Flat Plate collector panels are particularly suited to new-build applications.
They can be embedded within the roof structure to lie flush with the tiles, appearing like a Velux skylight.
The collector is fully assembled ready for installation  -  although larger units can be heavy and may require a crane to lift them into position.

Vacuum Tube collectors are some 15 / 25% more efficient than Flat Plate collectors for the same surface area, primarily due to the technology within the tube.

Manufactured from borosilicate glass (“Pyrex”), the tubes are very robust, requiring minimal maintenance throughout their expected 20 / 25 year life.

With scaffolding for access, the collector panel is assembled in situ on the roof.
The framework components and tubes are relatively light in weight and easy to handle, and would not normally require any special lifting equipment.

These features, combined with ease of installation, have resulted in the vacuum tube becoming the dominant solar thermal technology, accounting for some 70 / 80% of the global market.

A detailed comparison between Flat Plate vs Vacuum Tube collectors can be seen @@ here [3.1.3] @@.

A detailed description of Flat Plate collectors can be seen @@ here [3.1.1] @@, and for Vacuum Tube (or Evacuated Tube) can be seen @@ here[3.1.2] @@.

Our NER-Gaia vacuum tube collectors meet the primary British and European standard, BS / EN 12975, and have been awarded the European Solar KeyMark.

Full details of our NER-Gaia range of solar collectors and systems, and their technical specifications, are shown @@ here [4] @@.

Vacuum Tube Construction 

The tube itself is like a long vacuum flask, consisting of two concentric borosilicate glass (“Pyrex”) tubes.

The inner tube's outer surface is treated with a special selective coating that attracts the sun’s radiant energy into the tube, and its inner surface is mirrored to reflect and focus this energy on the core of the tube.

This combination of vacuum seal and mirrored coating retains some 93 / 97% of the heat and radiant energy generated within the tube, which is concentrated on its centre.

                                             
Vacuum Tube Structure with Selective and Mirrored Coatings on the Inner Tube

The energy generated within the tube is transferred via a Heat Pipe to the manifold, which acts as a heat exchanger.

Located along the centre of the tube, the heat pipe is a long thin copper pipe containing a small amount of liquid.
As it is heated this liquid vapourises and rises up to the bulb at the top of the pipe, which is located into the manifold.

The heat from this vapour is transfered to the water flowing through the manifold, which in turns heats the water in the hot water cylinder.

Meanwhile the vapour in the heat pipe bulb condenses and drops to the bottom of the pipe, to be heated and vapourised again in a continuous cycle.

Diagram Demonstrating the Heat Pipe Process within the Vacuum Tube.

The combination of high efficiency and ease of assembly has resulted in the vacuum tube becoming the dominant solar thermal technology, accounting for some 75 / 80% of the global market.

Our range of NER-Gaia vacuum tube collectors have been fully tested in one of Europe’s leading independent test houses.
They have been approved to the principal British and European standard, BS / EN 12975, and have also been awarded the European Solar KeyMark.

Full details of our NER-Gaia range of vacuum tube collectors and solar heating systems, and their technical specifications, are shown @@ here @@.

A comprehensive explanation of the vacuum tube and heat pipe technologies, and a guide for evaluating their quality, reliability and life expectancy, is shown @@ here @@.

Assembled Vacuum Tube and Heat Pipe, with bulb