Procom GHBVN50 Manual page 8

HORIZONTAL VENTING – COMMERCIAL
1. Horizontal commercial installations are for buildings which are not attached to living spaces. The vent may be
single wall vent material installed according to the sections General Recommendations and Requirements and
Horizontal Venting – General and Horizontal Venting − Commercial. See figures 4, 5, and 6.
2. The vent pipe diameter for horizontal commercial installations shall be 4" (102mm) on 45K Btu/hr units and
75K Btu/hr units. In most cases, a flue transition piece (supplied) is required to fit over the
outlet of the induced draft assembly on the appliance.
3. Refer to table 2 on page 6 for maximum vent connector lengths.
4. Select a wall termination point that will maintain 1/4" (6mm) rise per foot (305mm) slope of horizontal run of vent
pipe. The vent may be single wall material minimum 26 gauge galvanized steel or equivalent grade stainless steel.
Seal single wall vent material according to the section General Recommendations and Requirements. In areas
where local authorities having jurisdiction permit, a downward slope of maximum 1/4" (6mm) per foot (305mm) is
also acceptable. In such cases, the vent must be listed special vent for Category III appliances or single wall vent
pipe constructed of number 26 gauge galvanized steel or equivalent grade stainless steel. Seal single wall vent
material according to the section General Recommendations and Requirements. Condensate drainage can be
collected in a tee pipe section (figure 4) or allowed to drip through the vent termination, if permitted by local
authorities.
5. For upward sloped vent a condensate tee and drain must be installed within the first 5 feet (2m) from the unit
heater to protect the appliance. If a flexible condensate drain line is used, the drain line must include a loop filled
with water to prevent combustion products from entering the structure. If the unit is shut down for an extended
period of time and will be exposed to sub−freezing temperatures, the condensate may freeze.
Fig.4
Fig.5
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