Allocating central chiller consumption

Central chillers, mini-chillers, and VRF systems can provide efficient, quiet cooling without equipment inside each unit. The principal weakness of a shared chiller is that the building’s total electricity or gas bill does not reveal how much energy each unit consumed.

Bruntab installs heat/cooling energy meters to measure cooling in kWh, GJ, or another approved energy unit. Readings travel by cable or wireless communication to a Bruntab central reader and then to EEMS. The system can issue electricity sub-bills for compression chillers or gas sub-bills for absorption chillers.

How the system works

An energy meter is installed after the main riser and each unit’s supply and return branches and isolation valves. Two temperature sensors measure the supply/return temperature difference, while a flow sensor measures water volume. The calculator determines the energy used during an hour, day, month, or billing period.

EEMS applies Bruntab’s allocation formulas and the relevant utility tariff, including progressive tariff tiers. The total value of all unit sub-bills is reconciled with the building’s main bill.

Benefits

• Shows each unit’s true share of central cooling
• Reduces resident disputes
• Provides separate accounts and real-time consumption access
• Identifies high-consuming units and reveals temperature or flow imbalance between floors
• Allows residents to reduce consumption when away
• Supports optimization of chiller equipment with measured operating data
• Bruntab experience indicates potential energy reductions of about 13–43% after users see their real consumption

Implementation considerations

In occupied buildings, the site survey checks access-panel dimensions, available space after each isolation valve, cable routes between floors, and the condition of chilled-water piping. Because all units must be measured for a complete allocation, building-wide agreement is normally required. Large projects may be phased when the final design still accounts for every unit.

Frequently asked questions

Can each unit view its own consumption?

Yes. Each unit receives a separate EEMS account for live and historical consumption.

Is the platform suitable for billing?

Yes. Hourly readings and tariff-based calculations support accurate unit sub-bills whose combined value reconciles with the main bill.

Can only one unit be equipped?

A complete billing allocation requires readings for all units. A phased installation can be engineered for large buildings when all parties agree on the rollout.