Alfa Laval has launched Hukka-5 , a new exhaust gas steam boiler designed for cruise vessels and passenger ferries. The company introduced the system at SMM 2026. Hukka-5 uses exhaust gas waste heat to generate steam. This can help vessels reduce fuel consumption and CO₂ emissions. The new boiler is available immediately for project orders. New design targets greater energy efficiency Hukka-5 introduces a downward natural circulation design . Natural circulation removes the need for circulation pumps. Instead, the system uses physical principles to circulate water through the boiler. According to Alfa Laval, the new design allows operators to recover more waste heat without increasing the equipment footprint. This is particularly important on cruise vessels, where space inside funnels is limited. The system is designed for vessels with four-stroke engines. Alfa Laval sees particular potential for cruise ships and ferries with frequent port calls. “Our previous state-of-the-art WHR boiler, Aalborg XWi, set the standard for natural circulation on cruise vessels,” said Matti Takasuo, General Manager for BD & Sales for Power, Offshore & Cruise at Alfa Laval. He added that Hukka-5 can recover more waste heat without requiring additional space. Hukka-5 supports alternative fuels The Hukka-5 forms part of Alfa Laval’s Hukka exhaust gas steam boiler range. The range can work with engines and gas turbines using different fuels, including methanol and hydrogen . Its modular design also allows operators to select different heat recovery configurations. In addition, electrical steam generation can be integrated into the system. This can support steam production during port stays when shore power is available. Alfa Laval targets lower fuel use and emissions By recovering energy from exhaust gases, Hukka-5 can reduce the amount of additional fuel required for onboard energy needs. Alfa Laval said this can lower operating costs and CO₂ emissions. The company has comp