Suction Line Diagram. Pressure drop from the evaporator to the compressor suction exists because of the following. There should be no high spots where air can collect and cause the pump to lose its prime.
The suction pipe should be exactly horizontal or with a uniform slope upward from the sump to the pump as illustrated in figcpp7. Suction is firmly planted in hydrology as is evidenced with its extensive use as an adjective in pump ter minology ie suction connection suction line suction lift etc. Pressure drop allowance for the suction line is the balance of economic considerations of the size of suction line power consumption compressor size suction line insulation and installation costs.
This is a 3 ton split system with a 38 liquid line and a ¾ suction line 50 foot long.
If the rise to the main hot gas line is over 4 or 5 ft the branch lines should connect to the main line above the center of the main line piping. A liquid line supplies liquid refrigerant from the condenser to a thermal expansion tx valve adjacent to the coil. The figure on the following page shows the difference between 0 f and 15 f superheat. This is the conventional method for sizing and is accepted practice throughout the industry ashrae.