solar shop heater I built

[bobenhotep]

I finally built the solar shop heater I talked about. It cost me about 300 dollars and seems to work pretty good. This is it from the outside.



I worked out an easier, simpler interior setup for the fan. I will have pictures of it soon.

[bobenhotep]

The outside collectors are made of 2x lumber, aluminum flyscreen, and polycarb roofing.

There is an air duct in the bottom where air from inside the building can enter the collector. At the top of the internal opening there is a flap to keep cold air from sinking down through the opening at night. This is it in the open position.



This is it on the lower part of the wall, shown from a few feet away for perspective. You can see the fan at the top of the picture.



There is also a flap at the top for the same purpose. You really want to keep the still air inside the collector at night to help insulate, instead of it cooling the inside air.

[Alan Mclennan]

How well has it worked so far, sun at a low angle should warm that air well.....

[bobenhotep]

It does pretty well. On a sunny day the air in the top of the collector is about 45-50c/113-122f. On cloudy days where you can still make out the location of the sun it will still work, but the air in the top will be much cooler, but still warm enough to get usable heat. The fan at the top is regulated by an attic fan thermostat, so it will only blow out hot air if the collector is over 21c/ 70f. That keeps it from running at night. I am going to link it in series with a thermostat for an electric baseboard heater so that the fan will shut off when the shop gets to 66-67f, or around 19c.

Dan

[slick4x4]

Solar heat is something that is not used nearly enough
I have seen 20* days , that black tires are steaming , they are so hot
Very little to wear out , on a system like you built

Good job .

[bobenhotep]

Thanks. The collectors on the outside are based on the ones Gary Reysa built on http://www.builditsolar.com. However, I did not have access to the lower and upper edge of the wall to cut as many holes as he did in his shop wall. You also need a fan anyway to get the hot air off of the ceiling. I used all off the shelf parts, and the only wear items are all about 20 bucks apiece, being the fan, attic fan thermostat, and baseboard heater thermostat. I will take more pictures of the upper part since there seems to be interest in this project.

Dan

[bobenhotep]

This is the top air hole that the fan sucks from.There is a slick wiper rod used for a counterweight.



This is the fan thermostat.



Fan

[MadMaxetc]

Nice. Cool to see something different.

[Alan Mclennan]

Dan, I wonder if the wall was painted flat black, if it would work better, works on old cars!

[bobenhotep]

I actually started painting the wall and the screens flat black but ran out of paint. One day when the wind is not terrible I am going to paint the wall and redo the screens so that they are in a triple layer on each side to suck more heat out of the sun.

Dan