- How effective are smoke detectors?
Residential fire deaths have decreased
steadily as the number of homes with smoke detectors increased. Reports from the National
Fire Protection Association on residential fire deaths show that people have hearly a 50
percent better chance of surviving a fire if their home has the recommended number of
smoke detectors.
- Should I replace my smoke detector?
Smoke detectors that are 10 years old are
near the end of their service life and should be replaced. A smoke detector constantly
monitors the air 24 hours a day. At the end of 10 years, it has gone through over 3.5
million monitoring cycles. After this much use, components may become less reliable. This
means that as the detector gets older, the potential of failing to detect a fire
increases. Replacing them after 10 years reduces this possibility.
- My detectors are wired into my electrical system. Do I need to replace them as often
as battery-operated detectors
Yes. Both types of detectors are equally affected by
age.
- How many detectors should I have?
The average sized home or apartment needs
more than one smoke detector. The exact number depends on the number of levels in the home
and the number of bedrooms. National fire safety standards recommend a minimum of one
detector on each level of the home, one detector outside the bedroom area, and one in each
bedroom. The detector that is placed outside of the bedroom area should be installed near
enough to be heard at night through a closed bedroom door.
- Is there more than one type of smoke detector, and what is the difference?
There
are two type of smoke detectors for homes. One type is called an ionization detector
because it monitors "ions," or electrically charged particles. Smoke particles
entering the sensing chamber change the electrical balance of the air. The detector's horn
will sound when the change in electrical balance reaches a preset level.
The other type of detector is called photoelectric because its sensing chamber uses a
beam of light and a ilght sensor. Smoke particles entering the chamber change the amount
of light that reaches the light sensor. The detector sounds when the smoke density reaches
a preset level.
- Is one type better than the other?
The ioinization detector responds faster to
small smoke particles, while the photoelectric responds faster to large smoke particles.
As a rule of thumb, fast-flaming fires produce more small smoke particles and smoldering
fires produce more large particles. Thus, the response time of the two type of detectors
will vary, depending on the mix of small and large smoke particles in the fire. But test
results show that the differences in response time are small enough that both types
provide enough time to escape.
- What is more important, the type of detector or the number?
The number of
detectors is more important than the type. Installing several smoke detectors of each type
will provide better coverage in the extreme cases of long-term smoldering or fast flaming
fires. But since both types respond in time to escape, the most important thing is to
install enough detectors in the proper locations. Detectors are available with both types
of sensors in the same unit, but they are more expensive than models with a single sensor.
If the choice is between having only one of each type or having more of the same type,
more detectors is the better choice.
- My detector goes off when I cook. How can I stop this?
Smoke detectors are
designed to be very sensitive so they will alert occupants to a fire in time for them to
escape. If a detector regularly responds to smoke from cooking, there are several options
for handling this problem. One way is to replace the detector with one that has a button
that sliences it for a few minutes. Another way is to move the detector farther away,
giving the smoke a chance to dissapate. Moving a ceiling-mounted detector to a wall can
also reduce nuisance alarms. However, this will also make it a little slower to respond to
a real fire.
If the detector is the ionization type, another option is to replace it with a
photoelectric. This detector is less sensitive to smaller smoke particles and thus is less
affected by cooking smoke.
- How can I test my detector?
Every smoke detector comes with a test button. We
recomend that people test their detectors regularly, at least once a month.
- How can I test my detector?
Every smoke detector comes with a test button. We
recommend that people test their detectors regularly, at least once a month.
- Should I use real smoke to test my detectors?
This is not recommended because
the burning objects used to create the smoke might cause a fire. Some stores sell
pressurized cans of simulated smoke for this purpose. When using this product, follow the
operating instructions and do not get the can too close to the detector. This prevents the
smoke from coating the detector's sensing chamger, which can make the detector inoperable.
- How important is it to clean my detector?
Cleaning is easy. Just vacuum the
detector at least once a year. This will keep the openings to the sensing chamber free of
dust, residue from cooking vapors and insects.
- What about changing batteries?
Smoke detector batteries should last at least
one year under normal conditions. The biggest reason that smoke detectors don't work is
because people remove the batteries, e.g., to stop the low battery signal or a nuisance
alarm, and forget to replace them. When a battery reaches the end of its service life, the
detector will give a short beep every minute or so. It is easy to remove the battery and
then forget to replace it. The best way to prevent this is to replace batteries at the
same time each year before the low battery signal begins.
