Standard Spray Allowed in NFPA 13R Design?

3/20/2023

Can non-residential sprinklers be used in a NFPA 13R design?

NFPA 13R lists that residential sprinklers are permitted for use but does not list they are required to be used.

My understanding is that sprinklers used in NFPA 13 for light hazard would exceed or meet sprinkler requirements within NFPA 13R

On this premise, would installing a sprinkler for light hazard occupancy be exceeding NFPA 13R minimums, and thus be acceptable?

We have a dry sprinkler system we are installing in a small existing dormitory built with combustible construction.

We are using a NFPA 13R design approach which avoids sprinklering the attic space, with local AHJ approval. We need to have concealed sprinklers under request of the owner based on the occupancy, but there are not residential concealed dry pendent sprinklers, and the contractor is pushing to install recessed dry residential sprinklers.

Thanks in advance.

8 Comments

Anthony

3/20/2023 08:04:11 am

No you cant use standard response standard heads.
yes you can use quick response standard heads.

IF you use QR standard spray sprinkler you must use the design basis of NFPA 13. That would require a MINIMUM 900 sqft light hazard design. Assuming you're talking about inside the dwelling unit.

NFPA 13R-2016:
7.1.2 Quick-Response Sprinklers. Where quick-response
sprinklers are used in accordance with 6.2.1.3, the discharge
and design area requirements of NFPA 13 shall apply.

Key phrase here is "design area requirements of NFPA 13."

You cannot apply a 4 head residential sprinkler calculation to non-residential sprinklers.

Note: Residential sprinkler are designed and fire tested to operate with a special listing making them more effective for the smaller broken up and compartmentalized environment of a residential occupancy as compared to the larger open areas that standard spray sprinkler protect. They offer a flatter spray pattern with the objective of wetting walls to contain a fire to a single compartment allowing for residents to evacuate.

see the discussion of ESFR vs Extra hazard sprinklers for additional context on difference in sprinkler type:
https://www.meyerfire.com/daily/can-esfr-be-used-for-extra-hazard-group-2

Anthony

3/20/2023 08:10:54 am

Note you can get dry side wall sprinklers. but if you're using side wall sprinklers just us regular sprinklers that drain appropriately and are feed from the floor below.

Alex

3/20/2023 12:22:44 pm

If you are using a dry system because the attic isn’t heated, I would use Anthony’s approach and feed sidewalls from the floor below.

Great post, Anthony.

danefre

3/21/2023 02:59:09 pm

Question on that:

Is it just the density/area requirements that need to abide by NFPA 13? Can you still take a design area reduction even though closets/bathrooms are omitted? Maybe these dorms have common bathrooms over 55 sqft so that wouldn't be an issue.

Never done QR in 13R within dwelling units so not familiar with this.

To the OP: I would try to avoid dry systems in dwelling units. The 15s water delivery time is very difficult to achieve. Of course, this depends on the size of your system. Dry pendents + Dry valve is a lot of $$ compared to tenting over pipe with insulation.

Jesse

3/20/2023 08:24:14 am

I'm not familiar with dry, concealed pendents. I'm curious as to the driver for the dry system. Clearly the occupiable space is conditioned space. So is it just the attic that isn't conditioned? You're not protecting the attic so you might be able to use one of the freeze protection examples in 13R.

Shawn G.

3/20/2023 08:36:26 am

You will have to meet the requirements for 13 if you are going with a dry system (NFPA 13R 2016 - 5.4.3). Just fyi, I believe there is a required 15 second water delivery time associated with that.

3/20/2023 09:40:37 am

It sounds like NFPA 13-R 2019 6.2.1.3 is most applicable in this situation for using quick response sprinklers. Calculation as per 7.1.2. I am not sure why the limitation of four sprinklers within dwelling units other than to align with NFPA 13R calculation requirements or small room rules.

Outside dwelling units is layout of sprinklers as per 6.2.2.1 and calculated to 7.2.3 which does not state a limitation on the amount of sprinklers to be used within an area.

Pete H

3/20/2023 10:11:06 am

Reliable has a residential dry sidewall that's semi-recessed and not concealed.

Tyco does as well.

I'm going to agree with Anthony, the easiest installation for you would be concealed wet residential sidewalls fed from the floor below.

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.

Standard Spray Allowed in NFPA 13R Design?

Leave a Reply.

ALL-ACCESS

SUBSCRIBE

COMMUNITY

YOUR POST

PE EXAM

FILTERS

ARCHIVES

PE PREP SERIES