Venting and Combustion Air Guide
07/21/11 AERCO International, Inc.
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100 Oritani Dr.
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Blauvelt, NY 10913
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Ph: 800-526-0288 Page
165
of
200
GF-5050
TAG-0043_0C
3 VENT SYSTEM
The heater vent is fundamental for correct operation. Being a condensing heater, combustion gases are
discharged at a very low temperature. It is therefore necessary for the venting system to be perfectly
impermeable to combustion products condensate and to be made of corrosion resistant materials. Typical
Category IV venting and sealed combustion illustrations are shown in Figures 2 through 5. The various
funnel joints shall be well sealed and/or equipped with suitable gaskets, in order to avoid any condensate
drain and/or air intake. Ensure that the heater vent’s section and height conform to national and local
regulations (see 1.1 APPLICABLE FEDERAL CODES of this guide).
For water heaters designed for connection to gas vents or chimneys, vent installations shall be in
accordance with Part 7, Venting of Equipment, of the National Fuel Gas Code, ANSI Z223.1, or Section
7, Venting Systems and Air Supply for Appliances, of the CAN/CSA B149, Installation Codes, or
applicable provisions of the local building codes.
The vent system for the Innovation heaters must be installed in accordance with AERCO’s installation
instructions described in this guide.
For Category IV Heaters, the vents must be installed to prevent accumulation of
condensate, and have means provided for drainage of condensate.
3.1 VENT INSTALLATION
1. The heaters covered in this section are design-certified as Category IV for venting, only when
they are installed with manufacturer specified vent system components and installation practices.
2. Install vent pipe beginning at the water heater exhaust manifold vent connector and work toward
the vent cap. To attach the exhaust connector to the flue collector, use the screws and the gasket
supplied inside the plastic bag. Use a cross-tip (Phillips) screwdriver at least 12 inches (300 mm)
long. See Figure 1 for exhaust vent connectors.
3. Vent connectors serving appliances vented by natural draft shall not be connected into any
portion of mechanical draft systems operating under positive pressure
4.
For Innovation water heaters, horizontal runs shall be sloping upwards not less than 1/4 inch per
foot
(21 mm/m) from the heater to the vent termination.
5. The instructions for the installation of the venting system shall specify that the horizontal portions
of the venting system shall be supported to prevent dips or sags where condensate could collect.
6. Rigidly support vent pipe every 5 feet and at the elbows. Plumber straps may be used.
7. Clearances and enclosures. ALL vent pipe and fittings must be installed with appropriate air
space clearances to combustibles. These air space clearances apply to indoor or outdoor vents,
whether they are open, enclosed, horizontal or vertical or pass through floors, walls, roofs, or
framed spaces. The appropriate air space clearances should be observed between joists, studs,
sub floors, plywood, drywall, or plaster enclosures, insulated sheathing, rafters, roofing, and any
other combustible material. The minimum air space clearance also applies to electrical wires and
any kind of building insulation. For horizontal runs, maintain a minimum air space clearance of 0
inches for 4 inch and 6 inch vent pipe to any combustible material, electric wires, and building
materials.
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