Vacuum Tube Solar Collector

evacuated tube solar collector

What is a Evacuated Tube Solar Collector?

Vacuum tube solar collectors which is also known as evacuated tube solar collector is a water heating system that converts energy from the sun into heat that is used for heating water.

This solar water heating kit can be used for both domestic and commercial hot water heating needs. Sometimes it can also be used for heating  pool water.

Evacuated tube collectors are designed to solve the problem that comes with using flat plate solar collectors.

Since the flat place collectors are positioned  horizontally, it means that they will only be efficient when the sun is positioned directly above them.

A change of position of the sun will hamper the performance of the collector by a significant margin.

You should also keep in mind that the sun can strike the collector at different angles and be reflected back. This means that a good percentage of the energy will go to waste.

With the vacuum tube collectors, the rounded tubes are designed to be perpendicular to the  rays of the sun throughout the day.

This design allows the evacuated tube collector to operate at maximum levels of efficiency.

solar glass tube collectorEvacuated tube solar collector are also lightweight. This is possible because the solar tubes are not filled with large volumes of water. You will not be stressed by the physical and structural damage that the solar water heater will have on your roof.

Evacuated tube solar collectorHow do evacuated tube solar collector work?

An evacuated tube solar hot water system comprises of various components which in conjunction work together to achieve the goal of heating up the water.

These components are;

1.      Evacuated Tube

This  tube is designed to absorb the solar energy and converts it into heat. There exists a  vacuum between the two glass layer whose purpose is to provide insulation against any form of heat loss.

There is a heat transfer fin which helps to transfer the heat to the designated Heat Pipe.

A silicon rubber is placed at the end of the evacuated  tube and it provides protection against the destructive UV rays.

2.      Heat Pipe

This is basically a copper vacuum that does the work of transferring the heat  from the evacuated tube straight to the manifold.

3.      Manifold

A manifold of an evacuated solar tube is an insulated box that contains a copper header. This header is simply paired copper pipes  which have dry connect sockets. The heat pipes are plugged into these connect sockets.

A typical manifold casing is made of a strong aluminium alloy  which is designed in a  particular manner such that it forms a protective enclosure. This casing is then finished using a matte black coating that is resistant to the UV rays.

A glass insulation is used on the head pipe to provide  the necessary insulation against  the heat loss.

The design of the manifold helps to eliminate the unnecessary use of metals. It is also lightweight hence making it easy to install on the roof.

4.      Mounting frame

This frame basically acts as a point of attachment for the solar heater to the roof. It provides a platform for the easy installation of the solar  water heaters.

In most cases, this frame is made of strong marine grade steel which is resistant to rust and corrosion.

Evacuated tube solar collector working principle

From the above components, we can tell that the evacuated tube collector working principle is similar to that of a thermos flask which you use  for keeping your hot drinks.


The outer glass of the vacuum tube allows the solar light to penetrate through it. The second inner tube has a special coating that converts the solar energy to heat.


Reliable solar vacuum tube manufacturers use the best coating that will guarantee more than 90% efficiency. This means that only a small percentage of the solar energy will be lost.


The absorbed solar radiation is then taken by a  Heat Transfer Fluid which is within the tube. This fluid heats up and rises to the top of the tube.


Copper heat pipes then absorb the heat energy directly from the vacuum tubes. Copper is used because of its efficient conductivity. It minimizes the loss of heat.


From the heat pipes the energy is transferred to the hot water system.

During the process, hot water will rise and cold water will take its position. The hot water is then collected at the top of the collection chamber. It is then pumped  to the next stage for the designated use.

Evacuated tube solar collector available in 15 to 50 tube sizes and have a number of options depending on the local market requirements.
Collector TypeVerticalVerticalVerticalHorizontalHorizontal
Peak Output *1019W1339W2021W2678W3342W
Aperture Area
1.41 m2
1.88 m22.82 m23.76 m24.70 m2
Gross Area2.40 m23.17 m24.80 m26.34 m27.86 m2

We also manufacture compact solar water heaters. Please contact us for details.


Main Component Specifications
Materials & Specifications
Evacuated Tubes
Material: Borosilicate 3.3
Tube style: Twin wall all glass
Dimensions: ∅58mm outer tube; ∅47mm inner tube;  1.8m length, 1.65mm outer tube wall thickness
Solar Absorber Coating
Material: Graded AL/N on AL
Absorptance: >92% (AM1.5);
Emittance: <8% (80 C)
Vacuum: P<5×10-5 Pa;
Heat loss: <0.8W/(m2 C)
Outer Shell: Color Painted steel (standard) or Stainless Steel (optional) , 0.5mm thickness
Inner Shell: Stainless Steel 304-2B (standard) or 316L (optional) , 0.5mm thickness
Insulation Layer: Extreme High density Polyurethane Foam from Europe
Operating angle: 15-80 Degrees
Startup temperature: 0 C Degrees
Rubber Components
Material: HTV Silicone Rubber (UV stabilized)
Mounting Frame
Material: Zinc-Coated Galvanized Steel (standard) or Aluminum ally (optional)  or Stainless Steel (optional)
Local Team Installation Support

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