Every medium-size building project reaches the same fork in the road: run refrigerant to every room with a VRF system, or run chilled water from a central chiller plant to fan coil units. Both cool the building. The right answer depends on how your building is used, metered and maintained.
How each system works
A VRF (Variable Refrigerant Flow) system connects one outdoor unit to many indoor units on a refrigerant circuit. Inverter compressors modulate output to match the exact load of the rooms that are switched on.
A chiller system cools water — typically 7 °C supply, 12 °C return — and pumps it to terminal units (FCUs or AHUs) around the building. The refrigerant stays inside the machine.
Where VRF wins
- Part-load buildings. Hotels at 60% occupancy and multi-tenant offices only pay to cool occupied rooms.
- Metering by tenant. Individual control and simple cost allocation without a plant operator.
- No plant room. Outdoor units sit on the roof; no pumps, pipes-only installation, faster schedule.
- Buildings up to roughly 10,000 m². Above that, refrigerant pipe limits and system counts start to bite.
Where chillers win
- Large single-owner buildings. Malls, hospitals and towers get a lower cost per kW at scale, especially with water-cooled screw chillers.
- Long equipment life. Chillers routinely run 20+ years; terminals are cheap to replace.
- Process and mixed loads. Chilled water serves AHUs, process cooling and FCUs from one plant.
- Refrigerant containment. All refrigerant stays in the plant room — a growing compliance advantage in Europe.
The quick decision table
| Factor | VRF | Chiller + FCU |
|---|---|---|
| Building size | Small–medium (villas to ~10k m²) | Medium–large |
| Occupancy pattern | Variable, room-by-room | Uniform, long hours |
| Plant room | Not needed | Required (+pumps) |
| Individual billing | Easy | Needs BTU meters |
| Equipment life | ~15 years | 20+ years |
| 50 °C+ climates | T3 versions available | Standard with correct selection |
What we recommend to buyers
Don’t decide on the equipment price alone — model 10 years of energy and maintenance. In our project work, VRF usually wins hotels and offices under ~8,000 m², chillers win malls, hospitals and anything with process load. Send us your floor plans and we will run both selections for you, free: get a comparison quote.