CASE STUDY | BREEZE HOTEL FORCE OF NATURE The 11-storey Breeze Hotel in Amsterdam has a unique natural ventilation system that uses solar chimneys and water droplets sprayed into a shaft to move air around the building. Andy Pearson speaks to the academic behind the concept, Dr Ben Bronsema, and looks at how his earth, wind and fire theory became reality Solar chimney Earth, wind and re concept Climate cascade T he 198-room Breeze Hotel in Amsterdam is a pioneering, ultra-low-energy building. Developed by Amstelius/Dutch Green Company in association with Borghese Real Estate, it is the first building in the world to use the earth, wind and fire natural ventilation concept conceived by engineer Dr Ben Bronsema. As such, it eschews mechanical systems in favour of using the sun, wind and water to heat, cool and ventilate all 11 storeys. Bronsema was inspired to develop the concept after studying how African termites keep the internal temperature of their mounds at a constant 30C, even though external temperatures fluctuate from 50C in the midday sun to almost zero at night. I thought, can we build buildings the way termites do, using natural air conditioning to avoid the need for fans? said Bronsema, in a TEDx talk from 2013. The result of his cogitations was the earth, wind and fire concept, which subsequently became the subject of his PhD at the Technical University, Delft. As part of his research, Bronsema developed the natural air conditioning concept using simple computational modelling. This was refined using computational fluid dynamics and validated using experimental mock-ups of elements of the concept. The Breeze Hotel is the first building to make use of the concept, and Bronsema is working on the project with installation consultant Green Building Engineering and contractor Van Delft. When the hotel opens its doors this summer, some of its more observant guests may notice the two glazed columns on the southwest faade, which rise from the ground floor to the roof of 33m-high building. These are the solar chimneys that help drive the buildings natural air conditioning. In plan, Surplus of cold/warmth is being collected in the underground thermal energy storage 1 Warm air blows inside the turbines on the rooftop 2 Wind pressure pushes warm air into the climate cascade 3 The air is sprinkled with water of 13C 4 Cold air is blown into the building, providing cooling and ventilation 5 Warm air from the building is extracted by the solar chimney 6 The air heats up and ascends in the solar chimney 7 At the top of the solar chimney, the air reaches a heat exchanger 8 Warm air transfers heat to the thermal energy storage through the use of a heat recovery system. Excess air leaves the system Dr Ben Bronsema developed his natural ventilation concept after watching the building skills of termites in Africa 26 July 2019 www.cibsejournal.com CIBSE July19 pp26-28, 30 BreezeHotel.indd 26 21/06/2019 14:46