Most Popular Types
- Photoelectric type smoke alarms use a beam of light and a sensor to detect smoke particles in the air. When the sensor detects reflected light from smoke particles the alarm sounds.
- Ionization alarms use two oppositely charged plates and a tiny amount of radioactive material to ionize oxygen and nitrogen atoms to produce a small electric current. When smoke particles disrupt this current the alarm sounds.
Requirements for Smoke Alarms
The minimum requirements for the locations of smoke alarms in the home are as follows:
- Smoke alarms are to be installed within 21 feet of all bedroom doors
- At least one smoke alarms must be installed on each level of the home
- if required state building code at the time of construction, smoke alarms must be installed in all bedrooms.
- All smoke alarms are to be installed in accordance with the manufacturer’s installation instructions.
- Oregon law requires that smoke alarms older than 10 years be replaced prior to the transfer of ownership.
- Hard wired alarms may not be replaced by alarms operated solely by batteries
Requirements for Ionization Smoke Alarms
- Ionization type alarms are currently the most common as they are less expensive than the photoelectric alarms.
- Ionization smoke alarms can be operated solely by a battery or be hard wired with a battery back-up. The smoke alarms in newer homes must be hard wired with a battery back-up.
- Ionization smoke alarms operated solely by a battery must have ten year life batteries installed. Regular alkaline batteries may be used in hard wired alarms.
- Ionization smoke alarms must have a hush feature that allows the occupant to silence the alarm for not more than 15 minutes. This reduces nuisance alarms and keeps the alarms installed in the dwelling.
Locations for All Smoke Alarms
- The minimum requirement is one smoke alarm per level installed outside the sleeping areas.
- Current Building Codes require that smoke alarms be installed in all bedrooms at the time of construction.
- Older homes are not required to have smoke alarms installed in the bedrooms. However, installation of smoke alarms in the bedrooms is highly recommended.
- Smoke alarms shall be installed on the ceiling at least 4 inches from the nearest wall or high on the wall 4 to 12 inches from the ceiling.
Information obtained from the Oregon Office of State Fire Marshal – “What You Need to Know About Smoke Alarms Before You Sell Your Home”
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