Abstract: A system for controlling the climate of a cab of an autonomously operable machine when operated unmanned, and related machine. The system includes at least one temperature sensor to generate a signal indicative of the temperature within the cab and a controller configured to receive the signal as well as determine if the machine is being operated unmanned. If the machine is being operated unmanned, the controller is further configured to generate machine control commands to turn on the cab cooling device or cab heating device and adjust a blower as needed to maintain the cab temperature above the minimum and/or below the maximum temperature thresholds.

Abstract: A controller-implemented system and method for automated control of a climate control system of a machine when being operated unmanned. The method includes utilizing at least one temperature sensor to determine the temperature of the machine cab, and, if the machine is being operated unmanned, generating signals to turn on the blower to a minimum setting, comparing the sensed temperature to at least one of minimum and maximum temperature thresholds, and generating signals to turn on the cab cooling device or cab heating device and adjusting the blower to maintain the cab temperature above the minimum and/or below the maximum temperature thresholds.

Abstract: A controller for a heat, ventilation, and air conditioning (HVAC) unit may comprise a compressor control signal output; a condenser fan control signal output; a pressure sensor input that receives information regarding an output pressure of the compressor; a temperature input that receives information regarding ambient temperature; a processor coupled to the compressor control signal output, the condenser fan control signal output, the first pressure sensor input, and the temperature input; and a computer-readable memory that stores instructions. The processor may cause the controller to: turn on the compressor via the compressor control signal output based on a request for air conditioning, select a condenser fan speed, from condenser fan control data stored in the computer readable memory, based on the ambient temperature and an output pressure of the compressor, and set a speed of the condenser fan to the selected condenser fan speed via the condenser fan control signal.

Abstract: An air conditioning system for an operator cab of machine includes a condenser, an evaporator, a compressor and a controller operable to control an operation of the compressor. The controller maintains a pre-defined compressor run time when the compressor is in an ON state. The controller is configured to determine a temperature of the evaporator and compare it with at least one of a first lower threshold temperature value and a second lower threshold temperature value being less than the first lower threshold temperature value. The controller outputs a compressor control command signal to change the operational state of the compressor to an OFF state when the determined temperature of the evaporator is less than at least one of the first lower threshold temperature value for a first time period, and the second lower threshold temperature value for a second time period being less than the first time period.

Abstract: A heating, ventilation and air conditioning (HVAC) unit may both save energy and monitor for fault conditions by monitoring an ambient air temperature, compressor discharge pressure, and evaporator suction pressure and using these measurements to identify known conditions. Compressor discharge pressure and ambient temperature may be used as indices to a look up table or map to determine a speed and direction for a condenser fan. In some cases, the look up table may direct the fan to be reversed at full power in an attempt to remove a suspected buildup of dirt or debris at the condenser. Ambient temperature and evaporator suction pressure may be monitored for a combination of conditions that indicate low refrigerant levels, allowing the compressor to be turned off before damage to the compressor is sustained.

Abstract: A modular HVAC unit may incorporate a hydraulically powered refrigerant compressor to more efficiently provide air conditioning to an operator cab of a work machine. The refrigerant compressor may be fluidly powered by a hydraulic fluid motor fluidly coupled to and driven by a variable displacement pump. An electronic controller may be configured to vary hydraulic pump flow rates to the motor via use of a proportioning control valve to maintain a desired evaporator performance temperature. The control valve may be configured to stop the HVAC unit whenever a backup system may be used, when a discharge is to be prevented, and/or when operator air-conditioning is not desired. The controller may monitor evaporator performance via a fin temperature sensor, and may send appropriate signals to the control valve for modulating hydraulic flows through the motor. The arrangement may provide a significant increase in the life and performance of the compressor.