Working Principle

   Emmvee has established an in-house production facility to manufacture tray collectors which meets the international standards. This type of flat plate collector is made with single body structure with a unique glass locking mechanism. The advantages of this type of collector over normal collector are the higher efficiency and the elegant look.

Basic Working Principle of Solar Water Heating system
As shown in the diagram, by gravity flow, water from the cold-water tank enters the solar tank at point A and fills it up. The cold water from the solar tank in turn flows via point B in the bottom header pipe of the absorber, and into the copper tubes at point C, until all the absorber tubes and the header at the top of the absorber are full. When the sun rises to a certain level, its energy, which falls on the absorber fins and tubes, begins heating the water contained therein. The heated water being lighter than the cold water rises and via the top header pipe (point D) of the absorber, flows into the top of the solar tank through point E. The more cold water from the solar flows into the absorber tubes, gets heated and rises to the top, and so on. This process is called 'Thermosyphon Process' and this Thermosyphon Process continues until the temperature of the water in the solar tank and the absorber equalizes. Now the solar tank is full of hot water. (Note:- Average temperature is 60 degree centigrade at the end of 7-8 hours of bright sunshine.) Further when the hot water is drawn from the solar tank outlet (point F) to the utilities point, cold water enters into the solar tank and takes its place at point A, thus lowering the overall temperature of the hot temperature between the water in the solar tank and the absorber tubes, the thermosyphon process starts once again, as explained earlier. The diagram also shows the back up electrical heater (to be used during cloudy days) and the sacrificial anode rod in the solar tank to prevent galvanic corrosion (but not scale formation), if the hardness of the water quality is less than 140 ppm, thereby ensuring effective working for longer time.

Pressurised System
The basic working principle of solar water heating remains the same. A pressure pump is used to pump cold water from the source into the Solarizer tank.

This type of water heating system is used when
- The level of the overhead tank (The original cold water source) is at low level.
- High pressure hot water flow is required for various uses like shower panels, jet shower, telephone shower, etc.
- The number of hot water points are more than normal.

System For Multi-Storied Buildings
The solar water heating system installed for multi storied buildings, process industries, apartment complexes, hospitals, hotels. Works on the same basic principle, but is specifically designed to meet rigorous requirement of such conditions. Such installations have multiple hot water outlets at different levels of the building, it is important that all outlets should dispense hot water as soon as the taps are opened, and also minimize the wastage of cold water. To achieve this, a special device called the Electronics Control Unit is installed within the hot water plumbing lines. During the process of heating, if the temperature of the water goes below 30° C, the Electronics Control Unit (auto temperature controller) switches on the pump immediately. The pump then pumps out the cold water accumulated within the tube and fins, thereby allowing immediate flow of water.

The advantages of this system are
- Cold water wastage is not there.
- Hot water is readily available on the turn of the tap.
- Electricity is saved because wastage of cold water is minimized, thus saving precious resources.

Heat Exchanger
This type of Solar water heating system used when the original cold water (from the source) contains chemical contents and is therefore hard water. Thermal fluid (Distilled water) is filled through make-up tank to the outer tank shell. In turn, this fluid gets circulated through the solar fins and tubes and goes back into the top of the outer tank. This fluid acts as a heat transfer media and prevents clogging of the copper tubes due to chemical contents in the original water source. The inner tank gets filled with cold water from the original cold water source. Since the inner tank is immersed within the outer tank, the heat gets transferred to the inner tank through the conducted and convection method and the water in the inner tank gets heated up and available for hot water utility.

Forced Circulation
If the capacity of hot water requirement is more than 4000 upto 100000 LPD, the water requires additional force to push the hot water collected in the solar collector. The DTC senses the inlet and outlet temperature of the water. If the thermal difference is more than 10 degree centigrade, the DTC switches on the pump and the hot water in the collector is forced to flow into the storage tank. This system requires continuous supply of electricity for the motor to operate.

Fixed Circulation
This system is used in process industries where in the hot water requirement is between 4000-100000 LPD at a fixed hot water temperature, or when the collectors and the tanks are placed at different places. In this system, cold water the collectors and waits till it gets heated up to the set temperature.