At the end of last week, I did a little solar fan project. We have a small greenhouse that really isn't useful to grow things during the summer because it gets too hot. It's great for making starts from seeds in the spring, but by mid-summer it regularly gets between 125 and 140 degrees F.
I bought a 30 watt solar panel and a gable fan that runs off it. The setup is for drawing hot air out of the attic of a house, but I thought it would be perfect for drawing air through our greenhouse.
Here's what I got:
I'd replaced the panels of the greenhouse this year with new pieces of corrugated fiber glass typically used make an inexpensive patio covering. After about 4-5 years they get darker and clouded up which limits the amount of sunlight that gets through them. Below is a picture of the area that opened up when I removed one panel which is where I decided to place the solar fan:
Next I needed to make something that would support it. I have some old wood around the place that I use for just this type of project. I found some redwood pieces that would be perfect for this because they are lightweight and don't rot when they get wet for years. The fan itself is very lightweight so I didn't need any heavy pieces of wood to hold it up. I had some metal angle pieces used to hold wood pieces to other pieces of wood. These were angled at 90 degrees. So I cut them in half with my hacksaw to make four single straight pieces. I simply screwed them to the four pieces of redwood and I had my fan support ready to go.
More Greenhouse Solar Fan project stuff after the orange squiggle
After making sure it fit, which it did, I took the wood bracket out and cut what needed removing with my jigsaw. This created a "hole" that was just the right size for the fan.
Here's what it looks like with the fan mounted:
I then cut a hole in the fiberglass panel I'd removed to fit the size of the fan. Here it is reinstalled:
Here's what it looks like from the inside:
Now the roof of the greenhouse is slanted and, of course, faces south. I needed to figure out the angle it's tilted because I wanted to get the solar panel aligned with the sun as it moves through the sky. Paradise is at north latitude 39.76, so I wanted to angle the panel itself 40 degrees. To figure out the angle of the slant of the greenhouse roof, I looked at the angle of a gutter piece that lies on top of it against a deck that is flat.
This is what I saw which was perfect for my needs:
Remembering basic geometry there were two angles equal to each other that were the angle of the slant of the greenhouse roof. I've drawn in the angle marks to show you what I mean. I took my cheap plastic grade school protractor to measure the angle. The slant of the greenhouse roof turned out to be 15 degrees.
Well, that meant I'd have to angle the solar panel on top of the greenhouse roof facing due south another 25 degrees to equal 40 degrees total which results in the panel being at the best angle at my latitude to get the most direct sunlight possible year round. Here's the solar panel installed on my greenhouse roof:
Here's what I now get happening anytime the greenhouse gets hotter than 85 degrees F. The fan works perfectly and is using free electricity to operate, which is the whole point after all:
What do you want to kibitz about tonight?
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Kitchen Table Kibitzing is a community series for those who wish to share part of the evening around a virtual kitchen table with kossacks who are caring and supportive of one another. So bring your stories, jokes, photos, funny pics, music, and interesting videos, as well as links—including quotations—to diaries, news stories, and books that you think this community would appreciate. Readers may notice that most who post diaries and comments in this series already know one another to some degree, but newcomers should not feel excluded. We welcome guests at our kitchen table, and hope to make some new friends as well.
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