What type of compressors can overheat under deep vacuum conditions?

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Multiple Choice

What type of compressors can overheat under deep vacuum conditions?

When suction pressure drops toward a deep vacuum, the compressor has to raise gas from a much lower starting pressure to the discharge pressure, which means a higher compression ratio and higher discharge temperature. In a hermetic compressor, the motor and the compressor are enclosed in a sealed shell and rely on the refrigerant to carry away heat. Under deep vacuum, the refrigerant is less dense and its ability to remove heat from the shell is reduced, so heat builds up in the motor and compressor. Because the whole unit is sealed and not easily cooled from the outside, overheating becomes more likely. Other compressor types often have more direct cooling paths or serviceable cooling and lubrication arrangements, so they’re less susceptible in deep-vacuum conditions.

When suction pressure drops toward a deep vacuum, the compressor has to raise gas from a much lower starting pressure to the discharge pressure, which means a higher compression ratio and higher discharge temperature. In a hermetic compressor, the motor and the compressor are enclosed in a sealed shell and rely on the refrigerant to carry away heat. Under deep vacuum, the refrigerant is less dense and its ability to remove heat from the shell is reduced, so heat builds up in the motor and compressor. Because the whole unit is sealed and not easily cooled from the outside, overheating becomes more likely. Other compressor types often have more direct cooling paths or serviceable cooling and lubrication arrangements, so they’re less susceptible in deep-vacuum conditions.

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