Solar Water Heater---SPQBP series all glass vacuum tube unpressurized SWH

Un-pressurized tank for open circuit system
Stainless steel tank
PP side cover with additive for resistance to ultraviolet irradiation and ageing
Polyurethane insulation for perfect insulation

Silica gel ring sealing
Automatic argon protection weld technology preventing leakage problems
Consuming little installation space on the roof


The collector consists of all glass vacuum tubes. The vacuum tubes are comprised of two coaxial tubes made of borosilicate glass and have an external diameter D=47 mm and length M=1500 mm. The thickness of the glass is 1.5 mm. The inner tube is treated to act as selective surface with an absorption coefficient a>0.92 and an emission coefficient e<0.08. The air pressure between the two glass tubes is p<0.005 Pa. The stagnation temperature reaches over 200°C. The aluminium reflector is integrated with a plastic coated angle steel support frame. This solution provides an aesthetical result with built-in safety, durability and an easy installation. The tank is made of stainless steel 304 ( ocr18ni19) with a thickness of 0.6 mm. There is no contamination problem of the water quality. Automatic argon protection welding technology used for tank fabrication and the connection between tank and in/outlet pipe is an ideal welding technology which prevents leakage problems. The side cover of the tank is made of plastic ABS with additive for resistance to ultraviolet irradiation and ageing. The tank cover is made of a coloured steel plate giving the tank a beautiful and elegant design. The strength of the tank material and the cylinder structure design allow for a working pressure of up to 0.4 Mpa. Perfect insulation, rigidity and tightness is created by expanded polyurethane insulation which is injected in liquid form and expands after injection.
The storage tank and the evacuated tubes are installed as one unit on the roof of the building with the tubes connected to the storage tank on top. The system is open to air and relies on the natural circulation of water between the collector and the tank for heat transfer. Therefore, the internal circulation works without electricity except for an optional water level control. As the water in the vacuum tube is heated it rises naturally into the tank while cooler water in the tank flows down to the bottom of the vacuum tubes causing circulation throughout the system. The system is connected to the cold water pipe of the building and will be befilled in the morning. During the day the hot water can be consumed depending on the daily solar irradiation. The solar water heater is a non-pressurized system meaning the tank has an overflow and the flow-rate of hot water depends on the difference in elevation between the system and the hot water outlet.

Technical data





System type



All glass vacuum tube collector

Vacuum tube dimension

Ø47 x 1500mm

Quantity of tubes




Absorber area

2.5 m²

3.2 m²

3.6 m²

Capacity of tank

120 L

150 L

180 L

Inner material of tank

0.6 mm thick imported 304 stainless steel, Automatic argon protection wedding technology

Cover material of tank

Colored steel plate, 0.5 mm thick

Side cover material of tank



Expanded polyurethane foam 40~ 45kg /m3 , 45mm thickness


High quality aluminum plate, 0.4 mm thickness

Support frame (45° )

Angle steel with sputtered plastic coating

Electric heater





Thermo siphon open circulation

Gross weight with water




Available range

3~4 people

4~5 people

5~6 people