The Trane Company

James F Saunders

Robert E Krocker

A control and method for defrosting the outdoor heat exchanger of an air source heat pump. A defrost cycle is initiated when ice and frost have accumulated on the outdoor heat exchanger sufficiently such that, as a function of the indoor temperature of a comfort zone, the maximum permissible heat transfer degradation at which the efficiency and reliability of the temperature conditioning system are optimized, has occurred. Heat transfer degradation is determined from the outdoor ambient air temperature and the temperature of either the outdoor heat exchanger, or the compressor suction line. If the temperature of the outdoor heat exchanger or the suction line is less than a predetermined value, a deferred defrost cycle is initiated wherein the defrost cycle starts after a fixed time interval has elapsed. The defrost cycle is terminated when the relative tempratures of the outdoor heat exchanger and the outdoor ambient air indicate that sufficient frost is melted from the heat exchanger to insure adequate time between successive defrost cycles for optimizing the efficiency and reliability of the system, or after a predetermined time interval has elapsed, whichever condition occurs first.

Control and method for defrosting a heat pump outdoor heat exchanger

Apparatus and method for controlling a temperature conditioning system in which a plurality of stages of temperature conditioning apparatus may be selectively energized to meet a temperature conditioning demand in a comfort zone into which the flow of temperature conditioned air is varied in response to temperature therein. Control means are operative to determine the differential temperature of the return air and the supply air and to energize and de-energize stages of temperature conditioning in response thereto. Means are provided to measure the outdoor ambient temperature, thereby enabling the control means to determine the heating capacity of an ambient air source heat pump relative to the outdoor ambient air temperature, and to energize and de-energize heating stages as appropriate, to meet heating demand.

Apparatus and method for controlling a variable air volume temperature

Apparatus for rotating a fluid impeller of a centrifugal or axial flow fan, at multiple speeds. A fan is provided with a first and a second electric motor for drivingly rotating a fluid impeller at relatively fast and slow speeds, respectively. The rotor of the first motor directly drives the fluid impeller; the second motor is connected to the impeller shaft of the fan through a belt drive, with pulleys sized to reduce the impeller's rotational speed relative to that of the second motor. Only one of the motors is provided with a start winding. Control means selectively energize the first and second motors, and are operative to energize the one motor long enough to bring the other motor up to operating speed.

Multi-speed fan assembly

A control and method for defrosting the outdoor heat exchanger of an air source heat pump. A defrost cycle is initiated when ice and frost have accumulated on the outdoor heat exchanger sufficiently such that, as a function of the indoor temperature of a comfort zone, the maximum permissible heat transfer degradation at which the efficiency and reliability of the temperature conditioning system are optimized, has occurred. Heat transfer degradation is determined from the outdoor ambient air temperature and the temperature of either the outdoor heat exchanger, or the compressor suction line. If the temperature of the outdoor heat exchanger or the suction line is less than a predetermined value, a deferred defrost cycle is initiated wherein the defrost cycle starts after a fixed time interval has elapsed. The defrost cycle is terminated when the relative temperatures of the outdoor heat exchanger and the outdoor ambient air indicate that sufficient frost is melted from the heat exchanger to insure adequate time between successive defrost cycles for optimizing the efficiency and reliability of the system, or after a predetermined time interval has elapsed, whichever condition occurs first.

Apparatus and method for controlling one or more electrically powered devices. A control for a temperature conditioning system is shown which is operative to monitor the electrical current supplied to component devices, i.e., compressors, auxiliary heating elements, indoor fan, and outdoor fan; and to cause an indicator means to indicate that one or more of the devices has failed to operate in a manner consistent with the controlled status of the system. If a failure is detected, control means are operative to lock out one or more of the devices from operation.

Current monitoring control for electrically powered devices

Method and apparatus are disclosed for controlling and selectively setting back the comfort condition, such as temperature, within a conditioned zone utilizing a system which includes both preferred and back-up conditioning means, the former exhibiting more favorable energy consumption characteristics than the latter. The system is operable in both a normal mode, and in an economy mode during which the comfort condition is permitted to degrade toward an economy level during a setback period of predetermined duration. Selective operation of the preferred and back-up conditioning means is effected in order to minimize energy consumption during both modes and especially during the time that the comfort condition is restored to the normal level from the economy level. In a preferred embodiment, the preferred conditioning means comprise an electrically operated heat pump of the vapor compression type and the back-up conditioning means comprise electrical resistance-type heating means. A second aspect of the present invention involves the provision of a system which includes a refrigeration system for cooling a conditioned zone in conjunction with economizer means for supplying cool ambient air to the conditioned zone during those times when it is available and wherein operation thereof is effected in both normal and economy cooling modes so as to minimize the overall energy consumption of the system.

Method and apparatus for controlling comfort conditions including setback

Herein is disclosed an electronically controlled apparatus for accurately charging and/or venting refrigerant for an air conditioning system having an air cooled condenser and capillary tube control. The system includes means for stabilizing the sensed pressure values, means for rapidly charging a refrigeration system having a gross undercharge, means for automatically terminating the operation of the charge adjuster and means utilizing condenser heat to increase the speed at which refrigerant may be added to the refrigeration apparatus.

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Onalaska, WI, United States of America

James F Saunders