Shed Project: Solar Vent Fan
Wauchula, FL - Events of Friday, March 17 to Monday, March 20, 2017
A while back, one of the co-op members wrote a newsletter article describing a solar vent fan he built for his shed. His article had a few photos and a brief description of his setup, and he said anyone who was interested in building a similar fan could contact him for more info.
Even in winter, the sheds can get quite warm when they are closed up sitting in the hot Florida sun, so Paul thought having a vent fan sounded like a good idea. Paul talked to the fellow who wrote the article and got info on the installation including a parts list for most of the components. Paul ordered the parts from Amazon a few weeks ago. When the parts came in, he did some tests prior to starting the installation. He checked voltage output of the panel with the panel sitting at various angles to the sun and he tested the fans. Afterward, he tweaked the original design a bit and ordered a few additional parts that came in early last week.
With the gravel walkway complete, Paul started working on the solar fan setup last Friday. The design uses 4 computer fans blowing out the shed's gable vent. Outside air will be drawn in through smaller vents Paul installed down near the floor on three sides of the shed.
A number of years ago, Paul tried using a computer fan for cooling the overhead compartment that housed the DVR in the motor home we used to have, but the sleeve bearings of the inexpensive fan failed and began to squeal after only a couple of months. The new fans have hydro-dynamic (fluid) bearings with a claimed life of 300,000 hours, which equals 34 years, so the fans could theoretically outlast the shed itself.
On the inside of the shed, the gable vent is conveniently framed by support members for the shed wall and roof, so Paul used those supports to help form a plenum for the fans. Paul completed the plenum with a piece of ¼" plywood with 4 round openings in which to mount the fans.
The next step was to mount the 20 watt solar panel on the side of the shed roof that faces south. It was a little scary drilling mounting holes in the roof, but it had to be done. Paul caulked all the holes very carefully.
On the inside, the wire from the solar panel connects to the fans through an adjustable DC voltage regulator. The solar panel puts out almost 22 volts in full sun, and according to the manufacturer, the 12-volt fans can operate at a continuous voltage of up to 13.2 volts. Therefore, Paul set the voltage regulator to 13.0 volts.
The total cost for the solar fan setup was around $130 and includes 4 fans, a 20-watt solar panel, mounting brackets for the solar panel, an adjustable voltage regulator, and miscellaneous screws, wire and connectors. The fans seem to be fairly effective because the temperature inside the shed doesn't seem to be nearly as hot as it was previously. Over the next several days, Paul will be conducting some experiments with a thermometer inside the shed with the fans turned off and with the fans turned on to get a better idea of how effective the fans really are.
After Paul finalized the installation of the fans late on Monday morning, he had an afternoon appointment for his annual eye exam over in Sebring. When he got back to the rig, we decided to go to Giovann's Main Street Kitchen in Wauchula and have pizza for lupper. We had a 12" pizza with sausage and mushrooms ($7.99 plus $.50 each for the two toppings). This time instead of a bunch of garlic bread, we had side side salads ($2.99 each) and just a couple of slices of garlic bread to go with the salads. Everything was yummy as usual.
Stay tuned for our next update.