Abstract: An apparatus and method for exchanging air within building in order to exhaust air contaminated with radon gas or other pollutants. The apparatus includes a heat reclaim exchanger to recapture building heat which is dimensioned to be mountable between standard spaced and sized floor joists of a dwelling basement ceiling. A solar panel is used to produce electric power for system operation and cooperates with a trickle charge unit including a storage battery to provide power when there is insufficient light energy available to operate the device. A control unit operates one or more fans or blowers to provide a positive differential pressure within a basement area with respect to outside air pressure so as to inhibit and arrest the influx of radon or other gaseous pollutant into the basement or other confined space of device use.

Abstract: A solar collector-skylight assembly having movable parabolic concentrators wherein, in one position the parabolic concentrators direct solar energy to a collector to heat fluid circulating therethrough to thereby provide a solar heater; and when the concentrators are moved to another position, the assembly functions as a skylight wherein the solar energy is allowed to pass through the collector, to thereby illuminate the interior of a building upon which the solar collector-skylight assembly is mounted.

Abstract: A solar concentrator is provided having means allowing for deformation and precise adjustment of a cylindrical parabolic solar energy reflecting surface of the concentrator. The aforesaid means produces a geometrically correct concentrator surface which can be adjusted after fabrication to provide a sharp solar image on the receiver tube.