Six ways a building is cooled, drawn as working schematics

Most people who buy, run or audit cooling have never seen the plant drawn as a system.

Cooling is the largest energy load in a Singapore commercial building and the one most estate decisions turn on, yet the plant behind it usually appears as a line item or a manufacturer's photograph. An owner deciding between water-cooled and air-cooled, a facilities manager reading a chiller alarm, an auditor questioning an efficiency figure: each is reasoning about a system they have rarely seen as one picture. This explainer draws that picture six times, from the simplest configuration to the largest, so the differences become visible instead of asserted.

The same job, six configurations, one set of rules.

• Six working schematics. Air-cooled, water-cooled with a cooling tower, primary-secondary, variable primary, split and multi-split, and VRF. Every component is labelled, every pipe is colour-coded by fluid, and the plain-English and engineer explanations sit behind the same hover.
• A commissioning sequence you can scrub. Press Run start-up and the plant comes online in the order it actually does, with the counter-intuitive steps left intact: coil valves open first because zone requests enable the plant, and tower fans stage up on rising condenser-water temperature rather than with the pump.
• A live load model. Drag the building load and the flow tokens change speed, the equipment status table updates, and the readouts show cooling load, plant chilled-water flow, system delta T, plant efficiency in kW per refrigeration ton and chillers running. The efficiency bands come from AHRI 550/590 conditions and DOE FEMP guidance, and the page says what the model is and is not.
• Two reading levels. The Detail toggle switches every explanation between plain English and engineering notes, which is the difference between a page a tenant can read and one a design engineer can check.

What this is not.

The load model is indicative: a 1,000 RT design plant at nominal conditions, drawn to illustrate the hydraulic behaviour of each arrangement, and no figure on the page should be read as a rating for any real chiller. The schematics are teaching schematics, simplified to what a reader needs to see the system, and omit the valves, instruments and safeties a construction drawing carries. The engineering content was checked against ASHRAE Guideline 36, AHRI 550/590 and 1230, manufacturer installation manuals and Singapore NEA and BCA references, and the sources are listed at the foot of the page. Where a simplification was made for legibility, the engineer view says so.