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Why you need two types of smoke alarms

 

The James City County Fire Department suggests for the best fire protection citizens should install both photoelectric and ionization alarms. 

 

  • Ionization:  The most common type of smoke alarm.  It is cheaper and better at detecting the smaller amounts of smoke in a fast flaming fire.
  • Photoelectric:  Less common, it uses a light source and light chamber to detect the smoke from a fire.  It is better at sensing smoky fires. 

 

For more information about how these types of smoke alarms work, click here:  http://home.howstuffworks.com/smoke.htm

 

There are studies to support having both types of smoke alarms.  Click on the USFA Fire in the USA report, 1985-1994; page 76 reports fire fatalities in 19% of homes with working smoke alarms.  A 2006 NIST report suggests that while further study is needed the escape time has decreased dramatically.