Keeping Cool with Box Fans


In the continuing series about decreasing utility bills, I want to talk about probably the biggest weapon in our war chest of frugality when it comes to our electric bill.  Living in the southeast, I am acutely aware of of how miserable the weather can be with nearly 100% humidity and 90+ temperatures for weeks on end during the summer months.  Not surprisingly, most houses and apartments here have central AC or at least several window units.  Taking a stroll through our community on your average summer night one would see all the windows closed shut with a distinct humming noise coming from all the AC units sitting next to houses, usually behind a neat little fence as to not to offend the passerby with its unsightly mechanics.

Our next door neighbors are typical when it comes to the way many people use HVAC.  Every year in early spring they flip the system switch from Heat to Cool letting the programmable thermostat keep the house temperature close to the ideal 70 degrees.  In the fall, the switch is simply flipped back to Heat and the cycle repeats itself year after year.  I have never seen a window open in the house next door, even on a nice cool comfortable day when the temperature ranges from 65 to 75 degrees.  On most days, we fall asleep and wake up to the hum of their AC coming through our wide open bathroom window.  Of course there is a possibility that they have a medical condition, such as allergies, requiring filtered air in the house.  However, we personally know at least a couple of other families that are also “switch flippers” and they don’t suffer from any ailments.

Cooling a big house such as the one that we live in (3000+ sq. feet) is not cheap.  We can easily rack up a $200+ monthly electric bill if we put the AC on 79 degrees and leave it on auto for a month.  And 79 degrees is actually pretty warm according to some friends that visit and keep their own houses at around 70 degrees.  I would not be surprised if their bills come in at close to $300 per month at that temperature!

I am happy to say that our average monthly electric bills are nowhere near $200 or (gasp) $300.  We just celebrated the 4th of July and our AC has been on maybe 6 days total so far this season.  As you’ve probably guessed from the title,  several box fans are the weapon of choice to beat the heat, but there are other tricks that I’ve learned that I’ll share as well to maybe inspire you to give it a try this summer.

  • First, I use 4 box fans strategically placed in windows throughout the house.  These are the ones that you see in the picture above.  One is a Lasko model like this one and all of them are your standard size 20″ box fans.  It’s an interesting collection with one bought back in college to cool the dorm room, another added later for the first house, and the two other ones inherited from the relatives that were downsizing.  The last two look like they are from the 1970s, but they are still working great!  One goes in the master bedroom, another in son’s bedroom, third one in the attic and the fourth one downstairs in the living room or the kitchen depending on where we are.
  • Every morning starts with me walking around the house, taking the fans out of the windows and closing all the windows and blinds.  It took me some time to realize that leaving even one window blind up with the sun shining through it for 6 hours can raise the temperature inside the house significantly enough to be uncomfortable.  If all windows and blinds are closed for a day, the house will get a bit stuffy with the AC off, but the temperature will usually rise only a few degrees from where it was in the morning.
  • In the evening when the temperature starts going down, I open the windows on the shady side of the house and put the fans back in.  After the sun sets, I open a couple of windows on the other side of the house to create cross ventilation.
  • All fans are set up to blow the cooler outside air into the house.  I also open the door to the attic and the attic windows to help the hot air escape since the hot air rises.
  • Almost every room in the house has a ceiling fan and it is usually on if we are in that room.  For example, in the master we’ll have the box fan going on the lowest setting the whole night sucking in the cooler outside air while the ceiling fan is creating a nice breeze throughout the whole room.
  • Sometimes the house will not cool down below 80 degrees in the evening and going to bed can feel a bit uncomfortable.  Taking a quick cool shower right before bed usually solves that problem as long as the ceiling fan is on.
  • Our community has a pool and we often go there to get out of the heat.  It’s amazing how much cooler the air feels after we get out of the pool and walk back home.

I’ve also figured out our family limits on box fan usage.  I check the weather forecast every day and once it looks like the picture below, we shut the windows down and celebrate the AC set at a comfortable to us 79 degrees.  It turns out that once the night temperatures consistently hover over 70 with the day temperatures over 90, the house does not cool down enough at night to stay comfortable.


This method has worked for 5 years now and it really does not feel like we are suffering during the warmer months at all.  I actually prefer waking up in the morning with fresh air filling the room instead of the recirculated filtered AC air.

We were also pleasantly surprised to find another benefit of limiting our AC usage – we both feel like we can handle the heat better in general.  When we hear people complaining that it’s too hot out to do anything, we nod, fill up our water bottles and go for a walk.

Happy box fanning!

* If you found this post interesting, you can read more in Box Fans Revisited. 

5 thoughts on “Keeping Cool with Box Fans

  1. First of all, nice blog, and some nice tips, even though I won’t be using them very often in the rainy old UK 🙂

    I’ve always thought the American obsession with (over) air conditioning everything was rather strange and unnecessarily wasteful.

    The worst thing is it’s becoming a more increasing feature over here. A great example… I just got off the train to work, it’s 6.30am and the outside temperature must be 18 degrees, so 66ish to you. And they had the AC on! Ridiculous or what. At least you guys have the excuse that it IS bloody hot most of the time when you have it on, I don’t know what these companies are thinking over here, they obviously love chucking money down the drain. Train tickets have been rising above inflation for years on end, yet we always hear how these poor companies cannot stay in profit in these tough economic times. I’ll get my tiny air conditioned violin out shall I?

    One other thing that you touched upon is that I am pretty sure the human body has not evolved over thousands of years to become used to multiple extreme temperature fluctuations throughout the course of one day. It’s just not natural is it? This quite often makes me feel unwell and I think we’d all be a lot healthier long term if our bodies were just left to get on with their own temperature self-regulation mechanisms!

    • Yeh, it’s common to have 90+ temperatures with 90+ humidity here and for the past couple of weeks it’s been absolutely miserable outside with the heatwave hitting the East Coast hard. Unfortunately window fans don’t work at all in times like this since even at night the outside temperature does not drop below 78. Our AC has been on set at 79… but the minute this heat breaks we’ll be back to box fans and open windows!

  2. My AC went out for close to a month at the start of the summer and so my family made do with 2 box fans. Most days we were quite comfortable, and we adjusted so well to the lack of ac we were ready to forgo it after it was fixed (or at least delay its use for awhile longer). We went back to ac after my wife kept worrying about allowing so much humidity in the house. Have you run into problems with moisture in your house? I’m in NC. We compromised and set the ac on 84 (which is about the limit for our comfort level) and stopped using the box fans. I am still waiting to see how this will effect our electric bill. Do you have any thoughts/suggestions?

    • We’ve been using the box fan method for a few years now and have not ran into any issues. Started with 2 fans and now we are up to 4 you see in the picture. Depending on where you are in NC our climate is probably very similar and it’s definitely humid where we are as well. We still use AC when the weather gets too hot/humid and there is not enough drop in the nightly temperatures to cool the house down. For example, last two weeks there was a heatwave so the AC was on set at 79 but we are back to box fans this week. With nightly temperatures in the upper 60s and highs in the upper 80s and even low 90s it is super comfortable with the AC off!

      The biggest thing that will help with cooling is closing all the windows/blinds in the house in the morning as soon as the outside temperature starts going up. If my house is at 76 and the temperature outside is above that and the sun is shining I am closing all the windows/blinds. Usually if we start at 75-76 inside after fan cooling at night, the house will be anywhere between 78-81 at around 6PM depending on the outside temperature that day. I will open windows around 7-8PM to start the air circulating again. I have not tried or needed to do this myself, but I think running a dehumidifier during the day when the windows are closed might help with the humidity concerns.

      You might also need to see if there are other improvements you can make to keep the house cooler longer. We live in a newer house built about 15 years ago so the insulation is pretty good. The other thing that is helping a lot is the attic gable fan that I installed. I am going to do a DIY article on that as well. And of course I did this ghetto mod that is helping too 🙂

  3. Pingback: Escaping the Death Pledge – The History | Insourcelife

Comments are closed.