Hat Tip to "rick1", over at our EHP-Discussion forum for this post: My son in law was telling me about this, so I looked it up. How to build a solar furnace:
https://www.greenoptimistic.com/solar-f ... IBNmYhKjFg
Solar Furnace: How to Build It With Simple Tools
https://www.greenoptimistic.com/solar-furnace-build/#.XL8jbqZ7nq1
This solar furnace can heat up your room from 10 degrees Celsius to 29.
Here’s how to build one yourself.
(Photo 1) Solar furnace mounted on an external door
Warm air exits from the output port on the top ... ---CONTINUED---