Raypak 1334001 Installation & Operating Instructions Manual

Also see for RAYTHERM 133-4001: Installation & operating instructions

Contents

17Vent PipingVent piping of the same size as the drafthood outlet isrecommended, however, when the total vent height isat least ten (10) feet (drafthood relief opening to ventterminal), the vent pipe size may be reduced as spec-ified in the National Fuel Gas Code, ANSI Z223.1.Avoid long horizontal runs of vent pipe and too manyelbows. If installation requires horizontal non-verticalruns, the vent pipe must have a minimum of 1/4 inchper foot rise and should be supported at not more thanfive foot intervals. Plumber's tape, crisscrossed, willserve to space both horizontal and vertical piping. Gasvents supported only by the flashing and extendingabove the roof more than five feet should be securelyguyed or braced to withstand snow and wind loads.We recommend use of an insulated vent pipe spacerthrough the roofs and walls.For protection against rain or blockage by snow, thevent pipe must terminate with a vent cap which com-plies with the local codes or, in the absence of suchcodes, to the latest edition of the National Fuel GasCode, ANSI Z223.1.The discharge opening must be a minimum of two feetvertically from the roof surface and at least 2 feet high-er than any part of the building or equipment within tenfeet. The vent stack shall be at least 5 feet in verticalheight above the drafthood outlet. The vent cap loca-tion shall have a minimum clearance of 4 feethorizontally from, and in no case above or below,unless a 4-foot horizontal distance is maintained, fromelectric meters, gas meters regulators and relief equip-ment.The weight of the vent stack or chimney must not reston heater drafthood. Support must be provided incompliance with applicable codes. The heater top anddrafthood must be readily removable for maintenanceand inspection. Vent pipe should be adequately sup-ported to maintain proper clearances from combustibleconstruction Type "B" double wall or equivalent ventpipe is recommended. However single wall metal ventpipe may be used as specified in the latest edition ofthe National Flue Gas Code ANSI Z223.1.WARNING: Indoor heaters require a drafthood thatmust be connected to a vent pipe and properlyvented to the outside. Failure to follow this procedurecan cause fire or fatal carbon monoxide poisoning.5' MIN2' MIN10' OR LESS2' MINVENT CAPVENT PIPEDRAFT HOODHEATERFig. 13: Vent PipingManifolds that connect more than one heater to a com-mon chimney must be sized to handle the combinedload. Consult available guides for proper sizing of themanifold and the chimney. At no time should the areabe less than the area of the largest outlet.At the time of removal of an existing heater, the follow-ing steps shall be followed with each applianceremaining connected to the common venting systemplaced in operation, while the other appliances remain-ing connected to the common venting system are notin operation.(a) Seal any unused openings in the common ventingsystem.(b) Visually inspect the venting system for proper sizeand horizontal pitch and make sure there is noblockage or restriction, leakage, corrosion or otherdeficiency which could cause an unsafe condition.(c) Insofar as is practical, close all building doors andwindows and all doors between the space in whichthe appliances remaining connected to the com-mon venting system are located and other spacesof the building. Turn on clothes dryers and anyFig. 14: Common Vent Piping