Flat-plate solar collector
A common solar hot water panel that is used to generate hot water heated by the sun is the flat-plate solar collector. This type of technology is mainly used for residential homes to supply hot water at an affordable price to the homeowner. Anywhere there is a high demand for hot water, such as a large family that does frequent loads of laundry, will benefit from this technology. Businesses like car washes and convalescent homes and hospitals will save a lot of money on their monthly energy bill if they install a solar hot water system and that is manufactured after the many flat-panel collector designs. A flat-plate solar collector is typically a box that is very well insulated and has a black metal absorber sheet built with pipes. The flat-panel solar collector is usually placed directly facing the path of the sun. The heat generated from the sun will heat up water that is in the pipes. Once the water is heated, it will begin to circulate via a natural convection process. Technically this process is called thermosyphon. Once the water in the collector is heated, it passes onto a hot water storage tank. A fixed flat-plate solar collector obtains high efficiency ratings because it directly faces the sun at a sloping angle to the horizon. The slope of the solar collector is normally equal to the latitude plus 10 degrees and is very efficient in catching the sun’s heat in the flat-plate solar collector. Flat-plate solar collectors can be designed in various ways. All of them will have a flat-plate absorber. The absorber is what captures the solar energy. A transparent cover over the absorber will allow the sunlight to pass through and reduce heat loss for the absorber. Flat-plate panels are also made with a transport fluid such as anti-freeze or water. This transport fluid flows in the tubes to capture the heat from the absorber and take it to the storage tank. The flat-plate solar collector will also have an insulating backing to prevent heat loss. One certain flat-plate solar collector design is made to specifically contain potable water. This kind must be made of metal and completely drained by gravity before freezing temperatures can crack the collector during the winter. Another design makes the solar collector freeze tolerant. This type of collector has water channels that are made of polymers like silicone rubber. Silicone is a good choice of materials to make a solar collector from since it can remain flexible and stable in temperatures up to 200C. You can also find another particular design that is a sealed heat exchanger flat-rate solar collector. This type does not have potable water circulating in the collector. Instead, it will have a mixture of water and propylene glycol. Propylene glycol is also used in the food industry as a heat exchange fluid and will protect against freeze damage to a certain temperature. However, the use of propylene glycol in the mixture of the solar collector can lower the heat carrying capacity of the water slightly. A new type of flat-plate solar collector is glazed with a selective coating for maximized absorption of the sun’s rays. It is made of a weather resistant aluminum frame and has fiberglass insulation in the interior to increase its efficiency. An aluminum framed flat-plate panel can breeze through all kinds of environmental weather changes. Silicon Solar Inc. is making this new kind of collector and you can find several other designs made by other companies on the internet. Many collectors now use a new energy efficient copper flow procedure. This kind of flat-plate solar collector can provide extremely high BTU performance because they can transfer the maximum degree of heat which makes them a highly efficient type of solar collector.
