LOCATIONS TO AVOID
Nuisance alarms are caused by placing alarms where they will not operate properly. To avoid nuisance alarms, do not place alarms:
–Within 1 foot (.3m) from fluorescent lights. Electronic noise may cause false alarms.
–Within 5 feet (1.5m) of any cooking appliance.
–Closer than 20 feet (6m) away from a furnace or other fuel burning heat source or fuel burning appliances such as a water heater.
–Near an open window or door, because the fresh air entering the opening may delay CO from reaching the alarm.
–In extremely humid areas. This alarm should be at least 10 feet (3m) from a bath or shower, sauna, humidifier, vaporizer, dishwasher, laundry room, utility room or other source of high humidity.
–In very cold or very hot environments or in unheated buildings or outdoor rooms where the temperature can go below or above the operating range of the alarm. Temperature limits for proper operation are 40o to 100oF (4.4o to 37.8oC).
–In turbulent air, such as near ceiling fans, heat vents, air conditioners, fresh air returns or open windows. Blowing air may prevent CO from reaching the sensors.
–Good ventilation is recommended when household cleaning supplies or similar contaminants are used.
–Excessive spillage or reverse venting of fuel burning appliances caused by outdoor ambient conditions, such as:
–Wind direction and/or velocity, including high gusts of wind. Heavy air in the vent pipes (cold/humid air with extended periods between cycles).
–Negative pressure differential resulting from the use of exhaust fans.
–Simultaneous operation of several fuel burning appliances competing for limited internal air.
–Vent pipe connections vibrating loose from clothes dryers, furnaces, or water heaters.
–Obstructions in or unconventional vent pipe designs which can amplify the above situations.
–Extended operation of unvented fuel burning devices (range, oven, fireplace, etc.)
–Temperature inversions which can trap exhaust gasses near the ground.
–Car idling in an open or closed attached garage, or near a home.
What Levels of CO Cause an Alarm?
Underwriters Laboratories Inc. UL2034 defines three specific alarm points by which all residential CO alarms must alarm. They are measured in parts per million (ppm) of CO over time (in minutes).
UL2034 Required Alarm Points:
•If the alarm is exposed to 400 ppm of CO, IT MUST ALARM BETWEEN 4 and 15
MINUTES.
•If the alarm is exposed to 150 ppm of CO, IT MUST ALARM BETWEEN 10 and 50
MINUTES.
•If the alarm is exposed to 70 ppm of CO, IT MUST ALARM BETWEEN 60 and 240
MINUTES.
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