Chiller efficiency gets quoted constantly in Malaysian property marketing and almost always as a design figure. The distinction between a design figure and an operating one is not pedantry. It is the difference between what a building was sold as and what it costs to run.
Sunway Visio is a commercial office building of roughly 30,048 m² in Cheras, Kuala Lumpur, developed by Sunway Integrated Properties. First certified in 2019 and renewed to GreenRE Silver in 2022 at 77.25 points.
The numbers, and what they are
- 0.72 kW/RT, reported operating efficiency of the chilled-water system
- 405.02 RT average cooling load
- 5.84 degrees Celsius chilled-water temperature differential
- 95.29 kWh/m2/year reported Energy Efficiency Index for 2021
Air-conditioning systems scored 17.21 points on the strength of those figures.
These are measured, not modelled. That matters because a design figure describes equipment selected at full load under laboratory conditions, while an operating figure describes a plant running at part load, in Malaysian humidity, maintained by real people on a real budget.
Most plants perform worse in service than on paper. A building reporting 0.72 kW/RT in operation is doing well, and the temperature differential of 5.84 degrees tells you why: the plant is moving heat efficiently rather than pumping excess water around the building to compensate for poor coil performance.
The rest of the scorecard
Artificial lighting took the full 12 of 12, with daylighting in common areas, car park ventilation and common-area ventilation each contributing 2 points. Efficient lifts and escalators scored 3, with variable-voltage variable-frequency drives, standby and sleep functions and motion sensing.
Water conservation picked up points for usage monitoring, drought-tolerant planting and cooling tower management, with cycles of concentration reported at approximately 7.6.
Green Plot Ratio took the full 6 of 6 and noise compliance a full 2 of 2.
Indoor air quality was tested under DOSH ICOP IAQ 2010 alongside occupant surveys and lighting and noise assessments.
Why we publish these figures
Almost no consultancy in this market publishes operating data from the buildings it has certified. It is understandable: a measured figure can be checked, and a modelled one cannot.
That is exactly the reason to publish it. If you are evaluating a consultant, ask what the buildings they certified actually consume. If the answer is a design figure, you have learned something about the answer.
