HomeMy WebLinkAboutSmoke Detector Manual - FIR Letters / Memos - 9/28/2006 SeP,P. 28. 20i:i6 2 :43PM Emerald Ai re - [253] 872-5797 No. 8280 P. 1
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AIR CONDITIONING HEAUNG-REFRIGERATION CONTROLS SALES SE
RVICE-Ihl�;TALLATJONe 'A
www.ismarn(dai re.enm
5108 D Street NW Phone: (253) 872-5665 EMERAAI 055BL
Auburn, WA 98001 Fax: (253) 872-5797 www.emeraldaire.com
..
Date: 9/28/06
TO: MASON COUNTY :_: -- -
Attn: LARRY WATERS
Fax: 1-360427-7798 --:s
From: NESLI PETROVICH
RE: STARBUCKS-SMOKE DETECTOR
Pages: 15 TOTAL
(Including Cover)
!f._.
Remarks: HERE IS THE MANUAL ON THE DETECTOR
WE'LL BE INSTALLING. .;,. . ,
THANK YOU
Received By: Date:
5108 D Street NW Auburn,WA 98001 (253)872-5665 (800)291-5191 FAX(253)872-5797
CONT4 EMERAA1055BL
Sep. 28. 2006 2:43PM Emerald Aire — (2531 872-5797 No, 8280 P. 2
A P P I G ...A T I 0 N S G U I D
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Duct Application
Smoke Detectors
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Foreword
The propose of this guide is In provide much needed information concerning the proper use of smoke detector, in duct applications. poet mounted
smoke detectors are designed In provide a specific type of protection thlt cannot he use
f s o other
e of sysiem. However,
a tendency a misapply these devices in the past—auempting to use them as a suhstitute for an early warning woke detection system.This(athere ct,corn
pled wiilt new methods of detecting smoke i1 ducts, has prompted the writing of this industry guide. Piro Protection Engineers, McchariicsI and
Electrical Engineers,Fire Alarm System designers and installers should find the contents both educational and informative.
This information is intended as a technical guide,as distinct from mandatory requirements,
1
Sep. 28. 2006 2:44PM Emerald Aire — [2531 872-5797 No. 8280 P. 4
D U C T A P P L I C A T I O N
S M O K E U E T E I] T 1) R S
Section t Purpose of Duct
httroduction Applications
National and lncal safety
Stroke Detection NFPA 90A3, "Standard for the Installation of Air
standards and codes rt.-cognize Conditioning and Ventilating Systems", specifies that
the ability of air duct systems to transfer smoke toxic Smoke Detectors listed for use in air distribution systems
gases, and flame from area to area.Sometimes smoke can shall be located:
be of such quantity as to be a serious ha7.ard to life safety (a)Downstream of the air filters and ahead of any
unless blowers are shut down and dampers are actuated.
hrjnch Connections in air supply systems having a
The primary purpose of duct smoke detection,then,is ca icit
to prevent injury. P� Y greater than 2,(xxl CGn (949 C/see.),
ry, panic, and property damage by (b) At each story prior to the connection to a common
reducing the spread (reclt'eutation) of smoke t)uct return and prior to any recirculation or fresh air inlet
Smoke detection can also serve to protect the air Bondi- connection in air return systems having a capacity
Cloning system itself from fire and smoke damage,and can greater than 15,000 efm (7080 L/sec), and serving
be used to assist in equipment protection applications, for more than one story,
example, in the ventilation/ exhaust duct work of main. exception No. 1:
frame computers and tape drives. Return system smoke detectors are not required when
Perhaps more important is the identification of what duct its a Mitt
protected Pace
a system of area smoke detectors.
ce served by the air distribution system
smoke detection is not intended for rather than what it is. Exception No.2
•it is not a substintte for an area smoke detector. Fan units whose sole function is to remove air front
•It is not a substitute for early warning detection,
•It is not a replacement for'a building'snside the building to outside the building,"
detectint system. regular Cue
Application Documents
There are several iportant
NFPA 90A supports this by stating:"Prutectiun provided anct concerning theperformance,rents implicat or that andt,d'nstalla-
by the installatiou of smoke detectors and other related Lion of duct smoke detectors:
Iegttirements is intended to prevent the distribution of -U.L.Standard 268A,Standard for Smoke Detectors for
stroke through the supply air duct system and,preferably, Duct Applications
to exhaust a significant quantity of smoke to the outside. •NFFA Standard 90A, Installation of Air Conditioning
Neither function, however, will guarantee either early and Ventilating Systems
detection of fire or the detection of smoke concentrations
prior In dangerous smoke conditions if smoke movement is Ss
92A, Recommended Practice for Smoke Contra!
other than through the supply air system."! ytenrs
•NFPA Standard 72,National Fire Alarm Cute
NFPA 72 States: Detectors that are installed in the air •NFPA Standard i01,Life Safety Code
duct system,shall nor be used as a substitute for open area •ASHRAL Handbook and Product Offertory, Fin and
protection. f>f Smoke Control"
Dilution of smoke-laden air by clean air from other parts of Typical Scenarios
the building,or Dilution by outside air intakes.may avow Duct smoke detection may be useful in preventing injury
ecia- and property damage in instantts such as the following;
high densities of smoke in a single room with no appr
ble smoke in the air duct at the detector location.
A heating. ventilating, or air conditioning (HVAC) fan
Smoke may not be drawn from open areas when air con_ motor overheats and resulting smoke is sensed by the duct
ditioning or ventilating.systems are shut down,"2 smoke detector iintalled in the main supply duct.The duct
smoke detector is equipped with an auxiliary relay that
Area smoke detectors are tine preferred means of control- immediately nits power to the fan motor before significant
ling smoke spread since: amounts of smoke can be distributed to the occupied areas.
Duct smoke detectors can only detect smoke when smoke
laden air is circulating in the ductwork. Fans may not be Afire starts on the second floor of a building, The I1VAC
ntnning at all times, such as during cyclical operation or system serving the second floor also serves floors one
during temporary power failure through four; therefore, smoke is tieing spread to these
floors as well.If area smoke detectors are not provided,the
Duct stoke detectors sample great volunren of air from only means of automatic detection are the duct smoke
ia,ge areas of coverage-They Cannot be expected to match rteteetors ahead of t located in the return air ducts on each floor
the detection ability of area detectors. he main return plenum. The quantity of smoke
in the duct eventually reaches proportions sufficient to
Dirt containinated air filters can restrict air flow causing a alarm the second floor duct smoke detector which trans-
reduction in the operating effectiveness of the duct smoke `mts a signal to the building fire alum.ryslem.Evacuation
detectors, signaling and HVAC shutdown[unctions are the,,provided
by the fire alarm control unit.Refer to Chapter 11 of NFFA
_ 72,and NFFA 92A for control of smoke spread,
1 NFPA 9oA-]996,Section<4.2
NFFA 72-1996,Section 5-112
a NFPA 9OA-1996,Appcnditt A-4
2
Sep. 28. 2006 2:45PM Emerald Aire — [2531 872-5797 No, 8280 P. 5
S Y S T E M S E N S O R
Section 2 Since the primary try purpose consideration will show that the original Concentration is
Characteristics for detecting smoke in the given by Q/V where Q is the quantity of smoke particles
of Smoke in HVAC system Ls to automat- and v the volume in which they are dispersed. if a return
HVAC Systems ically initiate action to min- duct has four branches, each with equal air flow (cfnr),
imize the spread of smoke then after they join, the concentration will be ntrluced to
through the air handling system,it follows that the nature Q/4V.
of the smoke to be expected in various parts of the system
should he understood.The following discussion is a then- Tye precedi
ng ng assumes uniform disf,ersiou of panicles
retica]description Of smoke characteristics as they pertain which represents an ideal condition.Iri reality there is non-
to this application,as yet,not supported by fire test data. uniform dispersion and concentration can and does vary
from no smoke to a very high concentration of smoke in a
Smoke crOss-section area of a duct. This is especially true just
Smoke,as defined in NFPA 72,is "the totality of the air, downstream from my Point of entry. fn a return air duel,
borne visible or invisible particles of combustion,"Smoke for exunple, stratification can be expected immediately
detectors are designed to sense the presence of particles, downstream from each return air 011, Text books teach
but depending upon Elie sensing technology and other that uniform dispersion is reasonably assured at a distance
design factors,different detectors respond to different types equal to 10 duct widths downstream for a duct with turbu-
of particles.Detectors basal on ionization detection tech- lent air flow. (In practical considerations,NFPA 72 accepts
nology are most reslxinsive to the smaller, invisible sub- at least 6 duct widths, Lit the 10 duct width distance
micron sized particles. Detectors based on light scattering should be used when possible,)In those cases where strat-
visible part by contrast, are most responsive to the larger' iftcation is pre dominant, uniform dispersion might never
visible particles- Detectors based on light extinC[iou tech, be achieved,
nology respond to both visible and invisible particles.
Figure 3-1 shows the relative sensitivity of the three tech- Air velocity has tin direct effect upon the characteristics of
nologics as a function of particle diameter,assuming a con- smoke.It does affect the concentration hecause as velocity stant mass of particles, is increased, the total volume of smoke being produced
and dispeised at some rate, Q/dt (the quantity of smoke
It is generally accepted that particle size distribution varies per given time periud), increases proportionately. Stated
from sub-micron diameter particles predominant in the differently,in a One(trot square duct an air velocity of one
Proximity of the flame of a flaming fire to particles one or hundred feet per minute would transport one hundred
more orders of magnitude larger, Characteristic of smoke cubic feet Of air each minllIe.1nCIeasing the velocity f0 four
front a smoldering fire.Tye actual particle sin distribution hundred feet per minute would increase the volume o f air
depends upon a hose of other variables including the fuel transported to four hundred cubic feel per minute,thereby
and its Physical makeup,the availahility of oxygen includ- reducing the concentration of smoke particles by a factor of
ing air supply and fire gas discharge, and other ambient four,assuming Ehat the rate of smoke generation was the
conditions,especially humidity.Moreover, the particle size same in both cases.
distribution is not constant;as the fire gases cool., tite sub-
micron particles agglomerate and the very large onas pre,
Cipitate. Ire other words, as smoke travels away from the
fire source, the particle size distribution shows a relative to
decrease in smaller particles. Water vapor. which is aburt- T
dantly Preseut in Most fires,when cooled sufficiently will 5
condense to form fog Palticles—an effect frequently seen `
above tall chimneys. Since water condensatinn is basically 2
clear in color when mixed with other smoke particles, it \
can be expected to change the color of the mixture to a 1
lighter one. --
a5 `
From the above discussion,one can begin to get an idea of `
what"smoke"is Ill the various parrs of an air handling sys- ♦ A Scattered light principle
tem. Specifically,the farther away the point of observation 0.2 ♦ (according to Boll r
from lire fire source,the cooler Elie smoke will be and the ` B Ezanction-
� principle
more visible because of the growth of sub-micron particles 0.1 ` (according to Hossmann)
by agglomeration and recombination, There probably is
some loss in quantity,i.e„the mass of the smoke particles 11 05 `
at the point of entry to a duct systein is probably greater
than at Some furite point downstream. However, ai con• yr 0.02 G tonizetionchemlrer-principle
centrations of concern,to uses by Precipitation are probably lacCording to Hosemannl
i
negligihie. m
Change in Concentration 0•7 0•2 V 0.4 0.5 1 2
A much more important Consideration is the change in Particle Diameler rr'm
concentration because of dilution by clean air from other Figure 1;Relative Sensitivities of Three Technologies as a Function of Pamcle Diameter(Source:NOS
retun air ports in the duct system.A simple mathematical IR78-15M..,"Smoke Measurements in Largeand Small Scale Fire Testing;by Richard W.Bukowski)
3
Sep. 28. 2006 2 :45PM Emerald Aire — [2531 872-5797 No, 8280 P. 6
D U C T A P P I I C A T I O N S Art D K t D t T E r, T O R S
DSaestonl A duct smoke detector is a Typical smoke detection devices used for duct application
uct Smoke device or group of devices include smoke detector sensors within a housing mouned
Detection Equipment used to detect the presence Outside the duct utilizing sampling tubes (Figure 2),area
of smoke in the ai strearn of smoke detectors listed for in-duct or partial in-duct mount-
ductwork sections of the I4VAC air handling.systems rypi- ing, a light beam detector consisting of Projector and
sally used in commercial buildings, receiver mounted within the duct and an air sampling
detector.In all cases,alarm contacts are available either in
the detector or in the fire alarm control
r �►, r;�. Wtil to hilliate air movement control or to
perform other control functions.
Can"H*s
\�l An exlemally mountecl duct smoke detec-
., for enclosure inay h1corporate either an
Tek--Op,,TUbe`�� ____ _ ionization or photoelectric type smoke
e.••• �\— —�—_ -- a Tcr.wWctnp sensor. Air strearn sampling is accom-
TCWU4 ,e plished by sampling tubes that penetrate
�t�ro�as�rr� .I a rwwremro and Traverse either the supply or return air
ducts. The sampling tubes are Positioned
so air may be drawn through the detector,
sampled, and then returned to the air
ro
-- streary in the duct(Figure 3).
Nmphne Tub,Fr10tts jy
An area smoke detector, listed for the
application,may he mounted on an outlet
_ box totally within the duct or they may he
N`== mounted on the exterior of the duct,with
the sensing area of the detector protruding
Figure 2:Typical Duct Smoke Detector(exploded view) CrPbrr`dC— into the air stream (Figure 4).
s Screws
Another duct detection device may he the
light beam type detector, rhia unit per-
forms best when utilizing long beam
Tube support hole only for duccr more than 3 feet wide paths, e.g., in the large plenums rather
Expected air flow tlirection than small ducts.
Air sampling detection units are extremely
Duttwidth `� sensitive and can detect minute changes
in air particle concentration(Figure 5),All
air sampling detection tube or head is
--I inserted in the air Stream of the duct. Air
Insert plug aria end of inlet tube�� is drawn out and through the detection
device. 111e detection unit typically is set
Inlet tube holes face into air flow Exhansttube at an operating level of normal back-
ground particle concentration, An alarm
will sound when the concentration
Figure 3:Typical Inetatl;ttian Using Air Sampling Tubes exceeds a preset alarm threshold value.
Conduit '
/Av Duct
Eloctricul Box \
Access Pa.,or\- sX4tl0aWd rur DotYclw
�`_- Ssnpang PoBn
Detector \�
-`\
Air durttor B.cempla
Figure 0:Pendant Mounted Air Duct Installation hrwm Supply --der
Figure 5:Typical Air Sampling Detector Installation
4
Sep, 28. 2006 2:45PM Emerald Aire — [2531 872-5797 No, 8280 P. 7
S Y S T E M S E N S 0 H
Section heating, ventilating and air EvwmA:
Typical Air Handlin 8 conditionin "a'""9"°°°a"b01N"9s^'°`
g .rysiems, as,
Systems applied to coulrnercial
buildings,condition and dig-
tribute air usually through a network of ducts.The air lean-
dling system can be divided into four basic sections: Mixed —
air, conditioning,fan,and tenuinal, Figure 6 shows a sun- 1/1/ �00^oLo7 �N d y cw
SIgDMhu Ui.charp
plified schematic view of a typical air handling System. &Kb_ � _ I �Tsnnin.�sec0on
Mixed Air Section
This section Consists of a plenum where recirculated
L
(re(urn) air and fresh (outside) air me introduced and UWY&A:
mixed. A filter removes dirt,dust and other airborne parti
cles from the air before it enters the conditioning section. .ear seem" cOAdtl"q$0o°0" Ftri sO Tffmirl samm
Figure 6:Typical Air Handling System
Conditioning Section through longer ducts. Maximum velocities encountered
The cnnditoning section generally consists of a heating then can be as much as 4500 ft/IIliu (22,9 m/s), Tlie air
coil,a cooling coil,a humidifier or any combination there- velocity in die supply (fun discharge) side will be larger
of. These Coils may be arranged in series,in parallel or in than ill the return side.Velocities in the return side may he
a combination of series and parallel. as low as 200-300 ft/m (1.02- 1.52 m/s).
'rhe cooling coil lowers tine temperature of the air passing The range of sizes in duct work varies greatly,The smaller
through either by using chilled water or direct expansion ducts are similar in size to the air ducts used in a residen-
of a refrigerant gas supplied from a remote refrigeration tial dwelling and may be less than V x 1' (.3 in x .3 m).
compressor. The maximum duel sizes used in large air handling sys-
The heating coil .uses the temperature of the air passing tells are:
through it by means of steam,hot water,or electric heaters. System Type Supply Side Return Side
Humidifiers add moisture in the form of dry stearn directly High Pressure 8'x 8'(2.78 in x Z78 m) Can be very large,12'x 12'(4.18 in x 4.19 rnl or more
into the air stream.A humidifier is stint off Whenever the
Low Pressure 6'(2.09 m)diameter Can be very large,t2`x i2'f4.18 m x 4.i8 ml or more
system supply fall is not running to avoid moisture damage
to the duct system.
Tile air pressure inside a duct with respect to the air pres-
Fen Section sure outside the duct is positive on the supply side of the
This sectiou consists of one or more fans powered by a sin- fun and is negative on the return side.
gle electric motor.Tile fan section clay be placed before or pressure in laches Hz0(kPa)'
after the conditioning coils.
System Supply Side Supply Side Return Side Return Side
The fail section may include a device to regulate the static Type Max In typical Max In
pressure developed by the fan. This device might be an High Pressure t5(1.24)
Typical
inlet vane (vortex) damper, discharge damper, suction +4.0(.99) _y 150j .-1(.25)
damper,or a device to regulate illc fan speed. Low Pressure +2(,50) ti.5(.37) -2(,50)
'(I"HA=24H kPa)
Terminal Section
The temperature inside the duct of an operating air han-
This section controls the volume or the final conditioning dling system is between 421F and 180°F (5.6°C and
of the sit' before it is supplied to the conditioned space. 82-2°C). Cooling applicat"inns have the lowest tempera-
Sornerimes terminal devices are located in the ,aurae tures, For heating applications, the typical temperature is
mechanical cyuipment room that houses the air handler. about 100°F(37.8°C), The 180°F (82,21C) temperature is
More often, terminal devices are located remote from the unusual and is encountered only in areas near a steam coil.
individual spaces that they serve. These terminal devices VJllen the fan is off,temperatures in the vicinity of a steam
can induction units,reheat coils, mixing boxes, variahle volume boxes coil
and induction may reach 2404E(115.6°C).A device located here may
be even warmer due to radiation from the steam coil.
Key Parameters The temperature of the air in tilt mixed air and outside air
The capacity of air handling systems are typically rated in Sections are affected by the outdoor temperature. in very
cfm(cubic feet per minute).This is determined by multiply- Cold climates,the temperature in these sections can be as
ing the cross sectional awa of the duct in square feet doles low as-40°F(-40'C),
the velocity of the air in feet per minute. (Note for a metric
System tilt capacity is rated in cubic metin per second,) The expected temperature range surrounding the duct
system is:
Air velocities used in duct systems are typically 5o0 ft/m Indoor areas Outdoor areas
(2.54 m/s)which is the rating for most of the heating and 45°Fto 120°F -WFto 150'F
cooling coils used in the systems,higher velocities May be (7.2°C to 48.9'C) (-40"C to 71,1IQ
encountered in applications where air must be moved
5
Sep, 28. 2006 2:46PM Emerald Aire — [2531 872-5797 No. 8280 P. 8
D U C T A P P L I C A T 1 0 N S M O K E O E T F C T O fl $
section 5 An HVAC system supplies Typical Single Zone NVAC System
How Duct Detection conditioned air to virtually Figure 7 shows a typical Single Zone IIVAC system.A return
Systems Are Used to every area of the btrildintg" air fan is not used in all Systems. Detectors may be placed
Control Smoke Smoke inWoduced into this in the outdoor air Su
a into th
,,it duct system covers the Supply to sense if smoky is being drawn
entire building"Smoke detectors designed for use in air duct e system from outside of the huildirtg,It would then
Sr. are used to sense presence of smoke in the duct, close the outdoor air damper allowing the rest of the 14VAC
system to continue operating.
NFPA 90A ]n the typical fans stem shown i
-Y n Figure 7,when any duct
NFPA 90A, "Standard for Air Conditioning and ventilating surnke detector senses smoke, the fan system will be
Systems", requires that smoke detectors listed for duct turned off and all the dampers shown will go to their
installations he installed at a suitable location in the main closed positions. "these actions are intended to prevent
supply duct on the downstream Side of the filters to auto- smoke from being distributed via the air handling system
matically stop the supply fans in systems over2.000 cfnn" to unaffected areas of a building,
For systems over 15,000 cfm additional detectors are
required in the return.system of each floor,at the point of An alternate method that may he used is to only stop the
entry into the common return,or a system of smoke deter- suPPly fan and keep the return fan running.in this method
tnrq is required to provide total area coverage, (NWE! the outdoor air damper and the mixed air damper go
Users of this manual shroud refer to NFPA 90A for mote closed and the(exhaust) air damper is opened.This tech-
information on smoke control requirenicrtts.) nique will help exhaust smoke-laden air from the building"
EXhauatAh Mixed Air Duct Smoke Optional Return Return Air In addition to the require,
— Damper Detector Air Fan mentg of NFPA 90A, duct
smoke detectors may also
he used within duct sys-
tems as detection devices in
i El �— engineered smoke control
_ systems. These systems are
TyplcaiFloor enagineered for the specific
Dampers Heating Cal Return building. They use the
building construction and
;2,
air handling systems to
fDuct
contain and reduce the
spread of smoke.
Outside Air Cooling Coil Conditioned Air Space NFPA 90Af requires that
Supply Fan when there is an approved
Fitter okefin alarm system innstalled
r
Figure 7:Typical Single Zone System Humidifier in a building,required duct
smoke detectors must be
connected In the fire alarm
system so that activation of
any duct smoke detector
will cause a supervisory
Li Signal to be indicated at a
—1 �— constantly attended loca-
Line Side l2—. non•or will cause an alarm
— Load Side signal,
Typical Fan
Contactor Control Circuit
H
N Figtnre 8 shows a typical fall
On Off control circuit.
Y
Overkrad Safety
Contrds
Luiclor Duct Smoke Control
Auxiliary Detector Contact Contactor
Contact (Opens When Smoke
is Detacted)
Figure 8:Typical Fan Control Shut Down Circuit
t NFPA Standard 9OA-1996,
fi Section 4.4,41
Sep. 28. 2006 2:46PM Emerald Aire — [2531 872-5797 No, 8280 P. 9
5 Y S T t M S E N S 0 R
Section lication A
APp pendant detector arrangement should be mounted rigid-
Procedure for Duct Select supply and exhaust ly to withstand the pressure and resonant vibrations
Smoke Detector ducts to he monitored by caused by the air velocity, (see Figure 9.)
Application and smoke deiectors.l
Installation conduit ` Air Duct
Locate supply or exhaust
input/output putts, fillers, diluters, dampers, chillers, Ilffaa
heaters, humidifiers, dehumidifiers, air cleaners, control
devices, deflectors, bends and reatrictors in engineering Electrical Box
drawings and specifications. Access Panel or
Supply duct Smoke detector installation should he down- /
stream of fails,filters,chillers,heaters,and hunlfdifiers. Detector
Duct smnke detectors in the return air stream should be
located at every return air opening within ells smoke com-
partment,or whem the air exits each smoke compartment, Figure 9:Pendant Mounted Air Duct Installation
or in the duct system before air enters the return air system
Common to more dean one comparv»uut. Following are procedures that aid in properly installing
Exception:Additional smoke detectors are not required in smuke detectors that mount to the side of the duct and
ducts whets the air duct system passes thivugh other sample smoke by means of tubes that project into the duct.
smoke compartments not served by the duct. A well placed duct sniuke detector monitors representative
samples of air flowing through a duct. While any air sam-
Location of detectors mounted in Fir oil air ducts should pie may seem sufficient,there can he several problems:
he between 6 and 10 duct widths downstream from any
duct ope,ungs, deflection plates, sharp bends or branch Dilution: If outside air mixes with circulated air, it can
cortnectious. dilure combustion particle concentration and prevent a
Exception:where it is physically impossible to locate the detector from sensing a fire. Remember that detectors
detector accordingly, the detector can be positioned closer alarm only when Combustion particles constitute a speci-
than 6 duct widths, but as far as possible from the open- feed percentage of air being sampled. Th avoid dilution,
ing,bend or deflection plates. detectors should be located before fresh air intakes and
before the exhaust air output,
Upon selection of location for duct smoke detector instal-
lation,drill a hole into the duct and measure dud air vclnc- Stratification: detector placement should he such that
ity,, humidity,and temperature.Refer to duct instrumcnta- there is w,iform air flow in the cross section area. In prac-
tion for instrument use in this manual (pages 8-9). tice, this ideal condition may not always be achievable,
Tllc distance from a bend or vent is usually given as a nlul-
Measure room temperature and humidity in the area of tiple of duct width or diameter.Within a duct,air and con,-
intended duct smoke detector installation. bustiun panicles may stratify ill such a way that proper
sampling cannot take place,The wider the duct,die greater
Detectors should he listed by a third party testing laborato- the possibility of stratification taking place. A method of
ry for the environment mcasured in the duct and room at getting a representative air sample is to locate a duct
the installation site. Relocate the detector if ntpasurements smoke detector directly after a bend in the duct after an air
fall outside of rated limits. inlet which creates turbulence (See Figure 10). A distance
of 6 duct widths should separate the duct housing from the
Installation bend or inlet, (See. Exception noted above under
Installation of duct smoke detectors may be within the Application )
duct, protruding into the duct, mowited in an enclosure
with sampling ntbes protruding into or Iraversing the duct.
Drill only required holes for duct installation. A template /" �ocrMaau.wsweu , u,r,o
specifying hole diameters or entry dimensions should be - I J
provided to locate mounting holes for detector enclosure,
sampling tubes,access panels,or doors. --► ��—
Detector installation within the duct can be of the pendant
or hear types. t e^►r t t
6 Doer Wi kh, r��—yt
minim-(GopiaA a nus.wddv
The pendant duct smoke detector should be mounted to an w eioo�.n
Figuro 10:Typical Duct Smoke Detector Placement
appropriate electrical box. The box pendant extension
arrangement should be mounted from either the top or side
walls extending to the center of the air duct stream.
An access panel or door is incorporated in the duct side t See NFPA 90A for details of where duct amokc detectors can be eliminated in systems of less than 2,000
walls and is used during installation and fnr maintenance ON Capacity or in buildings equipped with a system of smoke detectors providing total area coverage.
and test.
7
Sep, 28. 2006 2:46PM Emerald Aire — [2531 872-5797 No, 8280 P. 10
U IJ C F A P P L I C A T I O v S h7 0 !C E 1) E 7 E C T O R S
Excess Humldlty:As with open area detectum,high levels Position holes or openings located along the length of the
Of humidity or cOrrdensation within the duct can cause false sampling tube into the air flow. Secure tube position with
alarm problems.Duct smoke detectors should be located at locking means provided.A tube visual indicator shuuid be
a minimum of ten feel downstream from humidifiers, provided to indicate the tube hole location without dis.
Air Filters:Air filters within ducts tend to collect paper•, manlhng the duct installation.
lint and trash-- all flammable materials. For this reason. Plug sampling tube end with all air stopper.
duct smoke detectors should be located on tlne downstream
side of fillers, The duel smoke detector enclosure and sampling tubes
should be mounted Air Velocity:Duct smoke detectors arc nnsuaIIy designed in mechanical fatigue. rigidly t0 prevent noisy c.hauer and
be used in air handling systems having a certain ringe of
air velocities.Be sure to check engineering specifications to Avoid air leaks.Air leaks in or out of the duct or detector
make sure duct air velocity falls within these parameters. dilute or redirect smoke within the duct.Caskets and duct
Placement: Duct smoke detector assemblies mounted seal can be used to avoid or seal any leaks,
within the duct should be located on the sides or top of a If duct sampling ulbe protrudes through opposite side of
duct, Detectors listed for use in open air applications duct, seal the opening around the tube on the outside of
should not be used inside a duct in place of a duct smoke the duct with duct sealant.
detector,
After
Duct smoke detectors mounted in an enclosure with son_ installing mo the sampling
duct enclosure to the duct and
and exhaust tubes,verify that there
pling tubes call he installed Ornto any wall of the duct is air flow through the duct smoke detector,niis is accum-
unless otherwise restricted by the manufacnnrer's instruc- plished by measuring the static pressure difference
Guns, between (he inlet and outlet tubes using a manometer as
illus
rated in the
Select the proper sampling tube length for duct enclosure sure tdifferential cannot nbe atent leaituied, check foon of this r leaksl.rfprop-
installation if duct is more than three feet wide drill an er orientation of hole placement on sample tube,air veloc,
appropriate diameter hole directly opposite but 2-3 in. icy, and stratification of airflow in are duct. Relocate the
lower to support the sampling tube of lengths longer than duct smoke detector if the pre
three feet, ssure differential specified by
the manufacturer cannot he attained after checking all pos-
Exhaust tube length is not usually a critical dimension. It sible fault causing problems,
play vary from a club to the full width of the duct.Be sure Prior to completing the installation,clean the duct enclo-
to follow the recommendations of the manufacturer regard- sure,and check indicators for hole orientation,
ing the exhaust tube.
Install the sawn tin Duct Instrumentation
p g and Exhaust tubes to the mounting Pressere Reading lost. meats
holes on the duct enclosure.
Used for reading:
Tubes may be marked or, as indicated Lit manufacturer's *Air velocities in ducts
installationinstructions,provided with inhibitors t0 ensure Pressure drops across components
that the tubes are instilled in their proper duct input and Tnstrmnent readings taken by:
output ports. inclined liquid manometer
•Vertical liquid manometer
•Pre-sure differential gauges
•Micrometer liquid hook gauge
Tube support hole only for ducts more than 3 feet wide
—� Expected air flow direction
Ductwidth =�� —�1►
Insert plug this end of inlet tube
Inlet tube holes face into air flow Exhauut tube
Figure IT:fillet Tube Orientation
6
Sep, 28. 2006 2 :46PM Emerald Aire — [2531 872-5797 No, 8280 P. 11
S y 5 T E M S E N S O R
Manometer gauges are used in conjunction with pitot tubes, manometer and gauge use. See 1•igure 13 for manometer
snaight metal tubes and varfom static Pressure sensors. type,and Figure 14 for magnehelic gauge,
Pressure drops are best read with a magnehelic gauge.For Aif V■loeity Reading lestrumeets
bower velocity readings in the range between 400 and 2000 Used for reading:
fpm a '/.-inch manometer is the most accurate instrument •Air pow through duct openings
to use along with the pitot tube. For higher velocity read- •Air now through duct filters,coils,louvers
ings in ducts,the 10 inch vertical or the one inch inclined Instrunlent readings taken by;
manometer is required. See Figure 12 for example of -Velometer
•Thermo-Anemometer(see Figure 15)
�Damilrr kilter
Goofing ing Total Discharge
coo lHeat
Ca Pressure
Louver 0 0
Sratic Pressure/,ury-y )Ik o
� J
Pilot rube
RA �rotalSuctipn Traverse�;4—j
t'rsssure �\Static Pressure
ReadindsAcross TotslAirVolume
hirers and Coils
Figure 12:After electrical and Ipm readings are taken,the total volume of air,fan pressure and pressure drops are reed.
7OW and Posfive Lavapng Bubble
Pressq FillinguFillinguw anal Pes4be
Pressure Ruirp
M, 20 25
ILL50O _
200h
Leve6npBob tscolsFlare FPM inches of Log tor
Adiustrncnt Diraa WatefDauge Able Setting
fer2aroirq I'eetPer Basic
Minute t/lapft
keadng Inclemaas
Scale
Figure 13:115-AV inclined manometer for velocity pressure readings in love velocYly ducts,00 to 20M fpm.
,.f
7
_ {
w.
Figure 14:Magnehellc gauge for reeding static pressures in air ayslcma
Figure 15-Thermo-Anemometer
9
Sep. 28. 2006 2:46PM Emerald Aire — [2531 872-5797 No. 8280 P. 12
D Li C T A P P L I C A T 1 0 N S M O K E D E T E C T O R S
Secties r Smoke detectors are Other maintenance checks:
Maintenance and designed to be as mzinte• •Holes or cracks in duct work neat'vicinity of detector.
Service of Detectors nance free as possible. • Air leaks where detector housing or sampling nibes
for Use in Ducts However, dust, dirt, and are attached to duct.
other foreign matter can •Dust accumulations in or on sampling tubes,sampling
accumulate inside a detector and change its sensitivity; tube filters,and detector head.
this is especially true with duct type smoke detectors.1'Itey • wiring terminal screw tightness.
can become more sensitive, which may cause unwanted
alanns, or less sensitive, which may reduce the level of Typical Testing Procedures
protection. Both are undesirable. Therefore, detectors All detectors should he;
should be.. tested periodically and maintained at regular
(a)'tested or hispecred at least annually to ensure that
intervals. Follow closely the manufacturer's specific rec- they
nm (b) Tested at least annually
mended practices for maintenance and testing. Also sample ttic air ally n.
refer to Section 4-4 and Appendix B of NFPA 90A, and Test causing them to initiate an
they
Chapter 7 of NFPA 72. alarm at their installed location to ensure that rbey
are operative and produce the intended response.
(c)Checked within one year aflcr installation and every
Typical Maintenance Practices alternate year thereafter to assure that they are with-
Under normal conditions detectors require routine mainte- in their listed and marked sensitivity range,
nance at least twice a year,more frequently in dirtier than
normal environments. It is not recommended that duct fires be used to test duct
smoke detectors. This procedure does tint provide a con-
Notify the proper authorities that the smoke detector sys- sisrent,measurable method of determining if the delectors
tem is undergoing maintenance, and therefore the system are performing properly. The tcht procedures and test
will be temporarily out of service. equipment recommended by the detector manufacturer are
CAUTION the best way to test these detectors.
Disable the zone or system undergoing maintenance to pre- Most detectors are equipped with a built-in test mecha-
veilt unwanted alarms and possible dispatch of the fire nism,elccirunic metering equipment,or aerosol iest appa-
department, rates.Refer to manufactunrer's specifications for details.
Notify the proper authorities that the smoke detector sys-
Most duct smoke detectors have detector sensors that can tem is being tested. All persons who would automatically
be accessed for cleaning. Use a vacuum cleaner and receive a real fire alarm signal should be notified to prevent
remove dust from the detector by placing the nuzzle as an unnecessary response.
close as possible to the Openings in the outside housing.A
nozzle with a brush attachment will assist in dust removal. Follow the manufacturer's recommended test methods.
Some detectors can be removed for more thorough clean-
ing; refer to manufacturer's recommended procedure for if a detcclar functions properly and its sensitivity is Within
details. Also check the sampling tube holes to snake sure specifications, nothing further need he done to the
they are not closed. detector. However the routine maintenance procedure
described under"Typical Maintenance Pracricts"above is
Test each detector's sensitivity. recommended.if a detector's sensitivity is not within spec-
ifications,it should be replaced,or refer to manufacturer's
If a detector's sensitivity is within specifications,nothing recommended procedure.
further need he done to the detector. If the detector's sen-
silivity is outside specifications,replace the detector of fol- Restore the zone or system at the completion of the testing.
low the manufacturer's recommended procedure.
Notify all I he persons contacted at the beginning of the test
Restom the zone or system at the completion of testing, that testing has been completed and the system is again
operational.
Notify the proper authorities that testing has been com-
pleted and the system is back in service.
10
Sep. 28. 2006 2:47PM Emerald Aire — [2531 872-5797 No. 8280 P. 13
S Y S T E M S F N S 0 R
Recommended Testing and clearly described with information on the tyre of detector,
Maintenance Log Procedures the model nunilxY,the seria)number(if any),the location,
it is recommended that a permanent Detector Test Log be and the type of environment, Data entries Should include
set up and maintained, with a record for each individual test dates,type of test mode,test results,maintenance,and
smoke detector in each building, Each detector should be comments.A sample detector test log page is shown below_
Detector Test Log
Deft tnr Identification Infatuation
Manufacturer and Detector Model:
Serial Number: Date Installed:
Description of Detector Location:
Example:3rd 1200r Of uhst wing in elBmror lobby.
Test Results and Maintenance Dab
Date Tested Test Mode Test Results Maintenance Performed and Comments
,Example., deielor test bntron passed none
it
_ I
Sep, 28. 2006 2 :47PM Emerald Aire — [2531 872-5797 No. 8280 P. 14
0 U C 1 A P r L I C A T 1 0 N S M O K E 0 E T E C T 0 R S
Saa1O1 I Air Sampling Detector lonizatioa Detector
Glossary of Terms Aa extremely sensitive A smoke detector using the principle of ion flow within a
stroke detection device that chamber to detect visible and invisible particles of com•
can sample, test and evaluate the amount of particle con• bustiun (within a sire range normally encountered as a
centration within an air sample- result of(fire).
Area Smoke Detector Light Beam Detector
A device that will detect visible or invisible particles of A smoke de tes on the smoke
device that opera
combustion. Also called a spot type detector, obscura[ion principle.
Coil
Magnehelic Gauge
A cooling Or heating clenlenl made of pipe or RtbitrK- Gauge for reading static;pressures in air systems.
Coil,direct expansion Photoelectric Detector
coil using the deed refrigeration method, Photoelectric
stroke detector using the principle of Optical detecIIon of
CM visible particles of combustion.
Unit volume of air flow—Cubic Feet per minute. Pilot Tube
FPM A device used to measure the total pressure of a fluid
stream.It is essentially a tube attached to a manometer at
Unit velocity of air flow—Peet Per Minute.
one end and pointed upstream at the other.
Damper Pressrre
A valve or plate regulating the flow of air or other fluid. The norotai forte exerted by a homogenous liquid or gas
Damper,mrftiple louver per unit of area on the wall of a container,
A damper!laving a number of adjustable blades, used to Pressare Differential
vary the volume of air passing tluOugh a confined section A pressure difference(usually specified in inches of water)
by varying the cross sectional area. between two points in a duct.
Duct Ratum Exhaust
A passageway made of sheet metal or other suitable mate- The duct which is used to return the air to the 14vAC pm-
rial not necessarily leak-tight, used for conveying air or Cessing center for conditioning.
other gas at low pressures-
Duct Smoke Detector Sampling Tube
with holes Lhat
A device located within the duct,piviruding into the duct, duct and brings it luethe detection devicelects air from the
or located outside the duct that detects visible or invisible
particles of combustion flowing withiit the duct.Actuation Smoke Detector
of the device may allow nperalgon of certain control funs- A device used to automatically sense the preseacc of parti-
tions, cles Of combustion,
ExhauatTebe
Usually a round tube that provides a path for sampled air Stratificalion
to return from the detection device to the duct. A phenomenon where smoke or other gases travel in lay-
Fan ers at different levels within the duct, rather than being
An air mnving device comprising a wheel or blade and a
evenly distributed throughout the duct,
housing or orifice plate. Supply Duct
The duct which distributes conditioned air, i.e-, cooled,
Humidifier heated,cleaned,humidified, etc.
A device to add moisture to the air.
Inch of Water Thermo-aaemomelar
A unit of pressure equal to the pressure exerted by a col- A device used to measure air velocity,
urrtn of water at a temperature of 4.0°C(39.2'r)- Venturi Principle
Inlet Sampling Tube A tube with a narrow throat(a constriction)that increases
the velocity and lowers the pressure of the liquid or gas
usually a touted tube with]toles that collects air from the passing through it,creating a partial vacuum immediately
duct and brings it to the detection device, after the conslriction in the tube. The vacuum Created has
a sucking effect (eduction), and a Venturi is commonly
used to introduce a liquid (such as a regenerant) or gas
(Such aS air)into a flowing water stream,
12
J
Sep. 28. 2006 2 :47PM Emerald Aire — [2531 872-5797 No, 8280 P. 15
SYSTEM
SENSOR"
OdvOnced 68CIS.advanced scAuth,5-
8 0 0 / 7 3 6 - 7 6 7 2
w w w- B y s t e-s e n S p r. c o m
Q2002 System Sensor.The company reserves the right to change specifications at any time.
Ao5-1006-003