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Refrigerant Charge Estimator

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Refrigerant Charge Estimator
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Features & Capabilities

Multi-Refrigerant Support

Supports R-410A, R-32, R-22, R-134a, R-454B, and other common HVAC refrigerants with charge rates specific to each refrigerant type.

Manufacturer Charge Rates

Charge rates by liquid line OD sourced from published installation manuals from Mitsubishi, Daikin, Carrier, and AHRI 210/240 guidelines.

Unit Conversion

Automatic conversion between ounces, grams, and pounds for the additional charge amount.

Maximum Length Warnings

Warns when total line set exceeds manufacturer-recommended maximum length limits, which may require a larger liquid line or different unit selection.

Line Volume Breakdown

Shows both liquid line and suction line volume contributions separately so you can see where the additional charge comes from.

Frequently Asked Questions

It is the maximum line set length the factory charge can support, typically 25 feet for most residential mini-splits. If your actual line set matches or is shorter than this length, no additional refrigerant is needed. The exact value is in the unit's installation manual.
Vertical rise does not change the volume of refrigerant in the line set, but it does affect system performance. Most manufacturers limit total vertical rise (typically 30-50 feet) and may require an oil trap in the suction line on long vertical runs to ensure oil return to the compressor.
No. This calculator sizes additional charge for a single refrigerant type. R-454B has different density and charge rates than R-410A. Never mix refrigerants. If converting a system, follow the equipment manufacturer's specific conversion procedure.
Disclaimer: This calculator provides charge estimates based on published manufacturer data. Always refer to the specific unit's installation manual for the exact charge rate, maximum line set length, and any model-specific adjustments. Field conditions including elevation, ambient temperature, and vertical rise may require additional adjustment.

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