What are Evacuated Tubes?

Solar Hot Water Systems from Endless Solar use the exceptional efficiency and power of Evacuated Tube Technology. This breakthrough technology is recognised around the world as a much better way to heat water using the sun’s endless energy.

Evacuated Tubes from Endless Solar provide a new level of performance and expectation in the solar water heating industry. They deliver many advantages over all other types of solar heaters.

Evacuated Tubes are a proven technology now widely accepted in Australia… all the way from consumers and plumbers – right through to the Federal Government level. There are many suppliers of Evacuated Tubes in Australia. Endless Solar’s reputation has been earned through our attention to detail, product quality & performance… and our exceptional service levels and experience. We also have an excellent reputation for our DIY option. For more information about DIY please click here.

Endless Solar is recognised as the leader in advanced solar thermal design and has many years of expertise in solar. Endless Solar stands apart from all other Evacuated Tube suppliers in the market. Give us a call to find out more.

All Evacuated Tube products from Endless Solar are Australian Standards approved. Evacuated Tubes are sleek, stylish and super-efficient. They work by absorbing the sun’s energy, trapping it like a giant thermos flask, and efficiently transferring heat to the water supply.

How do Evacuated Tubes work?



Each Evacuated Tube consists of 2 layers of Borosilicate glass with a vacuum layer between them. This vacuum provides superb insulation and helps to retain an amazing amount of heat… up to 97% of the sun’s thermal energy is held in the tube.

Absorber Coating

Each Evacuated Tube has a special coating on the inner tube layer. This coating absorbs radiation from the sun. The sun’s energy is then trapped inside the tube by the vacuum.

The coating is formulated to catch as much of the sun’s energy as possible, but at the same time not lose it through radiation.

Of course, the performance of any Evacuated Tube coating depends on it’s formulation and its quality.

Endless Solar uses only the best, premium quality absorber coating for our Evacuated Tubes.

Heat Pipe – A simple and effective thermal engine

The sun’s thermal energy is transferred to the water supply at the top of the solar collector via a heat pipe located in the centre of each tube. Inside the heat pipe there is a partial vacuum that contains a small amount of evaporative liquid.

As the Evacuated Tube is heated by the sun, the liquid in the heat pipe changes state and becomes a gas. The gas rises to the top of each pipe. The rising gas carries the heat to the top of the collector.

The cold water in the tank is circulated through the top of the collector and absorbs this heat. The heated water is then returned and stored in a storage vessel on the ground.

The Result

The result is an incredibly efficient system to harness the heat of the sun even in extremely cold areas. Because the system is so efficient it does not require full sun and it can work in cloudy or even rainy days.

Why are Endless Solar’s Evacuated Tubes so Efficient?

Evacuated Tube technology delivers significantly better performance than traditional ‘flat plate’ collectors on the market today. They are incredibly efficient, and don’t lose energy when the weather is cold. Evacuated Tube products supplied by Endless Solar are also known to perform exceptionally well when compared to other types of Evacuated Tubes.

The round surface of each tube passively tracks the sun as it moves across the sky. This means that the face of the absorber in each tube is always perpendicular to the sun, and the round surface of the tube catches and re-directs the sun’s energy inside.

The secret to the brilliant performance of Evacuated Tubes in cold weather is the superb insulation provided by the vacuum in between the two layer of glass. This ensures that the sun’s energy you are catching is not lost. Other systems lose heat when it’s cool outside.

Benefits of Evacuated Tubes from Endless Solar