Coal in the Winter Solar In the Summer

I have a solar panel that I want to use to make domestic hot water in the summer. I have a standard oil fired hot water heater and will run the water from the tank to the panels on the roof and then back in a large loop. I want to make sure that at night the water stops circulating when the temps get colder. I need a control to open and close a valve and shutoff the circulator when the temps fall under say 85 degrees? Can anyone advice me on what type of control would do what I want? My ultimate goal is to get off oil for my home.

Hey traderfjp,

Usually on ebay there is controllers offerd that work off temperature differential between panel and holding tank. Some come with the sensores been goin for around $120. How well does that large coil in your stove work I'm planning the same thing. Or use a solar powered pump from a pv panel only runs when the sun is out.
try ebay # 260249654759.

The custom coil I had made is about 48 ft. of pipe. It works very well and heats my basement on all but the coldest days. I hardly use any oil at all.

Frank

Better Plan,

Work the solar year round and in the winter route all hot water through the solar heat storage tank prior to going through the coal DHW coil.

If you can raise water form the 40-60 degrees it typically comes into the house to say 90 degrees inw inter, you will use significantly less coal to heat it up the next 30-40 degrees for comnsumption.

1 BTU raises one pound of water one degree farenheit.

8 lbs of water to the gallon.

If you can use solar to raise a gallon of water 50 degrees prior to the coal boiler, you save 400 btu per gallon.

If you use 50 gallons of hot water per day... That is 20,000 btu saved. A little over a pound and a half of coal when you consider energy efficiency of coal boiler.