I have a covered mall under 30' tall that requires hose valve connections in accordance with the International Building Code, Section 905.3.3.

Do these hose valve connections count as a standpipe that requires a monitored isolation valve as per NFPA 14 6.3.2?

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Should return air duct smoke detectors associated with a fan system close only the associated damper and shutdown the fan or close all dampers on the system (including supply return spill and outside air)?

How should outside air and spill air fire smoke dampers be controlled? Should these to be controlled by fire alarm?

Thanks in advance.

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Solution | Posted 07/09/20

When performing hydraulic calcs for NFPA 13 residential occupancies, what is the best approach to address small Ordinary Hazard rooms, such as janitor's closets or laundry rooms located on an otherwise-residential floor?

Room design is not always an option due to the prerequisites listed in NFPA 13, but area/density seems excessive when the calculation method given for residential occupancies is the 4 most demanding adjacent heads.

A 1,500 square foot area seems to go well beyond this approach, defeating the purpose of the residential design method. Other than room design, is there a justifiable code basis for calculating only the heads in the most demanding ordinary hazard room on such a floor?

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A 4-inch schedule 40 main is routed parallel in-between two beams and requires a trapeze hanger. The main is 2 ft. from one beam and 8.5 ft. from the other for a total span of 10.5 ft. What is the smallest schedule 10 pipe diameter capable of supporting this main as a trapeze hanger?
a. 2-inch
b. 2-1/2 inch
c. 3 inch
​d. 3-1/2 inch

Solution | Posted 07/08/20

We are having a discussion in our office; we are doing a 14,000 square foot addition. The existing riser has 2 systems that are approximately 40,000 square foot each. On the middle of one of the systems there is a dry system for the loading dock.

Does the dry system count as its own system or is it included in the 40,000 square feet for purposes of a total system area?

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This week is the third of our 2020 PE Prep Series - it's 20-weeks worth of mini Fire Protection PE Exams. 

Each week we'll post the leaderboard here with the results of that week's exams. To see full leadership board and more details, visit the PE Prep Series page here.
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Solution | Posted 07/07/20

I am working on a project with an attic. The pitch of the attic is 12:12 and the structure is combustible construction. The area is being used as a mechanical room so the fire sprinkler layout will be Ordinary Hazard Group 1 and a wet system will protect the space since the temperature will be maintained above 40ºF. Standard spray sprinklers are being utilized because Attic sprinklers are only listed for Light Hazard use.

Using a quick response area reduction, the remote area will be 1,500ft² (OH1) x 1.3 (30% pitch increase) x 0.6 (40% quick response decrease) = 1,170ft².

Since the sprinklers are spaced along the 12:12 pitch, the floor area in plan view is substantially less than the square footage being protected along this steep slope which picks up a ton of sprinklers when I draw my remote area based on the floor. I can't find any guidance in NFPA 13 about remote area on a slope besides the typical 1.2 x √RA split between sprinklers.

Should the 1,170ft² remote area be measured based on the coverage of the sprinkler along the slope (as the protection is spaced) or should the remote area be based on the floor even though it picks up way more sprinklers than 1,170ft² of actual coverage based on the slope?

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Anybody in this group has experience to design or approval of parking stackers inside the building?

This is outside the code will be reviewed as Amended Means & Methods.

They occur on two different projects (1) The Car's engine shall be off when enter the parking garage and electronic left will park the cars in stack, and (2) The car will be driven inside the garage to platform to be parked.

In both cases the fire sprinkler design density, exhaust system and means of egress requirements are in question.

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Thanks to everyone on the forum for another record month. This site was created exactly for the fire protection knowledge sharing, and it is your input and expertise that makes it happen. Here are the top commenters for June 2020:

I am currently renovating a lab for a healthcare facility and am trying to figure out which NFPA 13 hazard classification an autopsy or morgue would be under.

Any suggestions?

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We have an exit enclosure that is rated as Class I Division I. My understanding of an accessible route and means of egress, is that it is a "safe" means of egress.

Can an accessible route have a Class I Division I (explosion hazardous classification), or does it need to be purged and pressurized according to Type X requirements?

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We have a fire pump room which is very constrained. 

NFPA 20 (Edition 2016), A.4.21.1.2 (2) For horizontal split-case fire pumps, there should be a distance of not less than 10 diameters of suction pipe for side connection (not recommended) to the fire pump suction flange.

The main pumps have a capacity of 3000 gpm (two are electrically-driven and two are diesel-driven) with two jockey pumps at 300 gpm capacity. All are in one room. Pumps suction and discharge pipe  size is 12" as per Table 4.27 (a).

In this scenario, what is the meaning of 10 diameters - is it 10 times of suction size diameter of pump (means 10x12= 120") or something else?

Why is this requirement only limited to suction and why not for discharge side as there is tapping for pressure monitoring? Any thought would be much appreciated.

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I’m a Fire Inspector/Design Reviewer and I have a problem that I’ve been trying to tackle.  NFPA 14 systems are designed for high volume low pressure firefighting tactics, but the majority of fire departments in America use high pressure low volume equipment.  Here are the key points: 

NFPA 14 Type 1 standpipe systems provide 250 gpm at 100 psi with 200 ft to most remote location in a sprinkled building.  In the firefighting world this equates to a fire attack with 250 ft of 2.5” hose and a 1-1/8” smooth bore nozzle.  The 250 ft comes from, 50 ft to stretch to the hose connection on the floor below the fire floor and 200 ft to most remote location on the fire floor.  Fire ground friction loss calculations for 250 gpm through 2.5” hose is 15 psi loss per 100 ft.  A smooth bore nozzle requires 50 psi to operate properly.  We are stretching from the floor below so we have roughly 6 psi head loss.  So the required pressure at the hose valve is 93.5 psi.  You can see that the NFPA 14 design requirements are in line with the use of this higher volume lower pressure equipment.  

The problem is that 2.5” hose is very heavy and requires a lot of man power.  2.5” attach lines are used by large city departments like Seattle, New York, and Chicago.  Many smaller city and town departments don’t have the staffing to stretch such big lines.  We may only have a couple firefighters stretching an attack line where as the big cities would have 6 or more.  So we use smaller more maneuverable hose and more pressure demanding fog nozzles.

A more typical firefighting set up in the majority of fire departments would be 1.75” or 2” hose and a 75 psi or 100 psi fog nozzle flowing between 150-200 gpm.  I’ll use Bozeman as an example.  We use 1.75” hose, a 75 psi fog nozzle, and a target flow of 175 gpm.  In our experience the pressure loss per 100-ft of 1.75” hose with 175 gpm is 50 psi.  So if we need to stretch 250 ft of hose, we would need 206 psi at the hose valve on the landing below the fire floor.  Add in that the tallest building we have is 11 stories, and a 25 psi pressure loss adjustment for pumping the FDC, and we are up to 285 psi required at the FDC.  

There seems to be a disconnect between the design world and the firefighting world.  This poses all sorts of problems such as compromising sprinkler systems and old standpipe systems since they may have components that are not rated for such high pressures.  Even worse are systems with pressure reducing hose valves that wouldn’t even allow us to pump the FDC to get anywhere near the pressures we need with our equipment (see One Meridian Plaza fire in Philadelphia).  

I think that Fire Departments need to communicate their design needs to designers, and Fire Departments also need to look at the equipment they use, and see how they can make changes to operate more closely to what NFPA 14 systems are designed for.   

If you have any knowledge on this topic I would love to hear it, thanks in advance.

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Does anyone have any pressure maintenance pumps installed on their sprinkler systems without having a fire pump?

In other words, having a pump on the sprinkler system that is only there for the purposes of preventing a false alarm (due to pressure ebbs and spikes in the water supply) instead of boosting the water pressure like a traditional fire and jockey pump combination.

We have some legacy jockey pumps installed like this and it runs into a grey area for maintenance as they don't affect the performance of the sprinkler system they are connected to. Any thoughts?

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We are pressure testing a sprinkler system but there is no water available.

How much air pressure should be used to equal a 200 psi hydro test?

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Design criteria for storage occupancies have changed substantially over the years from pipe schedules to the NFPA 231's to NFPA 13, 2016. Everyone talks about "grandfathering" old system designs, but no one can ever point out any specific codes, standards, or formal documents that give any solid guidance on this matter.

In our state, this situation varies by jurisdiction, but the opinions are all over the place and usually wind up at the classic "ask the AHJ". This is very time consuming and often times not very helpful since most of them enforce the newest NFPA editions when unless you can provide as-built documentation which we can't do 95% of the time for old buildings. We all know that it depends on the situation, but there has to be some level of formalized consistency out there to start with.

As a NICET certified Fire sprinkler designer, I have my own professional opinions on the matter based on my understanding of the intent of grandfathering and my own project experiences.

​That said, can anyone point me to specific codes, standards, or formal documents that I can utilize to create a formalized opinion that can be submitted to local AHJ's for a more "standardized" understanding?

I'm pretty well versed in NFPA 13 so I'm really looking for IBC, NFPA 101, NFPA 1 references, but all feedback is appreciated.

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Anyone familiar with the historic tax credit requirements in Massachusetts regarding minimum distance of mechanical systems from the windows?

We are being asked to keep all pipe and heads a minimum of 3'-0" from exterior windows. Not a huge issue for installation, we're just curious where this is stated. We haven't been successful in getting this information from the A&E team. Any ideas? Thank you.

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I'm working within a campus environment, and costs are something that always arise at some point during ITM conversations.

Does anyone have a great resource or tool to help to estimate a ballpark cost of ITM over a life of the building?

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Does the 'small room rule' apply to NFPA 13D sprinkler systems?

I could not find any mention of it in 13D. If 13D does not allow it, why not?

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While working on a sprinkler project I came across a Spiral Freezer. It is a conveyor system. 

I am mostly interested in how it needs to be protected. At this time I see two and neither have protection within the Freezers. This facility is not new, but I know they are upgrading the fire protection throughout.

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