High efficiency components are combined to heat water. Solar collector, drainback, closed loop and open loop tank systems.
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Building Integrated Solar Water Heating

Installed under a metal roof during new construction or a re-roofing process, the system collects solar energy and conducts it through the metal roof into a collection system.   Quoted

Uses the sun to preheat water for a standard electric or gas water heater. Save up to 20% of total household energy costs...
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Thermosiphon Passive Solar Water Heater

Solar Panels contain food grade glycol, which, when heated by the sun, rises up to circulate through the ceramic lined water tank, heating the water.
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Eco-$mart offers a full line of energy efficient tankless gas water heaters. Rheem tankless water heaters deliver hot water on demand with a digital control system designed for highest safety and lowest energy use.   Quoted

Enersol Solar Pool Heating Kit

The Enersol solar pool heating system is simple, clean, easy to install, virtually maintenance free, and most importantly - it works. Do-it-yourself installation kit available.
List: $258.00\  Eco-$mart Price: $215.00

Solar Attic Pool Heater

Heat exchanger that cools your attic while heating your pool. No roof-mounted panels, efficient and quiet operation. Fully automatic system with controller.