Carbon Monoxide Detectors

More and more citizens are realizing the importance of installing quality CO detectors in their residences. While most fire departments will not endorse or recommend a CO detector, it's helpful to have a reliable source of information available when citizens seek our advice. An October 2001 Consumer Reports (CR) magazine contains information that citizens may find useful and can assist fire department officials as they answer citizen inquiries.

  • Consumer Reports tested nineteen (19) widely available carbon monoxide detectors. The CR ratings listed the tested detectors in order of overall score, based mainly on the speed of the alarm's response to CO and how quickly the alarm stopped once the gas was cleared out of the affected area. The scoring scale for the tested devices was 0 to 100: 81 to 100 excellent; 61 to 80 very good; 41 to 60 good; 21 to 40 fair; and below 40 poor.

  • CR tested both battery-operated and AC powered units. The AC powered units included units which were plug-in models but which had a version that can be hard-wired into a home's electrical circuit. They also included units with power cords that can be hung or placed on a table. Some include battery backup so they can function during a blackout.

  • Using the time specified in the Underwriters Laboratory (UL) standard, CR judged the response of the alarm's speed of detection when placed in CO contaminated atmosphere. Detectors rated Excellent or Very Good always went off within the time specified. Those rated Good closely missed the target time once or twice. Detectors rated Fair experienced more frequent late alarms than permitted by the UL standard.

  • CR's examination of the CO detectors also included a test for "recovery" or how fast the alarm silenced itself when the detector was exposed to fresh air after an exposure test. Detectors receiving the highest scores shut off in 3 to 6 minutes. Models judged to be Fair took about an hour. The worst units took several hours to recover and were rated poor.

  • CR also tested the CO detectors for their ability to sound again, "repeat," if the Hush or Reset button was pressed. For the test purposes the time was expressed in minutes and applied when CO levels persisted in the affected area. Models that list a range of times reactivated their alarm more slowly at low CO levels and faster at high levels. Since several models tested did not have reset buttons, they could not be rated.

Overall Ratings

 

 

CO Sensing

 

Brand & Model

Price

Low Levels

High Levels

Comments

ALARMS WITH DIGITAL DISPLAY Best overall--show CO levels reasonably well.

Senco Model One
SIMILAR: Model One Plus

$50

Excellent

Excellent

Battery powered. Impressive high- and low-level CO sensing.

Kidde Nighthawk Premium Plus KN-COPP-3

$46

Very Good

Excellent

Plug-in, with battery backup. LED display easy to see in dim light. Power cord allows hanging unit on wall.

American Sensors C0910

$40

Excellent

Excellent

Plug-in. Fewer features than top-rated models. No memory for peak CO reading. LED display less accurate than most.

American Sensors C0920

$45

Very Good

Excellent

Plug-in, with battery backup. No memory for peak CO reading. LED display slightly less accurate than most.

Kidde Nighthawk KN-COP-C

$43

Very Good

Very Good

Plug-in. LED display easy to see in dim light. Power cord allows hanging unit on wall.

Kidde Nighthawk Premium KN-COP-DP

$43

Very Good

Very Good

Plug-in. LED display easy to see in dim light.

First Alert FCD4 [CL]

$50

Fair

Excellent

Plug-in, with battery backup.

First Alert FCD2DDN [CL]

$30

Fair

Excellent

Plug-in. Display slightly less accurate than most.

 

 

 

 

 

ALARMS WITHOUT DIGITAL DISPLAY These don't display levels, but most worked effectively.

AMERICAN SENSORS C0800EL

$43

Excellent

Very Good

Plug-in.

Senco 2002

$40

Excellent

Excellent

Battery powered. Has high/low indicators, but lacks digital display's precision. Available only online and at Wal-Mart.

Senco 2003

$25

Excellent

Excellent

Battery powered.

Kidde KN-COB-B

$23

Very Good

Very Good

Plug-in.

Kidde KN-COB-DP

$30

Very Good

Very Good

Plug-in.

First Alert FCD2N [CL]

$27

Fair

Excellent

Plug-in.

First Alert FCD3N [CL]

$22

Good

Good

Battery powered.

 

CO/SMOKE ALARMS These non-display models also sense smoke, though they're better for flaming fires.

Kidde Nighthawk Smoke & CO KN-COSM-B

$50

Excellent

Excellent

Battery powered. Includes ionization-type smoke alarm.

First Alert Smoke and Carbon Monoxide SCO1N

$40

Very Good

Good

Battery powered. Includes ionization-type smoke alarm.

 

 

 

 

 

HARDWIRED ALARMS Can warn about CO in remote locations.

BRK Electronics CO5120B

$55

Good

Excellent

Uses 3-wire system to link to and sound other CO alarms from same manufacturer.

Macurco CM-15
SIMILAR: CM-15A

$110

Poor

Good

Connects to home security system and uses its horn. 2-year warranty. Available only through wholesale suppliers.

 

The Tests Behind the Ratings
Overall score
reflects response time to lower and higher levels of CO, and includes accuracy of the digital display, where applicable. Under CO sensing, low levels shows response time to a CO concentration of 150 parts per million; high levels shows response time to a CO concentration of 400 parts per million. Price is the approximate retail. Most models: Carry UL listing. Sound with a sufficiently loud 85-decibel alarm. Have Test and Hush buttons. Chirp when batteries are weak (applies to battery alarms and plug-in models that include a battery-backup feature). Include a 5- to 6-year warranty.

 

Information provided by Consumer Reports, October 2001