Introduction
Many
people believe that smoke alarm installation is so simple that no training is
required. In many cases this is true, if
the person installing the alarm reads the instructions provided by the
manufacturer and follows them carefully.
Unfortunately, that doesn’t always happen, and some instructions are not
clearly written. This manual will help
you understand the two primary types of smoke alarms, how they work, where they
should be installed and how to install them.
If you need additional information you should contact any of the
organizations listed in the final section of this manual.
This
manual is intended for two different audiences.
It is useful to the person who wants to install a smoke alarm in their
own home, or the home of a friend or family member. It is also intended for use by individuals
who will be installing smoke alarms in homes in their communities as part of a
residential fire safety project conducted in cooperation with the Kentucky
Injury Prevention and Research Center (KIPRC).
Regardless of which group you are in, this manual can help you do a
better job of selecting and installing smoke alarms.
The Purpose of Smoke Alarms
Smoke
alarms are designed to warn people in a building when a fire occurs in that
building. They are especially useful in
residential structures - houses, apartments and mobile homes - or any other
building where people may sleep. A smoke
alarm that is properly installed and well maintained can warn sleeping
individuals of a fire before they are overcome by smoke or toxic gasses
produced by the fire.
Residential
fires are extremely dangerous. People
usually feel safe in their home. This
feeling of safety may cause them to relax and become less careful than they
might be elsewhere. People are also more
vulnerable when they sleep, because they are less able to notice and respond to
a potentially dangerous situation when they are asleep. Residential smoke alarms provide around-the-clock
protection for people who are at home.
Whether someone is awake or asleep, a properly maintained smoke alarm is
always awake - ready to sound the alarm if a fire occurs.
Types of Smoke Alarms
Types of Smoke Alarms
Smoke
alarms work by detecting a byproduct of combustion - the particles of smoke
given off by burning material. There are
two common ways to detect smoke particles.
Some smoke alarms use one method, and some use the other. This results in two major types of smoke
alarms: ionization alarms and photoelectric alarms.
Ionization Alarms
Ionization
alarms are better at detecting fast, flaming fires like grease fires. They detect combustion particles of .01 to 3
microns in diameter. (A human hair is
about 50 microns in diameter.) They are
most sensitive to dark or black smoke.
They are more sensitive to steam than photoelectric alarms, so they may
produce nuisance alarms if they are installed in or near a kitchen, bathroom or
laundry room.
Ionization
detectors work like this:
·
A weak radiation source (a small bit of
Americium 241) ionizes the air in the detector chamber in the alarm.
·
The ionized air conducts a weak
electrical current through the chamber.
·
This electrical current is sensed by
the detector circuit. As long as the
current is present, the alarm does not sound.
·
When particles of smoke enter the
detection chamber, they interfere with the current flow. The current flow is reduced.
·
When the current flow is reduced, the
detector circuit turns on the alarm horn.
Photoelectric Alarms
Photoelectric
alarms are best at detecting slow, smoldering fires such as furniture
upholstery ignited by a cigarette. They
detect combustion particles from .3 to 10 microns in diameter. Photoelectric alarms are more responsive to
light gray smoke.
Photo
electric detectors work like this:
·
An infrared light emitting diode (LED)
shines a beam of light into the detection chamber.
·
A receiver senses the small amount of
light reflected from the chamber. It
does this by converting the light falling on it into an electrical signal.
·
When smoke particles enter the chamber
they scatter the light beam. This
reflects more light back toward the sensor.
·
The receiver picks up more light and
the electrical signal it produces is increased.
·
When the electrical signal increases,
the detector circuit turns on the alarm horn.
Combination Alarms
Sometimes
two types of detectors are combined in one alarm. You can find alarms that combine both
ionization and photoelectric detectors and also ionization smoke alarms that
include a carbon monoxide (CO) detector.
These alarms are considerably more expensive than standard ionization or
photoelectric alarms.
Smoke Alarm Power Sources
All
types of smoke alarms require electrical power in order to operate. They can be powered in different ways. The common methods of powering smoke alarms
are:
·
Hard wired - the alarm is wired into
the home’s normal AC wiring and draws power from the regular electrical
system. Hard wired alarms may or may not
have backup battery power, but all hard-wired alarms should have backup
batteries that will operate the alarm even if the regular AC power fails.
·
9-volt alkaline or zinc carbon battery
- the alarm is powered by a standard 9-volt battery. Alkaline batteries last longer and are more
reliable than zinc carbon (“standard duty”) batteries. An alkaline battery will power most 9-volt
smoke alarms for a full year.
·
9-volt lithium battery - the alarm is
powered by a special 9-volt battery that can last up to ten years. The battery is the same size and shape as a
standard or alkaline 9-volt battery, but it uses different chemicals to
generate electrical energy. (Currently,
“ten year” lithium batteries can only be found in ionization-type smoke
alarms.)
Smoke Alarm Maintenance
Smoke
alarms are electronic devices. Like any
other piece of electronic equipment, a smoke alarm may fail due to age or poor
maintenance. This section explains how
to care for your smoke alarms.
Change the Battery
Smoke
alarms must have electrical power to operate.
If the battery powering a smoke alarm is dead, the alarm will not
work. Many people forget to change the
battery regularly. Some people take out
the battery to silence a nuisance alarm and then forget (or decide) not to put
it back in the alarm. Others may even
take the battery out of a smoke alarm to put into a child’s toy or other
electronic device.
Most
modern smoke alarms will beep or chirp when the battery is low. When this happens, the battery should be
replaced immediately. If standard zinc
carbon batteries are used in a smoke alarm they should be replaced at least
twice each year. It is easier to
remember to do this if you replace the batteries whenever you change your
clocks to and from Daylight Savings Time.
Some fire departments and other organizations sponsor “Change your
clocks - change your batteries” campaigns to help remind people to change the
batteries in their smoke alarms.
If
you use alkaline batteries in a smoke alarm they will probably only need to be
changed once per year. Lithium batteries
may last up to ten years. Always read
the smoke alarm instructions when you install an alarm. The instructions will tell you how long you
may expect the battery to last. Even if
the battery is almost new, change it if the low battery alert (beeps or chirps)
sounds.
The
backup batteries in hard-wired smoke alarms may need to be changed too. In some cases the backup battery may be a
rechargeable battery wired into the system, but in some models the backup
battery is simply a 9-volt battery. For
these systems the backup battery should be replaced at least once per year, so
that it will be fresh and ready to work if needed.
Cleaning
Smoke
alarms will not work if they are covered in dust and cobwebs. Dust, cobwebs, insects or similar
obstructions can keep smoke from entering the detection chamber by blocking the
small vents in the alarm housing. They
can also cause nuisance alarms by blocking the ionization process in ionization
alarms or by scattering the light beam in photoelectric alarms. Smoke alarms should be cleaned at least once
each month to prevent the buildup of dust, cobwebs and other foreign material.
It
is easy to clean most smoke alarms.
Simply use a vacuum with a hose and wand attachment or a soft
feather duster or brush to remove dirt, dust and cobwebs from the smoke
alarm. If you use a vacuum you should
not need to open the smoke alarm case.
You may need to open the case if you clean the alarm with a feather
duster
or brush. Gently brush any dust or other foreign
material out of the alarm and then close the case. Never use water, spray-on cleaning solutions
or any liquid cleaning product to clean a smoke alarm.
Testing the Alarm
A
smoke alarm should be tested regularly.
Like any other electronic device, a smoke alarm can stop working due to
an electrical problem of some kind within the alarm. To make sure that smoke alarms are ready to
provide protection when they are needed, they must be tested. Alarms should be tested according to the
instructions provided by the manufacturer.
Some manufacturers recommend that alarms be tested each week, while
others say that once per month is adequate.
If you don’t have instructions for a smoke alarm, you should assume that
it should be tested every week.
To
test a smoke alarm, press the “test” button on the alarm and hold it for at
least two seconds. If the alarm horn
sounds then the smoke alarm is working properly. If the alarm does not sound, change the
battery and press the “test” button again.
If the smoke alarm still does not sound an alarm, it is broken. Replace it immediately.
Replacing Outdated Smoke Alarms
Smoke
alarms are designed to last about ten years.
When an alarm becomes ten years old it should be replaced. Older alarms have a much higher chance of
failing due to electrical problems within the alarm circuits. If you’re not sure how old a smoke alarm is,
and it doesn’t look relatively new, it’s a good idea to replace it.
Smoke alarms are like any other piece
of electronic equipment - they require electrical power and regular care to
operate properly, and they tend to break down with age. Smoke alarms that are properly maintained
should last for ten years, however, and provide critical around-the-clock
protection from fires.
Nuisance
Alarms
A
nuisance alarm occurs whenever a smoke alarm sounds when there is not really a
fire. Some people call them “false
alarms,” but they really aren’t false - something caused the smoke alarm to
sound. Understanding why nuisance alarms
occur can help you prevent them.
Many
nuisance alarms occur when they are exposed to smoke. If there is smoke in the air a properly
working smoke alarm will do just what it was designed to do - sound the
alarm. Unfortunately, there are sometimes
situations where smoke may be produced by normal household activities. Smoke from a wood stove that is opened for
refueling, a fireplace, a candle or cooking food may trigger a smoke alarm. In these cases the problem can usually be
solved by airing out the room to clear the smoke.
In
some cases nuisance alarms are caused by steam from cooking, bathing or
laundry. In these cases it may be harder
to clear the area, since the steam will continue to be created as long as the
activity continues. Some smoke alarms
may also detect the combustion products produced by appliances burning natural
gas, especially if the appliance is not vented.
Photoelectric detectors may work better in areas where this type of
nuisance alarm is likely to occur, because they are less sensitive to
steam. A better approach may be to avoid
installing smoke alarms too close to areas where cooking, bathing or laundry is
done.
Some
people deal with nuisance alarms by removing the battery from the smoke
alarm. Never disable a working smoke
alarm by removing the battery. If the
alarm is malfunctioning due to an internal electrical problem, replace the
alarm with a new one. If nuisance alarms
are a problem, install an alarm with a “silence” or “hush” button that will
disable the alarm temporarily while the room is being cleared. If this doesn’t resolve the problem, relocate
the alarm further away from the cause of the nuisance alarms.
Problems
with Smoke Alarm Use
Several
problems have been found with the way smoke alarms are used in the United
States. These problems are changing the
way smoke alarms are designed and installed.
Problems
Non-functional
or “dead” alarms are the biggest problem.
The Consumer Product Safety Commission (CPSC) estimates that there are
just over 11 million homes in the US that do not have smoke alarms. There are more than 16 million homes that
appear to have smoke alarms - but where not a single alarm is actually working. Alarms where alarms are installed but are
non-functional are a greater problem than homes with no alarms at all.
The
biggest problem is electrical power.
Nearly 20 percent (1 of every 5) smoke alarms in the US is without
power. Five percent have dead batteries,
while 15 percent have missing or disconnected batteries or AC power. Some of the alarms that are disconnected were
disconnected by accident, or by a previous occupant of the home, but more than
33 percent (1/3) of them were disconnected deliberately.
Why
do people deliberately disconnect alarms?
The biggest reason is nuisance alarms.
In a study conducted by CPSC in 1994, most people who had disconnected
their smoke alarms said that they disconnected them to stop nuisance
alarms. In most cases the nuisance
alarms were caused by ionization-type detectors that were within 5 feet of the
nuisance source, and many of the smoke alarms were not cleaned. Simply cleaning the alarms and moving them a
few feet might have solved most of the problems. Instead, people had simply disabled the
alarms. The willingness of people to
disable smoke alarms rather than try other solutions to nuisance alarms is a
major safety problem.
Potential Solutions
Smoke
alarm manufacturers and government officials are trying to find ways to solve
these problems. Many areas require hard
wired smoke alarms in new homes because they are harder to disconnect and they
will usually work even if the resident forgets to change the batteries. Most areas do not require that hard-wired
alarms be installed in older homes, however, because it is very expensive to
retrofit existing buildings with hard-wired alarms. They also do not solve the problem of
nuisance alarms.
Alarms
with long life lithium batteries also help by reducing the need to change
batteries regularly. These alarms still
beep or chirp when the battery is low, but in many cases one battery may last
for the entire ten year life of the alarm.
These alarms also do not solve the problem of nuisance alarms, and they
can be disabled by removing the battery just like standard battery powered
smoke alarms. There are also not any
commonly available photoelectric or combination alarms using lithium batteries.
There
are also new types of smoke alarms being developed. These alarms use multiple sensors, “fuzzy
logic” and other new technologies to help reduce the number of nuisance
alarms. Unfortunately these alarms are
not yet readily available for normal residential use. Until those alarms are available, the best
way to minimize nuisance alarms will remain the proper selection of installation
locations.
Installing
Smoke Alarms
The
goal when installing smoke alarms is to install them in locations where they
can adequately detect fires while avoiding locations that may increase nuisance
alarms. This can be a challenge,
especially in smaller residences. In a
small home it may be impossible to install a smoke alarm far enough from the
kitchen or bathroom to prevent steam alarms, for example.
The NFPA’s National Fire Alarm Code,
NFPA 72, provides guidelines for installing
smoke alarms in a home.
·
There should be at least one smoke
alarm on every occupied level of the home, including the basement. This means that a two-story home with a
basement would need an absolute minimum of three smoke alarms. Smoke alarms are not typically installed in
unoccupied levels of a home such as crawl spaces or attics.
·
A smoke alarm should be installed
outside every separate sleeping area.
This means that if there is a bedroom on one end of a floor and another
bedroom at the opposite end of that floor, two smoke alarms will be needed on
that floor.
·
In new construction, smoke alarms
should be installed in every sleeping room.
·
If alarms are in or near a kitchen they
must either be photoelectric or have a “silence” button (“hush” button) to
temporarily silence the alarm.
·
All smoke alarms installed in homes
should be tested regularly.
·
All residential smoke detectors should
be replaced when they are ten years old.
Following these guidelines will help to
provide high quality fire detection and warning capabilities while minimizing
nuisance alarms.
Alarm Selection
If
you want to use a lithium battery powered smoke alarm you are pretty much
limited to ionization type alarms.
Otherwise, choose whichever alarm is best suited for the particular location
(see Types of Smoke Alarms). Photoelectric alarms work better near
kitchens, bathrooms, laundry rooms or other areas where steam may be
present. Both alarm types work well in
other areas, so you can choose the one that best fits the décor or your budget,
or even use a combination ionization and photoelectric alarm for even better
protection. For new homes hard-wired
alarms with backup batteries should be used.
For existing homes, battery powered alarms may be more practical.
Location
Installing
smoke alarms in appropriate locations is important. Remember, there should be at least one smoke
alarm on each occupied level of the home, even if there are no sleeping areas
on that level. There should also be one
smoke alarm outside each separate sleeping area, even if they are on the same
level. Sleeping areas are ‘separate’ if
they are in different areas of the house - bedrooms immediately adjacent to each other are not ‘separate
sleeping areas’ for the purpose of installing smoke alarms, while bedrooms on
opposite ends of the house are ‘separate sleeping areas.’
Avoid
installing alarms in or very near kitchens, bathrooms or laundry areas unless
the smoke alarm instructions say that it is OK to install the alarm in these
locations. Ionization-type alarms often
produce nuisance alarms when installed in these areas.
You should also avoid installing alarms in the corners of rooms within 2 feet of the corner. Corners create “dead zones” where air movement is minimized. Always place smoke alarms in areas where air movement is not restricted. The drawing below shows some examples of correct and improper smoke alarm placement.
Methods for Mounting the Alarm
Hard-wired
smoke alarms must be installed in electrical mounting boxes just like ceiling
lamps. If you are not familiar with home
wiring you should have this job performed by a qualified electrician.
Battery
powered alarms can be installed easily.
Locate the proper location for the alarm and use the mounting screws (if
any) provided by the manufacturer or some similar method to attach the alarm to
the ceiling or wall. Double-sided
mounting tape can be used in situations where screws cannot be used if
the tape sticks firmly to both the alarm and the ceiling or wall material. Tape is not recommended if screws will work,
however, because the tape might pull free if it becomes hot. The hot gasses produced by a fire can cause
the air near the ceiling of a room to reach several hundred degrees Fahrenheit
very quickly.
Many
smoke alarms have holes for the mount screws in the back of the alarm
housing. The alarm housing must be
opened to install the alarm. Other
alarms have a separate mounting ring or bracket. The bracket is secured to the ceiling or wall
and then the alarm snaps into the bracket.
Some
smoke alarms have a pin or other device that secures the alarm to the mounting
bracket, or that keeps the alarm housing from being opened, to make the removal
of the battery difficult. If you are
installing alarms with lithium batteries it is usually a good idea to use this
tamper-resistant feature if the alarm has one.
It will help discourage people from removing the battery in order to
silence a nuisance alarm. The
tamper-resistant feature should not be used if the alarm uses a standard 9-volt
battery, since it will be necessary to open the alarm regularly to replace the
battery.
Read the Instructions
Unless
you are already personally familiar with a particular model of smoke alarm, you
should read the instructions provided by the alarm manufacturer before you
install the alarm. The instructions will
tell you where and how to install the alarm for
best performance.
Fire
Safety Resource Agencies
Learning
about fire safety and the proper installation and maintenance of smoke alarms
can help you protect yourself, your family and others you may know. You can contact any of the following
organizations for more information about fire safety and proper smoke alarm
installation:
KY Injury Prev. and Research Center www.kiprc.uky.edu/fire/ (859) 257-4954
Kentucky Firefighters’ Association www.kyfa.org (270)
746-7461
United States Fire Administration www.usfa.fema.gov (866) 274-0960
National Safety Council www.nsc.org (630)
285-1121
Natl. Center for Injury Prev. and
Control www.cdc.gov/ncipc/ (770) 488-1506
SECTION
II - INSTALLATION OF SMOKE ALARMS FOR THE
RESIDENTIAL
FIRE INJURY PREVENTION PROGRAM
This
section of the manual is intended for individuals who will be installing smoke
alarms in homes in their community as part of a joint project between the
Kentucky Injury Prevention and Research Center (KIPRC) and their local
organization. This section includes
information on preparing for, conducting, documenting and closing out a smoke
alarm installation trip.
The
instructions in this section assume that you will be going to install alarms in
homes where people have already signed up to receive alarms. If you are doing door-to-door canvassing, you
will not have previously completed enrollment forms for each household that you
visit. You need to complete an
enrollment form for each household prior to installing smoke alarms in that
home.
Preparing for the Installation Trip
You will generally begin each installation trip by meeting
with your organization’s project coordinator to pick up smoke alarms,
installation supplies, educational materials and the list of homes you will
visit during that trip. When preparing
to start an installation trip you should have the following materials:
·
completed enrollment forms for those
households you will visit (or blank enrollment forms, if you are doing
door-to-door canvassing)
·
tools - a screwdriver that fits the
installation screws packed with each alarm, a flashlight and a pair of pliers
·
smoke alarms - approximately 2.5 alarms
per home, with instructions
·
double-sided tape - for use in case
screws cannot be used to mount an alarm
·
9-volt alkaline batteries - a small
number, in case you find nearly new alarms that just need batteries (if
available)
·
fire safety educational materials
- Wake Up, Kentucky!
smoke alarm instruction card 1
per home
- 10 Tips for Fire Safety
brochure 1
per home
- E.D.I.T.H.
brochure 1
per home
- Fire Safety for People With
Disabilities brochure several
*
- how to prevent fires (Remembering When)
booklet several *
|
In addition to the items already listed, you should always carry a few extra enrollment forms. A neighbor, visitor or other person may be present in a home that you are visiting to install alarms and want to sign up to have alarms installed in their own home. (Be sure that any individuals you enroll live within your organization’s project area.)
If
your local organization does door-to-door canvassing, be sure to take plenty of
enrollment forms with you. KIPRC must
have a properly completed and signed enrollment form for each home in which you
install smoke alarms.
Doing the Installation
The
actual smoke alarm installation process is fairly simple, but you should follow
these steps to insure that you don’t forget anything during the installation
process.
1. Be
careful when you arrive - park in an appropriate spot, and wear your uniform,
ID
or
other means of identification. (Some
residents may be nervous if you approach
their
home unexpectedly, especially if you are doing installations during evening
hours.)
2. When
the door is answered, identify yourself and verify that the person(s) living in
the
residence have requested smoke alarms.
(Some people may have moved,
or
changed their mind.)
a. If the current resident(s) want alarms
installed and you have a signed enrollment
form
from them, continue with Step 3.
b. If the current resident(s) want alarms, but
the enrollment form was signed by
someone
who no longer lives there (or if you do not have an enrollment form for
this
address), do a new enrollment form and have a person 18 or older sign it.
Then
continue with Step 3.
c. If the current resident(s) do not want smoke
alarms, mark ‘REFUSED’ in
large
letters on the bottom portion of the enrollment form, along with the date
and
time. Go on to the next home on your
list.
If
no one is home, note the date and time of your visit on the margin of the form
and
go
to the next home on your list.
3. Check
the home for existing smoke alarms. If
the home already has functional
smoke
alarms on each inhabited level, explain to the residents that they do not
need
more smoke alarms. Provide them with
fire safety education materials,
explain
the materials, then go to the next home on your list.
a. If smoke alarms are present in the residence
but non-functional, try replacing
the
batteries. If this makes the alarms
functional, provide fire safety education
materials,
explain the materials, and go to the next home on your list.
b. If there are no existing smoke alarms, or if
the existing alarm(s) do not work
after
you have tried replacing the batteries, install smoke alarms.
4. Locate
appropriate locations for the smoke alarms, using the information provided
in
this manual and these guidelines:
a. Place one alarm on each habitable floor of
the home. On floors with bedroom
areas,
place the alarms just outside the bedrooms (in the hall, etc.).
b. If there are bedroom areas in two separate
areas of the home, even if they are
on
the same floor, place one alarm outside each bedroom area.
c. Do not place alarms in or very near
kitchens or bathrooms, or close to wood-
burning
stoves, clothes dryers or other appliances which normally become
warm
or give off dust or steam during operation.
d. Place alarms on the ceiling at least 4” from
the nearest wall, and at
least
2’ from the nearest corner, or place them on a wall at least 4” below
the
ceiling, but not more than 12” below the ceiling, and 2’ from the nearest
corner.
e. If you need more information, refer to the
installation information in this manual
and
the instructions packed with the smoke alarm.
5. Test
each smoke alarm before you install it.
6. Install
the smoke alarm(s). If you are using
double-sided tape, apply it directly to
the
back of the alarm, then press the alarm firmly against the mounting surface
and
hold it in place for approximately 30 seconds.
If you are using screws to mount
the
alarm, follow the instructions provided with the alarm.
7. If
there is a preliminary survey included in the installation process, ask one
adult
in
the household to answer the survey questions.
Record their answers on the
survey
form and attach it to the installation record form.
8. Provide
fire safety education to the residents.
Provide them with copies of the
educational
materials and brochures, and explain the information in the brochures
to
them. (Don’t just hand them the
brochures and leave; many people won’t read
them
if you just leave them and don’t explain the information in them.)
Residents
should receive at least the following materials:
Wake Up, Kentucky! smoke alarm
instruction card
E.D.I.T.H.
brochure
how
to prevent fires brochure, if there is an older adult in the home
Fire
Safety for People With Disabilities brochure, if there is a disabled
individual
in
the home
Other
materials should be provided if they are being used by your organization.
8. Complete
the bottom portion of the enrollment form, including the date, time, and
number
of smoke alarms installed. Sign the
form in the section provided for the
installer’s
signature.
9. Give
the back (pink) copy of the installation record form to an adult in the
household.
10. Thank
the residents for participating in the project.
Go to the next home on your
list.
Finishing
Up the Installation Trip
1. Return
any unused smoke alarms to your organization’s project coordinator.
Remember
- the number of smoke alarms installed, plus the number returned,
must
equal the number you received at the beginning of the installation trip.
2. Give
the completed enrollment forms, including those marked ‘REFUSED’ or other-
wise
not installed, to the person in your organization who is responsible for
keeping
records
of the alarms installed. If you had any problems during the trip, note them
on
the enrollment forms or attach a note explaining what happened. If you are
injured
while installing alarms, or someone else is injured, or property damage
occurs,
notify the head of your organization or your supervisor immediately.
3. Return
any unused supplies to their proper location.
Clean up any tools provided
by
your organization and return them to their proper location, or to the person
responsible
for them.
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