Lennox HS29-072 Installation Instructions Manual page 11

At 45°F Evaporating Temperature and 125°F Condensing Temperature
40 30 20 15
30
25
20
15
12.5
10
9
8
7
6
5
4
3
2
1.5
1.0
.9
.8
.7
40 30 20 15
To use this chart, first find the capacity (tons) on the left side of chart. To find the pipe size, proceed right to the smallest pipe
size. You can then determine the pressure drop (vertical at line) and velocity (diagonal lines) for the pipe size you selected.
For example, for (2) 7.5 ton units, select 5/8 in. O.D. line.
HCFC 22 Liquid Line Pressure Drop/Velocity
HCFC 22 Liquid Line Pressure Drop (lbs./100 Feet)
10 9 8 7 6 5 4 3
EXAMPLE:
10−TON UNIT
5/8 IN. O.D. LINE 4.25
PSIG DROP PER 100
FEET
275 FPM VELOCITY
10 9 8 7 6 5 4 3
HCFC 22 Liquid Line Pressure Drop (lbs./100 Feet)
Figure 10
Page 11
2 1.5 1.0 .9 .8 .7 .6
2 1.5 1.0 .9 .8 .7 .6
NOTE − Shaded area represents unacceptable velocity range.
.5 .4 .3 .2
30
25
20
15
10
9
8
7
6
5
4
3
2
1.5
1.0
.9
.8
.7
.5 .4 .3 .2