Solution for Blackwells

And the large amount of glazed windows

Blackwell Holden and Mazda



Since 1923, the name Blackwells has been taking the lead in ‘the great New Zealand driving experience’ and became one of the largest independently owned motor companies in New Zealand. In Christchurch's city centre; Blackwells has two separate businesses side by side on a single site (Blackwells Holden and Blackwells Mazda) creating more selection, more value, and more quality for their customers and their vehicle needs. 

Location: Christchurch
Main Contractor: Leighs
Mechanical Contractor: CityCare
Consultant: TM Consultants


Like most showrooms, there is a large number of glazed windows and open space allowing for outside viewing. With the possibility of condensation during the cooler months, TM consultants specified a perimeter trench heater system positioned around the glazed façade from where the showroom vehicles can be seen from the street. Heat can be delivered directly to the façade preventing the formation of condensation on the windows and reducing the radiant cooling effect inside which improves the comfort and functionality of the building.

21x individual trench heater units were placed throughout the two showrooms on this site, the trench heaters were supplied with “dummy” and “corner” elements and configured in a way to allow multiple units to be combined into a seamless continuous trench with a single grille for improved aesthetics. The system in each building was powered by a large air-to-water heat pump feeding a 100L Fiorini buffer tank. From this buffer tank, the heating water was pumped to a commercial-grade FAR manifold from where each group of trench heaters is fed via insulated feeds run under the concrete floor.


Blackwells strive for quality vehicles for their customers. It is a necessity that their showroom felt high quality and provide a comfortable area for their customers and employees. Working closely with the installing contractor Central Heating New Zealand was able to assist with providing an efficient and practical solution that delivers a comfortable environment and maintains the functionality of the showroom.

Blackwell Holden Exterior Blackwell Mazda Exterior Blackwells Mazda Showroom Corner Trench Heater Holden Mazda Trench Heater

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