Evacuated Solar Hot Water Tubes
These new systems have a 58mm tube instead of a 47mm and the length of
the tubes are 1800mm instead of 1500mm. The new manifold is extruded
aluminum and it is very hi tech.
The new tubes put out a lot more hot water because not only of their
added diameter and length but because of their one piece heat sink that is
inside the tube. The older system had segmented heat sinks but the new ones
are all one piece. This allows the 30 tube system to produce about 40,000
BTUs on a sunny day. This is assuming the system is set up for facing
south in the northern hemisphere.
The Evacuated Tube Solar Heating System
is a breakthrough in the efficiency of hot water production for
residential and commercial uses. The tubes, similar to the inside of a
thermos, are placed in the sun. Being round gives them maximum sun
exposure at every sun angle during the day. Also, because of the
vacuum chamber between the two walls of the tube, the tubes remain cool
even in bright sunlight and, most importantly, the tubes can still
produce hot water on cloudy days. They are very superior in
performance in cold weather conditions. A flat plate collector would
radiate a lot of the generated heat through the single panel glass. The
Evacuated Tubes work with a vacuum so this doesn't happen.
How the Evacuated Tubes Work
Sunlight heats the inner black
tube which in turn heats the aluminum
heat sinks that runs the length of the inner tube. A small copper tube is
located in a slot in the aluminum heatsink.. Inside this tube is a small amount of
glycol which changes to steam that goes up the tube end into the manifold
where the water changes state from steam to water. This is called latent
vaporization and it is this changing of state from steam to water that
gives the tubes the high efficiency that makes them produce about 40%
more hot water than a flat plate collector.
After the heat pipe gets heated, it transfers its heat from
the heat tube end into the water flowing through the aluminum manifold.
It does this by conduction. The Evacuated Hot Water SystemThis
evacuated tube hot water system contains 22 glass tubes or 30 with the
stretch version. There is also one extra tube and all the
components including the manifold frame and component assembly necessary
to put together the tube system. It does not include pumps, expansion
tank or other accessories. We can provide all this necessary
equipment but you would have to contact us to help you design a solar
hot water system.
One of these 22-tube hot water systems usually provides enough hot
water for an average family of four.
After the frame is attached
to a roof, it is easy to slip each tube into its slot in the manifold
while the bottom gets attached to the bottom rail. Hence there is no
heavy lifting required as the tubes get installed one at a time. (Water
must be flowing through the manifold when the tubes are installed.)
The evacuated tubes can be connected to a radiant floor heating system
as the temperature output is perfect for Pex tubing.. The tubes
can also be used with some of the new Absorption Air
Conditioners; we think this is, without doubt, the future
of air conditioners. The tubes are
made out of a glass similar to Pyrex (Borosilicate glass) and they are
breakable but once they are installed on a roof they should give many
years of service.
Federal Tax CreditThere is up to a
$2,000 Federal Tax Credit available for up to 30% of a solar hot water
system that is used for domestic hot water or space heating. The
evacuated tube hot water system is qualified for the rebates requiring
SRCC certification.
There is a pilot solar thermal rebate program in San Diego for California
residents. This program is scheduled to go statewide at the beginning
of 2009. It will provide a $1,500 rebate per system. We are still waiting
for it to take effect statewide.
| Evacuated Tubes
Pricing (US$) |
| 22-Tube System |
$879 |
| 30-Tube System |
$1249 |
| Call for a shipping quote |
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Evacuated Tube Specifications
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