The Singapore Green Building Council (SGBC), the industry body that promotes sustainable construction in the city-state, published an article on September 29, 2026 claiming that coordinating ceiling fans with air-conditioning can cut a building’s cooling energy by a third. The number comes from two different experiments, neither of which used the automated control product the article recommends to actually achieve it — and that product will not be commercially available until October 2026.

The Claim Making the Rounds Among ASEAN Facility Teams

SGBC’s piece, titled “Making 27°C Feel Like 24°C,” opens with a framing familiar to anyone managing a tropical building’s energy bill: cooling accounts for the bulk of a typical Singapore building’s electricity consumption and carbon emissions, according to SGBC. Pairing ceiling fans with air-conditioning, so occupants feel comfortable at a higher thermostat setting, is positioned as the fix — with a headline figure of roughly one-third less cooling energy.

That is a specific, quotable number, and it is already circulating in Singapore’s building-services circles as shorthand for what hybrid cooling can deliver. It deserves more scrutiny than a headline gets.

What the Data Behind “a Third” Actually Shows

The SGBC article cites a 20-week field study by researchers at the National University of Singapore (NUS) that tracked households adopting mixed-mode ventilation — pairing natural ventilation and ceiling fans with air-conditioning used only as needed. That study found a 48 percent reduction in monthly cooling energy costs compared with running air-conditioning continuously at 24°C, with 92 percent of participants reporting comfort with the approach by the end.

The one-third figure itself comes from a separate, unrelated office-setting test: raising the thermostat setpoint from 24°C to 26.5°C while maintaining tenant comfort, which SGBC says cut close to a third of the building’s cooling energy. SGBC also cites a cost rule of thumb from the same material: each 1°C increase in setpoint translates to roughly $15 to $20 in monthly bill savings.

Neither experiment used an automated system to hold that higher setpoint comfortable. The residential trial relied on occupants manually adjusting fans and air-conditioning as conditions changed. The office figure describes what a setpoint change alone can save — not what happens when a building tries to sustain that setpoint with fans running on their own logic rather than a person’s hand on the remote.

The Sentence That Undercuts the Headline: “Manual Doesn’t Scale”

SGBC’s own article concedes the gap: scaling mixed-mode ventilation beyond individual households requires automated coordination, because manual adjustment does not scale to a commercial floor plate with dozens of occupants and a facilities team that cannot staff a thermostat around the clock.

The product offered as the answer is ClimaSync, a feature from PRISM+, the Singapore consumer-electronics brand that manufactures both air-conditioners and smart ceiling fans. ClimaSync brings a building’s air-conditioners and fans under one control logic, coordinating them automatically to hold a target “feels like” temperature rather than a raw thermostat reading. It is currently in alpha testing. A full launch, on the PRISM+ Connect app, for both home and business users, is planned for October 2026 — after the article promoting the one-third figure was published, and after most readers will have already filed the number away as proven.

That sequencing matters. The 48 percent figure belongs to a completed study. The one-third figure belongs to a setpoint change tested without automation. The product meant to deliver both outcomes at commercial scale has not yet shipped to a single paying office tenant. Three different claims are being read as one validated pipeline, and only the first has been tested in the field for the length of time SGBC cites.

What a Facility or Portfolio Team Should Actually Do Before Budgeting Around It

None of this means hybrid cooling is a bad bet — the underlying physics of pairing air movement with a higher setpoint is well established in tropical building research, and the comfort data from the NUS trial is real. The caution is narrower: a facility team that budgets this quarter’s retrofit plan around a one-third cooling-energy reduction is budgeting around a number that has not yet been demonstrated with the automated system marketed to deliver it, in a commercial building, at any scale.

The practical move is to treat ClimaSync’s October 2026 launch as the start of an evaluation period, not a purchase decision. A portfolio manager should ask a vendor for post-launch performance data from an actual office deployment — not the residential field study or the unautomated office setpoint test — before attributing a specific percentage saving to a capital or operating budget line. For a multi-tenant building, the more relevant question is also unanswered by SGBC’s piece: how does automated fan-and-AC coordination perform when different tenants on the same floor have different comfort expectations, lease terms that assign HVAC costs differently, and no single party controlling the thermostat.

Key takeaways

  • SGBC’s claim that hybrid cooling cuts cooling energy by a third combines a 20-week NUS residential field trial with a separate, unautomated office setpoint test, not a single validated result.
  • The automated product recommended to scale the approach to commercial buildings, PRISM+’s ClimaSync, is still in alpha and will not reach a commercial launch until October 2026.
  • SGBC’s own article acknowledges that manual coordination of fans and air-conditioning does not scale beyond individual households, which is the gap ClimaSync is meant to close.
  • Facility and portfolio managers should request post-launch commercial performance data before attributing a specific energy-savings percentage to a retrofit budget.
  • Multi-tenant buildings face an unanswered question the current data does not address: how automated coordination performs when tenants on one floor have different comfort expectations and HVAC cost arrangements.