Lennox REAL VPC H4-3P Series

26
Branch Pipe Kit Calculation
Add .22 lb. (.09 kg) per EACH liquid line branch pipe for additional charge calculation.
Table 11. Refrigerant Charge Adjustment
Liquid Line
Pipe Size
Additional Refrigerant Per Foot of
Pipe Length lb. (kg)
1/4 in. 0.015 lb. (0.007 kg)
3/8 in. 0.040 lb. (0.018 kg)
1/2 in. 0.080 lb. (0.036 kg)
Additional Refrigerant Charge
When refrigerant piping connections have been
completed, it will be necessary to adjust the system
refrigerant charge based on the diameter and length
of the liquid line pipe between the outdoor and indoor
unit(s).
Table 11 lists the refrigerant piping sizes along with
the refrigerant adjustment required per foot of liquid
line pipe.
This system is suitable for use with R-410A
refrigerant only.
1. Calculate the additional refrigerant charge using
the diameter and length of the liquid pipe (only)
using Table 11 below.
2. Calculate the additional refrigerant charge for
each liquid line branch pipe kit.
3. If the ratio of VMDB or V33B Indoor unit capacity
exceeds 80% of all indoor units, use Table 12
to determine the additional refrigerant charge
to add. For VPC036H4M-3PD units and larger,
refer to Table 12 to know how much additional
refrigerant to add for any VRF indoor unit.
4. Total all calculations.
5. Add the calculated additional refrigerant to the
system.
Liquid Line Length Calculation
Calculate additional refrigerant charge using the diameter and length of the liquid pipe.
Table 12. Additional Charge Amount of Indoor Unit
Outdoor Unit
Model
Indoor Unit is VRF Unit lb. (kg)
Indoor Unit
is Non-VRF
Air Handler/
Furnace lb. (kg)
VVCB indoor units
exceed 80% of all
indoor units and
indoor unit amount
≥ 2
V33B indoor units
exceed 80% of all
indoor units and
indoor unit amount
≥ 2
Other
VPC018H4M-3P - 0.66 lb. (0.30 kg) 0.33 lb. (0.15 kg) -
VPC024H4M-3P 1.54 lb. (0.70 kg) 1.10 lb. (0.50 kg) 0.66 lb. (0.30 kg) -
VPC036H4M-3PS 1.65 lb. (0.75 kg) 1.52 lb. (0.69 kg) 0.66 lb. (0.30 kg) -
VPC036H4M-3PD 1.32 lb. (0.60 kg) 1.76 lb. (0.80 kg) - 0.44 lb. (0.20 kg)
VPC048H4M-3P 3.31 lb. (1.50 kg) 2.20 lb. (1.00 kg) - 0.66 lb. (0.30 kg)
VPC060H4M-3P 4.96 lb. (2.25 kg) 2.20 lb. (1.00 kg) - 0.73 lb. (0.33 kg)
Liquid Line
Pipe Size
Additional Refrigerant Per Foot of
Pipe Length lb. (kg)
5/8 in. 0.120 lb. (0.054 kg)
3/4 in. 0.181 lb. (0.082 kg)
7/8 in. 0.255 lb. (0.116 kg)
Table 13. Maximum Refrigerant Charge Amount
Outdoor Unit
Model
Maximum Refrigerant Charge
Amount lb. (kg)
VPC018H4M-3P 22.77 lb. (10.32 kg)
VPC024H4M-3P
24.80 lb. (11.25 kg)
VPC036H4M-3PS 25.00 lb. (11.34 kg)
Outdoor Unit
Model
Maximum Refrigerant Charge
Amount lb. (kg)
VPC036H4M-3PD 30.35 lb. (13.76 kg)
VPC048H4M-3P
30.35 lb. (13.76 kg)
VPC060H4M-3P 30.35 lb. (13.76 kg)
NOTE - Follow the auto charge procedure when the charging information is not available in this manual. For
example, when matching with a Non-VRF air handler or furnace with unknown coil volume and construction.