Method of operating a refrigerant compressor

A vapor compression system configured for environmentally conditioning a space comprising:

• a compressor, an indoor heat exchanger, and outdoor heat exchanger, and an expansion valve disposed in a closed loop in operable communication with one another, wherein the indoor heat exchanger is disposed in thermal communication with the space,
• a variable speed drive disposed in operable communication with the compressor and configured for adjusting a speed of the compressor,
• a controller in operable communication with the variable speed drive and a sensor configured to determine a condition of a parameter of the closed loop, wherein the controller is configured to determine a demand speed of the compressor based at least in part on a user selected target value for an environmental condition within the space, determine a maximum allowable compressor speed of the compressor based at least in part on the condition of the parameter, reduce the speed of the compressor from a first speed to a second speed corresponding to the maximum allowable compressor speed when the maximum allowable compressor speed is less than the first speed, maintain the speed of the compressor below the first speed when the maximum allowable compressor speed is greater than the first speed, and
• operate the compressor at the demand speed once a startup condition is satisfied.