The project required the design and supply of modular, high-efficiency heat exchangers capable of ensuring reliable, stable cooling of transformer oil under demanding operating conditions. The equipment had to operate within a wide temperature range from –40°C to 95°C, while also maintaining low noise levels to comply with strict acoustic requirements. A significant challenge was the need to integrate the solution into the customer’s limited installation space, which required a compact yet highly efficient design. In addition, the heat exchangers had to deliver long-term durability and excellent corrosion resistance, as they were intended for continuous operation in harsh outdoor conditions. These combined requirements defined a complex technical challenge and demanded a carefully engineered, precisely tailored cooling solution. At the same time, the customer expected easy access for inspection and servicing, to minimise maintenance time and keep the system running smoothly. Meeting all constraints in one compact package required an optimised balance between thermal performance, acoustics, structural robustness and lifecycle reliability.

To meet the demanding project requirements, AIC S.A. supplied OFAF (Oil Forced Air Forced) heat exchangers engineered for transformer oil cooling. The AIC engineering team designed compact, modular cooler units for vertical installation, ensuring integration into the customer’s limited space. Each unit delivers up to 350 kW and is equipped with three low-noise fans, enabling optimisation of performance, efficiency and acoustic levels. The heat exchangers operate in a fully forced-circulation mode on both the oil and air sides, ensuring stable thermal performance under fluctuating loads. Their reinforced mechanical design is built to withstand vibrations and harsh outdoor conditions. The units are made of stainless steel and aluminium for corrosion resistance and efficient heat transfer, with protective coatings compliant with EN ISO 12944 to extend outdoor durability. All heat exchangers are manufactured in accordance with ASME Sec. VIII Div. 1 and PED 2014/68/EU. For easier maintenance, the solution includes open fan assemblies for quick access and removable oil covers for inspection and cleaning. Nitrogen flushing is applied to maintain internal cleanliness and protect against moisture ingress, enhancing reliability and service life.

By using ambient air as a cooling medium, our systems provide significant advantages. Air is freely available, non-corrosive, and it eliminates the risk of thermal overload on nearby water sources, making it an environmentally friendly choice. Additionally, our transformer oil coolers operate efficiently wherever a power supply is available, eliminating the need for complex auxiliary circuits. The implementation of AIC S.A.’s OFAF heat exchangers delivered measurable improvements to the client’s transformer cooling system. The new solution ensured stable and well-controlled oil temperatures, allowing the transformer to operate at full performance across all load conditions. Even during peak demand, the risk of overheating was significantly reduced, enhancing overall operational safety. The system has demonstrated high reliability with zero downtime.

As a result, the client gained a robust, low-maintenance cooling solution designed for long-term outdoor operation. This translates into predictable maintenance and long-term reliability for a critical transformer asset.