A “Cooler” Way Forward: Chilled Beams Systems
By Lian Yuyang
Melting in a non-air-conditioned room, one stares at the empty ceiling while the fans stir the stagnant air, sluggish and listless. Across the wall in the neighbouring room, the aircon is working nonstop, and the absence of the owner, who is probably out for a walk, piques our attention. This reflects an everyday scene in Singapore: you have to choose between fans and AC, or the world will end in an apocalypse. Indeed, air-conditioning saves lives, but it’s slowly killing our Earth as it accounts for roughly 3% of global greenhouse gas emissions. (Our World in Data, 2024) While electric fans significantly reduce energy use, one cannot help but twitch at the idea of having only fans in a shopping mall. But the number is staggering: in Singapore, cooling alone accounts for 40% to 60% of a commercial building’s total energy use.
To this we ask: are there alternative cooling technologies (ACTs) available to cool buildings more efficiently and comfortably? Yes, and Chilled Beams (CB) are among the most innovative and avant-garde cooling solutions around the globe. (BCA, 2026)
Although the system has been used in Europe for many years, it is a relatively new concept to many in Singapore. Interestingly, the system is not just about blasting air; it uses chilled water in a coil to cool a space through convection and induction. There are two types of this Heating, Ventilation and Air-Conditioning (HVAC) terminal unit. One is the passive CB (PCB), which capitalises on the density of air molecules: as heat gives energy to air particles, they bounce off each other and expand the space between them. As the warm air rises and passes over the chilled water coil, it loses heat and falls due to its higher density, returning to the room in a refreshed state.
While PCB uses natural convection, Active CB (ACB) uses forced convection and induction: as high-density primary air is discharged through specialised nozzles, it creates a low-pressure zone around the beam. This process is called the induction effect, where a fast-moving stream of fresh primary air induces a much larger volume of room air. Warm room air is then pulled up across the chilled coil to be cooled, then mixed with primary air and supplied to the whole room. Because one part of fresh primary air can induce up to five parts of room air, ACB is highly efficient and can handle a much higher cooling load than PCB, making it more common in demanding environments where comfort and efficiency are paramount, such as commercial offices. (Trane, 2011)
Indeed, CB systems reduce fan energy use and overcooling, provide quiet operation as patented nozzles minimise noise, while supporting better occupant well-being and a more stable, conducive atmosphere for work and daily activities. Although ACB systems have an initial cost premium compared to conventional ACMV systems, at $450-$500 per square metre, they deliver significant energy savings of 20-50%, with a payback period of approximately 5 to 10 years. (BCA, 2026) Nonetheless, there is still room for performance improvements compared with the relatively mature ACMV systems. First, there is a valid call to conceal discharge vents to improve office space aesthetics, as they are now obnoxiously conspicuous; secondly, the system shall strive to achieve true 360-degree air discharge to create the shortest possible air throws.
Nonetheless, Singapore’s high humidity presents a key challenge for CB adoption, since excessive moisture in the air can cause condensation on the chilled coils if temperatures fall below the dew point. This means CB systems require delicate humidity control and integration with dedicated outdoor air systems, increasing design complexity and cost. Their relatively limited adoption in Singapore may therefore reflect not only higher upfront costs, but also the need for greater adaptation to the tropical climate. In practice, chilled beams may be most suitable for new-build offices and well-controlled commercial spaces with stable occupancy and high cooling demand, where their energy savings and quiet operation can better justify the investment.
Looking ahead, Singapore could further explore CB systems as part of its transition towards more energy-efficient cooling, particularly in offices and new commercial developments. Their huge potential could be strengthened by integrating them with Singapore’s district cooling networks, where chilled water is centrally produced and distributed through underground pipes. (SP Group, n.d.) This will reduce reliance on individual building-level cooling systems.
Ultimately, chilled beams remind us that cooling does not have to mean more noise and more energy. As buildings demand more from their cooling systems, the future may lie not in choosing between comfort and sustainability, but in designing for both. The real question is no longer how much we can cool, but how we can do it more intelligently.
REFERENCES
Building and Construction Authority. (2026). Green Mark 2021: Accelerating transformation of the built environment. https://www1.bca.gov.sg/sustainability/greenmark/act/
Building and Construction Authority. (2026). New BCA study confirms 80% energy efficiency target is within reach for Singapore’s built environment sector. https://www1.bca.gov.sg/resources/newsroom/new-bca-study-confirms-80--energy-efficiency-target-is-within-reach-for-singapore-s-built-environment-sector/
Our World in Data. (2024). Air conditioning causes around greenhouse gas emissions—How will this change in the future? https://ourworldindata.org/air-conditioning-causes-around-greenhouse-gas-emissions-will-change-future
Trane. (2011). Airside design manual: Application guide. https://www.trane.com/content/dam/Trane/Commercial/global/products-systems/education-training/engineers-newsletters/airside-design/adm_apn034en_1209.pdf
SP Group. (n.d.). District cooling & heating. https://www.spgroup.com.sg/sustainable-energy-solutions/district-cooling-and-heating
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