How many air changes per hour are nickel-cadmium battery shops mechanically ventilated to provide?

How many air changes per hour are nickel-cadmium battery shops mechanically ventilated to provide?

• A. One air change per hour.
• B. Three to four air changes per hour.
• C. Five to six air changes per hour.
• D. Seven to eight air changes per hour.

Answer: (B)

Ventilation in nickel-cadmium battery charging areas is there to dilute hydrogen and other fumes produced during charging. The typical mechanical ventilation rate for these shops is about three to four air changes per hour. This means the room’s entire air volume is replaced three to four times each hour, which helps keep hydrogen concentrations well below flammable levels while avoiding unnecessary energy use. If only one air change per hour were provided, gas could accumulate to unsafe levels; conversely, five to six or seven to eight changes per hour would be more than needed for most shop sizes and would waste energy. The concept of air changes per hour is simply the ventilation rate divided by the room volume, indicating how many times the air in the room is refreshed each hour. Follow the specific safety guidelines and codes for exact requirements in your facility.

Ventilation in nickel-cadmium battery charging areas is there to dilute hydrogen and other fumes produced during charging. The typical mechanical ventilation rate for these shops is about three to four air changes per hour. This means the room’s entire air volume is replaced three to four times each hour, which helps keep hydrogen concentrations well below flammable levels while avoiding unnecessary energy use. If only one air change per hour were provided, gas could accumulate to unsafe levels; conversely, five to six or seven to eight changes per hour would be more than needed for most shop sizes and would waste energy. The concept of air changes per hour is simply the ventilation rate divided by the room volume, indicating how many times the air in the room is refreshed each hour. Follow the specific safety guidelines and codes for exact requirements in your facility.