Bill Bianchi wrote:Heating water during summer months in barrels inside the greenhouse seems doable, in theory. The advantage I think I see is the ability to heat a larger volume of water, which would be advantageous for a large family---7 family members in my home. Ideally, I'd like to shut my hot water heater off during the summer and draw from a large reserve of solar heated water, instead. Possible? Don't know.
As for an air heater during winter months, I just don't know if that would work. Maybe not. There is a greater volume of air in a greenhouse, but if most of it is lost due to poor insulation in the greenhouse, then that use is probably not going to work. Just exploring ideas at this time. Fully aware both uses of a greenhouse may not work very well.
Bill Bianchi wrote:If I have these replies straight, a greenhouse gets hot enough in the summer to kill crops if not well ventilated, but not hot enough to heat water for home use, even if I use black barrels and put reflective material on the back wall to reflect more sunlight onto the black barrels.
During winter months, it's not going to be warm enough to heat air for home heating due to poor insulation. I assume putting a more traditional hot air heater inside the greenhouse wouldn't improve the performance of that solar heater, either.