Lennox VPB Series, Installation & Operation Instructions

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25
Incoming Liquid Line Pipe
Only use this pipe size to
determine the amount of
additional refrigerant charge for
EACH liquid line branch pipe.
Branch Pipe Kit Calculation
Add 1.60 ft. (488 mm) per EACH liquid line branch pipe (incoming pipe size only) for additional charge calculation.
Example: The branch pipe kit
has an incoming pipe size of
7/8” and outgoing pipe sizes
of 3/8” and 5/8”. Use only the
incoming pipe size of 7/8”
to calculate the additional
refrigerant charge for this
branch pipe kit.
Refrigerant Flow
1/4 in.
1/2 in. 15 ft.
1/4 in.
1/2 in. 15 ft.
3/8 in.
5/8 in. 20 ft.
3/8 in.
5/8 in. 20 ft.
3/8 in.
5/8 in. 20 ft.
9k
15k
36k
48k
48k
12k
24k
36k
36k
48k
1/4 in.
1/2 in. 15 ft.
3/8 in.
5/8 in. 20 ft.
3/8 in.
5/8 in. 30 ft.
3/8 in.
5/8 in. 15 ft.
3/8 in.
5/8 in. 20 ft.
5/8 in.
7/8 in.
1 - 1/8 in.
50 ft.
5/8 in.
7/8 in.
1 - 1/8 in.
40 ft.
7/8 in.
1
-
1/8 in.
1 - 3/8 in.
50 ft.
5/8 in.
7/8 in.
1 - 1/8 in.
10 ft.
3/4 in.
1 - 1/8 in.
1
-
3/8 in.
4 ft.
MS06
MS08
10 Ton 16 Ton
Refrigerant Charge Amount Calculation
1. Additional refrigerant charge amount of outdoor units = 6.39+15.87 = 22.26 lbs.
2. Additional refrigerant charge amount of MS boxes = 2.2+4.41 = 6.61 lbs.
3. Additional refrigerant charge amount of pipes = (0.12*10+0.181*4) + (0.255*(50+1.6*2)+0.12*50+0.12*40) +
[0.015*(15+15+15) + 0.04*(20+20+20+20+30+15+20)] = 32.79 lbs.
4. Additional refrigerant charge amount of indoor units = 15.12 lbs.
The total additional refrigerant charge amount = 22.26+6.61+31.95+15.12 = 76.78 lbs.
Refrigerant Charge Calculation Example