The Benefits Of Solar Heat

Solar-powered devices feature renewable energy, environmental friendliness, and affordability. For example, solar-heated water can lower annual gas bills by 80 percent, and annual electric bills by 25 percent. There are several types of heating systems from which to choose.

Direct systems are also called open loop. These are inexpensive alternatives which circulate potable (drinkable) water through solar collectors. However, there are a few drawbacks. These systems usually do not incorporate overheat protection. Also, unless the collectors are freeze-resistant, these systems are susceptible to freezing. In hard water areas, they also have a tendency to accumulate scale.

Indirect systems are also known as closed loop. This more advanced design incorporates a heat exchanger which separates the potable water from the heat-transfer fluid (HTF) circulating through the collector. The most commonly used heat-transfer fluids incorporate mixtures of antifreeze. They usually have non-toxic bases of propylene glycol.

A system may be active or passive. Active systems tend to be a bit more costly, but they are more efficient and offer several advantages. Since their storage tanks can be placed lower than their collectors, there is more freedom of design. As a result, existing tanks can be incorporated into new systems more easily. Since there is more flexibility in the placement of the storage tanks, they may be hidden from view more easily, and can be placed in semi-conditioned spaces which helps to prevent heat loss.

The passive units rely on convection or heat pipes for circulation. These systems are very low maintenance and affordable. However, freezing and overheating are major problems. Also, their energy efficiency is much lower than that of active systems.

A variety of solar thermal collectors are available. They include the batch and the flat plate models. Batch collectors reduce heat-loss by accumulating water in insulated boxes. While three of the walls are thermally insulated, the top is covered by glass, taking full advantage of the sun's warmth.

Flat plate collectors are also topped with glass. These oven-type boxes usually have horizontal pipes along the tops and bottoms, with numerous smaller vertical pipes connecting them. Since these models utilize tempered, low-iron glass, they are very durable, and can even withstand hailstorms.

Solar water heater professionals can assist the home and business owner with simple but effective upgrades to their existing systems. There are several incentives available to encourage the installation of modern sun-powered heating systems. They include significant state and federal tax credits which, in some cases, can cover up to 85 percent of the installation costs.