Archives 2001
Issue No. 1
Issue No. 2
Issue No. 3
Issue No. 4
Issue No. 5
Issue No. 6
Issue No. 7
Issue No. 8
Issue No. 9
Issue No. 10
Issue No. 11
Issue No. 12
Issue No. 13
Issue No. 14
Issue No. 15
Issue No. 16
Issue No. 17
Issue No. 18
Issue No. 19
Issue No. 20
Issue No. 21
Issue No. 22
Issue No. 23
Issue No. 24
Issue No. 25
Issue No. 26
Issue No. 27

  Log In

 

August 26, 2001

                   Northwest NICET Newsletter
================================================================
Volume 1 Issue 9                                       8-26-2001
================================================================

        News for Fire Protection Engineering Technicians
        ------------------------------------------------

Contents:
---------
- News
- Tech Tip
- Class Schedule
- Administrivia

================================================================
NEWS
================================================================

ORAFAA
------
The reactivation activities of the Oregon Automatic Fire Alarm Association
(ORAFAA) is heating up! If you would like to participate in this worthwhile
effort to make improvements to our industry in Oregon, contact Larry
Tate --> larry@nwfire.com.

----------------------------------------------------------------

NEVADA ADMINISTRATIVE CODE
CHAPTER 477 - STATE FIRE MARSHAL
LICENSES AND CERTIFICATES OF REGISTRATION
NAC 477.300 Application; requirements; effect; branch offices; designer of
fire sprinkler and alarm systems.
8.  On and after January 1, 2003, a designer of fire sprinkler and alarm
systems must hold a Level II certification from the National Institute for
Certification in Engineering Technologies (NICET) or an equivalent
certification.

Source: http://www.leg.state.nv.us/NAC/NAC-477.html

================================================================
TECH TIP
================================================================

Modifying Smoke Detector Spacing due to High Air Movement
---------------------------------------------------------

This is project 2 of 2 for he Redmond seminar attendees. Read through the
example then perform the problem that follows and send it to me by 9/9/01.
If you have questions, email me at TheBakerGroup@home.com or call me 8am-5pm
Mon-Fri 503-209-7345.

NFPA 72-1999 2-3.4.1.1 The location and spacing of smoke detectors shall
result from an evaluation based on the guidelines detailed in this code and
on engineering judgment. Some of the conditions that shall be included in
the evaluation are the following:
(1) Ceiling shape and surface
(2) Ceiling height
(3) Configuration of contents in the area to be protected
(4) Burning characteristics of the combustible materials present
(5) Ventilation
(6) Ambient environment

NFPA 72-1999 2-3.6.6 The purpose and scope of 2-3.6.6 shall be to provided
location and spacing guidance for smoke detectors intended for early warning
of fire in high air-movement areas.

NFPA 72-1999 Table 2-3.6.6.3 Smoke Detector Spacing Based on Air Movement

In the following example, determine the de-rated spacing (if any) for
spot-type smoke-sensing fire detectors to be installed in the room based
upon air movement.

+---------------------------------------------+ -
|     +-+     +-+     +-+     +-+     +-+     | ^
|     +-+     +-+     +-+     +-+     +-+     | |
|     each air supply register = 360 CFM      | |
|     +-+     +-+     +-+     +-+     +-+     | |
|     +-+     +-+     +-+     +-+     +-+     | |
|                                             | 40'
|     +-+     +-+     +-+     +-+     +-+     | |
|     +-+     +-+     +-+     +-+     +-+     | |
|                                             | |
|     +-+     +-+     +-+     +-+     +-+     | |
|     +-+     +-+     +-+     +-+     +-+     | |
+---------------------------------------------+ -

|<------------------ 75' -------------------->|

Smooth and flat ceiling height = 12 feet
Air return = air supply


Step 1)
-------
Table 2-3.6.6.3 describes the allowable area of detection per detector in
square feet. Because NFPA 72 allows us to use 30 feet spacing as a guide
[2-3.4.5.1.1] --> 30 ft X 30 ft = 900 ft^2. If all of the air in the room is
changed or turned over less than 7.5 times per hour (or less than 8 minutes
per air change), then no modification to spacing is required.

To determine whether modification to spacing is required in this example, we
must determine how often all of the air in the room is changed.


Step 2)
-------
The answer we are seeking will be expressed in air changes per hour (or
minutes per air change);
The volume of the room in ft^3 per hour.

To arrive at this we must determine the volume of the room in cubic feet:

Length X Width X Height = Volume
75 ft X 40 ft X 12 ft = 36000 ft^3

Room volume = 36000 ft^3


Step 3)
-------
Without air supply (and air return) we wouldn't be required to modify
spacing, and it would get rather stuffy. The drawing shows that each air
supply vent provides 360 cubic feet per minute and that there are a total of
20 air supply vents. To determine how rapidly the air in the room is turning
over, we multiply the air supply per vent times the total number of vents:

360 ft^3/minute X 20 = 7200 ft^3/minute

Air supply = 7200 ft^3/minute


Step 4)
-------
How often is the entire volume of air in the room replaced?

Volume of the room = 36000 ft^3
Air supply rate = 7200 ft^3/minute

36000 ft^3      1 minute
------------- X ---------
1 Room Volume   7200 ft^3
(air change)

Using algebra, the ft^3 units cancel each other out and we're left with
minutes per air change:

5 minutes / air change

or;

1 air change   60 minutes
------------ X ---------- = 12 air changes per hour
5 minutes      1 hour


Step 5)
-------
At 5 minutes per air change (or 12 air changes per hour), Table 2-3.6.6.3
requires 625 ft^2 spacing.

To determine spacing in linear feet, we have to find the square root of 625
ft^2 = 25 ft.

[30 ft spacing -> 30 ft X 30 ft = 900 ft^2; sqrt of 900 ft^2 = 30 ft]

The modified spacing for this example is 25 ft.


Try this one on your own
------------------------

Determine the de-rated spacing (if any) for spot-type smoke-sensing fire
detectors to be installed in this room based upon air movement.

+-------------------------------------+ -
|     +-+     +-+     +-+     +-+     | ^
|     +-+     +-+     +-+     +-+     | |
| each air supply register = 200 CFM  | |
|     +-+     +-+     +-+     +-+     | |
|     +-+     +-+     +-+     +-+     | |
|                                     | 20'
|     +-+     +-+     +-+     +-+     | |
|     +-+     +-+     +-+     +-+     | |
|                                     | |
|     +-+     +-+     +-+     +-+     | |
|     +-+     +-+     +-+     +-+     | |
+-------------------------------------+ -

|<--------------- 32' --------------->|

Smooth and flat ceiling height = 10 feet
Air return = air supply

================================================================
CLASS SCHEDULE
================================================================

Clackamas Community College is sponsoring a 16-hour weekday evening seminar
in September:

--> 9-10-2001 6pm - 10pm NICET Certification application process

--> 9-12-2001 6pm - 10pm Fire Alarm Systems Level I Element Review

--> 9-17-2001 6pm - 10pm Fire Alarm Systems Level II Element Review part 1

--> 9-19-2001 6pm - 10pm Fire Alarm Systems Level II Element Review part 2

Call 503-657-0135 to register.

================================================================
ADMINISTRIVIA
================================================================

I've added a page to my web site called NICET Certification Requirements by
Fiefdom --> http://www.geocities.com/michaelbaker/fiefdom.html

Send your contributions, suggestions, comments, and questions to -->
mailto:TheBakerGroup@home.com

To unsubscribe, click the reply button and type 'unsubscribe' in the subject
line.

Good luck and have fun!

Mike  http://go.to/baker

================================================================
:::::::::::::::::::::::: ADVERTISEMENT :::::::::::::::::::::::::
================================================================

Purchase the book used in my seminars:

Fire Alarm Handbook
NICET Level I and II
Element Review
ISBN 0-9707229-0-7

It is available in the Portland metro area at:

Building Tech Bookstore http://www.buildingtechbooks.com/
8020 SW Cirrus Drive
Beaverton, OR 97008-5986
(503) 641-8020
(800) ASK-BOOK

In the Seattle metro area at:

CW Cable, Inc.
20422 87th Ave.
Kent, WA 98031
(253) 872-6590
(800) 444-4961

or nationwide through:

NAAA [National Alarm Association of America] http://www.naaa.org/nicet.htm
800-283-6285

----------------------------------------------------------------

Coming soon...
Fire Alarm Handbook
NICET Level III and IV
Element Review
ISBN 0-9707229-1-5

With seminars to follow...

================================================================
The NICET acronym belongs to:
National Institute for Certification in Engineering Technologies
http://www.nicet.org
--------------------------------------O/-----------------------
NW NICET Newsletter Copyright (c) 2001 Michael B. Baker
Send a link to a friend        
 

 

Home - Clients - Book Store - NICET Level I - NICET Level II - NICET Level III - NICET Level IV - Glossary - External Links - Licensing - Photographs - Employment - Disney Crud(SM) - Archives 2001 - Archives 2002 - Archives 2003 - Archives 2004 - Archives 2005 - Archives 2006 - Archives 2007 - Archives 2008 - Archives 2009 - Archives 2010 - Archives 2011 - Archives 2012 - Archives 2013 - Misc

ET NewsSM content copyright © 2017
by Michael B. Baker. All rights reserved.
ISSN 1554-074X

RSS Content
Some information may be found within this web site that is reprinted with permission from one or more of the following: NFPA 70 National Electrical Code®,NFPA 72® National Fire Alarm Code®, & NFPA 101® Life Safety Code®, Copyright© NFPA, Quincy, MA 02269.

This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.