This is what happens when space heating is called for

Back to Option II | Setup 1 | Setup 2 | Setup 3 | Setup 4

When heating for the building space is wanted, the heating pump comes on and circulates water from the solar storage tanks, through the backup tank, and then through heating pipes within the floor. The water gives up its heat to the floor and circulates back to the storage tank. If the solar storage tank is not warm enough, the backup tank will come on and make up the difference.