Legacy Solar

Clean Energy Legacies for a Sustainable Future

Solar Domestic Hot Water System

The numbers used in the following text refer to the system diagram below. The main components of this system are: the flat plate collectors (1), the heat exchanger/storage tank (2), the circulating pump (3), the photovoltaic module (4), and the mixing valve (5).

When the sun shines on the collectors (1), it heats up the fluid. At the same time, that sunlight provides power to the circulating pump (3) via the photovoltaic module (4). The heat absorbed by the collectors is transferred to the potable water in the storage tank (2) via a built in heat exchanger in the bottom of the tank. Cooler fluid exits the heat exchanger and returns to the collectors to be reheated by the sun.

The solar heated potable water in the storage tank (2) is fed directly to your conventional water heater where additional heat may be added (if needed). From the water heater, the hot water enters the mixing valve (5) that provides scalding protection in case the storage tank water is hotter than the desired hot water tap temperature. The output of the mixing valve is connected to the house hot water supply.

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