Trane R Series, Installation Operation & Maintenance

Page: 49 / 188

RLC-SVX07A-EN 49
Installation - Remote Condenser
NOTE: Table 7 states the equivalent length, in feet, for various non-ferrous
valves and fittings. When calculating the equivalent length, do not include
piping of the unit. Only field piping must be considered.
Liquid Line Sizing
The Trane Company recommends that the liquid line diameter be as small as
possible, while maintaining acceptable pressure drop. This is necessary to
minimize refrigerant charge. The total length between the components must
not exceed 200 actual feet or 300 equivalent feet. Refer to
Table 11 for the
maximum allowable liquid line drainable to the evaporator, listed in actual feet,
for applications with the condenser above the unit.
Liquid risers in the system will require an additional 0.5 psig pressure drop
per foot of vertical rise. The liquid line risers must not exceed 15 feet from the
base of the air-cooled condenser. The liquid line does not have to be pitched.
Liquid line sizing for these units are shown in
Tables 7 to 9 .
Liquid lines are not typically insulated. However, if the lines run through an
area of high ambient temperature (eg. boiler room), subcooling may drop
below required levels. In these situations, insulate the liquid lines.
NOTE: In case of power failure to the expansion valve, the amount of liquid
refrigerant contained in the liquid line above the evaporator must not exceed
the holding capacity of the evaporator. Therefore, the actual length of the
drainable liquid in the liquid line is restricted to the above values.
Table 7 Equivalent Lengths of Non-ferrous Valves and Fittings
LINE SIZE
Inches OD GLOBE
Valve (Ft) ANGLE
Valve (Ft) SHORT
Radius Elbow (Ft) LONG
Radius Elbow (Ft)
1 1/8 87 29 2.7 1.9
1 3/8 102 33 3.2 2.2
1 5/8 115 34 3.8 2.6
2 1/8 141 39 5.2 3.4
2 5/8 159 44 6.5 4.2
3 1/8 185 53 8 5.1
3 5/8 216 66 10 6.3
4 1/8 248 76 12 7.3
Reproduced by permission of the Air Conditioning and Refrigeration Institute.