Raypak HD401 Installation & Operating Instructions Manual

Also see for HI DELTA HD101 THRU 2342B: Brochure & specs User's information manual User manual Installation & operating instructions Installation & operating instructions

26Natural Draft Vertical VentingSystem InstallationNatural draft venting uses the natural buoyancy of theheated flue products to create a thermal driving headthat expels the exhaust gases from the flue. The neg-ative draft must be within the range of –0.01 in.to –0.08 in. WC as measured 12 in. from the applianceflue outlet to ensure proper operation. Vent materialmust be listed by a nationally recognized test agency.The maximum and minimum venting length forCategory I appliance shall be determined per the latestedition of the NFGC (U.S.) or B149 Installation Code(Canada).The diameter of vent flue pipe should be sized accord-ing to Part 11 of the latest edition of the NFGC (U.S.)and part 7 and appendix B of the B149 InstallationCode (Canada). The minimum flue pipe diameter forconventional negative draft venting using double-wallB type vent is 4” for HD101 and HD151, 5” for HD201,HD251 and HD301, and 6” for HD401.The connection from the appliance vent to the stackmust be as direct as possible and shall be the samediameter as, or larger than the vent outlet. The hori-zontal breaching of a vent must have an upward slopeof not less than 1/4 inch per linear foot from the heaterto the vent terminal. The horizontal portions of the ventshall also be supported for the design and weight ofthe material employed to maintain clearances and toprevent physical damage or separation of joints.Natural Draft Vertical VentTerminationThe vent terminal should be vertical and should termi-nate outside the building at least two (2) feet above thehighest point of the roof that is within 10 feet. The ventcap should have a minimum clearance of four (4) feethorizontally from and in no case above or below(unless a four (4) foot horizontal distance is main-tained) electric meters, gas meters, regulators andrelief equipment. The distance of the vent terminalfrom adjacent public walkways, adjacent buildings,open windows and building openings must be consis-tent with the NFGC, or in Canada, the B149Installation Code for Gas Burning Appliances andEquipment. Gas vents supported only by flashing andextended above the roof more than five feet should besecurely guyed or braced to withstand snow and windloads.Natural Draft Vertical Venting withCommon Venting System, Category IAppliance OnlyManifolds 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 areaof the vent be less than the area of the largest heaterexhaust outlet.Common venting systems may be too large when anexisting unit is removed. At the time of removal of anexisting appliance, the following steps must be fol-lowed with each appliance remaining connected to thecommon venting system placed in operation, while theother appliances remaining connected to the commonventing system are not in operation.a) Seal any unused opening in the common ventingsystem.b) Visually inspect the venting system for proper sizeand horizontal pitch and determine there is noblockage or restriction, leakage, corrosion or otherunsafe 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 anyappliance not connected to the common vent sys-tem. Turn on any exhaust fans, such as rangehoods and bathroom exhausts, so they will oper-ate at maximum speed. Do not operate summerexhaust fan. Close fireplace dampers.d) Place in operation the appliances being inspected.Follow the manufacturers instructions for lightingNOTE: Vent Adapter will have to be used to connectB vent to the unit.CAUTION: Listed vent cap terminal must be usedand sized adequately to evacuate the flue productsfrom the heaters.WARNING: Vent connectors serving appliancesvented by natural draft shall not be connected intoany portion of mechanical draft systems operatingunder a positive pressure.CAUTION: Vent connectors for natural draftventing systems must be type “B” vent or better.