Focus Technology Solar Collectors
The Focus Technology range of solar collectors use twin-glass selectively coated solar tubes as the solar absorber. Each solar tube is fitted with a pair of metal heat transfer fins, which serve two purposes, firstly to aid heat transfer, and secondly to secure the copper heat transfer heat pipes tightly against the inner wall of the solar tube. The copper heat pipes are evacuated and contain a small volume of purified H2O, which, due to the vacuum, at low temperatures (>30°C) boils and vaporizes. The excellent heat transfer properties of the heat pipes facilitate the transfer of thermal energy from within the solar tubes to the collector header.
The manifold header comprises two 18mm copper pipes, which have copper “ports” brazed between them. The 18mm copper pipes are contoured to the shape of copper ports in order to increase contact area. In addition the contoured shape of the header creates turbulent water flow, thus further enhancing heat transfer. The heat pipes plug into the header ports, which are tapered at the end to ensure firm contact for optimal heat transfer. The header is insulated with compressed (~70kg/m3) glass wool and housed by plastic powder coated (UV stabilized) 0.8mm thick aluminum.
The manifold and solar tubes are secured to a frame constructed of 1.5mm thick 304-2B stainless steel, with all bolts and fittings also made from 304 stainless steel.
The standard frame suits installation on a pitched roof (clay tiles, corrugated iron, asphalt tiles).
For installation on a flat surface, a flat roof adjustable angle frame is available, which is also made from 1.5mm 304-2B stainless steel, with attachment feet made from 2mm thickness stainless steel.
The AP solar collector is suitable for installation in an active, split system configuration, in either a closed or open circulation loop. The header is suitable for potable water flow, or the use of glycol-water mix for enhanced freeze protection.
The manifold is designed to be able to withstand wet or dry stagnation without damage to the system; however in a well designed system stagnation should rarely occur.
The copper header is rated to withstand a maximum pressure of 800kPa / 116psi. SPF and SRCC tested according to 600kPa max pressure (the standard in Europe and USA), but since that time sales in regions with higher mains pressure water levels have required a revision of the max pressure rating. No modifications to the design or manufacturing process have been made to the header to achieve the higher rating, with all headers individually tested to a pressure exceeding 800kPa / 116psi prior to assembly.
Technical Specification for Focus Technology Solar Collectors
