Munchkin HIGH EFFICIENCY HEATER with the "925" Controller - Manual (Page 17)

17
VENTING
Friction Loss Equivalent in Piping and Fittings
Fittings or Piping Equivalent Feet
90 degree elbow = 5
45 degree elbow = 3
Coupling = 0
air inlet tee = 0
Plastic Pipe = 1
concentric vent kit = 3
V500 or V1000 vent kit = 0
Example: Installation requires the following material for both inlet and exhaust piping for the
Munchkin
Required: 4 Pcs. (2" or 3") 90 degree elbow (4 x 5 = 20 Equivalent Feet) = 20 Equivalent Feet
Required: 20' of (2" or 3") Plastic PVC Pipe (20 x 1 = 20 Equivalent Feet) = 20 Equivalent Feet
Total Friction Loss in Equivalent Feet (20 + 20 = 40 Equivalent Feet) = 40 Equivalent Feet
C. LONGER VENT RUNS
The connection of the air inlet and exhaust vent at the heater must remain at the standard vent size
from the unit (2" for the T50/T80) (3" for the 80M/140M/199M). If a transition is required, it must occur
at a minimum of 15 equivalent feet for both intake and exhaust. Then transition to the next size pipe.
See the friction loss equivalent table to apply longer vent runs. The overall extended combined
length of pipe on the inlet and exhaust must not exceed 125 equivalent feet total.
Example: Installation requires the following material for both the inlet and exhaust piping when
extending the vent run for the Munchkin.
3" Vented Appliance
2 Pcs. – 3" 90 degree elbow (2 x 5 = 10 Equivalent Feet) = 10 Equivalent Feet
20' of 3" Plastic PVC Pipe (20 x 1 = 20 Equivalent Feet) = 20 Equivalent Feet
Total of 3" Equivalent Piping with Fittings = 30 Equivalent Feet
Transitioning to 4" Venting
6 Pcs. – 4" 90 degree elbows (6 x 3 = 18 Equivalent Feet) = 18 Equivalent Feet
4 Pcs. – 4" 45 degree elbows (4 x 1 = 4 Equivalent Feet) = 4 Equivalent Feet
40' of 4" Plastic PVC Pipe (40 x 1 = 40 Equivalent Feet) = 40 Equivalent Feet
Total of 4" Equivalent Piping with Fittings = 62 Equivalent Feet
Total Friction Loss in Equivalent Feet for both 3" and 4"
(30 + 62 = 92 Equivalent Feet) = 92 Equivalent Feet
CAUTION
Do not exceed the 85 foot maximum requirement (intake plus exhaust piping added
together) including fitting allowance.
CAUTION
Transitioning from 2" to 3" or 3" to 4" should be done in the Vertical position to avoid
condensation blockage. If done in the horizontal position check to make sure
condensation blockage will not occur.