Solar Hot Water Heating Systems

Solar Hot Water Heating Systems

As people become aware of the necessity to become more environmentally friendly, they are turning to natural sources of energy for everyday use. A solar hot water heating system is one way that is environmentally friendly, and could save you money on your energy bills and in some cases even make you money by selling back excess energy to your supplier.

When selecting a solar hot water heating system, there are several factors that need to be considered. These include; system design, geographic location, collector direction and collector size. These will determine the amount of energy that can be provided for domestic hot water heating. Most solar hot water heating systems have a back-up water heater such as electricity or gas.

Solar hot water heating systems are made up of insulated storage tanks to store the hot water and solar panels called collectors. A collector is fixed to the roof of a house or building or on a wall facing the sun. This will heat the water using solar energy.

The collectors accumulate the heat from the sun and use this heat to warm water, which in turn is stored in the hot water cylinder. Solar storage tanks have an additional outlet connected to and from the collector.

There are two types of solar heating systems: active, which have circulating pumps and controls, and passive which don't. In two-tank systems, the solar water heater preheats water before it enters the conventional water heater. In one-tank systems, the back-up heater is combined with the solar storage in one tank. The running water can be pumped through the heating system as an active system or can be driven by normal convection as in a passive system.

There are three types of solar collectors that are used for residential, domestic applications. These are; Flat- plate collectors, integral collector-storage systems and evacuated-tube solar collectors.

Flat-plate collectors work by absorbing the solar radiation into glazed flat plates. These are made of a weatherproofed outer metallic box covered with a glass or plastic sheet on top. Inside the water is carried through dark, flat metallic absorber sheets that are partly coated with built in channels or riser tubes and are connected to copper pipes. The absorber absorbs the solar radiation and transmits the heat to the flowing water.

Integral collector-storage systems include one or more black tanks or tubes in a weatherproofed, glazed black box. Initially cold water passes through the solar collector, which preheats the water. The water then flows into the standard backup water heater, thus offering a reliable source of hot water. These heaters should be installed during mild-freeze climates only, as the outdoor pipes may possibly freeze in severe cold weather conditions.

Evacuated tube collectors are made up of a pair of transparent borosillicate glass tubes. These are evacuated to provide insulation. Each tube contains a glass outer tube and metal absorber tube attached to a fin. The coating of the fin absorbs solar energy while preventing heat loss. These types of collectors are mainly used for commercial use in the US.

Solar hot water heating systems almost always require a backup system for cloudy days or to cover increased demand. Conventional storage water heaters usually provide backup and may be part of the solar power package. The proper installation of solar water heaters is vital. So it is important to do some research on the factors already mentioned. You should also investigate local codes, covenants and regulations regarding the installation of solar heating systems. And screen your chosen contractor carefully to make sure they have the right experience for the job.