Installing a Solar Water Heater

How to install a store-bought or homemade water heater that uses solar energy.

| January/February 1986

Regardless of the season, the demand for hot water in many households invariably seems to outstrip the supply. And even though basic conservation measures do a lot to combat the problem, the energy consumed in heating water for baths, laundry and dishes can be surprisingly expensive.

It's no wonder, then, that a number of homeowners have sought help from the sun to preheat the supply that enters their domestic water heaters. This method of temperature boosting is uncomplicated, relatively inexpensive, and easily adaptable to existing plumbing. Here's how to install a homemade or store-bought solar water heater with minimum fuss.

Solar Water Heater Installation Basics

Essentially, all you'll be doing is circulating solar-heated water through a continuous loop of plumbing that runs from the roof mounted panels down to a heat exchanger, through a pump, and back to the panels again. The heat exchanger is simply a tank-within-a-tank that transfers the approximately 140 degrees Fahrenheit warmth of the loop water to the considerably cooler supply reservoir surrounding it.

Fittings tapped into that reservoir allow it to be placed in line between the well or city water source that feeds your house and the cold water inlet pipe to your electric or gas hot water heater.

Unfortunately, installation isn't quite that easy, since the pump must be regulated to keep it from operating when sunlight is not available. Therefore, the system must include a differential controller that utilizes sensors at the collectors and in the storage reservoir to govern the pump's operation. More sophisticated controllers incorporate features that deactivate the pump at preset upper and lower temperature limits and provide for freeze protection by intermittently circulating the closed-loop water or opening a drain-down valve. (A minimal-investment system could use a nontoxic antifreeze as a transfer fluid to achieve the same goal.)

Of course, for any installation to work, your site must be suitable for a solar application. Whether you plan on having a roof- or a wall-mounted system, make sure that no obstructions — especially buildings or trees — will be in front of the collector panels. Remember that you'll be using hot water the whole year round, so in addition to sighting the morning-to-evening swing of the sun (the azimuth), check the solar altitude at the winter and summer solstices. And, while you're at it, make a quick check of your proposed plumbing path, looking specifically for obstacles such as ductwork, headers, wiring, or waterlines that could thwart your efforts to get the copper tubing from point A to point B.

Hannan Ahmad
12/13/2013 2:57:07 AM

The solar water heater is definitely an efficient way to heat up the water, but its repair requires only the smart minds to work over it. Solar panels need electrical and plumbing support all side-by-side, due to which their repair is not like a do-it-yourself task type. If you hire some specialized company for solar water heater repair, you will get rid from a number of headaches.

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