Double-circuit solar collector - has one set of collector tubes overlying another in horizontal channels in solid block

摘要

The two circuits run horizontally across an accumulator mass and from bottom to top of the mass. Pref. one circuit comprises black tubes underlaying and joined to translucent tubes forming the other circuit, the tubes being within channels in the mass. The underlying tube is pref. held in the channel by shoulders and is installed by expanding the tube in situ with high pressure hot water. To ensure exposure of the upper tubes to the sun for all the sun's movement, the front face of the mass is pref. angled at 35 degrees to the vertical. In this position the lower side of the tube is horizontal and receives the sun's rays when the sun makes less than 35 degrees to the vertical. Corrosion is inhibited. The collector is partic. useful for swimming pools and can be installed in surfaces such as pool surrounds, steps, and terraces, the upper surfaces of the tubes being made non-slip. The upper tube can be emptied and thus serves to insulate the lower tube when air temps. drop but heat can still be extracted from the accumulator mass, (e.g. paving slabs).