Useful Facts for Homeowners to Know About Solar Thermal Collectors
Solar water heaters have come a long way to become a reliable technology for domestic hot water provision. The system is arguably the most economical and efficient, ensuring a reduction in household energy bills. At the heart of a solar water heater system are thermal collectors installed on the roof to capture the sun's radiation. In turn, the radiation is used to heat water. Here are valuable facts to consider before buying thermal collectors for a residential solar water heater system.
Solar Collectors vs. Solar Panels
Unlike conventional solar panels that transform solar energy into electricity, collectors have absorber plates that transfer the sun's energy into a thermal fluid. A heat exchanger then efficiently and safely transfers the energy absorbed by the thermal fluid to domestic water. Therefore, the efficiency of a solar water heater system largely depends on the type of solar collectors installed.
Glazed Liquid Flat-Plate Solar Collectors
There are various types of solar collectors modules to choose from. However, the choice depends on several factors, such as climate. A common type of collectors is the glazed liquid flat-plate solar collectors. The modules comprise an insulated box with a plastic or glass covering and a metal absorber plate situated at the bottom. Below the absorber plates lie metal tubes, which allow a thermal transfer fluid to flow through the heat exchanger into a storage tank. The collectors are glazed with a coating for enhanced heat retention. Notably, the modules are cost-effective for residential solar water heating needs. Besides, the collectors are durable, leading to a low cost of ownership.
Unglazed Liquid Flat-Plate Solar Collectors
This type of collectors does not have selective insulation or absorber coatings. Therefore, the collectors are a low-cost option for homeowners on a low budget. However, the design is not ideal for windy locations due to inherent thermal losses. According to experts, unglazed flat-plate collectors should only be used during hot summer months in cold regions. Overall, the solar collectors are durable and cost-effective, and thus, preferred by many homeowners.
Evacuated Tube Collectors
The evacuated tube solar collectors consist of hollow glass pipes with an interior absorber lining for efficient absorption of solar radiation. When the pipes are heated, the air inside the tubes escapes, creating a vacuum and allowing heat to be trapped. As a result, the evacuated tube collectors are much more efficient than flat-plate collectors. Thus, they are ideal for applications that require water to be heated to temperatures ranging between 76°C to 1760°C (170°F to 350°F).
To learn more, contact companies that sell or install solar panels.