VRF Hits SCOP 5.35, Cutting Primary Energy 67% in a Real University Building

A 2025 paper in Applied Sciences by Arroyo Gómez and colleagues at the University of Valladolid gives commercial HVAC contractors something useful the next time a client asks if VRF really pays off. The team measured a variable refrigerant flow system installed in a university building and logged a seasonal COP of 5.35, with 67% less primary energy use and 79% lower emissions per square meter than the gas-boiler baseline it replaced.

Those are real numbers from a real building. Not a manufacturer data sheet.

The methodology matters. The authors built a seasonal performance protocol tailored to VRF rather than relying on rated conditions, which lets them compare apples to apples against the prior gas-boiler setup. The building ran on a grid that was 83% renewable during the measurement window, which drives the emissions figure, but the primary-energy reduction holds regardless of grid mix.

For contractors pitching commercial retrofits, 5.35 SCOP is a number worth memorizing. European regulatory floors sit around 2.5 depending on climate zone. A measured 5.35 clears that floor by more than 2x. That framing alone can reset a customer's expectation of what good looks like.

Where the efficiency actually comes from

Zoning is the short answer. A VRF system modulates compressor speed and refrigerant flow to each indoor unit based on actual load in that zone. Classrooms on the shaded side of the building in the morning don't get the same treatment as ones baking in the afternoon sun. The controls handle that transition without dumping energy.

Heat recovery is the other piece. In a shoulder season, one zone may be calling for cooling while another calls for heat. A VRF system in heat-recovery mode can move that thermal energy internally rather than pulling from outdoor ambient. The university building's seasonal profile showed this pattern clearly, especially in fall.

What it means on the ground

The 67% primary-energy cut is sensitive to the baseline. A gas-fired boiler is an easy target. A well-tuned electric chiller plus air-source heat pump baseline would shrink the delta. Contractors should be honest about what the system is being compared to when they quote.

The 79% emissions reduction per square meter is the strongest talking point for institutional clients with sustainability targets. Universities, hospitals, municipal buildings, and anyone chasing a GHG inventory number will respond to that framing more than they will to EER or SEER2.

Installation quality matters as much as equipment selection. VRF systems that are poorly commissioned — bad refrigerant charge, incorrect line-set routing, wrong zoning map — routinely underperform their ratings by 20% or more. The paper's numbers assume good commissioning. Pass that message along to the customer early.

For more on commercial HVAC adoption, see our heat pumps outsell gas furnaces article and the EPA refrigerant transition update.

Source

Arroyo Gómez, Y., et al. (2025). "Optimizing Energy Efficiency and Sustainability in Winter Climate Control: Innovative Use of Variable Refrigerant Flow (VRF) Systems in University Buildings." Applied Sciences, 15(5), 2374. https://www.mdpi.com/2076-3417/15/5/2374