You are looking at the components of my solar thermal roof collector and water storage tank experiment that I’m conducting on my property to see how effective it is for space heat.

When the temperature inside the collector is 18 degrees hotter than the water in the tank, which is in the basement and used for space heat, the pump kicks on and pumps the 260 gallons in the tank through the collector and back to the tank.

One square foot of collector heats 1.5 gallons of water 40 degrees F. higher on a full sunny day in winter in Philadelphia, USA area. I thought by putting it in line with my forced air system it would pre-heat the air, which it does. However, 20 degrees of the solar heat is left in the tank and can’t make it out overnight. THEREFORE DON’T DO EXACTLY THIS. Instead, insulate the free-standing tank, put on another smaller pump and connect it to radiant heat Pex pipe which should be installed underneath the floor to heat a floor in your house. Using this method you can get the heat out of the tank and into the house where you need it. Also, I recommend that you buy the collectors as they will qualify for federal or state subsidies and be free standing from the roof.