Why do parking garages need carbon monoxide sensors?
Parking garages, maintenance bays, and other areas that will have vehicles running in an enclosed space must be ventilated to prevent the build-up of carbon monoxide and other dangerous gases from vehicle exhaust. In the past these areas had been fitted with very large ventilation fans that would run 24 hours a day. Over the past 20 years, we have begun to focus heavily on energy efficiency, and the electricity that is needed to run these big fans at all times is costly and wasteful. To combat this excess energy usage the industry has developed an alternate strategy to ventilate these enclosed spaces. This involves actually measuring the amount of carbon monoxide or other gases in the garage, and only operating the fan at full speed when it is actually necessary. Building owners can see energy savings of 80-90% when these systems are installed and they are becoming required by local code in many cases.
How do parking garage sensors function?
These sensor operate by electro-chemical reaction. That is, when the sensor is contacted by carbon monoxide (CO) or nitrogen dioxide (NO2) a change in voltage happens which triggers the fan to activate. As the sensor is contacted by gas over months or years, these chemicals begin to wear out and they no longer trigger the fan at the proper concentration of hazardous gases. For that reason, the manufacturer’s require that the sensors be calibrated every 6-12 months and replaced every 2-7 years. If this doesn’t happen, then we can either create a safety issue due to gas buildup, or lose our energy saving by having the fan read a fault and always operate.
We perform calibrations, maintenance, and repair on these sensors frequently through our other division Hawk Equipment Services ( https://hawkequip.com ). In the field, we are finding that 90+% of the sensors that were installed have never been calibrated, and 50-75% have completely failed and are no longer working at all.
How are toxic gas sensors calibrated?
Getting these systems up and running again is a fairly inexpensive and painless process. Our technicians will visit the site and assess the quantity, brand, and location of each carbon monoxide or nitrogen dioxide sensor. They will apply the proper span gases and run through the manufacturer’s calibration procedures. Sensors that pass calibration will have a certificate generated and calibration label affixed. The client is then provided with a calibration report and ongoing operations and maintenance plan for this system
Sensors that do not pass calibration, are expired, or otherwise damaged can easily by replaced with the same brand or upgraded to a modern version. Our filed techs will recommend the most durable and cost-effective solution to the facilities manager.