I remember growing up in the South always having a whole house fan. It occupied a 2′ x 2′ hole in the ceiling usually upstairs. We almost never ran it and as a kid I remember thinking, “why do we have this contraption that we never use?” The switch to turn it on was high on the wall almost intentionally designed to be difficult to use for a kid.
Fast forward till I was about 16 after my folks just put in brand-new white carpet. I decided I would turn on the whole house fan without opening any windows. Well, as you can guess the giant fan pulled air straight down the chimney and put ash all over my mom’s new white carpet. Needless to say – I never turned on that fan again.
Whole house fans I never thought made a whole lot of sense in the South. Running the whole house fan brings in a bunch of humidity which air-conditioning then needs to kick on and remove.
Once I moved to California, I quickly enjoyed the warm dry days and cool nights. What surprised me though – is that I didn’t know anyone with a whole house fan. It seemed like a perfect marriage with the dry climate, cool nights, and relatively expensive electricity. Even more surprising – when I explained the idea most people thought I was talking about an attic fan. Attic fans vent air from the attic out to the open space. Whole house fans pull air through your windows, across the house, into the attic, and out the attic vents. They have the advantage to exchange air within the house and the attic.
This past year I went to the home show and came across a local rep (Got Watts Electric and Solar) representing QuietCool fans. I step into the booth and the salesperson asks me to step into a small makeshift closet with the fan on top so I can “feel the power” of the QuietCool fan. While not a tornado, I was impressed with the amount of air movement and the quiet nature of the fan.
QuietCool is a newer type of whole house fan manufactured in Southern California. It’s not the loud, obnoxious fan of yesteryear. It’s actually pretty quiet. It is about the same noise level as my air conditioner running. Given that I was interested in minimizing the amount I run air-conditioning – I decided to bite. The show special did me in.
A few days later Got Watts came to install the fan. Unfortunately, there was record-breaking heat that lasted the next two weeks. Whole house fans only work if the air outside is cooler than the air inside. That was not the case. Once the temperature relented, the whole house fan really began to show its value.
What makes this fan a bit different is that the fan is not directly on the ceiling. The fan is hung back in the attic and there’s a hose that connects to the ceiling. I think this gives it an advantage in being a bit quieter as there is some distance between the motor and the ceiling. Dampers close to help reduce cold air leakage in cooler months.
At night, the temperature inside the house is often between 78 and 80 on a summer day. I get lots of western sun in the afternoon which makes the house warm. As soon as it starts cooling off, I open up a window at each corner of the house and let the fan run all night. The QuietCool comes with a switch with one, two, four, eight-hour settings, and one for continuous usage. I run the fan for eight hours so I don’t pick up morning air as the sun comes up.
Come morning, the house is generally between 59 and 65°, which is awesome. Even on the warmest of summer days, I don’t have to turn on air-conditioning until mid or late afternoon and run it until the sun goes down.
The other side benefit is that the air inside of the house regularly changes over. Whole house fans are measured in CFM or cubic feet per minute. Typically you want a fan that has three times the CFM as you have square footage in your house. If I recall correctly, when running, the fan turns over all the air in my house about 10 times every hour.
It is also good to run the whole house fan on that stray warm, winter day to keep the air in the house fresh. Since installing the whole house fan it’s become a regular part of my HVAC system at home.
I also run a Nest thermostat. I kept thinking there had to be a way to link the Nest with the whole house fan. Unfortunately, there was nothing on Works with Nest. A friend of mine, however, suggested a service called IFTTT, If This Then That. IFTTT allows you to connect diverse devices and services together in simple ways to help automate the minutia of life.
If you suffer from allergies, the whole house fan will pull air from the outside in (including any pollens). It’s very effective at clearing out indoor air and the corresponding indoor airborne allergens. Run the fan when outdoor allergens are less triggering than indoor ones. Running your HVAC fan can then filter out any remaining allergens if you have a filter with a high MERV rating. Talk to your HVAC technician if you have any concerns here.
I use IFTTT to send me an alert every time the temperature drops below 75° outside of the house. That’s my cue to turn on the whole house fan. Ideally, I could automate the whole process but the whole house fan requires me to manually open windows.
All in all, I’m very happy with the whole house fan. I highly recommend them for those in western climates that have low humidity and significant variability between daytime and evening temperatures. Would I do it again? Absolutely!
If you have any gas burning appliances in the home, make sure to call those out to your installer. Whole house fans can cause backdrafting so it’s important to make sure your installer includes them in the design of your system.
If you live in the San Francisco East Bay, reach out to Got Watts Electric and Solar. Got Watts really owned my project, talked through key challenges and delivered a great outcome. Plus, they are really good people who did a top notch job on my install!