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Phase 1 – Capture of solar energy and primary energy transfer

The Solar energy is absorbed by the film on the inside of the borosilicate glass vacuum tube.

*This energy is then trapped by the strong vacuum within the tube walls, thus the high efficiency.

It is the basic mechanics of the cylindrical form that allow this strong vacuum to be created.

Almost a thermos flask inner and you may also recognise the silvering (spattering) at the base of the tube from valve radio days, which gives the vacuum its final edge.  Two old technologies rearranged.

In warm climates these tubes can be arranged to directly heat water, i.e. often seen in south Turkey.

For cold climates a foil and heat tube are used to conduct the energy out of the evacuated tube.

The foil, usually aluminium transfers the energy from the special film across to the heat tube.

The copper heat tube contains an amount of liquid with a partial vacuum to reduce the boiling point.

These heat tubes are also a known technology and can be found in cooling system for electronics.

When heated by the captured solar energy this liquid vaporises and rises to the top of the heat tube.

Thus the energy is now out of the evacuated tube and ready for use, effectively this is the flame!

* FMEA ‘failure mode and effect analysis’ show this systems to be naturally reliable. Achieved by the use of known technologies and no moving parts means there is nothing much to go wrong.

Phase 2 – Secondary transfer of energy to indirect circuit.

A bank of the tubes described above and their heat tubes plug into the collectors arrays manifold. Various sizes and numbers of tubes per solar collector array and numbers of arrays can be arranged to meet your power requirements.  This web site shows small, medium and large domestic options, but this is in no way a limitation. The heads of heat tubes fit into sockets cross welded into a pipe within the manifold.  A white silicon paste in the joint transmits the energy across into this pipe.

Now you have a very simple boiler! *This heat tube system, when compared to others, is fundamentally reliable due its simplicity and individual tube failure will not stop the system working.

The energy is circulated in a conventional closed loop indirect FLOW and RETURN system.

We use a specially developed German made Energy Transfer Fluid based on propane diolthol.  *It has superior energy transfer capabilities and it is chemically stable across full system temp range.

Unit – Pumping Station

The tried and tested Resol controller measures the array and lower cylinder temperatures.

When a determined temp differential is reached the pump in operated/pulsed accordingly.

*This extracts the maximum energy from the arrays with minimal pump power usage. The controller also monitors and controls maximum system temperatures to ensure safe operation.  When ether of these maximum temperatures is reached the system locks out shutting down the pump.  The transfer fluid will then vaporise in the array and partly down the pipe work, this expansion is taken up by the expansion vessel. A non return valve NRV is fitted and has two function, to prevent thermal siphon reversing the system and to block the vapour reaching and damaging the pump.The design features of our unique pumping station are explained in the Why Aztec section.

Phase 3 – Heating of domestic hot water

Unit – Hot Water Cylinder

The domestic hot water is heated by the fluid passing through an independent high efficiency finned solar coil in the bottom of the hot water cylinder.  This solution has no direct connections to any other heating circuits in the cylinder but works in tandem with them. The system relies on the strange nature of water to form layers at different temperatures, called thermo climes.  You may have noticed this effect when swimming in open water and dangling your feet down to find colder water.  It happens because water is a poor conductor but a good convector of energy, thus the heat energy travels upward but cannot get back down.  If another boiler is running when the solar system starts working the heat energy will convect upwards and activate the boilers control stat switching the boiler off.  This is why we only use systems incorporating hot water cylinders with a bottom mounted independent solar coil.  Because the coil is independent it can be used in vented, pressurised, or thermal store cylinders and is compatible with any systems within them.

Phase 4 – Distribution of hot water

Unit – Domestic circuit

This is not part of the solar heating circuit but the normally installed domestic or commercial buildings circuit.  The above is an explanation of the basic principles of a Solar system and in no way suggests any limitation of potential use.  In fact the system should be considered as a heat energy generator with applications such as swimming pool heaters or even to heat the de-greasing agent in an engine block cleaning machine. Theoretically it could be connected to a central heating circuit but unfortunately it would be at max power in the summer and min in the winter.  However we are currently working on an air heating system based on the same technology for space heating.