VENTING GAS APPLIANCES NFPA 54 CODE

Transcription

1 VENTING GAS APPLIANCES NFPA 54 CODE Better Buildings: Better Business Robert Parkhurst March 3, 2017

2 Objectives Standardize terminology Examine gas piping size and safety Simplify design rules Selection of table(s) for sizing of venting Category I appliances

3 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

4 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

5 Draft (?) Chapter 3 Definitions 5

6 Chapter 3 Definitions Vented Appliance (?) 6

7 Category I Chapter 3 Definitions 7

8 Category IV Chapter 3 Definitions 8

9 Category I Chapter 3 Definitions 9

10 Fan Assisted Chapter 3 Definitions 10

11 Chapter 3 Definitions Vent Connector Chimney Flue Appliance Flue

12 Chapter 3 Definitions L (lateral) H (height) R (rise)

13 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

14 Chapter 5 Gas Piping Copper Type K or Type L Steel -- Black Iron Pipe 14

15 Chapter 5 Gas Piping CSST Corrugated Stainless Steel Tubing Safety Bonding 15

16 Chapter 7 Gas Piping

17 Chapter 6 Gas Piping Sizing Inlet Pressure Pressure Drop 17

18 Chapter 6 Gas Piping Sizing cubic feet per hour

19 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

20 Chapter 9 Installation Indoor Air Requirements Furnace and Water Heater 120 x 50 = 6000 ft ft 7 ½ ft ceiling 20

21 Chapter 9 Installation Indoor Air Requirements <.4 ACH 21

22 Chapter 9 Installation Indoor Air Requirements Tested at.3 ACH Fan Assisted Furnace 15/.3 x 80 = Water Heater 21/.3 x 40 = ft 3 or about 907 ft 2 22

23 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

24 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

25 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

26 Category IV Direct Venting Intake and Exhaust Pipes 26

27 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

28 Category IV Direct Venting Intake and Exhaust Pipes 28

29 Category IV Direct Venting Intake and Exhaust Pipes 29

30 Venting of Category I Appliances The 70s

31 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

32 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

33 Venting of Category I Appliances Gas Vents Termination 7x rule Not smaller Labeled in chimney 33

34 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

35 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

36 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

37 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

38 13.1 (c) Masonry Chimney Type B Double-Wall Connector from appliance 13.1 (d) Masonry Chimney Single-wall Metal Connector from appliance 38

39 Chapter 13 Elbows 39

40 Table 13.1(a) B-Vent

41 Table 13.1(b) B-Vent Single Connector

42 Table 13.1(c) Masonry B-Vent Connector

43 Table 13.1(d) Masonry Single Connector

44 Table 13.1(c) and 13.1(d) Chimney Area

45 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

46 13.2 (c) Masonry Chimney Type B Double-Wall Connectors from appliances 13.2 (d) Masonry Chimney Single-wall Metal Connectors from appliances 46

47 13.2 Common Connector 47

48 Table 13.2(c) Masonry B-Vent Connector

49 13.2(a) Vent Capacities

50 13.2(b) Vent Capacities

51 13.2(c) Vent Capacities

52 13.2(d) Vent Capacities

53 Sizing Examples Single Appliance

54 Questions Thank You