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 three-inch nominal diameter PVC Schedule 40 pipe meet- ing ASTM D1785, PVC primer meeting ASTM F656, and PVC solvent cement meetingASTM D2564 specifications must be used. Fittings must be DWV type fittings meeting ASTM D2665 and ASTM D3311. Carefully follow the pipe manufacturer’s instruc- tions for cutting, cleaning, and solvent cementing of PVC.
The use of Schedule 40 PVC Cellular Core (Foam Core) plastic pipe is also acceptable as a flue/vent and intake pipe material. PVC primer meetingASTM F656 and PVC solvent cement meet- ing ASTM D2564 specifications must be used. Fittings must be DWV type fittings meetingASTM D2665 andASTM D3311. Care- fully follow the manufactures instructions for cutting, cleaning and solvent cementing of PVC.
MATERIALSANDJOININGMETHODS
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. Two-or-three-inch ABS Schedule 40 pipe must meet ASTM D1527 and, if used in Canada, must be CSA listed. Solvent cement for ABS to ABS joints must meet ASTM D2235 and, if used in Canada, must be CSA listed. The solvent cement for the PVC toABS transition joint must meetASTM D3138. Fittings must be DWV type fittings meeting ASTM D2661 and ASTM D3311 and, if used in Canada, must be CSAlisted. Care- fully follow the manufacturers’ instructions for cutting, cleaning, and solvent cementing PVC and/orABS.
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.
PROPERVENT/FLUEANDCOMBUSTIONAIRPIPINGPRACTICES
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 freezing inside the vent/flue pipe and/or at the vent/flue pipe termination. All vent/flue piping exposed to freezing temperatures below 35°F for extended periods of time must 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) must be insulated with 1/2” thick closed cell foam. Inspect piping for leaks prior to installing insulation.
TERMINATIONLOCATIONS
NOTE: Refer to Location Requirements and Considerations for combustion air contaminant restrictions.
The following bullets and diagram describe the restrictions con- cerning the appropriate location of vent/flue pipe and combustion air intake pipe (when applicable) terminations. Refer to Non-Direct Vent (Single Pipe) Piping and Direct Vent (Dual Pipe) Piping lo- cated in this section for specific details on termination construc- tion.
•All terminations (flue and/or intake) must be located at least12inchesabovegroundlevelortheanticipatedsnow level.
•Vent terminations (non-direct and direct vent) must terminate at least 3 feet above any forced air inlet located within 10 feet.
NOTE: This provision does not apply to the combustion air intake termination of a direct vent application.
•The vent termination of a non-direct vent application must terminate at least 4 feet below, 4 feet horizontally from, or 1 foot above any door, window, or gravity air inlet into any building.
•The vent termination of a direct vent application must terminate at least 12 inches from any opening through which flue gases may enter a building (door, window, or gravity air inlet).
•The vent termination of vent pipe run vertically through a roof must terminate at least 12 inches above the roof line (or the anticipated snow level) and be at least 12 inches from any vertical wall (including any anticipated snow build up).
•Aventterminationshallnotterminateoverpublicwalkways or over an area where condensate or vapor could create a nuisance or hazard or could be detrimental to the operation of regulators, relief valves, or other equipment.
•The combustion air intake termination of a direct vent application should not terminate in an area which is frequently dusty or dirty.