ICC Commercial Mechanical Practice Exam

In stationary storage battery systems, what part of the area must the exhaust system ensure air movement across for gases with a vapor density greater than air?

1. floor

2. ceiling

3. exterior

4. interior

The correct answer is: floor

In stationary storage battery systems, particularly those using lead-acid batteries, gases that are released, such as hydrogen and sulfuric acid vapors, are lighter than air and tend to accumulate at the ceiling level. However, when focusing on the exhaust system and the specific air movement across areas where the greatest potential for gas accumulation exists, the floor becomes a critical area to address. Gases that are heavier than air can settle near the ground, creating risks such as explosions or harmful exposure. Therefore, ensuring good ventilation and air movement at the floor level is essential in properly exhausting any potentially hazardous vapors. This means the exhaust system must effectively draw air from the floor area, preventing accumulation of dangerous gases that could pose safety risks to individuals working near or within the battery storage area. The other areas like the ceiling, exterior, and interior focus on different aspects of ventilation but do not adequately target the floor level where gases can concentrate. Thus, the emphasis on floor ventilation is vital for safety and compliance with regulatory standards in environments utilizing stationary storage battery systems.