Smoke Detector at Elevator Door & at Ceiling?

9/21/2021

A project I'm on has a lobby area with a 35-foot tall ceiling next to the elevator door.

NFPA 72-2010/2013 Section 17.7.3.1.3 and 17.7.3.1.4 allows a smoke detector within 60-inches of the top of each elevator door to protect the opening. This can be used for elevator recall.

In addition to this smoke detector, do I also need one at the ceiling (35-feet) for normal coverage?

Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

6 Comments

Alex Riley

9/21/2021 07:28:23 am

Hi Anonymous,

Great question. I’m having trouble finding a code section to back my claims completely, but here’s what I got:

NFPA 72 (2019) 17.7.3.1.1 states that “the location and spacing of smoke detectors shall be based upon the anticipated smoke flows due to the plume and ceiling jet produced by the anticipated fire, as well as any pre-existing ambient airflows that could exist in the protected compartment”.

NFPA 72 (2019) 21.3.5.1 and 21.3.5.2 state that a smoke detector must be located within 21 feet of the centerline of each elevator door, and for ceiling configurations exceed 15 feet in height, the design shall follow Chapter 17. Section 17.7.3.1.3 states that if the “intent is to protect against a specific hazard”, smoke from an elevator for elevator recall, “detectors shall be permitted to be installed closer to the hazard in a position where the detector can intercept the smoke”.

From both of these code sections, I believe that for your situation, you are required to install smokes above the elevator for recall, and additional smokes at the ceiling to protect against the anticipated smoke flows due to the possible plume form a fire originating within the lobby.

Looking forward to seeing what everyone else digs up.
Alex

schulman

9/21/2021 08:10:06 am

I agree with Alex but not based on the code.
Seems like two covers the space better AND provides for the specific elevator shaft coverage. I'm not trying to save money on Fire Alarm systems. Pretty sure the AHJ isn't going to be upset with "possible additional coverage".

9/21/2021 08:28:50 am

NFPA 72:17.4.7
States that if the intent is to initiate action when smoke or fire threatens a specific object or space, the detector shall be permitted to be installed in close proximity to that object or space.

A17.4.7
This sections indicates that areas that do not require full area protection but do require detection can have coverage within close proximity to protect against fire or smoke. Elevator lobbies with ceilings greater than 15' allow for the detector to be within 60" of the top of the elevator.

DTW FPE link

9/21/2021 02:22:38 pm

In the early days of elevator recall it was not uncommon to install the smokes just above the elevator door opening as the idea was to protect the elevator shaft from ingesting smoke if it were to open in a smoke filled lobby. While more detectors might be better for finding smoke in a lobby, it doesn't help the function of the elevator lobby detector.

Also, who would want to be the one servicing a detector 35 feet in the air? In the end it might end up being a beam detector from a servicing and coverage aspect...not a inexpensive solution.

Shafi Sneha link

12/23/2021 01:26:31 am

Thank you for sharing this information. This is very useful.

Jason Lupa, PE

8/24/2022 10:18:11 am

For lobby ceiling configurations exceeding 15 ft in height or that are other than flat and smooth, detector locations are determined per NFPA 72 Chapter 17. The detector should be within 60" of the top of each elevator door opening to protect the opening, typically mounted on the wall. This is allowed because it is not being used for general detection, but rather, for the protection of the opening.

The IBC references NFPA 72. Chapter 21.3.5 references Chapter 17 for proper detector placement in elevator lobbies which have ceilings exceeding 15’. NFPA 72 [2016] 17.7.3.1.3 & 17.4.8 states: “If the intent is to initiate action when smoke/fire threatens a specific object or space, the detector shall be permitted to be installed in close proximity to that object or space.” The Annex adds: When specific objects or spaces are threatened by smoke or fire, such as at elevator landings that have high ceilings in excess of 15 feet, detection should be placed on the wall above and within 60 inches from the top of the elevator doors. This allows the detector to be located where it may be readily installed, tested and serviced while also providing the necessary smoke detection coverage for the landing. For multiple elevators utilizing wall-mounted detectors, each door opening must be within 5ft of a detector, measured horizontally (perpendicular to the doorway) per Chapter 17.

Leave a Reply.

Home
Our Cause

The Blog
The Forum

PE Exam Prep
The Toolkit
MeyerFire University

Pricing
Login
Support
Contact Us

MeyerFire.com is a startup community built to help fire protection professionals shine.
Our goal is to improve fire protection practices worldwide. We promote the industry by creating helpful tools and resources, and by bringing together industry professionals to share their expertise.

MeyerFire, LLC is a NICET Recognized Training Provider and International Code Council Preferred Education Provider.
All text, images, and media Copyright © 2016-2024 MeyerFire, LLC

We respect your privacy and personal data. See our Privacy Policy and Terms of Service. The views, opinions, and information found on this site represent solely the author and do not represent the opinions of any other party, nor does the presented material assume responsibility for its use. Fire protection and life safety systems constitute a critical component for public health and safety and you should consult with a licensed professional for proper design and code adherence.

Discussions are solely for the purpose of peer review and the exchange of ideas. All comments are reviewed. Comments which do not contribute, are not relevant, are spam, or are disrespectful in nature may be removed. Information presented and opinions expressed should not be relied upon as a replacement for consulting services. Some (not all) outbound links on this website, such as Amazon links, are affiliate-based where we receive a small commission for orders placed elsewhere.

Smoke Detector at Elevator Door & at Ceiling?

Leave a Reply.

ALL-ACCESS

SUBSCRIBE

COMMUNITY

YOUR POST

PE EXAM

FILTERS

ARCHIVES

PE PREP SERIES