The Apricus System Features
Main Apricus Page | Features Overview | FAQ | Technical InformationUnder Pressure
Powertech’s Apricus solar collector is designed to be used with pressure up to 8 bar / 116 psi. 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.
Circulation
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. Powertech’s Apricus solar collectors are suitable for both open or closed systems as long as pressure, heat and freezing are controlled.Pump
Powertech’s Apricus solar collector does not have a built-in tank, in fact the manifold of the 20 tube solar collector only contains about 510ml/1 pint 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.
Freeze
Thick glass wool surrounds Powertech’s 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.
Efficiency
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, Powertech’s Apricus solar collector can deliver excellent heat output all year round. The IAM (Incidence Angle Modifier) values of Powertech’s Apricus system 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.QUICK PRODUCT NAVIGATION
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