Low Energy House - Solar Heating Panels - Solar Collectors
When solar heating panels are installed, a properly designed and installed solar water heating system can be expected to provide between 40 and 80 per cent of a building’s hot water requirements
What are Solar Heating Panels?
Solar heating panels collect the thermal energy of the sun and use it to heat domestic hot water in a home or business. They can provide almost all the domestic hot water during the summer months and they will even contribute in the winter.
Solar Heating Panels - Savings
Solar water heating is a clean, reliable and cost-effective technology. It is already reducing the demand for electricity, heating oil and natural gas and saving money on utility bills for thousands of homes and businesses
Solar Heating Panels - Seasonal
Solar Water Heating depends on solar radiation not direct sunlight so it works even on dull days. In winter, although a panel can be effective in helping to warm domestic hot water, a hot water boiler will still be required to provide most of the building's water heating needs.
Solar Heating Panels - Pre-Heating
It is important to note that solar heating panels are not designed to work in conjunction with the central heating radiators. They will only pre-heat the domestic hot water system.
Solar Heating Panels - Domestic Hot Water Supply
The solar heating panels gather the heat from solar radiation and transfer it to the domestic hot water system in the building. This heated water flows out of the solar heating panels to the hot water cylinder, and is used for sinks, washbasins, baths and showers. The central heating boiler can remain connected to the hot water tank for back-up, if desired.
Solar Heating Panels - Orientation
Orientation and tilt are probably the most important design factors affecting system efficiency, after the type of system selected. The ideal orientation is due south but any orientation on the southern half of the compass can be used, right up to due east or due west. At these extremes the annual yield will be reduced by around 15 per cent. Above all, it is important to ensure that no part of the system is shaded.
Solar Heating Panels - Angle of Tilt
Solar heating panels are most efficient when mounted at an angle of tilt of about 30 degrees. However, their is some flexibility and solar heating panels can be mounted at an angle as low as 12 degrees. At this angle, the system efficiency may be reduced by around 5 per cent but the tilt is still steep enough to stop dirt building up on the collectors.
Solar Heating Panels
There are several types of solar heating panels available but the evacuated tube collector is the most popular solar collector in general use in the UK. Evacuated tube collectors consist of rows of parallel, transparent glass tubes that have had the air removed.
Solar Heating Panels - Evacuated Tube
In an evacuated tube collector, small diameter metal pipes act as absorbers inside the larger evacuated glass tubes. These small diameter pipes are called 'heat pipes'. The evacuated glass tubes retain the absorbed heat. They are interconnected by a manifold, situated along the top of the solar heating panel.
A heat pipe collector incorporates a special heat transfer fluid that vaporises at low temperatures and is resistant to freezing. The vapour rises in the individual heat pipes and warms up the fluid in the manifold. After giving up its heat, the condensed liquid then flows back into the base of the heat pipe.
Evacuated tubes perform more efficiently than other collectors in cloudy weather and tend to reach higher temperatures than flat plate collectors. Glass tubes can be fragile and should be handled carefully. Evacuated tube collectors are also suited to situations requiring high temperature fluids, such as in commercial or industrial processes.
Solar Heating Panels - Heat Transfer Fluid
Heat transfer fluid is typically a combination of propylene glycol and water which is the industry standard heat transfer fluid, for situations where freezing is likely. In an active system, the pump circulates heat transfer fluid through pipes from the storage tank to the solar heating panel.
Solar Heating Panels - Hot Water Cylinder
Most systems that heat domestic hot water directly have only hot water cylinder that typically has an auxiliary coil. The tank has hot water delivered directly from the solar heating panels, with supplemental heat coming from the boiler, to meet domestic needs.
Solar Heating Panels - Packaged Systems
Packaged systems can greatly simplify installation, save space and reduce labour costs. Some systems combine controllers, sensors, pumps, gauges and valves.
Solar water heating systems use heat from the sun to work alongside your conventional hot water boiler. The technology is well developed with a large choice of equipment to suit many applications
About Solar Heating Panels - Solar Water Heating