How are A3 refrigerants expected to be managed in B28 installations?

• A. By using minimal ventilation to maintain pressure.
• B. By relying on normal building ventilation without special controls.
• C. With enhanced ventilation, ignition-source control, leak detection, proper electrical classifications, and strict maintenance and training.
• D. By avoiding leak detection to reduce nuisance alarms.

Answer: (C)

A3 refrigerants are highly flammable, so B28 installations must implement a comprehensive approach to prevent vapor buildup and ignition. The best management plan includes enhanced ventilation to dilute any leaked vapor, ignition-source control to eliminate potential ignition sources (no open flames, proper storage of ignition sources, and equipment rated for hazardous locations), reliable leak detection to find leaks quickly, electrical classifications and equipment appropriate for flammable atmospheres to minimize ignition risk, and strict maintenance and training so staff consistently follows procedures and respond effectively to any issues. This combination directly reduces the chance that leaked refrigerant vapors reach flammable concentrations and encounter an ignition source, which is essential with A3 refrigerants.

Relying on minimal or normal building ventilation without additional controls isn’t enough to prevent vapor accumulation. Avoiding leak detection leaves leaks undetected and can allow hazardous concentrations to develop.