Raypak MVB 504A Installation & Operating Manual

Raypak MVB 504A Installation & Operating Manual Manual pdf 30 page image

30Canadian InstallationsRefer to latest edition of the B149 Installation Code.A vent shall not terminate:1. Directly above a paved sidewalk or drivewaywhich is located between two single-family dwell-ings and serves both dwellings.2. Less than 7 ft (2.13 m) above a paved sidewalk orpaved driveway located on public property.3. Within 6 ft (1.8 m) of a mechanical air supply inletto any building.4. Above a meter/regulator assembly within 3 ft (915mm) horizontally of the vertical centre-line of theregulator.5. Within 6 ft (1.8 m) of any gas service regulatorvent outlet.6. Less than 1 ft (305 mm) above grade level.7. Within 3 ft (915 mm) of a window or door whichcan be opened in any building, any non-mechani-cal air supply inlet to any building or thecombustion air inlet of any other appliance.8. Underneath a verandah, porch or deck, unless theverandah, porch or deck is fully open on a mini-mum of two sides beneath the floor, and thedistance between the top of the vent terminationand the underside of the verandah, porch or deckis greater than 1 ft (305 mm).Venting Installation TipsSupport piping:• horizontal runs—at least every 5 ft (1.5m)• vertical runs—use braces• under or near elbowsVenting ConfigurationsFor heaters connected to gas vents or chimneys, ventinstallations shall be in accordance with the NFGC(U.S.), or B149 (Canada), or applicable provisions oflocal building codes.WARNING: Examine the venting system at leastonce a year. Check all joints and vent pipeconnections for tightness, corrosion or deterioration.Vertical Venting (Category I)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 nega-tive draft must be within the range of -.01 to -.08 in.WC as measured 12 in. above the appliance flue out-let to ensure proper operation. Vent material must belisted by a nationally recognized test agency.The venting for Category I appliances shall be deter-mined per the NFGC (U.S.) or B149 (Canada).The connection from the appliance vent to the stackmust be as direct as possible and shall be the same di-ameter as the vent outlet. The horizontal breaching ofa vent must have an upward slope of not less than 1/4inch per linear foot from the heater to the vent termi-nal. The horizontal portions of the vent shall also besupported for the design and weight of the materialemployed to maintain clearances and to prevent physi-cal damage or separation of joints.TerminationThe vent terminal should be vertical and should termi-nate outside the building at least 2 ft above the highestpoint of the roof that is within 8 ft for models 504 to1504 and within 10 ft for model 2004. 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 distance of the vent terminal from adjacent publicwalkways, adjacent buildings, open windows andbuilding openings must be consistent with the NFGC(U.S.) or B149 (Canada). Gas vents supported only byflashing and extended above the roof more than 5 ftshould be se-curely guyed or braced to withstandsnow and wind loads.NOTE: A vent adapter (field-supplied) may be re-quired to connect the Category I vent to the heater.CAUTION: A listed vent cap terminal suitable forconnection to the Cat I vent materials, adequatelysized, must be used to evacuate the flue productsfrom the building.