1. Design Fires for Smoke Control
Dr. John H. Klote PE
Fire and Smoke Consulting

2. Learning Objectives
Provide an understanding of fire growth, flashover, fully developed fire and fire decay.
Provide an overview of the basic concepts of developing design fires for smoke control systems.

3. Extensive Treatment of All Aspects of Smoke Control
For more information about design fires, see Chapter 5 “Fire Physics & Design Fires”

4. Design Fires Used for Atrium Smoke Control and Tenability Systems IBC
No Prescribed Design Fires
Requires Analysis of Design Fires
Many Engineers – New to Design Fires
This Talk:
Overview of Analysis of Design Fires
Focus on Highlights

5. UK Information on Design Fires
Industrial & Warehouse (not high racked) Smoke Ventilation Association Guide:
Sprinklered Steady Fires - 3m x 3m to 9m x 9m.
Unsprinkleres Steady Fires – 2 Times as Big
Steady Fires in Car Parks – BS
Guidance for Offices & Hotels – BS and 5 and in BR368
General Information on Specific Objects:
BS 7974 (UK fire engineering standard)
BRE design fires database CD

7. Design Fires
Normally Most Important Property - Heat Release Rate (HRR)
Other Properties (toxic gases, reduced visibility, etc.) - Tenability Systems
For simplicity - Only Discuss HRR
HRR of a Design Fire:
Steady
Unsteady
Steady HRR – Peak of Unsteady HRR

16. Fully Developed Fire Called “Ventilation Controlled Fire”
Room with One Opening
HRR Controlled by Opening Size – HRR Equation

17. HRR Measurement Oxygen Consumption Calorimeters
HRR per unit O2 Consumed – Almost Constant (13.1 MJ per kg of oxygen + 6%)
Open Air Calorimeter
Room Calorimeter

24. Design Fires Normal Fuels - Objects Planned for Space
Transient Fuels - In a Space Temporarily
Examples: Trash, Stacked Wood Pallets, Furniture After Delivery, etc.
Atrium Fires
Normal & Transient Fuels
No Benefit of Sprinklers (Ceilings > 35 – 45 ft)
Transient Fuels: Suggest Min Btu/s
Non-Atrium Fires
Fires w/ Axisymmetric Plume – CFAST
Shielded Fires (NIST & NRCC Models)

40. Questions? Dr. John H. Klote PE john@SmokeControlExpert.com