Whole House Fans: Are they Effective?
According to the United States Department of Energy (DOE), a whole house fan is the most cost-effective way to cool down your home.
Whole house fans are unique in that they are used when it is cooler outside during the early morning and evening hours. Basically, whenever the outside air cools off. This is opposite to a traditional air conditioning system that runs almost 24/7, regardless of the temperature outside.
In most climate areas, there is a 30 to 50 degree temperature swing every day between the high and low weather forecast each day. This is why whole house fans work so well.
Most people only pay attention to the high temperature forecast of the day during the warmer months of the year. While this is important for figuring out what type of clothes you will wear for the day, it doesn’t tell the whole story when thinking about cooling your home. When looking at the low temperature, you will most likely see it happening in the very early morning hours, but over the course of the night, the temperature is usually at a very comfortable level to where a whole house fan would work very effectively at cooling the home.
When running the whole house fan during the evening and early morning hours, you are effectively pre-cooling the home for the heat of the next day. That way, when it gets to the peak temperature of the day, the home is not as hot as it would be if you didn’t have a whole house fan.
This helps homeowners save up to 90% off their A/C usage, and in some climates it can eliminate A/C usage completely!