Abstract: A radiant energy collecting/emitting element, including an absorber plate with a cylindrical bore through which a tool comprising a mandrel having lands is drawn to form helical grooves. A tube formed of a ductile metal dissimilar to the plate metal is placed within the bore and a second tool is then drawn through the tube. The second tool has an outer diameter greater than the inner diameter of the tube so that the tube is radially expanded outwardly into intimate surface contact with the bore. During expansion the material of the tube cold flows into the grooves to form lands which lock the tube against displacement relative to the plate.

Abstract: An air conditioning system having a refrigerant system including a compressor, a condenser coil and fan, and an evaporator coil and fan and including a control system which comprises an electrically operated timer switch for alternately connecting the compressor for a preselected first period of time and disconnecting said compressor for a preselected second period of time, a thermostat for starting the timer when the sensed ambient temperature falls outside a preselected temperature range and for stopping and overriding the timer to disconnect the compressor from the terminals when the ambient temperature falls within the preselected temperature range. The evaporator fan continues to run after the compressor has been turned off thereby continuing to provide additional air cooling without the expenditure of energy to run the compressor.

Abstract: A fluid tank, with an inlet and an outlet, is provided with first heating means for heating the fluid in the tank to a first temperature and a second heating means for heating the fluid to a second temperature which is lower than the first temperature. A thermostatic switch is disposed to be responsive to the temperature of the fluid in the tank outlet to enable the first heating means only when the temperature in the outlet is above a predetermined level. The fluid in the tank is maintained at a low temperature during periods of non-use, and at an increased temperature only during periods of use, thus economizing on heating energy.

Abstract: An air diffuser embodying a housing, defining an air chamber, adapted to be mounted in a suitable opening in a wall or ceiling of a room, and having an air inlet in one side thereof adapted to be connected to an air duct, or the like, and an air outlet on the opposite side thereof, with a substantially flat air deflector unit extending across the air outlet and defining the outer face of the air diffuser remote from the air inlet, and deflector unit having a plurality of adjustable modules having openings constituted and arranged therein in such a manner as to cause air discharged from the outlet to flow laterally away from the diffuser along the wall or ceiling in which the diffuser is mounted.