Heating, ventilation, air-conditioning, and refrigeration system with variable speed compressor

A method comprising:

• removing heat from a refrigerant using a high side heat exchanger;
• when operating in a first mode:
• directing the refrigerant from the high side heat exchanger to a load rather than the second heat exchanger;
• using, by the load, the refrigerant from the high side heat exchanger to remove heat from the space;
• and
• directing, by the load, the refrigerant away from a second heat exchanger and towards a variable speed compressor;
• when operating in a second mode:
• directing the refrigerant from the high side heat exchanger to the second heat exchanger before the refrigerant reaches the load;
• removing heat from the refrigerant using the second heat exchanger;
• directing the refrigerant from the second heat exchanger to the load;
• and
• using the refrigerant to remove heat from a space proximate the load;
• compressing the refrigerant from the load using the variable speed compressor;
• directing the compressed refrigerant to the high side heat exchanger;
• detecting a temperature of the refrigerant;
• and
• switching from operating in the first mode to the second mode in response to the detected temperature exceeding a threshold.

A system comprising:

• a high side heat exchanger configured to remove heat from a refrigerant;
• a second heat exchanger configured to remove heat from the refrigerant;
• a load configured to use the refrigerant to remove heat from a space proximate the load;
• a variable speed compressor configured to compress the refrigerant from the load and to direct the compressed refrigerant to the high side heat exchanger;
• a three-way valve configured to:
• when operating in a first mode, direct the refrigerant from the high side heat exchanger to the load rather than the second heat exchanger such that the load:
• uses the refrigerant from the high side heat exchanger to remove heat from the space;
• and
• directs the refrigerant away from the second heat exchanger and towards the variable speed compressor;
• and
• when operating in a second mode, direct the refrigerant from the high side heat exchanger to the second heat exchanger before the refrigerant reaches the load;
• a controller configured to switch the operation of the three-way valve between the first mode and the second mode;
• and
• a temperature sensor configured to detect a temperature of the refrigerant, wherein the three-way valve is further configured to switch from operating in the first mode to the second mode in response to the temperature sensor detecting a temperature of the refrigerant that exceeds a threshold.