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The
Apricus 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 Apricus 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 Apricus 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 Apricus solar collector
can deliver excellent heat output all year round. The
IAM (Incidence Angle Modifier) values of the Apricus 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 Apricus 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 colours. The manifold is available in black, dark
brown, or silver powder coated aluminium, 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 Apricus 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 Apricus 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, Apricus 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 Apricus 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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Apricus solar collectors
are ideal for large scale solar water heating applictions,
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.
Apricus 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 labour cost involved in having a technician visit.
With this in mind the Apricus 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. |