Specifications

1
INTRODUCTION ................................................................................................................... 2
1. VENTING IN GENERAL ................................................................................................ 3
1.1 Designing Venting Systems..................................................................................... 3
1.2 Gravity vs. Mechanical Venting ............................................................................... 3
2. VENTING PROBLEMS AND POSSIBLE SOLUTIONS ................................................. 4
2.1 Chimney Performance Problems ............................................................................ 4
2.1.1 Problems associated with the venting system .............................................. 5
2.1.2 Problems associated with the heating appliance.......................................... 7
2.1.3 Problems associated with the building/house............................................... 9
2.1.4 Problems associated with the building’s environment .................................. 11
3. VENTING STANDARDS AND CODES .......................................................................... 13
3.1 Solid-fuel Standards and Codes.............................................................................. 13
3.2 Gas Standards and Codes ...................................................................................... 15
4. VENTING SYSTEM DESIGN ......................................................................................... 19
4.1. Gravity Systems ...................................................................................................... 19
4.1.1 The chimney ................................................................................................. 19
4.1.2 The heating appliance .................................................................................. 20
4.2 Mechanical Venting Systems .................................................................................. 21
4.2.1 Location of a mechanical draft system ......................................................... 21
4.2.2 Installation at termination point ..................................................................... 21
4.2.3 Installation on masonry chimneys ................................................................ 21
4.2.4 Chimney and ue sizing ............................................................................... 21
5. MECHANICAL SYSTEM DESIGN ................................................................................. 22
5.1 Design Guidelines for Mechanical Venting of Gas and Manually Fired
Appliances ............................................................................................................... 22
5.1.1 Fireplaces - wood or gas .............................................................................. 22
5.1.2 Stoves and replace inserts ......................................................................... 24
5.1.3 Other applications......................................................................................... 24
6. GUIDE FOR MECHANICAL DRAFT SYSTEMS ........................................................... 25
6.1 Mechanical Draft System for Wood-Fired Fireplace with a Single Flue .................. 25
6.2 Mechanical Draft System for Wood-Fired Fireplace with Multiple Flues ................. 26
6.3 Mechanical Draft System for Wood-Fired Fireplace with Safety System
per NFPA211/IMC-2000 edition ............................................................................... 27
6.4 Mechanical Draft System for a Wood-red Fireplace with Manual Damper and Safety
System per NFPA211/IMC-2000 edition .................................................................. 28
6.5 Mechanical Draft System for Gas-Fired Fireplace with a Single Flue
with Safety System per NFPA54/IFGC .................................................................... 29
6.6 Mechanical Draft System (automated) for a Gas-Fired Fireplace with a Single Flue
with Safety System per NFPA54/IFGC .................................................................... 30
6.7 Mechanical Draft System for Gas-Fired Fireplace with Multiple Flues with Safety
System per NFPA54/IFGC ...................................................................................... 31
6.8 Mechanical Draft System for Gas-Fired Fireplace with Multiple ues and Safety
System per NFPA54/IFGC ..................................................................................... 32
6.9 Mechanical Draft System for Gas-Fired Fireplace with Damper and Safety
System per NFPA54/IFGC ..................................................................................... 33
6.10 Mechanical Draft System (automated) for a Gas-Fired Fireplace with Modulating
Fan Speed and a Single Flue with Safety System per NFPA54/IFGC..................... 34
6.11 Mechanical Draft System for a Gas-Fired Fireplace with Modulating Fan Speed,
Damper and a Single Flue with Safety System per NFPA54/IFGC..................... .... 35
6.12 Mechanical Draft System for a Gas-red Fireplace with Modulating Fan Speed and
Multiple ues and Safety System per NFPA54/IFGC..................... ......................... 36
7. FREQUENTLY ASKED QUESTIONS ............................................................................ 37
APPENDIX A: DESIGN THEORY ................................................................................... 38
APPENDIX B: CONVERSION TABLE FROM RECTANGULAR TO ROUND FLUES... . 42
APPENDIX C: RESISTANCE FACTORS ....................................................................... 42
SOURCES AND REFERENCES .................................................................................... 43
Table of Contents