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.