Category Archives: How Apricus Systems Work

edenPOWER Solar Hot Water powered by Apricus………. What it looks like on the roof and how it works

Apricus solar collectors can be installed in many different configurations depending on your requirements, and type of house. The structure of the collector can be seen below. Normally the evacuated tubes are 1.8m long, and come in 10, 20, 22 or 30 tube sizes.


Apricus Collector




The Apricus evacuated tube technology is a highly efficient, reliable solution suitable for the diverse conditions of the Australian climate.

Manufactured in line with ISO9001:2000 quality management requirements, and meeting SRCC, AS2712, and, Solarkeymark requirements.  Apricus collectors are a quality choice for your home or commercial application.


Excellent Cold Weather Performance




Apricus collectors can perform well even in freezing conditions thanks to thick glass wool insulation and the vacuum insulated evacuated tubes. This is in contrast to flat plate collectors that perform poorly in cold conditions.


Passive Sun Tracking



Apricus collectors are designed with a round absorber surface that can passively track the sun throughout the day. This means more stable heat output throughout the day, not just at midday. The tubes are also spaced close together to minimise light loss between the tubes, and eliminate the need for a reflective panel.


Freeze Protected Heat Pipes



Apricus heat pipes are designed to withstand freezing without damage, which means that the collector can operate in very cold regions.


All Stainless Steel Mounting Frames



Stainless steel provides strength and corrosion resistance, and is used for all Apricus collector frame components.


Special Sprung Heat Pipe Design



Apricus has developed a special spring assembly design to ensure heat pipes are kept firmly in contact with the header pipe within the manifold. Tighter contact means faster heat transfer which is key for high collector efficiency.


How the Apricus Solar Collector Works


The operation of the Apricus solar collector is very simple.




Step 1. Solar Absorption

Solar radiation is absorbed by the evacuated tubes and converted into heat.


Step 2. Solar Heat Transfer

Heat pipes conduct the heat from within the solar tube up to the header


Step 3. Solar Energy Storage

Water is circulated through the header via intermittent pump cycling. Each time the water circulates through the header the temperatures is raised by a small amount. Throughout the day, the water in the storage tank is gradually heated. The temperature the water in the tank will reach will depend upon the amount of solar radiation, the size of the tank and the hot water usage throughout the day.


Evacuated Tubes


Apricus solar collectors use twin-glass evacuated tubes. They are comprised of two glass tubes, fused together at the top and bottom. The space between the two tubes is evacuated to form a vacuum. The structure is therefore very similar to a Thermos® flask you may use to keep water hot. The outer layer of the inner tubes is coated with a special selective layer which absorbs sunlight very efficiently. The vacuum layer insulates very well against heat loss providing excellent performance even in cold weather.




To learn more about the different types of solar collectors and evacuated tubes, please .


Apricus solar collectors have from 10 to 30 evacuated tubes, with each tube 1.8m / 70″ long and 58mm / 2.3″ in diameter. Each tube contains a long heat transfer fin and a heat pipe. The fin acts to hold the heat pipe in place against the inner wall of the tube, and also provides additional heat transfer.



Heat Pipes


Heat pipes are commonly used in many industries, in particular in computers, working to transfer the heat from the CPU away to the heat dissipator past which the fan blows air. Heat pipes are also used in many industries to move heat from one point to another.


Apricus has specially designed a heat pipe for use with evacuated tubes. The operating temperature range from freezing to more than 200 ºC / 395 ºF means that many common heat pipes designs are not viable. Apricus heat pipes are designed to be begin working at a low temperature (30 ºC / 86 ºF), are able to transfer heat consistently up to high temperatures and can withstand freezing conditions without damage.


Below is a diagram which shows the basic operation of the heat pipe.


Picture 1


The operation is very simple. The heat pipes is basically a copper pipe that has been evacuated for form a vacuum. The heat pipe contains a small volume of purified water which acts as the “working fluid”. Because the pressure in the heat pipe is very low, the water boils at only 30ºC / 86ºF. The resultant steam rushes to the top of the heat pipe where it off-loads heat, after which it condenses back to water and runs back down to repeat the cycle. Using this process, Apricus heat pipes have a heat transfer capacity in excess of 110Watts, with the evacuated tubes in strong sunlight able to provide around 50-60Watts.


Mounting Options


Depending on the roof surface, different attachment methods may be required. Apricus provides a range of accessories which allow installation on almost any surface.




Round Feet


Round feet are the standard option for high angle frame kits when installing on a flat roof, as they provide a strong foundation with large surface area.




Roof Track


The roof track provides the same mounting format as the standard frame, a C shaped channel, ideal for use on tiled roofs, asphalt shingles or galvanized steel roofing

The roof track can be attached to the roof using a roof attachment straps or rubber pads.



Mounting Accessories


The frame can be attached to almost any roof surface. The following accessories are used depending on the roofing material.




Rubber Foot Cover


If installing using round feet on a asphalt roof, the rubber foot cover is used to prevent the asphalt from melting when the metal foot gets hot in the summer.


For a galvanized steel roof, the rubber cover separates the stainless steel foot from the metal roof, preventing any galvanic reaction or scratching.




Rubber Pads


If installing using the standard frame, or a frame kit using the roof track option, rubber frame pads may be used.


Normal thickness rubber pads are ideal for corrugated roof roofing, as widely used in Australia and New Zealand. The pad is able to mould to the shape of the corrugation, forming a good seal and preventing directly contact between the metals.


Thick rubber pads are used on asphalt roofs to prevent the C channel cutting into the shingles, or melting them in sunny weather when the metal becomes hot.





Roof Attachment Straps


Use roof attachment straps when mounting the collector using the standard frame, or roof track option on a tiled roof.


The straps attached into the underside of the C channel, and then run under the tiles and are secured to the roof’s steel or wooden frame.


By all means contact us directly for more information at edenPOWER Inquiries.