Solar water heaters — also called solar domestic hot water systems — can be a cost-effective way to generate hot water for your home. They can be used in any climate, and the fuel they use — sunshine — is free. Solar water heating systems include storage tanks and solar collectors. There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don’t.
This system is active and heats a hot tub via heat exchange coil, as well as providing plenty winter showers.
This system has added reflectors for winter gain, they actually shade a bit in summer preventing overheating. Water temp maxes at about 180F for which the PEX tubing is rated. The hot tub exchanger coil measures 4″x18″ and is stainless steel 1/2″ by 25ft. We used timers and temperature controllers designed for brewing/fermentation to switch on and off a hot water circulating pump designed for residences. The hot tub stays 104F(40C) when the old tub behaves. It purifies with UV and ozone.