A suction-to-liquid line heat exchanger typically:

A suction-to-liquid line heat exchanger typically:

• A. Increases both superheat and subcooling
• B. Increases superheat but decreases subcooling
• C. Decreases superheat and subcooling
• D. No effect on superheat or subcooling

Answer: (A)

A suction-to-liquid line heat exchanger exchanges heat between the hot liquid returning from the condenser and the cooler suction gas from the evaporator. The liquid line is hot, so as it passes through the exchanger it gives up heat and becomes more subcooled (its temperature drops below the saturated liquid temperature). The suction line, meanwhile, absorbs heat from the liquid, warming the suction gas above the evaporating temperature at that pressure, which increases the measured superheat. So, both superheat and subcooling rise with this arrangement.

A suction-to-liquid line heat exchanger exchanges heat between the hot liquid returning from the condenser and the cooler suction gas from the evaporator. The liquid line is hot, so as it passes through the exchanger it gives up heat and becomes more subcooled (its temperature drops below the saturated liquid temperature). The suction line, meanwhile, absorbs heat from the liquid, warming the suction gas above the evaporating temperature at that pressure, which increases the measured superheat. So, both superheat and subcooling rise with this arrangement.