Any vent materials specified must be listed by a nationally recognized test agency for use as a Category IV vent material.
The venting system must be planned so as to avoid possible contact with concealed plumbing or electrical wiring inside walls, floors or ceilings. Locate the appliance as close as possible to a chimney or gas vent.
There shall be no reductions in vent diameter.
Horizontal portions of the venting system shall be supported to prevent sagging. Horizontal runs should slope upwards not less than 1/4 inch per foot (21 mm/m) from the drain tee installed in the flue to the vertical portion of the flue or to the vent terminal on sidewall venting installations. This ensures proper removal of any condensate that may form in the flue. Follow the installation instructions from the vent material manufacturer.
Do not use an existing chimney as a raceway if another appliance or fireplace is vented through the chimney. The weight of the venting system must not rest on the unit. Adequate support of the venting system must be provided in compliance with local codes and other applicable codes. All connections should be secured and sealed per the vent manufacturers specifications.
Vent connectors serving appliances vented by natural draft shall not be connected to any portion of the Category IV positive pressure vent system used by this appliance. Connection of a negative draft flue into the positive pressure stack from this appliance may cause flue products to be discharged into an occupied living space causing serious health injury.
When a Category IV vent system is disconnected for any reason, the flue must be reassembled and resealed according to the vent manufacturer’s instructions.
The installed length of the Category IV flue from the appliance to the point of termination, outside of the building, must not
exceed a maximum of 100 equivalent feet (30.5 m) in length.
Subtract 5 feet (1.5 m) of equivalent length for each 90° elbow installed in the vent. Subtract 2 1/2 feet (0.7 m) of equivalent length for each 45° elbow installed in the vent.
The flue may terminate either vertically at the roof top or horizontally on a sidewall. See the information about the specific vent termination location for recommended location and clearances.
General Category IV Vent Termination Clearances
The vent cap should have a minimum clearance of 4 feet (1.2 m) horizontally from and in no case above or below, unless a 4 foot (1.2 m) horizontal distance is maintained from electric meters, gas meters, regulators and relief equipment.
The venting system shall terminate at least 3 feet (0.9 m) above any forced air inlet within 10 feet (3.05 m).
The venting system shall terminate at least 4 feet (1.2 m) below, 4 feet (1.2 m) horizontally from, or 1 foot (30 cm) above any door, window or gravity air inlet into any building.
Do not terminate the vent in a window well, stairwell, alcove, courtyard or other recessed area. The vent cannot terminate below grade. The bottom of the vent terminal shall be located at least 12 inches (30 cm) above grade and above normal snow levels.
To avoid a blocked flue condition, keep the vent cap clear of snow, ice, leaves, debris, etc.
Flue gases from this appliance may contain large amounts of water vapor that will form a white plume in winter. Plume could obstruct a window view.
Flue gas condensate can freeze on exterior surfaces or on the vent cap. Frozen condensate on the vent cap can result in a blocked flue condition. Flue gas condensate can cause discoloration of exterior building surfaces. Adjacent brick or masonry surfaces should be protected with a rust resistant sheet metal plate.
The manufacturer shall NOT be held liable for any personal injury or property damage due to ice formation or the dislodging of ice from the vent system or the vent termination.
Drain Tee Installation
WIRE TIE
4" Ø
CIRCULAR TRAP
TO SUITABLE DRAIN
FIG. 12 Drain Tee
A drain tee MUST be installed in the Category IV vent pipe to collect and dispose of any condensate that may occur in the vent system. The drain tee should be installed at the point where the flue turns vertical for a roof top termination or as one of the first fittings in a horizontal flue that will terminate on a sidewall. Ensure that horizontal portions of the vent are properly sloped to allow condensate to be evacuated at the drain tee. See the typical vent installation drawings. Plastic drain tubing, sized per the vent manufacturer’s instructions, shall be provided as a drain line from
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