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Choosing And Installing The Right Smoke Detectors

Even the smallest of house fires can fill your home with dangerous smoke in a few minutes. It is important that you choose the right smoke detectors for your home, install them correctly, and test them at regular intervals.

There are two types of residential smoke detectors available: photoelectric and ionization. With a photoelectric detector, light is beamed into a chamber that contains a photocell. Smoke entering the chamber will scatter the light, enabling some of it to reach the photocell and cause an alarm. Smoldering fires tend to set off photoelectric detectors faster than flaming fires.

Ionization detectors use radiation that ionizes (breaks up) the air inside the unit, and gives it a small electrical charge. Smoke particles reduce this flow of current, and set the device into alarm.

Which type of detector works best? Each type has its advantages and disadvantages. Photoelectric models usually run on house current, which means they will not function during a power outage. Ionization models run on house current with a battery back up, but tend to be more susceptible to false alarms. It would be a good idea to use both – an ionization detector in your bedroom hallway, and photoelectric in your main living area.

A general rule is to have a minimum of one smoke detector for every level of your home. You should also keep these guidelines in mind:

Do not install smoke detectors close to the kitchen, furnace, garage, or just outside a bathroom door. Do not install smoke detectors in areas where the air circulation is poor, i.e. corners. Attach each detector to the ceiling, or high on a wall about 8 to 10 inches below ceiling level.

Once your detectors are installed, test each of them monthly. Most have a test button that makes this very easy. If you don’t see a test button, simply light a candle, blow out the flame, and hold the smoking wick about 6 inches below the detector. The smoke should set the unit into alarm.

Replace the batteries in battery-powered smoke detectors annually, on a date that you can easily remember such as your birthday, or the day you set your clocks back. While doing this, use a soft brush to clean the inside of the detector and its vents to ensure the unit’s reliability.

M Adley has over 10 years experience in the security industry and is webmaster at, an unbiased resource for reviews and information about Home Security System and Personal Alarm for the average consumer.