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The AP solar collector is designed to be used with
pressure up to
8 bar/116psi. This means it is compatible with
all low pressure, and most mains pressure domestic
hot water systems. In closed loop or sealed (dead
water) thermal store systems an expansion vessel is
often used to prevent pressure buildup as the water
expands. A pressure release valve should also be
used as a safety backup.
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| In areas where freezing is not of concern, open loop systems are often used. Open-loop systems are also appropriate for cold regions when used in combination with a Delta-T controller that incorporates a freeze protection feature. Closed loop systems usually incorporate the use of a heat exchanger, either inside or outside the hot water storage tank. Apricus solar collector are suitable for both open or closed systems, as long as pressure, heat and freezing are controlled. | |
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The AP solar collector does not have a built-in
tank, in fact the manifold of the 20 tube solar
collector only contains about 510ml/1pint of water.
A circulation pump is required to circulate the
water through the manifold and back to the solar
storage tank. Generally a
Delta-T controller is used to control the pump.
A flow rate of only
2L/min is required for most domestic
installations, and therefore a low wattage pump is
sufficient. Larger pumps are only necessary when
several solar collectors are connected in series, or
when the pump is required to overcome head pressure.
The pressure drop at low flow rates is very minimal,
only 700 Pa @ 3.3L/min for 20 tube manifold, and so
is not a major consideration when sizing pumps.
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Thick glass wool surrounds the AP solar collector's
copper header, providing excellent insulation. The
piping to and from the collector are however still
susceptible to freezing, and therefore traditional
freeze protection should be employed (low temp
controller setting, or glycol/water closed loop).
Solar tubes and heat pipes are able to withstand
extremely cold conditions without being damaged. (click
here for heat pipe details).
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The advantage of solar tubes is that they insulate
the inner tube from heat loss. This means that once
heat is absorbed, it is transferred to the water in
the manifold, and not lost to the outside
environment. This is the key difference between
solar tubes and flat plate solar collectors: the
insulative properties. Combined with the heat
transfer efficiency of the heat pipe, the AP solar
collector can deliver excellent heat output all year
round. The IAM (Incidence Angle Modifier) values of
the AP are also very different to solar collectors
with flat absorbers. The positive (>1) IAM values
mean that the solar collector actually performs best
mid morning and mid afternoon, resulting in a more
stable heat output throughout the day.
Click here to learn more about efficiency.
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When installing a solar collector on your roof, how
it looks is certainly important. The AP solar
collector is designed to be low profile, sitting
close to the surface of the roof. The tubes are
black and so blend in nicely with most roof colors.
The manifold is available in black, dark brown, or
silver powder coated aluminum, and with either rear
(R) or end (E) port models. The rear port manifold
allows the plumbing to be hidden behind the solar
collector manifold. In addition by using rear ports,
two or more solar collectors may be connected side
by side without a gap in between. End ports may be
preferred for large scale applications for ease of
connection in series, and reduction of pressure drop
through the piping. Click here to see some
installation photos.
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Corrosion is always a consideration for any system
that involves water and high temperatures. In warm
environments, heavily chlorinated water can become a
strong corrosive agent. In order to provide maximum
corrosion resistance, the AP solar collector uses
high purity (99.93%) copper piping and silver braze
for the header. Copper provides excellent corrosion
resistance and is commonly used in household
plumbing. If corrosive liquids are to be used in the
system, then a closed loop is highly recommended,
thus allowing a non-corrosive liquids to be used in
the solar collector loop.
If installed in open flow with a dead water thermal store style tank, corrosion and scale are almost eliminated as the system accepts almost no fresh water supply. |
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The high cost of solar tube style collectors, and in
fact all solar collectors, has been a major obstacle
to their popularity and wide scale use. The AP solar
collector is a high quality system that provides
excellent heat output and reliable operation. As a
result of clever product design and low
manufacturing costs, AP solar collectors are now
very affordable, providing fast payback times.*
Please contact you local distributor for retail pricing in your area. *Depends on factors such as total system cost, energy costs and solar insolation levels. |
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Scale formation is an issue in many regions, as it
gradually blocks up plumbing particularly in hot
water systems. With the high temperatures that the
AP solar collector produces, scale formation in the
manifold may occur. If water supply is very hard
there are two main options:
1. Use an electric or magnetic water softener on plumbing 2. Use a closed loop system 3. Use an dead water thermal store configuration. Option 1 may still be required to protect the rest of the system. A closed loop requires a more complicated system design and added cost. If there is no other reason to use a closed loop than to avoid scale, then it is advisable to use one of the widely available water softening devices. |
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AP solar collectors are ideal for large scale solar
water heating applications, able to be used in
hotels, airports, apartment buildings or anywhere
where hot water or heating is required. The
economics of large scale applications are generally
more favorable than domestic, as instead of having a
pump and tank for every one or two solar collectors,
a single tank and pump can be used for 50 solar
collectors. AP solar collectors can accept mains
pressure, are corrosion resistant and can be
installed in series and/or parallel, thus are suited
to a wide range of large and small scale
applications.
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The cost involved in repairing a household appliance
is increasing all the time, not due so much to spare
part costs, but rather the labor cost involved in
having a technician visit. With this in mind the AP
solar collector is designed to be maintenance free,
but if for some reason a solar tube should ever be
damaged, it can be replaced quickly and easily by
any person possessing basic trade skills.
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Copyright ? 2005 No Utility Bills Inc.
All rights reserved.
Last modified:
08/10/15