Every month we meet building owners who have been sold a technology rather than a solution — a VRF system where chilled water made sense, or dozens of splits bolted onto a facade that needed central plant. The right answer always starts with the building: its size, its occupancy pattern, its power supply and who will maintain it. Here is the decision framework we use.
Split and multi-split systems: 1–20 rooms
For small offices, retail units, clinics and branch networks, wall-mounted, cassette and ceiling-suspended splits remain the most cost-effective choice. Capital cost per kW is the lowest of any option, installation is fast, and a failed unit affects one room rather than a floor. The limits appear beyond roughly 20 indoor units: refrigerant pipe runs multiply, facades fill with condensers, and maintenance becomes a fleet-management problem.
VRF: the mid-size sweet spot
Variable Refrigerant Flow connects up to 60+ indoor units to a single outdoor system, modulating compressor output to match the exact load of each zone. For hotels, mid-rise offices and mixed-use buildings of roughly 500–5,000 m², VRF usually wins: individual room control, excellent part-load efficiency, no plant room required, and heat-recovery variants that cool the server room while warming the lobby. The trade-offs are higher capital cost than splits and a dependence on properly trained installers — refrigerant piping errors are unforgiving.
Chilled water: large and critical buildings
Above about 5,000 m², or wherever loads are dense and continuous — hospitals, data centres, shopping malls, towers — central chilled-water plant comes into its own. Chillers deliver the best efficiency at scale, water distribution eliminates long refrigerant runs, and N+1 plant configurations provide the redundancy critical facilities demand. It requires plant space, skilled operation and disciplined water treatment, which is why it pairs best with a structured maintenance contract.
The questions that decide it
How big is the cooled area, and how variable is occupancy? Is there space for plant? How reliable is the power supply, and what does standby generation cost per kW of cooling? Who maintains the system for the next 15 years? A one-hour conversation about these questions, backed by a heat-load calculation, produces a better outcome than any brochure comparison. That is exactly what our free site survey delivers.