IX. VENT/FLUE PIPE & COMBUSTION AIR PIPE
GENERAL
WARNING
FAILURE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN BODILY INJURY OR DEATH. CAREFULLY READ AND FOLLOW ALL INSTRUCTIONS GIVEN IN THIS SECTION.
WARNING
UPON COMPLETION OF THE FURNACE INSTALLATION, CAREFULLY INSPECT THE ENTIRE FLUE SYSTEM BOTH INSIDE AND OUTSIDE OF THE FURNACE TO ASSURE IT IS PROPERLY SEALED. LEAKS IN THE FLUE SYSTEM CAN RESULT IN SERIOUS PERSONAL INJURY OR DEATH DUE TO EXPOSURE TO FLUE PRODUCTS, INCLUDING CARBON MONOXIDE.
A condensing gas furnace achieves its high level of efficiency by ex- tracting almost all of the heat from the products of combustion and cooling them to the point where condensation takes place. Because of the relatively low flue gas temperature and water condensation re- quirements, PVC pipe is used as venting material.
This furnace must not be connected to Type B, BW, or L vent or vent connector, and must not be vented into any portion of a factory built or masonry chimney except when used as a pathway for PVC as described later in this section. Never common vent this appliance with another appliance or use a vent which is used by a solid fuel appliance. Do not use commercially available “no hub connec- tors” other than those shipped with this product.
It is the responsibility of the installer to follow the manufacturers’ recommendations and to verify that all vent/flue piping and con- nectors are compatible with furnace flue products. Additionally, it is the responsibility of the installer to ensure that all piping and connections possess adequate structural integrity and support to prevent flue pipe separation, shifting, or sagging during furnace operation.
DUAL CERTIFICATION: NON-DIRECT/DIRECT VENT
This furnace is dual certified and may be installed as a
MATERIALS AND JOINING METHODS
WARNING
TO AVOID BODILY INJURY, FIRE OR EXPLOSION, SOLVENT CEMENTS MUST BE KEPT AWAY FROM ALL IGNITION SOURCES (I.E., SPARKS, OPEN FLAMES, AND EXCESSIVE HEAT) AS THEY ARE COMBUSTIBLE LIQUIDS. AVOID BREATHING CEMENT VAPORS OR CONTACT WITH SKIN AND/OR EYES.
Two- or
The use of Schedule 40 PVC or ABS cellular core (Foam Core) plas-
tic pipe is also acceptable as a flue/vent and intake pipe material. PVC primer meeting ASTM F656 and PVC solvent cement meeting ASTM D2564 specifications must be used. Fittings must be DWV type fit- tings meeting ASTM D2665 and ASTM D3311. Carefully follow the manufactures instructions for cutting, cleaning and solvent cement- ing of PVC.
In addition to PVC and ABS pipe and fittings, Innoflue® by Centrotherm Eco Systems and PolyPro® by M&G Duravent are also approved vent and combustion air materials for installations in the U.S.A. and Canada. Manufacturers Installation instructions for these products must be followed. These products have specific instructions for installing, joining and terminating. Do not mix materials or compo- nents of one manufacturer with materials or components of another manufacturer.
For Canadian installations; all PVC pipe, fittings and joining mate- rials must be UL S636 listed.
As an alternative to PVC pipe, primer, solvent cement, and fittings, ABS materials which are in compliance with the following specifi- cations may be used.
All 90° elbows must be medium radius (1/4 bend DWV) or long radius (Long sweep 1/4 bend DWV) types conforming to ASTM D3311. A medium radius (1/4 bend DWV) elbow measures 3 1/ 16” minimum from the plane of one opening to the centerline of the other opening for 2” diameter pipe, and 4 9/16” minimum for 3” pipe.
PROPER VENT/FLUE AND COMBUSTION AIR PIPING PRACTICES
Adhere to these instructions to ensure safe and proper furnace performance. The length, diameter, and number of elbows of the vent/flue pipe and combustion air pipe (when applicable) affects the performance of the furnace and must be carefully sized. All piping must be installed in accordance with local codes and these instructions.
Piping must be adequately secured and supported to prohibit sag- ging, joint separation, and/or detachment from the furnace. Hori- zontal runs of vent/flue piping must be supported every three to five feet and must maintain a 1/4 inch per foot downward slope, back towards the furnace, to properly return condensate to the furnace’s drain system. Allowances should be made for minor expansion and contraction due to temperature variations. For this reason, particular care must be taken to secure piping when a long run is followed by a short offset of less than 40 inches.
Precautions should be taken to prevent condensate from freez- ing inside the vent/flue pipe and/or at the vent/flue pipe termina- tion. It is our recommendation that all vent/flue piping exposed to temperatures below 35°F for extended periods of time should be insulated with 1/2” thick closed cell foam. Also all vent/flue piping exposed outdoors in excess of the terminations shown in this manual (or in unheated areas) should be insulated with 1/2” thick closed cell foam. Inspect piping for leaks prior to installing insu- lation.
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