Frequently Asked Questions
On Fire Safety-smoke detectors
I heard there are two different types of smoke detectors, what are they and which is one is better? The two types are photo-electric and ionization. Photo electric uses a beam of light between two sensors (photo-eye) as smoke interrupts this light the alarm activates. Photo electric are better at detecting smoldering fires and produce fewer false alarms. Ionization type use a small radioactive device that senses differences in air particles between two sensors located in the device, when air particles change the alarm activates, that’s why it may activate when vacuuming it. Ionization types are better at detecting fast open burning fires.
Most of our nations fire officials recommend installing photo-electric smoke detectors in homes because most fires start small and smolder before they become open flaming. I agree to some degree with them, however today we have a large volume of plastic based products in the home that when heated especially with an open flame burn at an unprecedented rate. We want the detectors to operate during the very start of the fire when smoke is just being released and when smoldering and heating is present. However if the very start of the fire is from an open flame like a candle that spreads to plastic based furnishings or drapes a fast flaming fire will occur.
The most important thing is to have one no matter what type and replace the batteries at least annually and better yet twice a year and test it pushing the test button once a month.
Where and how many smoke detectors should my home have? You should have one detector on every level of your home near the sleeping areas and a detector in every bedroom. In new home construction detectors must be powered by the home electrical service with battery backup and be interconnected so all alarm when smoke is detected anywhere in the house. They are required in every sleeping room and on every floor. For existing homes single stand alone detector can be installed.
Install the detectors per the manufactures instructions; mounting them on the ceiling will give an alarm more quickly than on the wall however you may experience more false alarms when placed near bathrooms or kitchens. Mount the detectors located near these rooms on the wall 6 to 8 inches below the ceiling.
Why do they want so many smoke detectors to be installed? Having a detector on every floor especially interconnected ones has a better probability of waking you up no matter where the fire starts. If a fire starts in the basement and you sleep in a second or third floor bedroom you may not be aware of the basement detector sounding. Detectors in the bedroom protect you from a fire that starts there. For years we have asked that you sleep with the bedroom doors closed for protection from a fire starting outside of the bedroom however what happens if the fire starts inside the bedroom.
I have smoke detectors do I still need Carbon Monoxide Detectors? Yes, smoke detectors will not alarm to carbon monoxide. You should install at least one in or near your sleeping rooms.