Solar space heating is tricky. Air is harder to keep warm than water, and while most of us need a shower on a hot day—we tend to want space heating when the sun is not doing enough for us.

A solar pool heater uses a pump, a solar collector and piping in conjunction with your existing pool filter. The process is simple: The pump takes water from the pool, then forces it through the ...

For those cool summer days it’s sometimes nice to have a heated pool — but usually pretty expensive too. Looking for a simpler solution [Martin] came up with his own solar pool heater for under $100!