FSD Building Codes & Safety Standards 4 — Questions and Answers
Question 1: What is the maximum allowable leakage class for a smoke damper used in a smoke control system per UL 555S?
- Class I
- Class II
- Class III (Correct answer)
- Any class is acceptable
Correct answer: Class III
UL 555S leakage classes rate dampers as Class I (lowest leakage), II, or III (highest leakage); Class III is the maximum permitted for smoke control applications.
Question 2: Under the IBC, which of the following is NOT a recognized alternative to installing a fire damper at a duct penetration of a fire barrier?
- Constructing the duct of listed fire-resistive materials
- Using a corridor that is not a rated assembly (Correct answer)
- Installing automatic sprinklers within the duct
- Applying intumescent materials that seal the opening
Correct answer: Using a corridor that is not a rated assembly
Using an unrated corridor does not serve as a code-recognized alternative to a fire damper at a rated fire barrier penetration.
Question 3: ASHRAE 62.1 affects fire and smoke damper design primarily by establishing requirements for:
- Damper actuation speeds
- Outdoor air ventilation rates that influence duct sizing and damper placement (Correct answer)
- Fusible link temperature ratings
- Fire damper testing frequencies
Correct answer: Outdoor air ventilation rates that influence duct sizing and damper placement
ASHRAE 62.1 sets minimum ventilation rates that drive duct design, indirectly influencing where fire and smoke dampers must be located.
Question 4: What does the term 'smoke compartment' mean in the context of NFPA 101?
- A room rated for 2-hour fire resistance
- A space enclosed by smoke barriers on all sides including floor and ceiling (Correct answer)
- Any corridor separated by smoke doors
- A pressurized stairwell
Correct answer: A space enclosed by smoke barriers on all sides including floor and ceiling
A smoke compartment under NFPA 101 is a space enclosed on all sides — including top and bottom — by smoke barriers designed to limit smoke spread.
Question 5: According to IMC, when must a fire damper be provided at a duct penetration of a shaft enclosure?
- Always, regardless of sprinkler protection
- When the shaft connects more than two floors
- When the shaft is not required to be fire-resistance rated
- When the shaft enclosure has a fire-resistance rating of 2 hours or more (Correct answer)
Correct answer: When the shaft enclosure has a fire-resistance rating of 2 hours or more
The IMC requires fire dampers at duct penetrations of shaft enclosures that have a 2-hour or greater fire-resistance rating.
Question 6: Which organization publishes SMACNA guidelines that fire and smoke damper installers frequently reference for ductwork construction?
- Sheet Metal and Air Conditioning Contractors' National Association (Correct answer)
- Society of Mechanical and Architectural Codes Nationally Adopted
- Smoke Management and Air Control National Agency
- Standard Mechanical and Construction National Authority
Correct answer: Sheet Metal and Air Conditioning Contractors' National Association
SMACNA (Sheet Metal and Air Conditioning Contractors' National Association) publishes construction standards widely used for HVAC ductwork and damper installations.
Question 7: What is the primary purpose of a ceiling radiation damper (CRD)?
- To block smoke from entering ceiling plenums
- To prevent the passage of heat through a membrane ceiling into a concealed space above a fire-rated floor/ceiling assembly (Correct answer)
- To control airflow in radiant heating systems
- To protect ducts from radiation heat in industrial facilities
Correct answer: To prevent the passage of heat through a membrane ceiling into a concealed space above a fire-rated floor/ceiling assembly
Ceiling radiation dampers prevent heat transfer through membrane ceilings that are part of a fire-resistance-rated floor/ceiling or roof/ceiling assembly.
FSD Building Codes & Safety Standards 4
What is the maximum allowable leakage class for a smoke damper used in a smoke control system per UL 555S?