At Rockwill Green Energy E.A. we have two types of unique solar water heater,

1.Colored steel Non-Pressurized solar water heater

2.Stainless Steel Non-Pressurized solar water heater  <<More>>

Colored Steel Non-Pressurized thermosyphon solar water heater, Solar Geyser

The Non-pressurized thermosyphon solar water heater is the most popular and economical natural circulation system.The SFA evacuated tube solar water heating panel is the simplest vacuum tube system available. The stainless steel cylinder at the top of the panel is the well-insulated hot water cylinder – it is double skinned and has two inches of polyurethane foam between the two skins. The stainless steel construction means that it will not corrode, and its simplicity requires no ancillary components. The vacuum tubes are double-skinned, with a vacuum between the two layers of glass. The water in the cylinder is able to enter the central section of each vacuum tube, where it is heated by the sun. The tubes themselves are 93% efficient – so they are able to heat water even in low sunshine or when ambient air temperatures are low. The warmer, less dense water rises into the storage cylinder, displacing cooler water which descends into the tube for heating.

This type of system does not use heat pipes; instead the water is filled into the tubes, which in turn heat the header tank (which can vary between 85 and 220litres) by convection.It has obvious advantages:with a tank itself and the fittings are very low-cost. However, it is less functional, too large to appear roof-integrated, cannot accept pressure system kits.This type is commonly employed in hot countries such as Turkey, Greece, Mediterranean, Africa etc.

Solar water heater Feature: 

1)Beautiful in design and very convenient for family use
2) Reliable and efficient with twin-glass solar tubes
3) Easy plug-in installation
4) Outer tank material: stainless steel plate or powder coated color steel sheet
5) Inner tank material: 0.5mm thick SUS304 food grade stainless steel plate
6) Frame material: color steel
7) Superior heat preservation ensured by 50 – 65mm polyurethane foam insulation layer. Enjoy the hot water in cold evening
8) No corrosion: It can prevent corrosion lead from chorine ion, sea water, salt water or buck water
9) No leakage: Apply for special anti-corrosin layer
10)Sanitary water: The qualities showed above make it possible that water quality is pure and no twice pollution
11)Designing the  immersion heater hole in advance for the cloudy, snowy, rainy days


The Principle of Solar Water Heater Thermosyphon

The Principle of Solar Water Hater Thermosyphon

A. Tube coupled to a flow-through reservoir

B. Tube coupled to a closed tank

C. Open thermosyphon


Because of the larger proportion of hot water than cold water, cold water flows downward and hot water goes upward. The water will be heated continuous between water tank and vacuum tube. In other wards, hot water always floats on cold water.
The hot-water flows to the water tank from the vacuum tubes. Because of the proportion, cold water flows to vacuum tubes from the water tank.
The cold water is heated in vacuum tubes.After it becomes hot water, it flows to water tank again. The water circulates constantly between water tank and vacuum tubes; the cold water in water tank will be hotter and hotter.
Finally, all cold water will be heated to be hot water. This is the heating course of cold water.


Solar Water Heaters working principle


Tube & tank interaction during peak solar radiation conditions.


Scope of Application: 

SFA series Solar water heaters popular in Asia,Africa,torrid zone and warm area.

Notice : 

1) The angle of the frame can be changed in production as the local latitude condition of the customers. We can design the suitable angle for the customers
2) We offer the spare accessories and tubes for your order for free
3) We can offer the different material of water tank,frame anf tubes according to your request
4) We offer the fittings of this system,like immersion heater,water supplier,magnesium and so on.You can buy according to your requirement