere from 7,000 to 24,000+ BTU/hr.
So really, you want to make sure your ductless unit is sized to remove as much heat as the room takes on throughout the day.
Why? Well, square footage alone doesn’t give you an accurate picture of how much heat the room gains over time.
To get a more accurate glimpse of how much heat a room accumulates in an hour, answer the following questions:
The more you answered YES to the questions above, the more heat the room probably gains in an hour.
All this said, beware any tech that gives you a ductless installation estimate based on square footage alone. You could very well end up with a unit that’s too big or too small.
Let’s take a look at why oversized or undersized units are so bad…
The good news is that most ductless units can be slightly oversized and still work well. But a ductless unit that is too small won’t be able to remove heat from your room as fast as it needs to.
In other words, an undersized ductless unit will run nonstop and still leave you uncomfortable. Not to mention, you’ll see high energy bills and more frequent repairs due to your overworked ductless AC.
The bottom line is to make sure you pick a skilled tech to size your ductless unit correctly. True professionals will always perform a “load calculation” to ensure correct ductless sizing.
During this load calculation, the tech will measure the amount of heat that enters a room based on factors like:
This precise calculation allows a professional to determine the exact BTU output you need from your ductless mini split—no more, no less.
Most quality professionals will include a load calculation in the initial installation estimate (we do!).
We can help. We’ll send a professional to your home to perform a load calculation before determining the ductless size you need.