Solar Space Heater
On August 27, 2007 in water heating
I’ve decided to use the water heater tank as a space heater of sorts. We have an old cast iron radiator that I think would be perfect to heat our bedroom with. Since the bedroom is on the opposite side of the house from the wood stove, but also on the south side, this is good.
So far the plan is to setup the tank just like a batch style water heater, except since it gets so cold here in the winter, I’m going to run a glycol solution to prevent freezing, and rather than use the hot water, I’m going to circulate it through a radiator inside the room that needs to be heated.
I’ll put up a diagram soon, but the tank will go in an insulated enclosure with double glazing on the top (angled towards the sun) as well as on the sides. The enclosure will be insulated, and the bottom filled with sand and rocks to a level just above the bottom of the tank. This should help store some heat.
This morning I was able to get some work done. First I hooked the hose back up to the water heater and left the drain at the bottom open.
The water that was flowing out was clear for a good while so I closed the drain and filled the tank up about halfway. I rocked it back and forth a bit and managed to break loose some more crud. Opened and closed the drain a few times and let the water run again until it was clear for a good while.
After that I broke out the angle grinder and a braided wire wheel attachment, and went to work. Here is the tank mid-strip:
Don’t mind the strip of rust around the bottom, that’s the base where the old propane burner used to be. I left it on for now to keep the tank up off the ground.
After stripping the tank down, I went to work painting it. So far it has two coats of regular flat black spraypaint.
This is where the testing phase begins. I need to make sure the thermosyphon action that goes on will actually move the water the couple of feet it needs to go to get to the radiator.
Any thoughts or suggestions?
Good site!
Information learned on this site has persuaded me to think about using 3/8 soft copper tubing for my planned collector rather than 3/4 tubing with all the tee’s and soldered joints. I could use 3 or 4 continuous loops to make up for the smaller diameter. I should do a cost comparison to see which way is more economical.
If you do a cost comparison I’d be very interested in the details.
I can’t decide if I want to build an enclosure for the tank, and add some copper coils (the tank heats up SLOW but this could be due to it not being in an enclosure… so lots of heat loss) to help it heat up quicker, or just use flat panel collectors(copper tubing with strips of copper soldered on for more surface area) with the tank as the actual radiator inside the house.
I’ve also considered adding “fins” to the water heater tank to add some surface area, but not sure on that one yet as I don’t want to burn a hole through the tank trying to weld to it.
The best way to find out is to try it!
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