VRF System Sizing Calculator

Size Variable Refrigerant Flow outdoor units and verify connection ratios

Number of indoor fan coil units connected to this outdoor unit. Most VRF systems support up to 64 indoor units per outdoor unit.
Average rated capacity of each indoor unit. Typical wall-mount: 9,000-24,000 BTU/hr. Ducted: 12,000-48,000 BTU/hr.
BTU/hr
Longest refrigerant pipe run from outdoor unit to farthest indoor unit. Max typically 540-650 ft depending on manufacturer.
ft
Number of Y-branch or refnet joints in the piping system. Each branch adds pressure drop and capacity loss.
Percentage of indoor units operating simultaneously at peak. Offices: 80-90%, hotels: 50-70%, residential: 60-80%.
%

Results

Required Outdoor Unit CapacityBTU/hr
Connection Ratio%
Piping Correction Factor
Adjusted CapacityBTU/hr
Recommended Model Sizetons
References: VRF system design per manufacturer guidelines. Connection ratio (total indoor capacity / outdoor capacity) typically 50-130%. Piping length corrections per AHRI 1230.