Residential vs. Quick Response for a Hotel?

8/30/2021

I'm working on an NFPA 13 three-story hotel.

Code permits residential sprinklers or quick-response sprinklers in the dwelling units and adjoining corridors.

Is there any advantage to using one type of sprinkler over the other?

Thanks in advance for your comments.

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15 Comments

Alex

8/30/2021 06:20:44 am

Hi Anonymous,

When using residential sprinklers, you are allowed to increase your maximum coverage to the manufacture’s specifications (NFPA 13 (2016) 8.10.3). Where as when using your typical K5.6, you are limited to 15’ on center (NPA 13 (2016) Table 8.6.2.2.1(a)).

In addition, you are able to reduce your calculation to the most remote (4) sprinklers (NFPA 13 (2016) 11.3.1.1). This will in turn reduce your required pipe size.

Thanks!
Alex

Jeffrey Still

9/16/2021 01:34:51 pm

So are you not able to use the manufacture's specifications with standard pendants and uprights? Only residential?

ex: If I had EC pendant, with manufacture's spec @ 20 x 20 coverage, I still have to stick to table 8.6.2.2.1 maximum protection specs of 225 for light hazard?

Isabelle

8/30/2021 08:14:28 am

Also, remember that residential sprinklers are listed specifically to address the life safety of occupants who might be in the room where a fire originates. This is a big advantage!

Isabelle

Ahmed

8/30/2021 08:21:54 am

I agree with Alex. You can use both, the maximum manufacturer sprinkler spacing and the maximum area of coverage
8.10.2.1
Areas of coverage shall be in accordance with the
manufacturer’s listing.

Todd Wyatt

8/30/2021 08:23:37 am

The 2021 IBC (scoping document ... where required) permits NFPA 13R sprinklers in Group R Residential occupancies IF the building meets all the following : (4) stories of fewer abve grade plane, floor level of highest story is 30 feet or less above the lowest level of fire department vehicle access, floor level of lowest story is 30 feet or less below the lowest level of fire department vehicle access.

If this hotel (Group R-1) meets the above requirements, a NFPA 13R (reference standard ... how it is to be instaled, maintained, and inspected) automatic sprinkler sytem is permittable.

Darin Golden

8/30/2021 11:02:17 am

Be careful with only considering the IFC Ch.9 scoping requirements for when a 13R is allowed. Many architects use a NFPA 13 upgrade for compliance with IBC Ch.5 (Building Heights and Areas) e.g. Group R-2, Type VB construction only allows two stories but you get an extra story if you upgrade the system to 13. There are many other allowances, e.g. egress travel distance, allowable opening %, etc, only when 13 is used. So its best to get your required sprinkler standard from the building designer.

chad

8/30/2021 01:35:45 pm

Amen Darin.

A sole reliance on "scoping documents" is a bad practice that only causes problems down the line. A holistic approach is required when applying all codes..

Patrick

9/3/2021 09:30:28 am

Darren & Chad,

I agree that discussing these issues with the building designer and/or other trades is critical. We ran across a General Contractor who decided to swap metal studs for wood studs for cost reasons, and they were completely unaware that this would impact the requirement of above ceiling sprinklers as they had created a combustible concealed space. These decisions cannot be made is silos. Communication and collaboration is key in many instances to end up with the best design.

Todd Wyatt

8/31/2021 08:26:00 am

If the hotel-in-question does not meet all (3) conditions as outlined by 2021 IBC 903.1.2 NFPA 13R sprinkler systems, then NO matter what NFPA 13R may permit, it is not permitable by the IBC.

NFPA 13R is an IBC referenced standard and the IBC is the scoping Code. The NFPA 13R and NFPA 13 "in essence, are part of this (IBC) code to the EXTENT of the reference to the standard" as outlined in the 2021 IBC Ch 35 Reference Standards, User Note. The IBC, as the scoping Code, identifies where and where not the NFPA 13R can be used and the NFPA 13R "provides requirements for material and methods of construction" for the installation, testing, and maintenance for these automatic sprinkler systems.

If the IBC does NOT permit an installation of a NFPA 13R system based on the hotel NOT meeting the (3) requirements 903.1.3, the NFPA 13R cannot "overrule" this restriction just because the IBC identifies it as a "Referenced Standard."

Casey Milhorn

8/30/2021 08:40:05 am

As Alex said, it is a huge advantage to use residential type sprinklers. They allow for a 4 head design at a .05 gpm density, and you get to take advantage of the different K factors and spacing. There is a huge selection of heads with different capabilities. The downside is that you need to read all the listing requirements carefully. It is not a one size fits all.

Also as Todd says, you might be able to go 13R. Which sometimes isn't a huge difference, especially in the way you calc. The big difference will be if you have combustible concealed space or combustible attic spaces. That's where the cost comes in. BUT, if you are a contractor/designer I would stay away from being the engineer. You can ask it in a RFI, but don't try and be the specifier. IMO.

Jessica Lutz

8/31/2021 09:41:03 am

I concur with Casey on the advantages to having a variety of K-factors and pressure requirements to choose from.
If that's the route you go, definitely pull the cutsheet and read it VERY carefully.
It can vary depending on the manufacturer.

So funny, everyone thinks residential occupancy design is super simple and "cookie cutter," but it NEVER is.

Joshua Freedman

8/30/2021 09:53:57 am

I would just like to piggy back one advisory onto the 13R suggestions. 13R systems are less expensive to install but the client should be advised that 13R systems are designed for life safety and most insurance companies do not give sprinkler credit for 13R systems and will only provide their sprinklered rates for full NFPA 13 (0.10/4head) systems, so the money they save installing the 13R might be lost in insurance premiums in the long run.

Alex

8/30/2021 10:03:28 am

Awesome point, Joshua.

Jesse

8/30/2021 10:38:34 am

There's a big advantage in spacing with 13R sprinklers. But, if the floor plan is such that going to maximum spacing in a compartment isn't a benefit, then there may be value in using a different sprinkler.

John G

8/30/2021 05:46:44 pm

I agree with Joshua 100%. R-1,R-2: check the architectural code sheets, and look for the “ trade offs “ the architect took to build the building and I ve found that you can only put a 13 system in it. That will limit you to 5 or 7 heads in a corridor at a .10 density.
Or largest room, and I include 2 heads in the corridor( theory of door propped open). That will end up with 4 heads calc d. If bathrooms are back to back, you usually cannot delete the heads in them 55 sq ft, unless they have the required 30 minutes like the common separation wall.
I ve found commercial qr heads gives me more flexibility in the calculations. The smaller res orifice, at the .10 density spikes the pressure.

Residential vs. Quick Response for a Hotel?

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