Raypak B-R259 Installation & Operating Instructions Manual

Contents

20Double-wall Type B vent should be used to promotedraft and to minimize condensation in the vent.The connection from the appliance vent to the stackmust be as direct as possible. The horizontal breach-ing of a vent must have an upward slope of not lessthan 1/4 inch per linear foot from the heater to the ventterminal. The horizontal portions of the vent shall alsobe supported for the design and weight of the materialemployed to maintain clearances and to prevent phys-ical damage or separation of joints.TerminationThe vent terminal should be vertical and should termi-nate outside the building at least 2 ft above the high-est point of the roof that is within 10 ft. The vent capshould have a minimum clearance of 4 ft horizontallyfrom and in no case above or below (unless a 4 ft hori-zontal distance is maintained) electric meters, gasmeters, regulators and relief equipment. The distanceof the vent terminal from adjacent public walkways,adjacent buildings, open windows and building open-ings must be consistent with the NFGC (U.S.) or B149(Canada). Gas vents supported only by flashing andextended above the roof more than 5 ft should be se-curely guyed or braced to withstand snow and windloads.VENT CAPNOTE: With venting application of two or moreheaters, contact the factory.CAUTION: A listed vent cap terminal adequatelysized, must be used to evacuate the flue productsfrom the building.