At The Bridge ~ Practical Solar
The coaxial evacuated tubes ensure
efficient absorption by insulating
as well as a vacuum can,
while absorbing at peak until shaded by the adjoining tubes. The stainless steel collector frames are light weight and strong.
Installation is straight forward and
adaptable to many situations.
At The Bridge ~ Practical Solar Hot Water
The Heat Pipe Evacuated Tube system consists of the glass evacuated tube and a copper heat pipe which is installed in the inner glass tube. Overall collector conversion efficiency is at 72% in full bright sunlight regardless of wind or freezing temperatures.
Basically, this is a ‘50 watt per tube’ collector for less than $1 per rated watt. Balance of system components are described elsewhere.
Heat transfer can be done by AC electric pump or DC pump with PV panel.
We offer several sizes of integrated pump packages that provide system control and monitoring technology.
The image below shows an infra-red photograph,
of a flat panel collector (on left) side by side with an Evacuated Coaxial Tube unit (on right). The darker part indicates that nearly no heat is re-radiated outward from the evacuated tubes, allowing it to be transferred and used to heat water. Because the exterior of the tubes stays near ambient temperature, snow does not stick to them.
This may seem more complicated than it needs to be, but this method has proven to be the most efficient way of transferring all the heat from the tube absorber surface to the condenser tip.
The manifold fluid (usually glycol and water) is pumped to a heat exchanger. The heat exchanger is usually incorporated with a hot water tank, and does not allow mixing of the glycol solution with the potable water.
The image above shows how the outer circumference of the inner tube functions as the absorber. Thus, in the evacuated tube collector, solar energy passes through one glass surface and the vacuum, then is potentially absorbed all around and transfered to the heat pipe within (not shown here). This vastly increases the solar day aperture at constant peak absorption.
A Truly Great Design!
Most types of collectors work well in the heat of summer.
But did you know, even though the days are shorter
and often cloudy, the sunlight is often more intense in winter because of clearer air and earth being over
3.5 million miles nearer to the sun?
That, in addition to dwindling fuel resources
and rising global CO₂ levels, means it becomes even more vital to absorb the available solar energy in the most efficient way.
The heat that is absorbed by the coaxial evacuated tubes is transferred to the heat pipe, and then to the tip condenser and then to the manifold socket (not shown). We feature a NEW 24 mm diameter condenser that doubles heat transfer surface area over previous designs.
Home Heating can be accomplished with this same type of system by increasing the number of collectors and size of the storage tank.
Size depends on how much
heating load you want to replace.
Your current heating system
can become the back-up for
extended sunless periods.
Though larger systems cost more, the energy costs they replace are greater,
so payback is actually much higher.
Because CVT collectors are more efficient in the colder winter months, they are well suited to this purpose.
In addition, if the home heating system is hot air or if the home has an “air handler” it is possible to install a radiator in the plenum to extract excess heat from the hot water.
24 mm condenser on heat pipe, pulled out a little for ease of insertion into manifold socket
Inner CVT structure, pulled out of tube
Close-up shots of CVT frame & holders. ⬇
Aluminum Frame Leg, 70˚. 45˚ similar.
Rear Manifold Mount, top of frame.
Lower Left Corner, front view