Procom GHBVN50 Manual page 6

GENERAL RECOMMENDATIONS AND REQUIREMENTS
NOTE: The vent is a passageway, vertical or nearly so, used to convey flue gases from an appliance, or its vent connector,
to the outside atmosphere. The vent connector is the pipe or duct that connects a fuel−gas burning appliance to a vent or
chimney.
Unit heaters must be vented in compliance with ANSI Z223.1, section 5.3 and CSA−B149 for installation compliance codes,
or applicable provisions of local building codes, and the following instructions.
A metal stamped/extruded transition is supplied with this certified unit. It must not be modified or altered and must be
installed on the outlet of the combustion air inducer assembly prior to the installation of the vent connector. Failure to
comply with this requirement will void the certification of the unit by the approval agencies. Single wall vent material
shall have all seams and joints sealed with pressure sensitive aluminum tape or silicone rubber sealant. Aluminum tape
must meet the provisions of SMACNA AFTS−100−73 Standards. The aluminum tape has a temperature rating of 400°F
(204°C). Silicone rubber sealant must have a temperature rating of 482°F (250°C), For example, Dow Corning RTV−736 or
equivalent. All joints shall be secured with at least two corrosion resistant screws. All accessible joints must be checked for
gas tightness after installation.
VERTICAL VENTS USING METAL VENT PIPE –
COMMERCIAL AND RESIDENTIAL INSTALLATIONS
These compact unit heaters are listed as Category 1 appliances for vertical vent installations.
1. These unit heaters are to be used with NFPA− or ANSI− approved chimneys or U.L. listed type B−1 gas vents, single
wall metal pipe, or listed chimney lining system for gas venting where applicable, as well as the modifications and
imitations listed in figure 3. Seal single wall vent material according to section General Recommendations and
Requirements.
2. The vent connector shall be 4" (102mm) diameter on 45K Btuh units and 75K Btuh units. In all cases, a flue transition
piece (supplied) is required to fit over the outlet of the induced draft assembly on the appliance.
3. Keep the vent connector runs as short as possible with a minimum number of elbows. Refer to the current editions
of ANSI Z223.1, or CSA−B149 for installation compliance codes for maximum vent and vent connector lengths.
Horizontal run of the vent connector from the induced draft blow to the chimney/vent cannot exceed the values in
table 2. Single wall vent connector shall not be insulated.
4. When the length of a single wall vent connector, including elbows, exceeds 5 feet (2m), the vent connector shall
be insulated along its entire length with a minimum of 1/2" (15mm) thick foil faced fiberglass 1−1/2# density
insulation. If a single wall vent connector is used in an unheated area it shall be insulated. Failure to do so will
result in condensation of flue gases.
5 . The unit may be vented vertically as a single appliance or as a common vent with other gas−fired appliances. In
common venting situations, vent connectors for other appliances must maintain a 4" (102mm) vertical separation
between the vent connectors. Refer to common venting tables in the current editions of ANSI Z223.1 or
CSA−B149 for installation compliance codes for proper vent size.
6. Clearance to combustible material is 6" (152mm) for single wall vent material except where a listed clearance
thimble is used. Clearance to combustible material for type B−1 vent or factory−built chimney is per manufacturer's
instructions.
TABLE 2
MAXIMUM VENT CONNECTOR LENGTHS
No. of Elbows ft
1 25
2 20
3 15
4 10
5 5
Maximum length of vent connector not to exceed
m
7.6
6.1
4.6
3.0
1.5
6