Gravenhurst Volunteer Fire Department

A good fire escape plan will only be successful if we know early enough hat a fire has started. Fire may build rapidly and spread toxic gases and blinding smoke throughout your home. Then again the fire may start small and smolder slowly, all the while emitting deadly toxic gases. The installation of inexpensive early warning smoke alarms in your home will give you the precious time you need to escape the fire. Most fire deaths occur at night when people are asleep. Your smoke alarm will detect a fire in its early stages, sound the alarm and wake you up.

But what type of smoke alarm should I buy? There are a variety of makes and models on the market and are available at most hardware and department stores. There are basically two types of smoke alarms based upon how they detect fire. The first type is photoelectric. This type uses a Light Emitting Diode (LED) and a light sensitive sensor in the sensing chamber. The presence of suspended smoke particles in the chamber scatters the light beam. This scattered light is detected and sets off the alarm.

The second and more popular type are the ionization detectors. They use a small amount of radioactive material to ionize the air in the sensing chamber, This allows the air to become conductive and allow electric current to pass between two charged electrodes. When smoke is present in the air in the chamber this conductivity decreases. When the conductivity level is reduced to a set level, the alarm goes off.

The reason this type is more popular is price. Ionization detectors can be purchased for $5.00 to $10.00 where photoelectrics may cost $30.00 to $40.00. Which one is better? Unfortunately there is no simple answer. They both work on different principles and as such respond differently to conditions. Ionization for example, respond faster to flaming fires, where photoelectrics respond faster to slow, smoldering fires. Photo electrics also are less prone to nuisance alarms from cooking. However, both are tested to the same standard (CAN/ULC-S531) and you can't predict which type of fire is going to strike. The best prevention is to have detectors of both type installed in your home.

The other difference in detectors of both type is their power source. The first is battery powered, usually by a small 9-volt battery, that can be installed almost anywhere. The second type is hardwired into your household wiring. Some models of this type have battery back-up as well to continue protection when the power goes out.

The proper placement of smoke alarms is very important to achieve the best results and maximum protection. Always refer to the manufacturer's instructions or give us a shout for advice and assistance. For minimum protection place detectors in hallways outside sleeping areas and one alarm on each level, including the basement.

Place your smoke alarm on a ceiling in the center of the hallway or room. In homes where people are hard of hearing or where bedroom doors are closed at night, smoke alarms should be installed in each sleeping area. Some smoke alarms are equipped with a lamp that turns on when the alarm activates. This may be a good idea for the hearing impaired.

Locations to be avoided when installing your alarms include dead air spaces where ceiling and wall meet, near air supply registers and near ceiling fans. While false alarms from smoke alarms can be irritating, they can be minimized by avoiding installations near kitchens, bathrooms, furnaces, fireplaces and wood burning stoves. There are smoke alarms available that are specifically designed for these areas and have a special feature that temporarily silences the alarm. Never disconnect or remove the batteries in your smoke alarms.