EmiratesGreen Electrical & Mechanical Trading 
Abu Dhabi 
(UAE)

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Solar Water Heating Systems

Solar Energy

Solar / Thermal Energy is everywhere. It’s lights up our days. It heats the earth, our bodies and our homes. It dries our clothes and gives us produce like sun-dried tomatoes. All for free!

It’s also used to heat water for domestic use or even pools. There are two ways in which water can be heated:

1. Actively, when a conventional heating element within the solar hot water system heats water on hot days.

2. Passively, when water is preheated before it is delivered to the cold inlet of a conventional gas/ electric water heater.

EmiratesGreen offers Solar Water Heating Systems for Domestic & Commercial uses; System Design, Equipment and Materials Supply and Site Services. 

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Solar Water Heating Systems Basics

There are number of systems which can be used to heat your water. The great advantage of having a Solar Water heater is ITS FREE!.

Depending on your location and the quality of the water will depend on the type of system that is right for you. We can advise you on the correct system for your premises.There are several different type of Solar Heating Systems available:

  • Thermo Siphon Systems
  • Split Systems
  • Vacuum Tube Systems

For more information and full pricing please contact us now

SOLAR WATER HEATER (THERMO SYSTEM - Open Or Closed Loop)

A Thermo Siphon is the cheapest system available and is normally used to describe a Solar hot water system where the water tank and Solar panel are located together and installed ideally on the roof of the building although they can be installed in almost any location. 0-40FT will result in 1 bar of pressure from the water tank. The higher the system is installed the more pressure will be available.

SOLAR WATER HEATER (SPLIT SYSTEMS)

A split system is when the Solar Panel is placed on the roof and the actual water tank can be placed anywhere inside or outside the building. These systems are slightly more complicated and require a number of components.

Our systems come complete with electronic controller, electrical backup and circulation pump.

There are three sensors on the system, one at the top of the tank, one at the bottom of the tank and one on the collector. If there is more than an 8 degree difference between the three sensors, the system circulation pump will run automatically.

  1. Solar Collector (Panel).
  2. Storage tank.
  3. Heat Exchanger (if needed).
  4. Circulation pump.
  5. Controller.
  6. Element (electronic heater).
  7. Expansion Tank. (If needed)
  8. Valve, connection and other accessories. 
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Solar Water Heating Systems - Types

Solar water-heating systems can be either active or passive. Most common are active systems, which rely on pumps to move the liquid between the collector and the storage tank. Passive systems, on the other hand, rely on gravity and the tendency for water to naturally circulate as it is heated.

1. Active Solar Water-Heating Systems

Active solar water heaters rely on electric pumps, valves, and controllers to circulate water, or other heat-transfer fluids (usually a propylene-glycol mixture) through the collectors. There are the three types of active solar water-heating systems:

1a. Direct-circulation systems (or open systems) use pumps to circulate water 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 (SRCC) if they use recirculation freeze protection (circulating warm tank water during freeze conditions) because that requires electrical power for the protection to be effective.

1b. Indirect-circulation systems (or closed systems) pump heat-transfer fluids, such as a mixture of glycol and water antifreeze, through collectors. Heat exchangers transfer the heat from the fluid to the potable water stored in the tanks. Some indirect systems have overheat protection, which protects the collector and the glycol fluid from becoming super-heated when the load is low and the intensity of incoming solar radiation is high.

1c. 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.

Drainback solar water-heating systems are a good choice for cold climates.

2. Passive Solar Water-Heating Systems
Passive solar water heating systems are typically less expensive than active systems, but they're usually not as efficient. 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.

2a. Integral-collector storage systems consist of one or more storage tanks placed in an insulated box with a glazed side facing the sun. During the winter, they must be drained or protected from freezing. These solar collectors may be best 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.

2b. 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 water-heating systems almost always require a backup system for cloudy days and times of increased demand. Conventional storage water heaters usually provide backup and may already be part of the solar system package. A backup system may also be part of the solar collector, such as rooftop tanks with thermosyphon systems. Since an integral-collector storage system already stores hot water in addition to collecting solar heat, it may be packaged with a demand (tankless or instantaneous) water heater for backup.

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EmiratesGreen Electrical & Mechanical Trading

Email: solar@emiratesgreen.com