This presentation by David Sylvester of the Mircom Group of Companies discusses visible signaling devices in fire alarm systems. It walks through industry definitions, the physics of strobe lights, building code requirements, design best practices and Mircom's solutions for difficult environments.
2. 1. Definitions & Industry Trends
2. Physics of Visible Appliances
3. Visible Appliances Building Code Requirements
4. "Strobe” Layout Design Practices
5. Mircom Solutions for Difficult Environments
3. 1. Definitions & Industry Trends
A visible signal device which utilizes high intensity flashing
light to notify occupants of a building on the activation of the
fire alarm system.
4. NEEDS
“In Canada, the number of seniors aged 65 and
over increased 14.1% between 2006 and 2011
to nearly 5 million”
“According to a new Census Bureau
report, there were 40.3 million people age 65
and older on April 1, 2010, up 5.3 percent from
35 million in 2000”
6. 2. Physics of Visible Appliances
Candlepower is an obsolete scientific unit of luminous intensity
based on the light emitted from a candle made to a specific
formula
The candlepower as a scientific measure was replaced in 1948 by
the international unit (SI) known as the candela
Measures only the “PEAK”
• Candlepower and Candela have an equal ratio 1:1
INTENSITY
• Peak candlepower measures only the peak
PEAK
AREA
100 200 300 400 500
TIME IN MICROSECONDS
7. Effective candela rating is calculated by the total area under the light
intensity curve and includes all of its light energy
INTENSITY
Light
CANDELA
Intensity
Curve
100 200 300 400 500
TIME IN MICROSECONDS
8. • Measures the intensity in candela and the distance from the
light source
• This is called illumination and can be calculated by the following
formula
INTENSITY OF LIGHT DIVIDED BY THE DISTANCE SQUARED
SOURCE
9. 1. Peak Candlepower measures only the peak and looks at the
performance over a short period of time.
2. Effective Candela measures the total light energy, but does
not take into consideration the distance from the light source.
3. Illumination (Lumens or Foot-Candles) takes both factors
into consideration by measuring the power of the light and the
distance from the light source.
10. 3. Visible Appliances Building Code Requirements
NFPA 101 & NBCC require strobes in the following areas…..
•Where Ambient Sound Levels Exceed 87dB
(Noisy manufacturing plants or diesel generator areas)
•Where ear protection is worn
11. 3. Visible Appliances Building Code Requirements
NBCC & NFPA 101 require strobes in the following areas…..
•Sound insulated or audiometric booths
(Recording Studios or Sound Testing Rooms)
•Entertainment areas where sound levels may exceed 100dB
(Night Clubs & Concert Halls)
12. 3. Visible Appliances Building Code Requirements
NFPA 101 & NBCC require strobes in the following areas…..
•Building or portions of a building for persons with hearing impairment
•Minimum 10% of Hotel Rooms
13. 3. Visible Appliances Building Code Requirements
Installation of strobes in public corridors for
B Occupancy (Health Care) A Occupancy (Assembly
Strobes permitted in lieu of audible Areas)
signals in compartments including Strobes are required in
operating rooms and recovery corridors used by the
areas such as ICU and CCU public, and also floor areas
where public may congregate
14. 3. Visible Appliances Building Code Requirements
Installation of strobes in public corridors for
D Occupancy (Office) E Occupancy (Mercantile)
15. 3. Visible Appliances Building Code Requirements
OBC Not Required
•In classrooms •In care occupancy for up to 10
(A Occupancy) persons (B Occupancies)
•3.2.4.18.(6) (a) •3.2.4.18.(6) (b)
19. 39.2 meter corridor
4.6 m 4.6 m
30 m
Corridor Length (m) Minimum # of 15
Minimum 2 (15 Candela) Strobe
6m less in width Candela Strobes for corridor installations
0-9 1
Additional strobes placed not
10 - 40 2
more than 30m apart
41 – 70 3
71 – 100 4
Strobe must be located no
101 - 130 5 more than 4.6m from end of
131 - 160 6 corridor
20. 20.4m
4.6 20.4m
50 meter corridor
4.6 m 4.6 m
40.8m
Corridor Length (m) Minimum # of 15 Candela
Minimum 3 (15 Candela) Strobe
6m less in width Strobes for corridor installations
0-9 1
10 - 40 2 Additional strobes placed not
41 – 70 3 more than 30m apart
71 – 100 4
101 - 130 5
Strobe must be located no
more than 4.6m from end of
131 - 160 6
corridor
21. 38m
4.6 22m
4.6m
4.6m
4.6m
5.4.5.14 Where there is an interruption
of the concentrated viewing path, such 4.6m
as a fire door, an elevation change, or
any other obstruction, the area shall be 22m
treated as a separate corridor. Minimum 2 (15 Candela) Strobe for
corridor installations per corridors
Corridor Length Minimum # of 15
(m) Candela Strobes
6m less in width Strobe must be located no more
0-9 1 than 4.6m from end of corridor
10 - 40 2
41 – 70 3
71 – 100 4
101 - 130 5
131 - 160 6
23. 5.4.5.3 Wall-mounted visible signal
devices shall be installed such that the
entire lens is not less than 2000 mm
and not more than 2400 mm above
the finished floor.
Mircom offers FS-340 (“Potter”) and the “System Sensor” models
for wall mounted applications
24. LIGHT OUTPUT FOR WALL-MOUNTED VISIBLE SIGNAL DEVICES FOR VARIOUS ROOM SIZES
Maximum Area 1 Strobe per area 2 Strobes per area 4 Strobes per area
Coverage in (m)
6.10 X 6.10 15 N/A N/A
8.53 X 8.53 30 15 N/A
9.14 X 9.14 34 15 N/A
12.2 X 12.2 60 30 15
13.7 X 13.7 75 60 30
15.2 X 15.2 94 60 30
16.5 X 16.5 110 60 30
18.3 X 18.3 135 95 60
21.3 X 21.3 185 95 60
24.4 X 24.4 240 135 60
27.4 X 27.4 304 185 95
30.5 X 30.5 375 240 95
33.5 X 33.5 455 240 135
25. 4. "Strobe” Layout Design Practices
Application: 6m X 5m Room
6m
ULC-S524-06 Table 5 for wall mounted
devices requires a 15 Candela strobe for
a maximum room size of (6.10m X
6.10m)
5m
? Intensity Maximum Area
Coverage in (m)
1 Strobe
per area
2 Strobes
per area
4 Strobes
per area
6.10 X 6.10 15 N/A N/A
ONE 15 Candela Strobe will meet this
application
26. 4. "Strobe” Layout Design Practices
Do we mount the strobe on the short or long side of the wall?
Installation Tip -Spacing
allocation for wall
Long Side Coverage? mounted strobes are to be
located (at the mid-point
of the longest side of the
6m area served) NFPA 72
5m
Short Side
Coverage? 15 Candela
The mid-point of the longest side is the preferred method
27. Application - Four 15
Maximum Area
Coverage in (m)
1 Strobe
per area
2 Strobes
per area
4 Strobes
per area
Candela Strobes in a 12.2m
X 12.2m Room
12.2X 12.2 60 30 15
12.2 m In this example, we are
meeting minimum Candela
rating (illumination) but
the strobe allocation is
incorrect
Area Coverage of each
appliance is not maximized
12.2 m Moreover, if these were
(Horn/Strobe or Speaker
Strobe) combination units
the result may be
conflicting sound waves or
sound cancellation
28. Maximum Area 1 Strobe 2 Strobes 4 Strobes The correct method is by
Coverage in (m) per area per area per area following clause 5.4.5.8 in
CAN/ULC-S524-06
6.10 X 6.10 15 N/A N/A
Subdivide the room into multiple
12.2 m squares (6.1m x 4)
5.4.5.8 Where multiple wall-mounted visible
6.1m signal devices are used within a room, the room
shall be subdivided into multiple squares and
the selection of the device output and location
6.1m shall be in accordance with Table 5 and Figure 3.
• ULC-S524-06 Table 5 - room
12.2 m
size of 6.1m X 6.1m requires a 15
candela strobe
6.1m • Install four 15 candela strobes
(one for each 6.1m area)
Utilize Maximum Area
6.1m Coverage
29. • Application – Room size is 14m X 28m 5.4.5.8 WhereArea
Maximum multiple wall-mounted visible signal devices are
1 Strobe 2 Strobes 4 Strobes
used within ain (m) the room shall be per area into per area
Coverage room, per area subdivided multiple
• Divide the room into two 14m X 14m squares and the selection of the device output and location shall
15.2 X 15.2 94 60 30
be in accordance with Table 5 and Figure 3.
• Two 60 Candela or four 30 Candela strobes can be substituted
• Note that the two visible signal devices are located on opposite walls
28 m
14 m
14 m
14 m
30. If there are two appliances in a protected area, they must
be located on opposite walls
32. Maximum Area Size Maximum Mounting One Strobe Light
Height (Rated Candela)
6.10 X 6.10 3 15
9.14 X 9.14 3 30
12.2 X 12.2 3 60
15.2 x 15.2 3 95
6.10 X 6.10 6 30
9.14 X 9.14 6 45
12.2 X 12.2 6 80
15.2 x 15.2 6 115
6.10 X 6.10 9 55
9.14 X 9.14 9 75
12.2 X 12.2 9 115
15.2 x 15.2 9 150
33. 4. "Strobe” Layout Design Practices
• Ceiling mounted strobes have a different polar distribution than wall
mounted versions.
• The strobe’s reflector has to be designed to disperse the light 180
degrees.
• Mircom offers “System Sensor” models for ceiling mounted applications.
180 Degrees
Distribution
34. 4. "Strobe” Layout Design Practices
• Application 9.14 X 9.14 Room @ 3 meter Ceiling Height
• Ceiling Appliance Centered
• ULC-S524-06 Ceiling Mount Table 6 requires a 60 Candela Strobe for room
size 9.14m X 9.14m
• At 6m ceiling height, a 45 Candela is required
• At 9m ceiling height, a 75 Candela is required
9.14 m
Maximum Area Size Maximum Mounting Height One Strobe Light
(Rated Candela)
12.2 X 12.2 3 30
9.14 X 9.14 6 45
9.14 X 9.14 9 75
9.14 m
30 Candela
Strobe @ 3m
height
35. 4. "Strobe” Layout Design Practices
• Application 9m X 4.5m Room @ 3 meter Ceiling Height
• Ceiling Appliance Not Centered
Where the ceiling-mounted visible signal
4.5 m device is not located at the center of the
room, the effective intensity (candela) shall
One 95 or 2 be determined by doubling the distance
from the device to the farthest wall to
60 Candela
obtain the maximum room size.
Strobes can
be used We have a 7m distance from device to the
9m furthest wall - Doubling the distance gives
us 14m. The next closest room size is
7m 15.2m X 15.2m. The table shows that a 95
candela strobe is required
Maximum Area Size Maximum Mounting Height One Strobe Light
(Rated Candela)
15.2 X 12.2 3 95
12.2 X 12.2 3 60
36. 5. Mircom Solutions for Difficult Environments
Longitudinal
flue space
37
End View
42. NFP2-2010 18.5.4.5
Performance Based Alternative
Any design that provides a minimum of 0.4036 lumens/m2
(0.0375 lumens/ft2) of illumination at any point within the
covered area at all angles specified by the polar dispersion
planes for wall or ceiling-mounted visual appliances in
ANSI/UL 1971, Standard for Safety Signaling Devices for
Hearing Impaired
0.4036 lumens/m2
43. 1. Definitions & Industry Trends
2. Physics of Visible Appliances
3. Visible Appliances Building Code Requirements
4. "Strobe” Layout Design Practices
5. Mircom Solutions for Difficult Environments
strobe lightA high-intensity light flash: a high-intensity flashing beam of light produced by charging a capacitor to a very high voltage then discharging it as a high-intensity flash of light in a tubeA visible signal device which utilizes high intensity flashing light to notify occupants of a building to the activation of the fire alarm system.
The number of seniors aged 65 and over increased 14.1% between 2006 and 2011 to nearly 5 million. This rate of growth was higher than that of children aged 14 and under (0.5%) and people aged 15 to 64 (5.7%).According to a new Census Bureau report, there were 40.3 million people age 65 and older on April 1, 2010, up 5.3 percent from 35 million in 2000
Strobe must be located no more than 4.6m from end of corridorAdditional strobes placed not more than 30m apart15 Candela Strobes
Where there is an interruption of the concentrated viewing path, such as a fire door, an elevation change, or any other obstruction, the area shall be treated as a separate corridor
For example, in large warehouse spaces and large distribution spaces such as super stores, it ispossible to provide visible signaling using the appliances and applications of this chapter.However, mounting strobe lights at a height of 2030 mm to 2440 mm (80 in. to 96 in.) alongaisles with rack storage subjects the lights to frequent mechanical damage by forklift trucks andstock. Also, the number of appliances required would be very high. It might be possible to useother appliances and applications not specifically addressed by this chapter at this time.Alternative applications must be carefully engineered for reliability and function and wouldrequire permission of the authority having jurisdiction.Tests of a system in large warehouse/super stores designed using the prescriptive approach of7.5.4.3 showed that high ambient light levels resulted in both indirect and direct signalingeffects. The signal-to-noise ratio produced by the operating visible notification appliances waslow in many locations. However, with visible notification appliances located over the aisles orCopyright NFPAunobstructed by stock, indirect and some direct notification was sometimes achieved. Directnotification occurs even when occupants do not look up toward the ceiling-mounted visiblenotification appliances due to the extended cone of vision shown in Figure A.7.5.3(a). Thevisible notification appliance intensity and spacing resulting from the prescriptive design wasgenerally sufficient for occupant notification by a combination of direct and indirect signaling.Testing showed that the best performance was achieved where visible notification applianceswere directly over aisles or where visible notification appliances in adjacent aisles were notobstructed by stock. The performance-based design method will almost always result in aislesnot having a line of visible notification appliances in them, because the spacing of visiblenotification appliances can be greater than the spacing of aisles. Also, it is recognized thataisles might be relocated after installation of the system. Good design practice is to place visiblenotification appliances over aisles, especially those that are likely to remain unchanged such asmain aisles, and over checkout areas. Where reorganization of aisles results in visiblenotification appliances not in or over an aisle, or where that is the base design, it is important tohave a clear view from that aisle to a nearby visible notification appliance. See FigureA.7.5.3(b). Some spaces might have marginal visible notification appliance effect (direct orindirect). However, occupants in these large stores and storage occupancies move frequentlyand place themselves in a position where they receive notification via the visible notificationappliances. In addition, complete synchronization of the visible notification appliances in thespace produced a desirable effect.
Visible notification using the methods contained in 7.5.4.3 is achieved by indirect signaling.This means the viewer need not actually see the appliance, just the effect of the appliance. Thiscan be achieved by producing minimum illumination on surfaces near the appliance such as thefloor, walls, and desks. There must be a sufficient change in illumination to be noticeable. Thetables and charts in Section 7.5 specify a certain candela-effective light intensity for certain sizespaces. The data were based on extensive research and testing. Appliances do not typicallyproduce the same light intensity when measured off-axis. To ensure that the appliance producesthe desired illumination (effect), it must have some distribution of light intensity to the areassurrounding the appliance. UL 1971, Standard for Safety Signaling Devices for the HearingImpaired, specifies the distribution of light shown to provide effective notification by indirectvisible signaling.FIGURE A.
Any design that provides a minimum of 0.4036 lumens/m2 (0.0375 lumens/ft2) ofillumination at any point within the covered area at all angles specified by the polar dispersionplanes for wall or ceiling-mounted visual appliances in ANSI/UL 1971, Standard for SafetySignaling Devices for Hearing Impaired, or equivalent, as calculated for the maximum distancefrom the nearest visual notification appliance shall be permitted in lieu of the requirements