How To Choose The Right Size Window AC For Your Space

With summer practically upon us, many of us are getting ready to install our window AC units to help keep the warmer rooms in the house cool. The problem many people encounter when it comes to window air-conditioning units, however, is purchasing the right size for the space. If you buy one that's too small, it won't be an effective solution. But, if you buy one that's too large, it won't be able to pull enough moisture out of the atmosphere before blasting you with cold air. This ends up just making you cold and clammy, not to mention paying higher energy costs.

According to CNBC, in 2018, about a quarter of the homes in America had window AC units, as opposed to central air conditioning. Per the outlet, these window units can typically be found in larger cities in the U.S. that have a higher percentage of older dwellings. With this said, anyone, anywhere, can buy an AC window unit online or from their local home improvement or big-box store.

In fact, even some people who may have central air conditioning may still choose to supplement certain rooms with window air conditioners during part of the year, to save money. These units present a viable option for keeping smaller spaces cool at a more reasonable cost than putting central air in (or using central air all the time). But if you are going to install a window AC unit in your home, the question remains: What's the right size?

How to determine the right size window AC

To determine the right size for your window AC, the first thing you want to do is take measurements of the size of the room you want to cool. Window AC units are measured in BTUs, or British thermal units. It's a fairly simple process to figure out what the right size unit is for the space. Measure the width and the length of the room and multiply them for the square footage. Then you take the square footage and divide that number by .05 to get the amount of BTUs needed to cool the space. For example, a 15-foot-by-15-foot room equals 225 square feet. Dividing 225 by .05 equals 4,500 BTUs needed to cool the space.

However, it doesn't always work out to such a simple equation: Hence, the need for sizing advice. There are multiple other factors that should be taken into consideration that can affect a window AC unit's effectiveness. Because a window air-conditioning unit represents a significant enough amount of money initially, as well as even more that depends on its efficiency later, it's important to get the information needed in order to purchase the right unit for the space in the first place.

Additional factors to consider in determining correct sizing

As said, to know what size window AC your space will need, you first need to figure out the room's size. Next, determine how many windows are in the room. It's estimated that a home loses around 30% of its heat through its windows. At this same time, consider the amount of direct sunlight the space gets, especially without any shade trees or other hindrances. Is it one of the warmest rooms in the house? If so, you may need a larger capacity unit. Also, take into account how well the room is insulated.

The next question you'll want to ask is, is the space a popular one in the house? In other words, if there will be more than two people in the room a lot of the time, you should add 600 BTUs to your window AC's capacity for every person over two. The ceiling height is also a detail to consider, since recommendations are made in the first place based on 8-foot ceilings. When your ceilings are 10 feet high, you'll need to add 25% to the total BTUs necessary.

Lastly, you'll want to consult with an electrician if you don't have the correct amperage outlet or circuit breaker capabilities. Making sure you choose the right size window AC unit for your space is crucial to its energy efficiency. The right unit should easily be able to keep you as cool as a cucumber, all summer long!