The B:HIVE is a state-of-the art, mixed mode building designed specifically for its location and use. It taps into the potential offered by Auckland’s mild climate to save energy, and this is strongly expressed in its architecture.
This award-winning, mixed mode building relies on both mechanical cooling and natural ventilation for direct freecooling, and effectively mimics what people do at home for thermal comfort. When it's too cold outside, the building uses a centralised heat pump and/or local heaters for heating. When it's too hot outside, the building uses a centralised heat pump system for cooling. When it's neither too cold nor too hot outside, the windows are open.
Whenever the natural ventilation system operates, the energy consumption is reduced, the carbon footprint is reduced and the fresh air rate is increased as much as four times the minimum requirements of the building code.
In its current configuration, the natural ventilation system will be used approximately 1,700 hours a year or 35% of the time the building is occupied. Now the building is complete and Summer is almost over, the system can work as planned. Monitoring of the first three weeks of operation showed the temperature distribution is excellent.
The B-Hive should be seen as an integrated system, rather than a standard building, and uses a high performance façade, the organic shape of the atrium and the natural ventilation stacks, or solar chimneys around the façade, to provide optimum indoor environmental quality, including copious amounts of fresh air. Whenever natural ventilation is used, fresh air rates can be up to six times higher than required by the building code. Parts or all of the B-Hive can also be operated as a conventional building, depending on weather conditions and tenant’s requirements, hence providing great flexibility.
Computer modelling showed that the organic shape atrium provides better air distribution than a rectangular or square atrium. This means comfortable conditions for tenants when using natural ventilation.
Ventilation Chimneys have limited drought because they have no mechanical assistance. There’s an air lock on the ground floor to separate the retail spaces, hospitality business/food court from the office and enable the chimneys to work as intended. There’s also a synergy with noise control and odour containment: this glazed wall keeps the noisier food court area separate from the office areas.
Whilst there are synergies between natural ventilation and fire engineering, there are also roadblocks in urban areas, because of acoustics. A synergy was found between acoustic and mechanical services operation to achieve 42dBA background noise level: This involved repeated testing of units at the factory to get it right.
At Smales Farm for the B:Hive building, eCubed specified large natural ventilation chimneys and roof cowls - components within the integrated natural ventilation system - manufactured in the United Kingdom. The contractor offered a bespoke, cheaper and locally made alternative.
The risk of developing a new product was managed by testing prototypes, including at BRANZ for air flow, pressure drop, weather tightness, and factory inspections, e.g. checking welding and general fabrication to achieve compliance with clause B2/AS1 (durability) of the New Zealand building code.
Interior Awards - Winner, Supreme Award for Workplace Over 1000m2 - 2019
NZIA Auckland Architecture Award - Interior Architecture Category - 2019
NZ Property Industry Excellence Award - Commercial Office Category - 2019