UDAP/APD/UDBP Venting Requirements

Form I-UD&APD Series-V-PV (5-17), P/N 195675R20, Page 3
2.0 Venting Requirements and Instructions - Residential Installation
A Category III vent as dened by the National Fuel Gas Code Z223.1 or CAN/CSA B149.1 and B149.2 is required
for a residential installation of a Std Power Vent fan type unit heater. Some venting requirements will vary, however,
depending on whether the vent is horizontal or vertical.
Read and follow all of the requirements and instructions in Paragraphs 2.1 through 2.7.
Residential Installation
Std Power Vent fan type unit heater - Sizes 30, 45, 60, 75, 100, 125
2.1 Type of Vent
Pipe Required
for Vent Run
Type of Pipe for Standard Horizontal Vent (Category III)
• Vent pipe approved to UL Std 1738 for Category III appliance. Do not intermix
different vent systemparts from different manufacturers in the same
venting system.
Type of Pipe for Standard Vertical Vent (Category III)
• Vent pipe approved to UL Std 1738 for Category III appliance. Do not intermix
different vent system parts from different manufacturers in the same venting
system.
TABLE 1 - Vent Pipe Diameter and Maximum Vent Length for a Heater
with either a Horizontal or Vertical Vent
Heater
Size
Vent Pipe
Diameter
Maximum
Vent Length
Equivalent Straight
Length for 90° Elbow
Equivalent Straight
Length for 45° Elbow
Field-supplied taper type
reducer required at the
venter outlet
inches mm feet M feet M feet M
30
3 76 20 6.1 3 0.9 1.5 0.5 4” to 3” (102mm to 76mm)
4 102 10 3.0 2 0.6 1 0.3 None
45
3 76 20 6.1 3 0.9 1.5 0.5 4” to 3” (102mm to 76mm)
4 102 10 3.0 2 0.6 1 0.3 None
60
3 76 30 9.1 4 1.2 2 0.6 4” to 3” (102mm to 76mm)
4 102 15 4.6 2 0.6 1 0.3 None
75 4 102 30 9.1 4 1.2 2 0.6 None
100 4 102 40 12.2 5 1.5 2.5 0.8 None
125 4 102 40 12.2 5 1.5 2.5 0.8 None
•
2.2 Vent Pipe
Diameter and Vent Length
Vent pipe diameters and maximum vent lengths are shown in TABLE 1. Minimum vent
length is 3 feet (1M). Add all straight sections and equivalent lengths for elbows. The
total must not exceed the Maximum Vent Length listed. Use only one diameter of vent
pipe on an installation.
2.3 Venter (Flue)
Outlet Diameter
Depending on the size of vent pipe (either 3 or 4 inch) as determined in Paragraph 2.2,
attach a 4” appliance adapter from Category III pipe manufacturer directly to the collar,
then use a reducer if using 3” pipe.
TABLE 2 -
Venter Outlet
Diameter
Heater Size 30 45 60 75 100 125
Outlet
Diameter
inches mm inches mm inches mm inches mm inches mm inches mm
4 102 4 102 4 102 4 102 4 102 4 102
2.4 Vent System
Sealing
Follow the Category III pipe manufacturer’s instructions for joining pipe sections. When
attaching Category III pipe to the venter outlet or the vent cap, make secure, sealed
joints following a procedure that best suits the style of Category III pipe being used.