Green solar products
Low pressure solar water heater
   + Stainless inner tank   
   + Porcelain enamel inner tank  
Compact & pressue solar water heater
    + Stainless inner  tank  
    + Porcelain enamel inner tank  
Pre-heating solar water heater
    + Stainless inner tank  
Split & Pressure Solar System
    +  Solar System with stainless inner tank
    +  Solar System with porcelain enamel tank
Solar collector
     + Heat Pipe solar collector  
     + Vacuum tube solar collector  
     + Flat panel solar collector  
Solar project
     + Solar pool heating system
     + Solar space heating system
     + Solar water heating for villa
     + Others
Accessories
     + solar water heater accessories
     + solar controller
Home Appliance Products    
     + Freezer
     + Fefrigerator
     + Air Condition
     + Dishwasher
     + Gas Water Heater
Contact Us :

Factory in China
Tel : 86-519-85256385
Fax : 86-519-85256385
Cell : 86-13861291747
Email : timsolar@vip.163.com  
            timsolar2012@gmail.com
Contact  : Mr.Tim Liu
Site : www.greensolarchina.com 

Company in Greece
Tel : 30 2310 953421
Fax : 30 2310 953422
Cell : 30 6977 353638
Email : info@green-solar.net
Site: www.green-solar.net
  

 

Solar Water Heating For Villa

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 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:
1、Direct-circulation
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
circumstances.

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.