Abstract: A solar water heating system is provided which includes a domestic pressurized water tank with a non-pressurized solar water storage tank placed directly atop it. Because the solar loop is non-pressurized and because the fluid (water) used in said solar loop is non-toxic, a single-wall heat exchanger may be used. Draindown is accomplished by the use of a vacuum relief valve which permits draindown whenever the pump in the solar loop is not active. A differential thermostat, in conjunction with a sensor at the collector and a sensor at the domestic water tank, senses temperature variation and activates the pump in the solar loop and the pump in the heat exchanger loop whenever a given temperature variation occurs. High efficiency is achieved through the proper placement of extraction and expulsion pipes in the domestic water storage tank, as well as the placement of the pumps within the center of the solar water storage tank and the use of a single-wall heat exchanger.

Abstract: A portable hoist is provided and is adapted to be used for lifting and moving heavy objects or loads such as automobile engines, etc. The hoist is designed such that it is portable, in that it is fully foldable into a small, compact unit for storage or transport. The hoist is further mounted on rollable wheels, thereby permitting movement when loaded.