Modern building designs are often tightly sealed to minimise infiltration and heat loss and improve energy efficiency.
As a result, a suitable HVAC system should incorporate components that can mechanically ventilate outdoor air, free of harmful concentrations of pollutants to be supplied to occupants within the building. Insufficient levels of fresh outdoor air leads to poor indoor air quality and can contribute to the health and safety risks that designers must address.
To add to the challenge, this air needs to be supplied at a comfortable temperature and humidity level for the comfort and wellbeing of building occupants.
These were the issues facing designers of the Kings Gate 1 (K1) Building as part of a recent Brisbane Showgrounds Redevelopment Project.
The K1 Building is a nine-level office facility located in the heart of Brisbane’s commercial hub Kings Gate. Recently completed in June 2015, K1 occupies a 16,000m2 space for commercial, retail and leisure purposes including offices, green spaces, urban rooms, bars, cafes and shops open to the public. In a tightly concealed environment, indoor air quality can be compromised when there are insufficient levels of outdoor air.
As a solution, Air Change was able to supply HVAC units that could pre-condition outdoor air and supply this to the building at a comfortable temperature and humidity level.
The air-air heat exchangers incorporated into all Air Change units function by transferring energy (in the form of heat and moisture) from a ‘primary’ air path to a ‘secondary’.
Typically in most building service applications this means using cooler dry internal air to pre cool warmer, high humidity outside air. The heat exchanger works in a counter-flow plate arrangement which provides up to 75 per cent effectiveness.
On a 35oC degree day with 24oC internal conditions the heat exchanger can pre-cool outside air to 26.8oC. This can provide significant savings, particularly on projects that demand high amounts of outside air such as gyms, change rooms and end of trip facilities.
In this project Air Change has supplied K1 with in ceiling energy recovery ventilators (ERV-IC) units to various meeting rooms in this office tower. Designed to be compact and low profile, the ERV-IC units are able to pre-condition outside air and supply this directly to each room leading to a fresh air load saving of 75 per cent. The temperature and humidity level is also controlled through the heat exchanger, improving air quality and maintaining occupant comfort.
The units also incorporate EC plug fans for superior energy efficiency and variable airflow control. By doing so, the K1 building is efficiently ventilated to ensure large volumes of outdoor air is made available to a tightly concealed space.