Sand stores an enormous amount of heat energy. A 50lb bag of sand costs $4 at the hardware store, you only need a few lbs. Here are two versons, 1)a stainless steel pet bowl heated by two tealight candles, filled with sand or 2) a clay pot filled with sand one inch from the top, inverted over a clay plate, heated by two tealight candles
The idea I was working with was based around a fire pit, or a burn barrel, where you heat the pot outside over an open fire, then carefully transport the sand container back inside.
Designed for people who may not have a fire place (although placing a sand battery on a wood stove would extend your firewood supply), but could easily make a fire in their backyards with scrap wood.
Another design I’ve got is a sand container, where the wood stove exhaust pipe passes through it.
So the sand is heated by the waste heat, instead of being funneled outside where it’s wasted.
The idea I was working with was based around a fire pit, or a burn barrel, where you heat the pot outside over an open fire, then carefully transport the sand container back inside.
Designed for people who may not have a fire place (although placing a sand battery on a wood stove would extend your firewood supply), but could easily make a fire in their backyards with scrap wood.
Another design I’ve got is a sand container, where the wood stove exhaust pipe passes through it.
So the sand is heated by the waste heat, instead of being funneled outside where it’s wasted.
Great ideas, sun and magnifying glasses could work too as long as the sand is contained in non combustible material
Another possibility.
We built a few “solar can heaters”. Check those out. We also toyed with different ideas and designs.
The exhaust port could be vented through a sand battery to heat the sand.
The solar can heater put out about 130-150 F on a sunny day.
https://www.youtube.com/watch?v=PyVPNOUpOVg
Check this out
https://youtu.be/XIXE6Ebo8gw