Abstract: An evacuated tube solar thermal collector uses a set of evacuated solar thermal collector tubes in heat exchanging contact with a fluid flowing through a header tube. Two heat pipes are provided in each evacuated thermal collector tube, and the condenser ends of the heat pipes are positioned in the header tube with a spacing that provides improved heat transfer from the heat pipes to the header tube. When 14 mm heat pipes contained in 58 mm collector tubes are used in a header tube having a capacity of about 0.5 gallons with a heat transfer liquid that is flowing at a rate of about 0.3 gpm, the spacing between heat pipes in each collector tube is about 24 mm, center to center, and the spacing between corresponding heat pipes of immediately-adjacent collector tubes is about 80 mm.

Abstract: An evacuated tube solar thermal collector uses a set of evacuated solar thermal collector tubes in heat exchanging contact with a fluid flowing through a header tube. Two heat pipes are provided in each evacuated thermal collector tube, and the condenser ends of the heat pipes are positioned in the header tube with a spacing that provides improved heat transfer from the heat pipes to the header tube. When 14 mm heat pipes contained in 58 mm collector tubes are used in a header tube having a capacity of about 0.5 gallons with a heat transfer liquid that is flowing at a rate of about 0.3 gpm, the spacing between heat pipes in each collector tube is about 24 mm, center to center, and the spacing between corresponding heat pipes of immediately-adjacent collector tubes is about 80 mm.

Abstract: An evacuated tube solar thermal collector uses a set of evacuated solar thermal collector tubes in heat exchanging contact with a fluid flowing through a header tube. Two heat pipes are provided in each evacuated thermal collector tube, and the condenser ends of the heat pipes are positioned in the header tube with a spacing that provides improved heat transfer from the heat pipes to the header tube. When 14 mm heat pipes contained in 58 mm collector tubes are used in a header tube having a capacity of about 0.5 gallons with a heat transfer liquid that is flowing at a rate of about 0.3 gpm, the spacing between heat pipes in each collector tube is about 24 mm, center to center, and the spacing between corresponding heat pipes of immediately-adjacent collector tubes is about 80 mm.

Abstract: A high-efficiency solar radiation collection and conversion system is described. An array of evacuated collector tubes each includes two or more inner heat pipes that capture the solar energy and conduct it as heat through a condenser portion into a manifold that operates as part of a closed-loop circulation system. In another part of the loop, a heat exchanger transfers the heat into a hot-water holding tank or otherwise applies the heat energy in the circulating fluid.