This is an easy way to capture the sun’s energy and use it to heat a room. This Solar Window Heater measures 18 x 24 x 10 and weighs 9 lbs. When placed up against a south facing window, it can produce 130+ temperatures. There are 2 12v fans which can be powered with an AC adapter or with a solar panel.
The unit is aluminum cased with a glass cover and according to the US Solar Heating website:
“The panel has a built in digital thermometer which allows you to see the temperature of the air that the heater is blowing out.”
The unit usually sells $130 but visit this site where it is being sold for $98.