Redneck House fanAuthor: Dave Date: 06.12.13 - 5:07pm When i was a kid, we had a ceiling mount house fan which was amazing. Even on a hot day, the massive airflow it produced really cooled you down. At night it was even better refreshing all the hot air in teh house with cool night air. I cant replicate that in my current house because of the way the attic is, so I went looking for a window mount whole house fan. Its kind of a disappointing market. A 120 dollar Air King was super flimsy plastic, there werent any really good options. After returning the air king, I decided to buy a 24in industrial drum fan that had 7700cfm air flow. This thing puts out a pretty serious air stream, so now whats a quick easy way to non-permanently get it to function as a whole house window fan? After a little pondering, i decided to start my experiment with a removable frame that sat inside the window, with as large a circular cutout as I could. This turned out to be a 19in circle. To mate it to the 25in drum, I needed a skirt that was sealed on both ends and had a taper and a relatively smooth interior for a good airflow. To achieve this, I cut out a 25in circular template and hot glued a heavy sheet around it in several spots to keep the proper form. I then suspended the window frame above it on a pair of saw horses. Drawing the cloth through the center hole allowed me a decent workspace to draw the material to the best form I could achieve and staple it in place. The seam was hot glued all along its length with as much overlap as I could. 
The sheet actually already had gromets put in along its drum side edge from a previous project, so I just snaked a piece of rope around the large end, and cinched it tight around the lip of the drum. Not the prettiest thing, but it will work when required and is very easy to setup. 
To test it I opened one large window upstairs, and one downstairs, wet the backs of my forearms and stood in front of the open windows (1600 sqft house) and they both get a great breeze coming through. For about 2hrs worth of work, its a win. One more metric I need to run is a heat generation test. IE, taking the temperature of the motor after an hours operation with X square feet of intake window open, and then comparing that against the heat of it running normally for one hour. With the skirt in place, the extra suction the motor has to work against could potentially overheat the motor and shorten its lifespan. So this will be an important measurement to take and plot against the surface area of open windows its pulling the air through. Temperature can easily be taken with a non-contact infrared probe. Here are some measurements on an 80deg day. Looks like the fan should be safe to run continuous even with the extra load of having to decompress the house to get the air it needs to breathe. For reference the fan tested here is the MPro 24" drum fan
The highest temperature recorded so far has been 146F (stopped), which occurred when the house temp itself was 88 and with only 6ft of window space open to let it breath. Comments: (3)On 10.18.15 - 12:36am Dave wrote:
On 05.23.20 - 9:13am Dave wrote:
On 05.23.20 - 9:51am Dave wrote:
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