Work out refrigerant charge instantly with clear inputs, formula shown and shareable results.
A split system leaves the factory holding enough refrigerant for a stated line set length. Any liquid line beyond that allowance needs extra charge at the manufacturer's ounces-per-foot figure, which depends on line diameter. Sixteen ounces to the pound converts between the site measurement and the nameplate units.
Additional charge
oz to add = (line length - included length) x oz per foot
Total charge
Total lb = (factory lb x 16 + oz added) / 16
Preliminary estimate only. Refrigerant handling requires certification; always follow the equipment manufacturer's charging procedure.
oz to add = (line length - included length) x oz per foot. A split system leaves the factory holding enough refrigerant for a stated line set length.
Use it to know roughly what to expect, then confirm with superheat or subcooling readings. The line-length rule cannot see restrictions, leaks or a mis-set metering device.
This calculator takes 4 inputs: Factory charge, Total liquid line length, Line length included in factory charge, Charge per extra foot. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.