Case studies

Bowen Campus: Charles Fergusson Tower

The Charles Fergusson Tower, which sits tucked behind the Beehive on Bowen Street in Wellington, is part of a $203 million upgrade of the Bowen Campus. Since 2016 it has been undergoing extensive demolition and replacement of the façade, earthquake strengthening of the existing structure to 100% of the National Building Standards and full replacement mechanical services with new systems including specific tenant requirements.

The Challenge

Meeting this brief was an extensive collaboration between the developers, contractors, suppliers, engineers and consultants (of all disciplines) and other stakeholders to provide a solution which was energy efficient, cost-effective and fit within the limited outdoor space available for plant.

The Mitsubishi Electric Solution

With very limited space for outdoor air conditioning plant a water sourced solution was preferable. Mitsubishi Electric’s PQRY water sourced heat recovery condensers were able to be installed on each floor in a dedicated mechanical riser where the condenser water loop was able to be connected with ease.

The Mitsubishi Electric PQRY water sourced solution allows floor to floor heat recovery using the condenser water loop, offering efficiency through heat recovery.

Each PQRY unit has the ability to control the condenser water flow volume through the heat exchanger using a field-supplied 0-10V control valve to improve the efficiency.

With the implementation of intelligent Building Management Systems; efficiencies can be optimised year-round while providing comfort to the occupants. Primary water pumps are controlled by the Building Management System to field variables such as differential pressure between the flow and return pipework within the riser. The heat rejection plant consists of two cooling towers configured in a duty/ standby arrangement, similarly the heat injection plant consists of two gas boilers. Due to the limited space outside, the Plant Room is based on Level 17, where both heat rejection and heat injection plant is hosted with discharges through the roof.