Natural gas is lighter than air, and will rise and disperse within a facility. Garage upgrades are designed to detect a potential hazard, dilute the gas to reduce ignition risk, and then extract the gas for safe re-entry.
A few simple strategies can greatly reduce the cost and complexity of an alternative fuel upgrade.
Alarm System Demonstration
Participants at Gas Technology Institute’s Alternative Fuel Vehicle Maintenance Garage Workshop had the opportunity to see a demonstration of a two-level alarm system installed in a CNG and LNG maintenance garage just outside of Chicago. The requirement is for the alarm system to activate at 25% of the Lower Flammability Limit (LFL) of natural gas in air. To avoid false alarms and unnecessary evacuations, a best practice is to activate warning lights, a mild alarm, and ventilation at 20% of the LFL, and then a more extreme evacuation alarm along with hazard lights, strobe lights, and continued ventilation if 40% of LFL is reached. For more information on gas detection and alarm systems, see the best practices or the code reports.
HD Repair Forum Slides April 2–3, 2019 — Alternative Fuels and Repair Facilities
NTEA Work Truck Show Slides March 7, 2019 — Advancing Your Fleet Goals with Natural Gas