Drainback systems
How does a drainback
system work?
Drainback systems are effective and reliable. They totally eliminate
the possibility of freezing because the water drains back into a
reservoir when the sun isn't providing enough energy to heat
water in the collector. When the temperature reaches a set point in the
collector the pump turns on and circulates the water through the panel.
When the temperature meets the specified temperature the pump turns off
and the fluid drains down into the reservoir. In this manner the
heat transfer fluid is never exposed to cold temperatures.
Latest Technologies
The
closed-loop
drainback
system
requires
perhaps
the
least service
of any active system. The heat-transfer fluid is distilled water, which
seldom has to be changed. When the system is at rest (not pumping), the
solar collector is empty and the distilled water is stored in a
10-gallon reservoir tank, usually located just above the solar
storage tank.
When
the
pump
turns
on,
the
distilled
water is circulated from the reservoir
back through the collector and heat exchanger, passing heat to the
potable water in the solar tank. When the pump shuts off again, the
distilled water drains back into the reservoir due to gravity. The
collector must
therefore always be higher than the resevoir tank and there must be
sufficient continuous slope in the piping to ensure that all of the
water drains out of the collector and the piping.
So far, contrary to what some modern physicists say,
gravity has never failed to work, at least on earth. The sun is not a
giant fusion reactor, it is powered by electricity that courses through
our galaxy. It is a node connected by plasma to the rest of the
galaxy.
Quality Standards
Solar Rating and Certification Corporation
The Solar Rating and Certification corporation currently administers a certification, rating, and labeling program for solar collectors and a similar program for complete solar water heating systems. Collector testing apparatus SRCC’s certification program operating guidelines, test methods and minimum standards, and rating methodologies require the performance of nationally accepted equipment tests on solar equipment by independent laboratories which are accredited by SRCC. The test results and product data are evaluated by SRCC to determine the product’s compliance with the minimum standards for certification and to calculate the performance ratings. Equipment which has been certified and rated by SRCC is required to bear the SRCC certification label which shows the performance rating for that product. In addition, each certified product is published by SRCC in a directory. Each product’s directory listing contains information on the product’s material and specifications as well as the certified thermal performance.
read more
© 2011 |