Fran's Use of Subterranean Air to Defeat the Evil Air Conditioner

Fran describes his home cooling system below.  The system makes use of cool air blown up from the basement.  The system has provided 100% of Fran's home cooling needs for the past couple years, and eliminating the need to run his large AC unit.

The system is very simple, and easy to try.  Give it a try, and see if it will work in your situation.

Thanks very much to Fran for this interesting, well written, and entertaining article!

Fran's Description of his Cooling System

First, some background info. I use my basement entrance as my main entrance/exit because it is at driveway level. In my living room/dining area (open concept) there is installed in the north facing exterior wall a large capacity air conditioner with the capability of bringing the entire house down to the upper 50’s on a 90 degree day in not more than 30 minutes. It’s great, my electric company especially likes it!


The "evil" wall mounted Air Conditioner


For several summers whenever returning home from errands or shopping on blistering hot days the first thing I would always notice was how nice and cool (almost cold) it was upon entering my basement. There were even instances where I would purposely delay my 13 step climb up to my living area just to enjoy the cool a little longer. My pause in the basement would also delay the necessity of having to fire up the air conditioner which was an unavoidable requirement with a living area approaching 100 degrees! One day I said to myself “if I could only move my furniture from upstairs to down here, and move all this basement stuff upstairs….”, thinking that I would live in the basement in the summer, then back upstairs for the winter. Not the best logic as it would all have to be switched around again in the earlier autumn.

Then all of a sudden one day it hit me like a freight train! All I really wanted was the cool basement air to ‘reside’ upstairs in the living area with me! But how am I to get all this cool basement air (8,400 cu. ft) upstairs? Just then, along comes the second freight train…..A FAN!! After surveying my assortment of fans, I found a 3 speed box fan. As luck would have it, it just so happened that I had 2 empty oblong cardboard boxes from a gift that I had received. I had not yet put these out with the trash (thankfully). One box was slightly smaller than the other, with the larger having an opening that was 16” square, and they were each about 5 feet long. If I connected them end to end, could they possibly act like an air duct? Would the box fan fit the end of the cardboard box? I brought the box fan to the boxes….it fit into the end like a glove! Now that I had all my project pieces selected, I brought each one to the staircase that leads from the basement to my  living area. I placed each box end to end with the flaps from the smaller box over the end of the larger box. This was done so that the smaller box would not slide down inside the larger one. Once in place, I determined the direction of air flow from the fan and placed it inside the opening of the larger box which was on the first step up from the basement floor near the coolest air. Once this ‘assembly’ was together, I slid it under the hand railing to maximize foot space on the stair tread. Then a 2”X4” wood support from the basement floor to the fan to better insure the fan wouldn’t fall out of the end of the box from vibration. Next I plugged in the fan’s power cord to an outlet and flipped the switch to “hi”. I went upstairs and left the door at the top of the stairs as wide open as possible (180 degrees from the closed position).



Cardboard box fan duct.

Fan installed in duct.

Assembled duct ready to be installed in stairwell.

This new ‘cooling system’ arrangement was used in late spring, summer, and early autumn of 2007 without a problem. It was fairly effective, although on the very hot days it’s effectiveness was a little disappointing. Over the winter of 07/08 with time to think about it further, it dawned on me that I might be able to make a simple but dramatic improvement. Sure, I had been blowing cool air upstairs alright, but I was RETAINING the hot air i.e. not giving the warmest air near the ceilings an escape route! A bit like blowing air into a bottle, some will go into the bottle, but no real air FLOW! I couldn’t believe it! How could I have not taken that into consideration?

As later spring of 08 approached in Waterbury Ct, I was ready. My ‘cooling system’ was again placed into position on my basement staircase, ready for the battle. The day came. Weather report was for ‘unseasonably warm’. But wait! Before kicking on the fan in the basement, I would try my ‘improvement’ to the ‘system’. So I took a short walk down my hallway that leads to the bedrooms. I reached up, and pulled the cord to lower the folding staircase that provides access to the attic. This allowed the attic heat, and the heat building near my ceilings an escape route via the attic vents. It worked beautifully! In 08 I didn’t even need the fan to run hardly at all in the springtime. And when running during the summer, it gets almost as cold as if I was running that wall mounted 220v electric money monster fondly known as the air conditioner. My average daily Kwh/day usage for the hot months has dropped by a whopping 50%!

Now that I know for certain that the concept of moving the basement air up to my living space works, I’m considering installing floor vents in each room with ducting that drops to the basement floor, again, for the coldest air. My thinking is that with vents in every room, I may be able to eliminate the cardboard box/16” electric fan configuration.  Then with the basement door closed instead of open, I just might get a really nice “chimney” effect up through each room as the air flow makes its way to the attic opening. This will eliminate the electricity cost for the fan, and reduce the noise from it to zero. If the electric fan is needed, I may centrally install it in the ceiling of my living area. In the event that I can’t bring myself to cutting up my floors, I’ll just stay with the electric fan and boxes. The important thing is that I’ve eliminated that extra 11 Kilowatts/day saving money, and reducing my carbon footprint.




Fran and the fan



Fran's home is located in Waterbury, Connecticut.   Latitude: 41.56 N, Longitude: 73.04 W

"I have used this fan and cardboard box arrangement for the last 2 summers and it works great!
Honestly, I have not switched on my A/C unit since the summer of 2006!"




Gary February 19, 2009