Alexandra’s new Countdown supermarket achieves Green Star rating with efficient HVAC system

Opened on November 17, 2022, the newest member of the Alexandra community, a 3000 sqm Countdown supermarket, has been purpose-built to provide a beautiful shopping experience for the residents of the Central Otago town. And, with its Green Star status, its impact will extend further than just the local fridges and pantries it fills.

Sustainability was a key part of the brief, with the goal to achieve a four star green building certification. Tasked with designing the building’s HVAC system, air conditioning and refrigeration experts Fonko knew the design needed to incorporate energy saving features, whilst meeting specific store requirements.

“The store area needed to be at 55% humidity with a temperature of 21 degrees celsius during operation hours,” says Leandro Martins, Fonko Contracts Manager.

To achieve this, the Fonko team used a recognised energy modelling software to produce a comprehensive building energy model, with hourly heat transmission through the walls, roof, and windows.

“We also needed detailed information about the building occupancy, operation schedules, and lighting use, so multiple meetings were held with the client, and other trades, to collect this, and coordinate design features,” Martins explains.

The final design included heat load calculation, energy modelling, engineering drawings, system and equipment specification. This design is particularly unique, Martins adds, because Fonko was able to reduce the use of the main HVAC plant through heat reclaims from the refrigeration rack.

To achieve the building’s Green Star rating, a CO2 zone control was installed in the retail area to identify poor ventilation areas and allow fresh air to flow when required. The building also uses a building management system to monitor energy use and reduce consumption outside of business hours, and all HVAC equipment contains low global warming potential refrigerants.

Martins says the most complex part of the project was building the energy model. “We built three different models of the same building to compare and assess the amount of energy savings that could be achieved. The first model had the design parameters set by the Green Building Council, the second contained the H1 building envelope requirements, and the third included all the efficient equipment and energy saving features.”

Countdown Alexandra is one of only four Green Star rated supermarkets in the country, but it won’t be long before there are more. Woolworths Group have announced aims to revolutionise their business, setting ambitious sustainability goals wherein all new supermarkets will hold a four Green Star rating.

Learn more about Fonko.