Story by Aaron Blyleven, Powell Fenwick Mechanical Engineer

The Project

Hawke’s Bay Regional Aquatic Centre was recently opened to the public, by Prime Minister Rt. Hon. Jacinda Ardern, bringing yet another discipline of elite athlete training to the Mitre 10 Sports Park Complex.

The world-class aquatic facility provides an Olympic size competition lap pool, a 25-meter pool and a hydrotherapy centre. This facility will provide a wide variety of functions including international level swimming events, swim training and water safety classes, rehabilitation programmes, school and community sporting events, aquarobics, and other miscellaneous community activities.

The Hawke’s Bay Regional Aquatic Centre project was constructed by Apollo Projects, in collaboration with Hawke’s Bay Community Fitness Trust and Crown Infrastructure Partners. Powell Fenwick was engaged to provide engineering design for all internal services.

The Challenge

Humidity and temperature control is a crucial consideration of aquatic centre ventilation design to remove moisture from the air and reduce internal condensation risk. Moisture suspended within the internal air of an aquatic centre can result in catastrophic building structure and fabric damage if left unchecked for long periods, due to the corrosive nature of the chlorinated pool water.

Typically, aquatic centres across the South, and lower portions of the North Islands, can achieve tight humidity control via the introduction of fresh air to the internal pool hall spaces. The Hawke’s Bay region presented challenging weather conditions, with prolonged periods of high temperatures and high humidity. These conditions required a higher level of engineering to achieve a similar reduction of indoor relative humidity.

With the use of cutting-edge modelling software developed in-house, our team of engineers were able to simulate the annual conditions of the facility and design a complex heating, cooling, and dehumidification system to control the internal space. Put simply, this system achieves dehumidification by drastically cooling the air to remove the moisture before the dry air is reheated and re-enters the pool hall space, ensuring 40,000 litres of conditioned air is delivered to the pool hall every second.

The mechanical system utilises a variety of air and water source heat pumps, providing efficiencies of 300% to 500%, with capacity to provide heating to the pool water, pool air and the amenity spaces within the building. The design also allows the generation of free cooling for the facility as a by-product of heating generation.

The Result

With advanced modelling software and innovative engineering solutions, the Hawke’s Bay Regional Aquatic Centre HVAC system can be described as ground-breaking to complement their newly opened world class facility. Similar design methodology is currently being implemented in several North Island aquatic facilities with similar weather condition challenges. With Climate Change impacting ambient weather conditions, solutions like this will be required across larger areas of the country both in new facilities and refurbishment projects.