Green solar products
Pre-heating solar water heater
+ Stainless inner tank
Split & Pressure Solar System
+ Solar System with stainless inner tank
+ Solar System with porcelain enamel tank
+ Heat Pipe solar collector
+ Vacuum tube solar collector
+ Flat panel solar collector
+ Solar pool heating system
+ Solar space heating system
+ Solar water heating for villa
Home Appliance Products
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Factory in China
Tel : 86-519-85256385
Fax : 86-519-85256385
Cell : 86-13861291747
Email : firstname.lastname@example.org
Contact : Mr.Tim Liu
Site : www.greensolarchina.com
Company in Greece
Tel : 30 2310 953421
Fax : 30 2310 953422
Cell : 30 6977 353638
Email : email@example.com
Solar Water Heating For Villa
solar water-heating systems for buildings have two main parts:
(1) a solar collector
(2) a storage tank
Solar water heaters use the sun to heat either water or a heat-transfer fluid in the collector. Heated water is then held in the storage tank ready for use, with a conventional system providing additional heating as necessary. The tank can be a modified standard water heater, but it is usually larger and very well insulated. Solar water heating systems can be either active or passive, but the most common are active systems.
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:
systems use pumps to circulate pressurized potable water directly through the collectors. These systems are appropriate in areas that do not freeze for long periods and do not have hard or acidic water. These systems are not approved by the Solar Rating & Certification Corporation if they use recirculation freeze protection (circulating warm tank water during freeze conditions) because that requires electrical power for the protection to be effective.
2、Indirect-circulation systems pump heat-transfer fluids through collectors.
Heat exchangers transfer the heat from the fluid to the potable water. Some indirect systems have "overheat protection," which is a means to protect the collector and the glycol fluid from becoming super-heated when the load is low and the intensity of incoming solar radiation is high. The two most common indirect systems are:
a、Antifreeze. The heat transfer fluid is usually a glycol-water mixture with the glycol concentration depending on the expected minimum temperature. The glycol is usually food-grade propylene glycol because it is non-toxic.
b、Drainback systems, a type of indirect system, use pumps to circulate water through the collectors. The water in the collector loop drains into a reservoir tank when the pumps stop. This makes drainback systems a good choice in colder climates. Drainback systems must be carefully installed to assure that the piping always slopes downward, so that the water will completely drain from the piping. This can be difficult to achieve in some
Passive solar water heaters
Passive solar water heaters rely on gravity and the tendency for water to naturally circulate as it is heated.
Because they contain no electrical components, passive systems are generally more reliable, easier to maintain, and possibly have a longer work life than active systems. The two most popular types of passive systems are:
Integral-collector storage systems consist of one or more storage tanks placed in an insulated box with a glazed side facing the sun. These solar collectors are suited for areas where temperatures rarely go below freezing.
They are also good in households with significant daytime and evening hot-water needs; but they do not work well in households with predominantly morning draws because they lose most of the collected energy overnight. hermosyphon
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.