Thermal solar panels to pre-heat hot water tank
My 88 y/o mother who was a pioneer in the solar energy movement has 8 liquid-based thermal solar panels from the 1990’s sitting in storage. She never installed them, and now would like to donate them to us. Each panel is 8’x3′ in size. She installed 2 in her mountain home near Fairplay, CO (9000′ elevation and seriously COLD in the winter!) and they supply enough heat for her hot water needs. They passively circulate water, and have worked well for many years.
My question is, how do we estimate the number of panels we would need? We have a natural gas boiler and radiators for our home heating system, and the hot water heater is piggy-backed onto the boiler. The whole boiler system has to blast on every time we even use a cup of hot water in the sink – even in the summer. It seems very inefficient. Can we simply run glycol through thermal panels and then to a coil in the hot water tank to pre-heat the water? I’m thinking that then at least the boiler won’t need to fire up in the summer.
I know that photovoltaic would be the other way to pre-heat our water, but these panels would be free (except the installation). What would you recommend?
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