Hazeldean Business Park

The Challenge

The largest of three buildings on this site had to be designed to attain a 4 Star Greenstar rating from the New Zealand Green Building Council.

Haden and BDT would have to pool their expertise to ensure the integration of the heating, cooling, and ventilation requirements exceeded the requirements of this rating system, maximizing the owner’s Greenstar application.

The buildings have ample glazing on all sides which will offer good natural light but with this comes both solar gain and chilling load.

The Solution

The HVAC services to each building are made up of several separate, floor by floor, VRF simultaneous heating and cooling systems. Fresh air is provided with Lossnay heat and enthalpy recovery systems to ensure efficient and economic delivery of the fresh air to the building by recovering the heat from the exhaust air and using this to pre-heat the incoming fresh air supply.

Buildings on the site currently number three, excluding the car parking building. All office buildings include VRF air conditioning and Lossnay. The site overall has an installed cooling capacity of more than 1200kW, so energy consumption is a very important consideration.

Since the final commissioning Mitsubishi Electric has offered its TG2000 computer and software package to compliment the project with individual tenant energy monitoring and billing capabilities. This will be linked to the existing web based central control system based around 7 of the GB50A central control units. Having the ability to monitor energy usage and charge tenants accordingly makes good economic sense for the building owner and tenants alike and also promotes energy efficiency for HVAC services from a heat recovery, temperature control and time scheduling perspective.

The 2 pipe architecture of the Mitsubishi Electric VRF system not only allows simultaneous heating and cooling with heat recovery but the savings in labour and materials over other systems ensure the cost savings of the system efficiency are maximized and realized by the building owner and also tenants as early in the building life-cycle as possible.

The application of the Lossnay energy recovery ventilation and its control integration with the City Multi VRF Air Conditioning means that fresh air is introduced as and when required without the need for additional controls. Pre-heating of the fresh air using this technology is now commonplace in this type of HVAC installation but what is also important is the ability to offer free cooling when outside air conditions permit and also pre-cooling of the fresh air on days when the outside ambient air temperature is above that of the conditioned space air. All this adds to the system efficiency, ensuring the lowest possible running cost and of course a fresh comfortable working environment for the building tenants.