Water heating systems

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Use the Sun to heat water

Active solar heating systems use solar energy to heat a fluid -- either liquid or air -- and then transfer the solar heat directly to the interior space or to a storage system for later use. If the solar system cannot provide adequate space heating, an auxiliary or back-up system provides the additional heat. Liquid systems are more often used when storage is included, and are well suited for radiant heating systems, boilers with hot water radiators, and even absorption heat pumps and coolers. Both liquid and air systems can supplement forced air systems.

Liquid systems store solar heat in tanks of water or in the masonry mass of a radiant slab system. In tank type storage systems, heat from the working fluid transfers to a distribution fluid in a heat exchanger exterior to or within the tank.   

Tanks are pressurized or unpressurized, depending on overall system design. Before choosing a storage tank, consider cost, size, durability, where to place it (in the basement or outside), and how to install it. You may need to construct a tank on-site if a tank of the necessary size will not fit through existing doorways. Tanks also have limits for temperature and pressure, and must meet local building, plumbing, and mechanical codes. You should also note how much insulation is necessary to prevent excessive heat loss, and what kind of protective coating or sealing is necessary to avoid corrosion or leaks.

How does it work?


Active solar heating systems are most cost-effective in cold climates with good solar resources when they are displacing the more expensive heating fuels, such as electricity, propane, and oil. Some states offer sales tax exemptions, income tax credits or deductions, and property tax exemptions or deductions for solar energy systems.

The cost of an active solar heating system will vary. Commercially available collectors come with warranties of 10 years or more, and should easily last decades longer. The economics of an active space heating system improve if it also heats domestic water, because an otherwise idle collector can heat water in the summer.

Heating your home with an active solar energy system can significantly reduce your fuel bills in the winter. A solar heating system will also reduce the amount of air pollution and greenhouse gases that result from your use of fossil fuels for heating or generating the electricity.

Facts of Solar Heating:

A conventional domestic water system consists of approximately 1 m2 of solar panel per person and a 40-70 liter hot-water tank per m2 of solar panel.

A solar heating system provides up to 80% of the annual energy requirement for hot-water generation. 

Combined domestic water and space heating systems may be considerably larger, e.g. 9-18 m2, and may cover quite a significant portion of the overall heat energy requirements of the household.

On average, the sun shines more than 2500 hours a year in Jordan.                    
In Jordan, the global solar irradiation is approximately 2,200 kWh/m2 per year measured. Solar heating systems are usually capable of utilizing about 500 kWh/m2 of the solar energy.
Like other renewable energy systems, solar heating systems are fairly expensive to acquire but inexpensive to operate compared with fossil fuels.
Most of the 14% (Households) or so solar heating systems in Jordan are installed in private homes. Solar energy is also used in large-scale systems (swimming baths, hotels, and camping sites) with extensive hot-water use and in very large-scale collective systems connected to district heating plants. In these plants, solar energy is often used in combination with biomass heating systems.

Solar heating is thus used primarily for heating water in hot-water tanks. Therefore, it is very simple to use with other energy sources in homes – be it natural gas, oil furnaces, fuel furnaces, heating pumps or electric heating. It is also possible to use solar heating systems for heating of homes, e.g. in the form of under floor heating.

Use of solar energy as a primary source of heating (in these latitudes) suffers under the fact that the energy yield is highest at the time of year (summer) when we need it the least. However, it is not true that solar panels work only in the summer. A well-insulated solar panel will also provide a heat contribution on sunny winter days.