One of the most cost-effective ways to include renewable technologies into a Central New York home is by incorporating solar hot water.
A typical residential solar water-heating system reduces the need for conventional water heating by about two-thirds. It minimizes the expense of electricity or fossil fuel to heat the water and reduces the associated environmental impacts.
 Written by Syracuse Solar and Wind Installer
Active solar water heaters Active solar water heaters rely on electric pumps, and controllers to circulate water, or other heat-transfer fluids through the collectors. These are the three types of active solar water-heating systems:
|
|
Written by Syracuse Solar and Wind Installer
Written by Syracuse Solar and Wind Installer
|
Written by Syracuse Solar and Wind Installer
S evacuated tube collectors are efficient at high temperatures. The collectors are usually made of parallel rows of transparent glass tubes. Each tube contains a glass outer tube and metal absorber tube attached to a fin. The fin is covered with a coating that absorbs solar energy well, but which inhibits radiative heat loss. Air is removed, or evacuated, from the space between the two glass tubes to form a vacuum, which eliminates conductive and convective heat loss. A new evacuated tube design is available from manufacturers, such as: Sunmaxx. The design features a vacuum contained between two concentric glass tubes, with the absorber selective coating on the inside tube. Water is typically allowed to thermosyphon down and back out the inner cavity to transfer the heat to the storage tank. There are no glass-to-metal seals. This type of evacuated tube has the potential to become cost-competitive with flat plates. |
Thermosyphon systems are an economical and reliable choice, especially in new homes. These systems rely on the natural convection of warm water rising to circulate water through the collectors and to the tank (located above the collector). As water in the solar collector heats, it becomes lighter and rises naturally into the tank above. Meanwhile, the cooler water flows down the pipes to the bottom of the collector, enhancing the circulation. Some manufacturers place the storage tank in the house's attic, concealing it from view. Indirect thermosyphons (that use a glycol fluid in the collector loop) can be installed in freeze-prone climates if the piping in the unconditioned space is adequately protected. 
Solar hot water flat-plate collectors are the most common solar collector for solar water heading systems in homes and solar space heating. A typical flat-plate collector is an insulated metal box with a glass or plastic or glass cover and a dark-colored absorber plate. These collectors heat liquid or air at temperatures less than 180°F.
olar hot water evacuated tube collectors can achieve extremely high temperatures (170°F to 350°F), making them more appropriate for cooling applications and commercial and industrial application. However, evacuated-tube collectors are more expensive than flat-plate collectors, with unit area costs about twice that of flat-plate collectors.