Nortec GS Series - Manual (Page 20)

17 | GS Series Installation
Installation As A Category I Appliance
General
The GS Series humidifiers have a fan-assisted combustion which operates with a non-positive vent static
pressure when installed with the appropriate vent diameter.
Category I appliances must be vented vertically or nearly vertical (see Figure 7, 8, 9, 10 & 11).
This category appliance is restricted to vertical venting installations with limits placed on horizontal lengths
and vent diameters. Refer to the tables in local and/or national codes. No sidewall termination is accepted.
Vent piping must be UL or UL/CSA listed Type B. Required clearance for Type B vent is piping is 1” (25 mm).
A minimum equivalent vent length of 7 feet must be connected to the humidifier. Vent lengths must not
exceed 70’ (21 m). Each 90° elbow is equivalent to 10’ and each 45° elbow equals 5'. The vent run should
be as direct as possible with no more than 6 elbows in the system. Contact Nortec Technical Services if you
have any questions.
The vent pipe exiting the humidifier is sized for category III installations. A field supplied adapter is required
to increase the pipe immediately at the exit of the humidifier. The vent pipe must be expanded to the
minimum sizes listed below for each model, increasing as code requires.
GS 100 4” minimum diameter
GS 200 5”
GS 300/400 7”
GS 500/600 8”
The termination at the humidifier is a male connection. Standard venting hook-ups require a female path. It
is highly recommended that a female to female adapter be assembled onto the humidifier to establish the
proper venting sequence. Consult with the venting manufacturer for proper hook up.
Vent connectors shall not be connected into any portion of a mechanical draft system operating under
positive pressure.
Use only double wall (aluminum inner wall) b vent. Single wall venting cannot be used due to the increased
wet time in the lining. If the vent connector attaches to a lined masonry chimney, the chimney must be sized
and installed according to the provisions of the national fuel gas code or Canadian CSA B149.1 standards.
An approved venting manufacturer’s termination cap for the stack outlet must be used.
When the category I installation is selected it may be commonly vented with other listed gas fire appliances.
Total input rates of all appliances will determine the vent size the chimney must be sized and installed
according to the provisions of the national fuel gas code or Canadian CSA B149.1 standards.
A maximum of 4 gas appliances may be common vented on the same floor. Multiple story common venting
is not recommended.
Refer to the vent manufacturer’s instructions for proper clearances to combustibles.
Recommended B-Venting Manufacturers
Simpson Dura-vent
Selkirk Canada corporation
American metal products
Metal-fab Inc.