Trane BCHC, BCVC Field-Installing Evaporator Piping, Field-installed evaporation piping example

Installation Piping

Routing. To prevent residual or condensed refrigerant from “free-flowing” toward the compressor, install the suction line so it slopes slightly—1 inch per 10 feet of run [1 cm per 3 m]— toward the evaporator. Avoid putting refrigerant lines underground. Refrigerant condensation, installation debris inside the line, service access, and abrasion/corrosion can quickly impair system reliability.

Insulation. After operating the system and testing all fittings and joints to verify the system is leak-free, insulate the suction lines to prevent heat gain and unwanted condensation.

Components. Installing the suction line requires field installation of these components: an access port and possibly a suction filter. Position them as close to the compressor as possible.

•Access port

The access port is used to determine suction pressure and adjust the TEV. It should be located near the external equalizer line connection. This port is usually a Schraeder valve with a core.

•Suction filter

If required by the compressor unit, a replaceable-core suction filter is installed as close to the compressor unit as possible. Adding manual, ball-type shutoff valves upstream and downstream of the filter simplifies replacement of the filter core.

Field-Installing Evaporator Piping

See Figure 10 and refer to the instructions below to field-install evaporator piping.

1.Pitch the liquid line slightly—1 in./10 ft [1 cm/3 m]—so that the refrigerant drains toward the evaporator.

2.Provide one expansion valve per distributor.

3.Slightly pitch the outlet line from the suction header toward the suction riser — that is, 1 in./10 ft [1 cm/3 m] in the direction of flow. Use the tube diameter that matches the suction-header connection.

4.For the vertical riser, use the tube diameter recommended by the condensing unit manufacturer. Assure the top of the riser is higher than the evaporator coil.

5.Arrange the suction line so the refrigerant vapor leaving the coil flows downward, below the suction-header outlet, before turning upward.

6.Pitch the suction line slightly—1 in./10 ft [1 cm/3 m]—so the refrigerant drains toward the evaporator.

7.Insulate the suction line.

Figure 10. Field-installed evaporation piping example

	Evaporator Coil with
	Standard Circuiting
suction line
	liquid
sight	line
glass
thermal	solenoid filter drier
expansion	valve
valve (TXV)
distributor

40 BCXC-SVX01B-EN