Abstract: A coaxial ventilator exchanges atmosphere between parts of a building that are at differing heights. The coaxial ventilator includes an outer conduit that extends from an upper end thereof downward to a lower end thereof. The outer conduit surrounds an inner conduit that extends substantially the entire length of the outer conduit. Both the outer and inner conduits are open at their respective upper ends and lower ends. Temperatures of atmosphere both surrounding and within the outer conduit and the inner conduit induce an exchange of atmosphere between the coaxial ventilator and surrounding atmosphere.

Abstract: A coaxial ventilator exchanges atmosphere between parts of a building that are at differing heights. The coaxial ventilator includes an outer conduit that extends from an upper end thereof downward to a lower end thereof. The outer conduit surrounds an inner conduit that extends substantially the entire length of the outer conduit. Both the outer and inner conduits are open at their respective upper ends and lower ends. Temperatures of atmosphere both surrounding and within the outer conduit and the inner conduit induce an exchange of atmosphere between the coaxial ventilator and surrounding atmosphere.

Abstract: A coaxial ventilator exchanges atmosphere between parts of a building that are at differing heights. The coaxial ventilator includes an outer conduit that extends from an upper end thereof downward to a lower end thereof. The outer conduit surrounds an inner conduit that extends substantially the entire length of the outer conduit. Both the outer and inner conduits are open at their respective upper ends and lower ends. Temperatures of atmosphere both surrounding and within the outer conduit and the inner conduit induce an exchange of atmosphere between the coaxial ventilator and surrounding atmosphere.

Abstract: A cooling system including a ventilator that exchanges atmosphere between parts of a building that are at differing heights. The ventilator includes an outer conduit that extends from an upper end thereof downward to a lower end thereof. An inner conduit extends substantially the entire length of the outer conduit. Both the outer and inner conduits are open at their respective upper ends and lower ends. Temperatures of atmosphere both surrounding and within the outer conduit and the inner conduit induce an exchange of atmosphere between the ventilator and surrounding atmosphere.

Abstract: A solar heating system comprising: at least one collector array panel adapted for being located on a sloping roof of a building, the collector array panel including at least one thermosyphon heating tube; a liquid source adapted for supplying liquid to said heating tube of said collector array panel; and a cut-off valve coupled both to: a mains supply for receiving liquid therefrom; and said liquid source for automatically blocking liquid received by said cut-off valve from said mains supply from filling said heating tube of said collector array panel whenever such filling could damage said collector array panel, wherein said cut-off valve operates automatically responsive to light and/or temperature for blocking filling of said heating tube of said collector array panel whenever such filling could damage said collector array panel.

Abstract: A coaxial ventilator exchanges atmosphere between parts of a building that are at differing heights. The coaxial ventilator includes an outer conduit that extends from an upper end thereof downward to a lower end thereof. The outer conduit surrounds an inner conduit that extends substantially the entire length of the outer conduit. Both the outer and inner conduits are open at their respective upper ends and lower ends. Temperatures of atmosphere both surrounding and within the outer conduit and the inner conduit induce an exchange of atmosphere between the coaxial ventilator and surrounding atmosphere.

Abstract: Disclosed is a solar water-heating-and-cooling system (20) that included a collector array panel (32, 36) having thermosyphon coaxial heating/cooling tubes (52). The disclosed system (20) avoids damaging the collector array panel (32, 36) by filling the tubes (52): 1. only when environmental conditions ensure that damage won't occur,—and/or 2. using a filling method that ensures that damage won't occur. Thermosyphon coaxial heating/cooling tubes (52) disclosed herein may be open both at their upper and lower ends. Tubes (52) that are open at their, lower end enables capturing radiative cooling of liquid present within the tubes (52). A cold water storage tank (46) and cold radiator array (48) included in the water-heating-and-cooling system (20) permits preserving and using the radiative 'cooling. Also disclosed are coaxial tubes (104, 106) that enable simpler and easier installation of the system (20), and also provide a less architecturally intrusive system (20).

Abstract: A coaxial ventilator exchanges atmosphere between parts of a building that are at differing heights. The coaxial ventilator includes an outer conduit that extends from an upper end thereof downward to a lower end thereof. The outer conduit surrounds an inner conduit that extends substantially the entire length of the outer conduit. Both the outer and inner conduits are open at their respective upper ends and lower ends. Temperatures of atmosphere both surrounding and within the outer conduit and the inner conduit induce an exchange of atmosphere between the coaxial ventilator and surrounding atmosphere.

Abstract: A solar liquid-heating-and-cooling system (20) includes: 1. a hot-liquid storage-tank (22); 2. a hot-liquid manifold-tank (26); 3. a coaxial heating-and-cooling-tube (24) that connects downward from the hot-liquid storage-tank (22) to the hot-liquid manifold-tank (26); 4. a double layer heating-and-cooling collector-array-panel (32) located beneath the hot-liquid manifold-tank (26), the panel (32) including, connected to the hot-liquid manifold-tank (26): a. an upper layer of glazed heating-tubes (36); and b. a lower layer of unglazed cooling-tubes (56); 5. parabolic-trough mirror reflectors (64) that are located between the upper and lower layers of tubes (36, 56); 6. cold-liquid manifold-tank (92) located below the panel (32) connected to lower ends both of the glazed heating-tubes (36) and of the unglazed cooling-tubes (56); 7. a cold liquid storage tank (98); and 8.

Abstract: A coaxial ventilator (20) exchanges atmosphere between parts of a building (22) that are at differing heights. The coaxial ventilator (20) includes an outer conduit (24) that extends from an upper end (42) thereof downward to a lower end (44) thereof. The outer conduit (24) surrounds an inner conduit (62) that extends substantially the entire length of the outer conduit (24). Both the outer and inner conduits (24, 62) are open at their respective upper ends (42, 66) and lower ends (44, 68). Temperatures of atmosphere both surrounding and within the outer conduit (24) and the inner conduit (62) induce an exchange of atmosphere between the coaxial ventilator (20) and surrounding atmosphere.

Abstract: A coaxial ventilator (20) exchanges atmosphere between parts of a building (22) that are at differing heights. The coaxial ventilator (20) includes an outer conduit (24) that extends from an upper end (42) thereof downward to a lower end (44) thereof. The outer conduit (24) surrounds an inner conduit (62) that extends substantially the entire length of the outer conduit (24). Both the outer and inner conduits (24, 62) are open at their respective upper ends (42, 66) and lower ends (44, 68). Temperatures of atmosphere both surrounding and within the outer conduit (24) and the inner conduit (62) induce an exchange of atmosphere between the coaxial ventilator (20) and surrounding atmosphere.

Abstract: A coaxial ventilator exchanges atmosphere between parts of a building that are at differing heights. The coaxial ventilator includes an outer conduit that extends from an upper end thereof downward to a lower end thereof. The outer conduit surrounds an inner conduit that extends substantially the entire length of the outer conduit. Both the outer and inner conduits are open at their respective upper ends and lower ends. Temperatures of atmosphere both surrounding and within the outer conduit and the inner conduit induce an exchange of atmosphere between the coaxial ventilator and surrounding atmosphere.

Abstract: A coaxial ventilator (20) exchanges atmosphere between parts of a building (22) that are at differing heights. The coaxial ventilator (20) includes an outer conduit (24) that extends from an upper end (42) thereof downward to a lower end (44) thereof. The outer conduit (24) surrounds an inner conduit (62) that extends substantially the entire length of the outer conduit (24). Both the outer and inner conduits (24, 62) are open at their respective upper ends (42, 66) and lower ends (44, 68). Temperatures of atmosphere both surrounding and within the outer conduit (24) and the inner conduit (62) induce an exchange of atmosphere between the coaxial ventilator (20) and surrounding atmosphere.

Abstract: Disclosed is a solar water-heating-and-cooling system (20) that included a collector array panel (32, 36) having thermosyphon coaxial heating/cooling tubes (52). The disclosed system (20) avoids damaging the collector array panel (32, 36) by filling the tubes (52): 1. only when environmental conditions ensure that damage won't occur,—and/or 2. using a filling method that ensures that damage won't occur. Thermosyphon coaxial heating/cooling tubes (52) disclosed herein may be open both at their upper and lower ends. Tubes (52) that are open at their, lower end enables capturing radiative cooling of liquid present within the tubes (52). A cold water storage tank (46) and cold radiator array (48) included in the water-heating-and-cooling system (20) permits preserving and using the radiative ‘cooling. Also disclosed are coaxial tubes (104, 106) that enable simpler and easier installation of the system (20), and also provide a less architecturally intrusive system (20).

Abstract: A collector core (104) for a solar water-heating-system (100) includes a plurality of heat-absorbing pipes (108) each of which surrounds a cooler-water return-pipe (116). The heating-pipes (108) may connect directly to an insulated hot-water storage-tank (104) from which cooler water descends through the return-pipes (116) into the heating-pipes (108). Upon reaching the end of the return-pipes (116), the cooler water flows outward into the space between the surrounding heating-pipes (108) and the inner return-pipes (116). Upon warming, water between the two pipes (108, 116) rises upward back to the hot-water storage-tank (104) thus completing the thermosyphon flow cycle. Preferably, the inner return-pipe (116) is made of polyvinyl chloride ("PVC"), polybutelene ("PB"), or other compressible material which permits collector core (106) operation both in freezing and non-freezing environments.

Abstract: A collector core for a solar water-heating-system includes a plurality of heat-absorbing pipes each of which surrounds a cooler-water return-pipe. The heating-pipes may connect directly to an insulated hot-water storage-tank from which cooler water descends through the return-pipes into the heating-pipes. Upon reaching the end of the return-pipes, the cooler water flows outward into the space between the surrounding heating-pipes and the inner return-pipes. Upon warming, water between the two pipes rises upward back to the hot-water storage-tank thus completing the thermosyphon flow cycle. Preferably, the inner return-pipe is made of polyvinyl chloride (“PVC”), polybutelene (“PB”), or other compressible material which permits collector core operation both in freezing and non-freezing environments. Alternatively, the collector core may be added to an existing solar water-heating panel to improve its operation.