VENTING GAS APPLIANCES NFPA 54 CODE Better Buildings: Better Business Robert Parkhurst March 3, 2017
Objectives Standardize terminology Examine gas piping size and safety Simplify design rules Selection of table(s) for sizing of venting Category I appliances
Starting Together National Fire Protection Association Over 300 on Laundry List of Codes NFPA 70 Better know as NEC (National Electric Code) NFPA 54 National Fuel Gas Code 3
What Does It Address NFPA 54 Requirements cover the installation and operation of fuel gas piping systems, appliances, equipment, and related accessories, with rules for piping systems materials and components, piping system testing and purging, combustion and ventilation air supply, and venting of gas-fired appliances and equipment. 4
Draft (?) Chapter 3 Definitions 5
Chapter 3 Definitions Vented Appliance (?) 6
Category I Chapter 3 Definitions 7
Category IV Chapter 3 Definitions 8
Category I Chapter 3 Definitions 9
Fan Assisted Chapter 3 Definitions 10
Chapter 3 Definitions Vent Connector Chimney Flue Appliance Flue
Chapter 3 Definitions L (lateral) H (height) R (rise)
Chapter 3 Definitions NA -- Not Applicable or Not Allowed Vent configuration that is not allowed due to potential for condensate formation or pressurization of the venting system or that is not applicable due to physical or geometric restraints. 13
Chapter 5 Gas Piping Copper Type K or Type L Steel -- Black Iron Pipe 14
Chapter 5 Gas Piping CSST Corrugated Stainless Steel Tubing Safety Bonding 15
Chapter 7 Gas Piping
Chapter 6 Gas Piping Sizing Inlet Pressure Pressure Drop 17
Chapter 6 Gas Piping Sizing cubic feet per hour
Chapter 9 Installation Combustion air requirements Not Category I Follow manufacturer s instructions Category I Inside air if large enough volume Outside air is optional for small volumes 19
Chapter 9 Installation Indoor Air Requirements 80000 Furnace and 40000 Water Heater 120 x 50 = 6000 ft 3 800 ft 2 @ 7 ½ ft ceiling 20
Chapter 9 Installation Indoor Air Requirements <.4 ACH 21
Chapter 9 Installation Indoor Air Requirements Tested at.3 ACH 80000 Fan Assisted Furnace 15/.3 x 80 = 4000 40000 Water Heater 21/.3 x 40 = 2800 6800 ft 3 or about 907 ft 2 22
Chapter 12 Venting of Appliances Venting systems shall be designed and constructed to convey all flue and vent gases to the outdoors. Exceptions Ranges, cook tops Refrigerators Clothes Dryers (follow 10.4) 23
Mechanical Draft Venting Install according to both the appliance manufacturer s and venting system manufacturer s instructions Seal all seams under positive pressure No mixing with natural venting Must have safety built in to shut off gas to burners if venting system is not working 24
Category IV Direct Venting Intake and Exhaust Pipes PVC allowed (140 F limit) Furnace/Water Heater/Boiler Manual Size of pipe and allowable lengths (support) Terminations Through wall or through roof 12 above grade or anticipated snow level In same pressure location Concentric venting kit 25
Category IV Direct Venting Intake and Exhaust Pipes 26
Category IV Direct Venting Intake and Exhaust Pipes Exhaust 12 from doors & windows Exhaust 3 from intake of water heater Intake 3 from water heater exhaust Intake 3 from dryer exhaust 7 above public walkways 27
Category IV Direct Venting Intake and Exhaust Pipes 28
Category IV Direct Venting Intake and Exhaust Pipes 29
Venting of Category I Appliances The 70s
Venting of Category I Appliances Masonry Chimneys Flue no smaller than appliance flue Flue no more than 7 times appliance flue Must be lined per NFPA 211 Termination 31
Venting of Category I Appliances Masonry Chimneys with Liner Liner sizing in Chapter 13 tables Labeled as for gas use only Space around liner can not be used for: Venting other appliances Combustion air 32
Venting of Category I Appliances Gas Vents Termination 7x rule Not smaller Labeled in chimney 33
Chapter 13 Sizing of Category I Venting Systems Vent Connectors Slope ¼ in/ft upward to chimney/vent Not smaller than appliance flue Up to 2 sizes larger than appliance flue Length depends on type for single appliance Single wall 75% of vent height B-Vent 100% of vent height 18 /inch diameter for multiple appliances 34
Chapter 13 Sizing of Category I Venting Systems 13.1 Single Appliances Tables B-Vent or masonry chimney Type of connector Sizing based on: Height of vent/chimney Lateral length of connector 13.2 Multiple Appliances Tables Rise of connector for sizing not lateral 35
Chapter 13 Sizing of Category I Venting Systems Natural Draft Appliance Maximum BTU for size listed Fan Assisted Appliance Minimum BTU for size listed Maximum BTU for size listed 36
13.1 (a) B Double-Wall Gas Vent B-Vent directly connected to appliance Corrugated Chimney Liners Max capacity reduced to 80% listed 13.1 (b) B Double-Wall Gas Vent Single-wall Metal Connector from appliance 37
13.1 (c) Masonry Chimney Type B Double-Wall Connector from appliance 13.1 (d) Masonry Chimney Single-wall Metal Connector from appliance 38
Chapter 13 Elbows 39
Table 13.1(a) B-Vent
Table 13.1(b) B-Vent Single Connector
Table 13.1(c) Masonry B-Vent Connector
Table 13.1(d) Masonry Single Connector
Table 13.1(c) and 13.1(d) Chimney Area
13.2 (a) B Double-Wall Gas Vent B-Vent Connectors from appliances Corrugated Chimney Liners Max capacity reduced to 80% listed 13.2 (b) B Double-Wall Gas Vent Single-wall Metal Connectors from appliances 45
13.2 (c) Masonry Chimney Type B Double-Wall Connectors from appliances 13.2 (d) Masonry Chimney Single-wall Metal Connectors from appliances 46
13.2 Common Connector 47
Table 13.2(c) Masonry B-Vent Connector
13.2(a) Vent Capacities
13.2(b) Vent Capacities
13.2(c) Vent Capacities
13.2(d) Vent Capacities
Sizing Examples Single Appliance
Questions Thank You