This tool provides theoretical guidelines only. Copexa offers experimental tools for advanced users. No guarantees of safety or actual gas concentrations are made. All use is at your own risk. Full safety terms are available in our Scientific, Safety & Product Disclaimer and Terms of Service.
Cabinet Safety Calculator
Theoretical Guideline Only: This calculator illustrates the speed of gas accumulation inside a lower stand compartment to demonstrate the importance of ventilation. It does not model complex real-world airflow.
Theoretical Boundary
Understanding The Calculation
Hydrogen gas becomes combustible at a 4% concentration in air (Lower Explosive Limit). This model uses a conservative 3.0% safety boundary and applies a 50% volume penalty for equipment displacement. This is an educational simulation and does not account for complex real-world airflow.
Important Safety Considerations
- Mathematical Model Only: Actual stands vary in construction, seams, and airflow. These numbers are guidelines only. Dangerous concentrations can develop faster than predicted in real environments.
- Gas Pooling Risk: Hydrogen rises quickly. Even if average cabinet concentration appears safe, gas can accumulate in high pockets near the top of the enclosure.
- High-Point Ventilation Required: Vent holes or slots must be present at the highest point in the rear of the lower enclosure to allow rising gas to escape.
- Active Exhaust Fan Required: You must install and run the active exhaust fan kit whenever the system is operating to continuously remove accumulating gases.
Engineering Control: Airflow Blueprint
Proper structural installation is required to safely remove lighter-than-air hydrogen gas and prevent dangerous accumulation.
Active Exhaust Fan Placement
Mount the active exhaust fan at the highest point on the back panel of the lower stand, oriented to push air outward. Placing the fan lower allows gas to pool at the top.
Passive Intake Port Alignment
Place passive intake openings on the opposite side of the rear panel from the exhaust fan. This creates proper airflow across the top of the enclosure.
Do not place passive intake openings directly next to or below the exhaust fan. This causes short-circuiting — the fan will pull fresh air in a small loop and leave stagnant zones on the opposite side. Air must flow across the full top volume of the cabinet.
Legal Notice: This calculator is an educational simulation based on ideal gas laws. It does not constitute engineering validation for individual systems. Real-world environments vary in construction, airflow, and ignition sources. Copexa explicitly disclaims any warranty of safety based on these calculations. Active mechanical ventilation and proper high-point venting are required. Full details are available in our Scientific, Safety & Product Disclaimer.