UDX Venting Instructions
Table Of Contents
- VENTING INSTRUCTIONS FOR UNIT HEATERS (MODEL UBX: STANDARD POWER VENT BLOWER TYPE AND MODEL UDX: STANDARD POWER VENT FAN TYPE)
- GENERAL INFORMATION
- INSTALLATION
- Instructions for Commercial/Industrial Installations (Model UBX or UDX, All Unit Sizes)
- Instructions for Residential Installations (Model UDX, Unit Sizes 030, 045, 060, 075, 100, 125)
- Instructions for Commercial/Industrial or Residential Installations (Model UDX, Unit Sizes 030, 045, 060, 075, Vertical Category I)
- APPENDIX A: INSTRUCTIONS FOR ATTACHING DOUBLE-WALL TYPE B VENT PIPE TO SINGLE-WALL PIPE
- APPENDIX B: INSTRUCTIONS FOR INSTALLING FLEX-L BRANDCATEGORY III VENT PIPE
- FIGURES
- Figure 1. Roof Slope and Pitch
- Figure 2. Horizontal Vent Terminal (Commercial/Industrial Installations)
- Figure 3. Vertical Vent Terminal (Commercial/Industrial Installations)
- Figure 4. Horizontal Vent Terminal (Residential Installations)
- Figure 5. Vertical Vent Terminal (Residential Installations)
- Figure B1. Reducer and Vent Cap
- TABLES
3
CP-UBX-UDX-VENT (03-21) 1034631-0
Condensation Mitigation
• On units with long vent runs—over 50% of maximum vent length allowed—or installed in low ambient conditions
(below 50°F), it is recommended that vent pipes be fitted at the low point of the vent system with a tee, a drip leg,
and a cleanout cap to prevent any moisture in the vent pipe from entering the unit. The drip leg should be inspected
and cleaned out periodically during the heating season.
• Any length of single-wall vent pipe exposed to cold air or run through an unheated area or an area with an ambient
temperature of 50°F or less, must be insulated along its entire length with a minimum of 1/2-inch foil-faced fiberglass,
1-1/2# density insulation.
• On horizontal vent runs, the flue pipe must be pitched down toward the terminal end—1/4-inch per foot for condensate
drainage—for the entire length of the horizontal vent run.
⚠ CAUTION ⚠
• Failure to pitch the vent run properly may damage the heater due to condensate running back
into the unit.
• Exceeding vent pipe diameter and length requirements may result in condensate forming in the
vent pipe.
Vent Terminal (Type of Pipe and Vent Cap) Requirements
⚠ DANGER ⚠
• To prevent combustion products from entering the occupied space, all vent terminations must be
positioned or located away from fresh air intakes, doors, and windows. Failure to comply could
result in severe personal injury or death and/or property damage.
• Consider local snow depth conditions. The vent must be at least 6 inches (152 mm) above the
anticipated snow depth.
⚠ WARNING ⚠
• A different style vent cap could cause nuisance problems or unsafe conditions. The vent cap
must be the same size as the vent pipe.
• Do not locate a vent termination where it may cause hazardous frost or ice accumulations on
adjacent property surfaces.
• Maintain the required clearance from the wall to the vent terminal cap for stability under wind
conditions and to protect the building.
• Refer to Table 2 for horizontal vent terminals.
NOTE: Products of combustion can cause discoloration of some building finishes and deterioration
of masonry materials. Applying a clear silicone sealant that is normally used to protect concrete
driveways can protect masonry materials. If discoloration is an esthetic problem, relocate the vent
or install a vertical vent.