How to Determine If Your Window Fan Should Be Facing in or Out
For many people, window fans are an essential tool to keep them cool, especially if they don’t have (or are declining) air conditioning. Even with access to an air conditioner, window fans can provide much-needed ventilation in a stuffy room.
So the question is, should the fan be placed so that it points outward or inward? As it turns out, the answer is not as simple as you might think. Here’s what you need to know.
Should your window fan be pointing in or out?
Taking full advantage of the cooling power of a window fan takes more than just pointing it at your face and turning it on. Instead, consider a few factors to determine if your fan should be facing outward or inward:
The position of your house
Consider natural light in your home. In most cases, some rooms have more of it than others, depending on the direction of the house or building and the time of day. In addition, some rooms benefit from the shade of a large tree, for example. This means that even if the sun shines directly into the room, it will not heat up as much.
That’s why, generally speaking, window fans should be facing outward on the warmer side of your house – to blow hot air out – and inward on the cooler, darker side of your house to let that cold air in.
Number of levels of your house
As you probably remember from elementary school science class, hot air goes up and cold air goes down. So if you live in an apartment building, chances are the top floor(s) are warmer than the first floor, especially in summer.
If you use window fans to cool your home, Chris Regan, an engineer who also tests air conditioners for Consumer Reports, recommends the multi-fan approach. This means that fans must be constantly on – and facing outward – on the upper level(s) of the house to get rid of hot air trapped there.
Then, as soon as evening comes and it’s not so hot outside, turn on the inward-facing fans on the ground floor of your house. This will force cooler outside air inward and—combined with outward-facing fans on the upper levels—maximize airflow into the home, Regan explains.
In general, keep in mind that window fans are much more useful for removing hot air from a home (or apartment) than for bringing in cooler air.