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Steve Dale
01-30-2009, 03:18 PM
I was called today and ask a series of questions about what the NFPA 72 (2002 edition) requirements are when installing a fire alarm system in an assemble. The assemble is a church located in the State of Georgia and the main meeting hall is 69' by 112' with a 12' ceiling. The questions are as follows (the codes are in red and my questions are in blue):

1.) What are the required height for strobes light in the assembly hall meeting room and the bathrooms? 7.5.4* Appliance Location. Wall-mounted appliances shall be mounted such that the entire lens is not less than 80" (6.7') and not greater than 96" (8') above the finished floor. ADI said that ceiling mounted strobes are the best way to go (less devices needed) and according to NFPA 72: 7.5.4.3* Performance-Based Alternative. 7.5.4.3.1 Any design that provides a minimum of 0.4036 lumens/m2 (0.0375 lumens/ft2) of illumination at any point within the covered area as calculated for the maximum distance from the nearest visual notification appliance to any point within the covered area shall be permitted in lieu of the requirements of 7.5.4 excluding 7.5.4.4. So am I right in assuming that ADI is correct as long as the installing company provides the necessary documentation regarding illumination coverage to the AHJ?

2.) What type and how many smoke detectors are required in the assemble hall meeting room 69' by 112' with a 12' ceiling? Assuming it is a smooth type ceiling, "then all points on the ceiling shall have a detector within a distance equal to 0.7 times the selected spacing". NFPA 72 - 5.7.3.2.3(E)*, I calculated ? smoke detectors based on the below drawing configuration. Am I right or wrong?

In addition, I was told that the fire alarm system must voice annunciate the fire detection. The strobes must be seen from every vantage point and there must be pull stations properly placed all in accordance with the NFPA 72 2002 edition. Any thoughts on these points?

Sparky49
01-30-2009, 04:10 PM
1. See Table 7.5.4.1.1(b) for ceiling-mounted appliances in NFPA 72.

2. 12 detectors

3. Most state building codes only require voice if the A occupancy has an occupancy of over 1000. NFPA 72 makes only a requirement for 1 pull. Your state building code will determine if manual stations will be required. In California, the pull station requirement is waived if the building is fully sprinklered.

Steve Dale
01-30-2009, 04:20 PM
Hey Sparky your fast!, I'm still working on this post between phone calls. I haven't completed the drawing yet it will be up soon.

Anyway, you said "See Table 7.5.4.1.1(b)" but it does not give the dimensions 69' by 112' or a ceiling height of 12'. How would you get the info from this table? I'm confused...

Also, How did you calculate 12 detectors?

Your expert input is greatly appreciated. I'm going to call my past student who ask me this question and have him view our comments. Thanks Steve :thumbsup:

Sparky49
01-30-2009, 04:33 PM
Anyway, you said "See Table 7.5.4.1.1(b) but it does not give these dimensions (69' by 112' ) or a ceiling height of 12". How would you get the info from this table? I'm confused...
That table will tell you how high to set the candela on the strobe for a given covered distance. For instance, a ceiling strobe covering an area 50' x 50' will have to be set to 115 candela at 12'. Over 20' high the strobe would have to be set to 150 candela. Obviously, a room as large as the one you mention will have to be covered by multiple ceiling appliances.

How did you calculate 12 detectors?
See this thread.
http://www.nlvca.org/forum/showthread.php?t=131

Your expert input is greatly appreciated. I'm going to call my past student who ask me this question and have him view our comments. Thanks Steve :thumbsup:
Not a problem, Steve. You're welcome.

Georgia Home Theater
01-30-2009, 04:41 PM
I'm the one that asked the questions to Steve. My name is Brian. I appreciate you gentleman helping me out with this.

Just so you know the room is existing construction and was a retail store. Now a church wants to meet in this room. The room is 96' by 112'. I screwed up before in stating it was 69' by 112'. The ceiling is drop ceiling, smooth and flat.


How many smoke detectors, what type and how should they be laid out?
How many ceiling strobes and how should they be laid out? ADI Distributing was suggesting an adjustable ceiling strobe that has intensity adjustment up to 184 candela.
What type of communication can it be monitored by? Meaning, can I use cellular backup and forgo a telephone line? I mention this because the church does not want the expense of a hard phone line.

Thank you so much in advance for helping me with these questions.

Brian

Sparky49
01-30-2009, 04:44 PM
I would divide the ceiling into 6 40' x 40' sections each with a ceiling strobehorn (or speaker-strobe if necessary) set at a minimum of 80 candela. That will satisfy NFPA 72.

Moderator Edit: This spacing is based on room dimensions of 69' x 112' originally quoted and not the revised dimensions of 96' x 112'. See below for the revised spacing. -Gary

Steve Dale
01-30-2009, 04:48 PM
Sparky, I've never viewed that link before: http://www.nlvca.org/forum/showthread.php?t=131 (http://www.nlvca.org/forum/showthread.php?t=131) , it is very informative :notworthy: Thanks for providing clear and concise insight about smoke detector placement. It can be confusing to many people, including myself. :sweatdrop:

Sparky49
01-30-2009, 04:57 PM
I'm the one that asked the questions to Steve. My name is Brian. I appreciate you gentleman helping me out. with this.

Just so you know the room is existing construction and was a retail store. Now a church wants to meet in this room. The room is 96' by 112'. I screwed up before in stating it was 69' by 112'. The ceiling is drop ceiling, smooth and flat.


How many smoke detectors, what type and how should they be laid out?

Now it will be 16 detectors in a 4 x 4 grid. I prefer photoelectric.
How many ceiling strobes and how should they be laid out? ADI Distributing was suggesting an adjustable ceiling strobe that has intensity adjustment up to 184 candela. Now it will be 9 ceiling strobes, strobehorns or speaker-strobes utilizing 40' x 40' spacing and set to a minimum of 80 candela OR 6 appliances at 50' x 50' spacing set to a minimum of 115 candela. I prefer the GE Genesis product myself. The model will depend whether or not voice evacuation will be required.
What type of communication can it be monitored by? Meaning, can I use cellular backup and forgo a telephone line? I mention this because the church does not want the expense of a hard phone line. You can use a various combination of things. Just remember that fire alarm systems require 2 means of transmission.

Sparky49
01-30-2009, 05:00 PM
Sparky, I've never viewed that link before: http://www.nlvca.org/forum/showthread.php?t=131 (http://www.nlvca.org/forum/showthread.php?t=131) , it is very informative :notworthy: Thanks for providing clear and concise insight about smoke detector placement. It can be confusing to many people, including myself. :sweatdrop:


Glad to help.

Georgia Home Theater
01-30-2009, 05:09 PM
Sparky, do I need smoke detectors? There is an automatic sprinkler system monitored by an monitoring station and pull stations. I seem to believe they are needed in this case.

Sparky49
01-30-2009, 05:22 PM
Sparky, do I need smoke detectors? There is an automatic sprinkler system monitored by an monitoring station and pull stations. I seem to believe they are needed in this case.

Probably not. That question can't be answered in the NFPA 72 which only requires 1 detector at the FACP and 1 pull station. You'll have to look in the Georgia Fire Code for fire alarm requirements in "A" occupancies and I would also suggest checking the local Municipal Code for any changes the municipality may have made to the State Code. If your code is IBC based, most likely not unless it's required for area activation of a smoke/fire damper.

Sparky49
01-30-2009, 05:41 PM
Google says that the 2005 Georgia Fire Code is based on the 2003 IFC so I'll wager that smoke detectors and pull stations will not be required if the building is fully sprinklered.

Sparky49
01-30-2009, 09:37 PM
If your project is part of a larger retail complex, chances are very good that the sprinkler system may already be monitored. Up until recently, fire alarm systems did not require monitoring by themselves but sprinkler systems did. UFC-based codes only required monitoring on systems with 100 sprinkler heads or more. More recent IFC-based codes have changed that requirement so I again recommend reviewing your local Georgia Fire Code.

Churches are Assembly (A) occupancies. Your project will likely require a voice evacuation system if it is an A1 occupancy holding more than 1000 people.

Also remember that you'll have to submit plans to your local AHJ including voltage drop calculations for each NAC and a battery calculation.

I'll be glad to help if you have any other questions.

Gary

Sparky49
02-01-2009, 03:26 AM
After checking a little further, I found that Georgia has no actual fire code. What they do have is a small group of amendments to the International Fire Code (IFC).

Per section 907.2.1 of the IFC, Group A occupancies only require a manual fire alarm system (pull stations only). However, the manual system is not required if the building is protected by a full sprinkler system and the notification appliances are activated by the water flow. That means only 1 pull station will be required per NFPA 72 located either by the FACP or by the sprinkler riser depending on your AHJ requirement.

Besides the 1 smoke detector located at the FACP per NFPA 72 requirement, the only other smoke detectors that may be required would be those needed for smoke/fire damper activation. For example, a damper installed in a ceiling opening would require a spot detector in the affected room. Dampers located in corridor walls or corridor ceilings would require smoke detection throughout the corridor. Dampers located within ducts would require a duct detector on the duct within 5 feet of the damper.

I've attached all of section 907 (Fire Alarm and Detection Systems) from the 2003 IFC as a pdf document. This will pretty much cover all of your requirements when used in conjunction with NFPA 72.

one_crf_pilot
02-05-2009, 06:19 PM
Good job Gary....

Sparky49
02-05-2009, 07:13 PM
Good job Gary....

Thanks!

Georgia Home Theater
02-05-2009, 07:39 PM
Thank you! That was a huge help!
Brian

Sparky49
02-05-2009, 07:45 PM
Thank you! That was a huge help!
Brian

You're welcome. That's why I'm here... :)