Ammonia Charge Estimator

Estimate ammonia system charge with component breakdown and PSM/RMP threshold checks.

DX uses least charge. Flooded uses more. Recirculated (pumped) uses the most ammonia.
Total refrigeration capacity in tons (1 ton = 12,000 BTU/hr).
tons
Saturated suction temperature. Lower temps require more charge per ton.
deg F
Evaporative condensers hold more charge than air-cooled due to larger internal volume.
Total equivalent piping length including liquid, suction, and hot gas lines.
ft
High-pressure receiver volume. Holds liquid reserve and pump-down charge.
cu ft

Results

Evaporator Charge:
Ammonia charge in evaporator coils. Varies greatly by system type.
-lbs
Condenser Charge:
Ammonia charge held in the condenser during normal operation.
-lbs
Receiver Charge:
Charge in the high-pressure receiver at normal operating level.
-lbs
Piping Charge:
Ammonia charge in suction, liquid, and hot gas piping.
-lbs
Total System Charge:
Total estimated ammonia charge for the system.
-lbs
PSM Threshold (10,000 lbs):
OSHA PSM applies to ammonia systems with 10,000+ lbs. Requires written programs and audits.
-
RMP Threshold (10,000 lbs):
EPA RMP applies at 10,000+ lbs of ammonia. Requires risk management plan filing.
-
Reference: IIAR Bulletin 114 - Guidelines for Ammonia Charge Estimation. OSHA 29 CFR 1910.119 (PSM). EPA 40 CFR 68 (RMP).