solar thermal collectors

Solar Thermal Flat Plate Vs Evacuated Tube Collectors

in Solar Thermal

Homeowners today are heating thier water today across every climate zone in the world. Heating home hot water with solar is not a new idea, but there are new technologies available that make going solar easy enough for most folks who like to Do-It-Yourself.

The two most common types of solar thermal collectors are flat plate and evacuated tube solar collectors. Both are used extensively to collect heat for domestic hot water in homes as well as busineese across the country. Here is an explanation of how each works.

Flat plate solar hot water heating collectors are the far more common type, they have proven themselves in the field longer, and they generally are less expensive. They consist of (1) a dark flat-plate absorber of solar energy, (2) a transparent glazing that allows solar energy to pass through while minimizing heat loss, (3) a heat-transfer fluid (antifreeze or water) flowing through tubes to remove heat from the absorber, and (4) a heat insulating backing.

The solar thermal absorber consists of a thin absorber sheet (of heat-resistant polymers, aluminum, steel or copper, to which a black or selective coating is applied) backed by a grid or coil of fluid tubing. The Sunward design is unique in that the copper coil is bonded between two layers of aluminum for maximum heat transfer and longevity (this is what allows Sunward to offer an unprecedented 20 year warranty on its collectors). Fluid is circulated through the tubing to transfer heat from the collector to the heat exchanger and storage tank.

As an alternative to metal solar panel collectors, new polymer flat plate solar thermal hot water collectors are now being produced in Europe. These may be wholly polymer, or they may include metal plates combined with freeze-tolerant water channels made of silicone rubber. Polymers, being flexible and therefore freeze-tolerant, are able to contain plain water instead of antifreeze, so that they may be plumbed directly into existing water tanks instead of needing to use solar thermal hot water heat exchangers. However, polymer collectors can suffer from overheating, as stagnation temperatures in these collectors can reach 180°, while the melting temperature of polymers is 160°C.

In areas where freezing is a possibility, metal collectors must be carefully plumbed so they completely drain down using gravity before freezing is expected so that they do not crack. Sunward make some of the most unique and dependable solar thermal hot water collectors in the industry. The Sunward solar thermal hot water collectors are part of a sealed heat exchange system, rather than having the potable water flow directly through the collectors. A mixture of water and propylene glycol (which is used in the food industry) is used as a heat exchange fluid to protect against freeze damage, down to -58° F in the Sunward solar thermal hot water collectors.

Reduce energy costs By installing a solar water heating system, a typical household can meet 50 to 80 percent of their hot water needs. In southern climates, a solar water heater can meet nearly 100 percent of a household hot water needs. Solar thermal hot water is a proven efficient technology with many safety features.

Currently there are more than 300,000 solar hot water heaters installed across the United States (excluding swimming pool applications) and because these systems have been proven efficient and reliable, the number of installations continues to grow by the thousands every year. Improved Environment Reduced demand for fossil fuels will improve the environment by reducing air and water pollution as well as the heat-trapping gases that cause global warming. And though they cost a little bit more up front to install, a carbon free Solar Water Heating system will save consumers money in the long run as the fuel source will always be free.

Solar thermal hot water heating uses the suns energy to heat hot water year round. Solar hot water system can significantly lower your utility bills. Sunward solar hot water thermal systems have the longest warranties in the industry giving you confidence in your purchase plus the lowest prices in America. Sunward solar thermal kits come complete with all the part needed for a weekend of DIY bliss installing your owner solar thermal flat plate hot water heater.

Contributing Source: Sunward Solar Hot Water Heaters

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