The compressor and metering device split the system in two. The high side holds hot discharge gas, the condenser and the liquid line; the low side holds the evaporator and suction line back to the compressor. Gauge sets follow the split, with the red hose on the high side and the blue on the low. Techs talk about high side and low side readings as a pair, because the two numbers together tell the story.
Low side is low and high side is high, that smells like a restriction, feel the drier and the metering device.
Also heard as
- discharge side
Related terms
Head pressure
The compressor discharge or condensing pressure of a refrigeration system.
Condenser
The heat exchanger where hot, high-pressure refrigerant gives up heat and condenses back to a liquid.
Gauges
The manifold gauge set techs connect to service ports to read system pressures, saturation temperatures and charge.
Metering device
The restriction that drops refrigerant from high side to low side pressure and controls how much enters the evaporator.