LAARS U.H.E. - Service Manual - Manual (Page 7)

U.H.E Service Manual Page 7
Vent Tables
Notes:
1) Multiply the total number of 90° elbows (intake and exhaust) by 5 feet. Do not include the
termination fittings or 3" condensate elbow.
2) Multiply the total number of 45° elbows (intake and exhaust) by 2 ½ feet.
3) Add this to the total length of straight pipe - intake and exhaust.
4) The sum total of all elbows and straight pipe - intake and exhaust must not exceed maximum
lengths from tables above.
Example: UHE100T199
A 3" Balanced Direct vent system has 30 feet of straight exhaust pipe and 30 feet of straight intake pipe.
It has 3- 90° elbows in the exhaust and 3- 90° elbows in the intake. It has 1- 45° elbow in the exhaust and
1- 45° elbow in the intake.
Therefore:
6- 90° elbows x 5 feet = 30 feet.
2- 45° elbows x 2½ feet = 5 feet.
60 feet of straight pipe + 30 feet + 5 feet = 95 feet.
System is within “Maximum Combined Length” from table above.
Unbalanced Direct Vent Systems
Air intake CAN NOT exceed exhaust
by more than 30 feet
Power Vented Systems
PVC, CPVC
Total length of exhaust piping must not exceed
“Maximum Vent Length”
Shown below
Maximum Vent Length (feet)
Model Number 3"
UHE60T125, UHE100T150 120'
UHE60T150, UHE100T199
UHE60T199
UHE100T300
100'
80'
60'
4"
170'
150'
130'
110'
UHE100T399 50' 100'
Balanced Direct Vent Systems
PVC, CPVC
Total length of intake piping and exhaust piping
added together must not exceed “Maximum
Combined Length”
Shown below
Maximum Combined Length (feet)
Model Number 3"
UHE60T125, UHE100T150 120'
UHE60T150, UHE100T199
UHE100T250
UHE100T300
100'
80'
60'
4"
170'
150'
130'
110'
UHE100T399 50' 100'
7
UHE60T199 80' 130'
UHE100T250 80' 130'