I made several simple collector can projects two years ago. Looked at whether a core box could be used for a number of things -- tomato dryer in summer, solar cooker, maybe hooking up to window if power went out in winter.

I used soda cans sprayed flat black. Used hi temp but doubt if it was needed. I just used what insulations were on hand. Temps were in the mid 120's as I recall.

Maybe a solar dog house would've been the best use?

One box had 8oz seperate cans full of sand, the the other had linked empty cans glued together, the box at a angle.

3 words: Rocket Mass Heater for a frugal efficient heat source. I have a solar greenhouse as well, but in my case it would be hard to have a solar workshop due to where I live. A lot depends on your location and usage of the building I think, Insulate the shed well and install venting that fits for what you will be using the shed for. IE if you will be painting etc inside.

This post was edited by tomplum on Wed, Dec 11, 13 at 23:45

Did you ever actually use any of them on a building?

With no electricity, lack of lighting may be more of a problem than lack of heat. I bought a ready made 12x24 storage building a couple of years ago with two 24x24 inch windows and a 48 inch door, but it was so dark inside, even with the door open, I finally had to run electricity to the building. Of course you can fix that with solar lights if you can find some that don't cost a fortune. I have no input on the solar heat.

You mentioned solar lights. From everything I have read they barely do the job, and are short lived before the battery runs down.

What is your experience, and what lights did you install?

I bought some solar lights, mostly the cheap kind, some at the dollar store. Used them in the back yard in the garden area to show the VHS tape gently moving with the wind (and hopefully keeping the deer away from my tomatoes).

The battery store had replacement batteries at $1.50, but the whole light was only a buck to start with! Rust or corrosion made the light worthless at six to eighteen months.

I like the idea of having a half dozen lights that can be moved into the house during a power outage. One ice storm the power was out for five days. Leave the solar light outside to charge during the day and bring it inside after sundown.

FWIW, my barn is 24 X 48 with 10' side walls. I discovered a way to ...not heat it....but make it bearable was to use my gas grill. I store the gas grill in there during the winter and decided to see what one burner on low would do. It made a difference and provided a handy "hand warming" source as well. Obviously ventilation is a consideration.

Ev