If you’re planning to install or replace an air conditioner, there are lots of variables to consider -- brand, price, and energy rating are just a few. But whether you’re talking about a central A/C unit or a window air conditioner, there are several sizes to choose from, and getting the right size makes a big difference.
Not Too Big, Not Too Small
If an air conditioner is too big for a given space, it will cool that space down with lightning speed. Some people choose an oversized air conditioner on purpose, thinking that this is a good thing -- but they’re wrong.
When an air conditioner cools a room too quickly, it will cycle on and off more frequently. This can put much more wear and tear on a system compared to one that is appropriately sized, which means you’ll spend more on maintenance and repairs. And whenever the unit is running, you’re likely consuming more energy than necessary to keep the room cool.
Furthermore, air conditioners are responsible for removing humidity in addition to lowering temperature. When the cooling cycle is too short, the air conditioner doesn’t have the opportunity to remove enough humidity, resulting in a room that feels damp and clammy.
A unit that is too small, on the other hand, will run around-the-clock, driving up your energy bill. It may never reach your desired temperature, and can even fail to keep spaces comfortable during the hottest times of the year.
Finding Your Size
Sizing a central air conditioning unit can be a challenge because there are numerous factors to consider. The major factor is the square footage of the space you want to cool, but things like your climate, your home’s insulation and the layout of your rooms can also make a difference. So when it comes to choosing a central unit, it pays to consult an HVAC professional who can consider all these factors and present you with the pros and cons of choosing between two sizes if you’re right on the borderline.
Since window units are usually only used to cool one or two rooms, they’re a little easier to size. The most important step is to accurately calculate the square footage of the space you’re cooling. From there, you can consult ENERGY STAR’s chart to determine the ideal unit size for your area. Don’t forget to refer to the chart for adjustments based on sun exposure or the number of people who routinely occupy the space.