‘Retrofit-first’: Stolz Engineering optimises old cooling towers with sensor, AI-powered platform for energy savings

Stolz Engineering has developed the "Smart Cooling Tower Internet of Things (IoT) Sustainability Framework," an AI-powered platform that retrofits existing cooling towers with IoT sensors to automate functions such as fan-speed adjustment, and the company aims to deploy it by Q1 2027. A proof-of-concept using a Singapore Polytechnic cooling tower projects annual cost savings of up to S$2 million for a 40-cell tower with 60,000 refrigerant tonnes of cooling power, from 47.5 per cent fan energy reductions, 836 kilowatt-hour annual energy savings and 0.36 tonnes of carbon emissions reductions per fan annually. Stolz, which supports over 1,000 cooling facilities in Singapore plus more than 100 each in Malaysia and Thailand, won an Impact Enterprise Excellence Award (SME) at the 2026 Sustainability Impact Awards, and chief operating officer Mark Tan aims to implement the solution across its 1,000 Singapore facilities within two years.

‘Retrofit-first’: Stolz Engineering optimises old cooling towers with sensor, AI-powered platform for energy savings The company plans to deploy the platform by Q1 2027 Koh Kim Xuan SINGAPORE As companies with large-scale industrial operations in Asean face mounting pressure to meet decarbonisation targets, many may opt for replacement of existing, inefficient cooling towers, which can be disruptive and costly. To this, engineering services provider Stolz Engineering developed a solution that transforms old cooling towers into sustainability assets through technology. Named the “Smart Cooling Tower Internet of Things IoT Sustainability Framework”, it uses existing sensors on cooling towers, and non-invasive IoT-sensing technologies. Using data from the sensors, the platform automates the optimisation of cooling tower functions such as adjusting fan speeds. Information generated can also be reviewed by or guide operators to further improve the facilities. Stolz’s solution follows the “retrofit-first” sustainability approach, which prioritises improving existing buildings to enhance sustainability over demolition and rebuilding. “Our philosophy is that you must be able to measure before you can improve,” said Stolz chief operating officer Mark Tan. Established in 2007, the company supports over 1,000 cooling facilities in Singapore, along with more than 100 in both Malaysia and Thailand. Its clients include a large semiconductor plant in Woodlands, pharmaceutical plants such as Pfizer, Lonza and GSK, and data centres operated by Global Switch and Singtel. Stolz won an Impact Enterprise Excellence Award SME at the 2026 Sustainability Impact Awards, jointly organised by The Business Times and UOB. The award recognises businesses and individuals who have had a positive impact on the environment and community. The firm aims to deploy the AI-integrated platform by Q1 2027. Within two years, Tan aims to implement the solution across its 1,000 facilities in Singapore. How it works IoT field sensors and instruments are mounted on towers. They track temperature, water usage and pressure, weather and mechanical health of cooling infrastructures. Raw data from these physical sensors is then transmitted through an IoT gateway that delivers the information onto a cloud platform. Artificial intelligence AI then turns the data into meaningful insights human operators can act on. Information is visualised as real-time dashboards, alerts and reports, and environmental, social and governance insights. According to the company, the framework enhances operational visibility, reduces energy demand and lowers carbon emissions and extends asset lifecycle performance. It validated the platform through a proof-of-concept POC using a cooling tower from educational institution Singapore Polytechnic. The sensors and platform were tested under actual operating conditions. Based on the results of the POC, it is projected that for a 40-cell tower – a cooling system made of 40 individual cooling units – with 60,000 refrigerant tonnes of cooling power, cost savings of up to S$2 million would be achieved annually when the framework is applied. Monetary savings come from 47.5 per cent fan energy reductions, 836 kilowatt-hour annual energy savings and 0.36 tonnes of carbon emissions reductions per fan annually. “Cooling has become increasingly important especially for emission critical industries. It needs to be consistent,” said Tan, raising AI data centres and semiconductor plants as examples of facilities requiring intense cooling. He added: “The question right now is not so much about how companies can provide more cooling, but how it can be provided responsibly and more sustainably.” Plans for Asean As the platform aims to reduce energy demand and carbon emissions by buildings, Stolz sees it supporting the Singapore Green Plan 2030. The firm believes that Singapore’s sustainability challenge is not only to develop new green infrastructure, but also to improve the performance of existing infrastructure already operating today. Beyond Singapore, the company plans to roll out the platform for cooling towers across Asean, particularly Malaysia and Thailand where the company already installs towers. The framework is scalable across Stolz Engineering’s regional operating presence in Singapore, Malaysia and Thailand, supporting lower energy demand, improved operational resilience and more practical climate adaptation pathways across climate-vulnerable Asean regions. Decoding Asia newsletter: your guide to navigating Asia in a new global order. Sign up here to get Decoding Asia newsletter. Delivered to your inbox. Free. Share with us your feedback on BT's products and services