If you’re looking to save money on your energy bills while also ensuring your home stays cool in the summer, a whole-house fan can be a good option. Installing a whole-house fan can allow you to leave your AC shut off for longer periods while still effectively cooling your home. This can be a huge help in reducing wear and tear and potentially extending the life of your AC, and it can also save you quite a bit of money since the fan will use far less energy than your air conditioner will.

A whole-house fan can be a great investment, and it will definitely help keep your home cool in certain situations, but there are also times when it will have the opposite effect and make your home warmer. To understand why, here is a guide to how whole-house fans work and when they are most effective.

How Whole-House Fans Function

When used correctly, a whole-house fan can potentially lower your home’s temperature by around 20 degrees Fahrenheit in only an hour or two. The fan itself is installed in the attic, and a duct connects the fan to a vent in the ceiling. To be most effective, this vent should be installed in a central location such as a hallway or at the top of the stairwell leading to the upper floor.

Whole-house fans work by pulling cool air in from outside. At the same time, the fan also draws all of the hot, stale air inside the building up into the attic where it then flows back outside through the attic vents. Pulling air in from outside helps to create a breeze or draft that cools off the home. Another reason why this type of fan is so effective is that it also pushes back outside all the hot air that accumulates in the attic during the day.

For it to work properly, you need to have at least a few windows in the home partially cracked open so that the fan can bring air inside. This is one of the major limitations as it means you should only use the fan when the temperature outside is at or below your desired indoor temperature. If you were to run the fan during the hottest part of the day, all it would do is pull hot air in and quickly heat up the home. It is also important to never use the fan in overly humid weather since this will greatly increase the indoor humidity level.

Having at least a few windows slightly open is also important for safety reasons. If no windows are open, the fan will start pulling air in from other places. If your home has any gas-burning appliances, the fan can pull air in through the chimney or exhaust flue. This issue is known as a back draft, and it can be extremely dangerous since it could also draw carbon monoxide out of the flue and into your living spaces.

How to Effectively Use a Whole-House Fan to Cool Your Home

Whole-house fans always work best when you only have a few windows partially open by 6 inches or so. If too many windows are open or are open too far, the fan will struggle to create the circulation needed to properly draw cool air in from the outside and to pull the hot air out of the attic.

The best and most effective way to use a whole-house fan is employing it to cool one part of the home at a time. As soon as the temperature starts to cool in the evening, you can turn off the AC, crack open the windows in your kitchen and living room, and then turn on the fan. This will result in a cooling breeze that quickly starts to lower the temperature in those areas so you’re more comfortable. Once you’re getting ready to go to bed, you can then close all the other windows and open the windows in your bedrooms so that these areas stay cool all night long.

So that the fan doesn’t start pulling lots of heat and humidity inside, you will then want to close the windows, turn the fan off, and turn your AC back on before leaving for work the next morning. If you’ll be home all day, you can leave the fan on and the windows open until whenever it starts heating up and the temperature rises above whatever you normally have the thermostat set to.

The fact that whole-house fans only work when the windows are open does limit when they can be used. In most situations, you will only want the fan to run in the evening or morning during the hotter months. In the early spring or fall when the weather is milder, you can usually use the fan constantly and leave your AC shut off.

At Polar Express Plumbing, Heating and Air Conditioning, we install whole-house fans and most all other types of HVAC equipment. Our team also specializes in heating and cooling repairs and maintenance as well as indoor air quality services, and we serve customers throughout Lake Elsinore and the surrounding areas. For more information on whole-house fans or any of our other services, contact us today.

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Anthony Dieringer
Anthony Dieringer

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