JHBB - Sustainability - Passive by design

Monday, 24 February 2014

jhhbsustainability

JHBB - Sustainability - Passive by design

The John Henry Brookes Building is considered to have a best practice approach to sustainable design.  Many of these features are incorporated into the fabric of the building. Buried below the piazza is a series of ventilation tunnels and popping out of the building are a number of solar chimneys. Both these features help to control the airflow of the building.

To celebrate sustainability week, Space to Think will be highlighting a key sustainable feature of the John Henry Brookes Building every day this week.

Passive in design

The John Henry Brookes Building has a passive design philosophy.  Natural daylight will be maximised wherever possible in the building, but solar gain (overheating due to excessive sun light) will be kept to a minimum, as will heat loss in the winter. By incorporating features that manage the above into the design of the building the natural ventilation of the building will be more effective and be a significant feature of the building’s comfort strategy.

In terms of buildings ‘passive’ refers to how the flow of air in the building contributes towards the temperature and air quality management. The John Henry Brookes Building incorporates a substantial amount of exposed thermal mass (concrete) which acts as a heat sink. In the winter stores the warmth (in a similar manner to a storage heater) and in the summer the concrete will be cooled by opening windows during low occupancy night time hours. By cooling the concrete at night the coolness is stored reducing the need for mechanical temperature management in the daytime.

Pooled Teaching room

Following sun path analysis the pooled teaching rooms are located on the east side of the building; the corridors act as a buffer to hot afternoon sun. Glare down the corridors is also substantially reduced by the vibrant pink glass fins which also bath the corridors in colourful beams of light. By being on the east side of the building the teaching rooms are less affected by erratic temperature changes. The high ceilinged rooms are also ventilated with natural airflow. Either warm or cool air flows from one side of the room towards the solar ventilation chimney that pulls used air out of the room and allows fresh air in.

Lecture theatre passive ground cooling

The high occupancy in the John Henry Brookes Lecture Theatre will require a degree of mechanical ventilation. To help support and reduce the amount of energy needed to ventilate this flagship space a labyrinth of underground tunnels sit below the Piazza. These tunnels are similar to a cave and support a relatively constant temperature.

Air transition summerIn the summer warm outside air will get cooled through the tunnel system before being pulled into the lecture theatre. The dirty air is extracted from the room using a chimney that has a reflective layer at the top. Known as a solar chimney the reflective material heats the air at the top of the chimney, as this air heats up it rises and pulls the cooler air from below into the lecture theatre, leaving room for clean air coming from the series of tunnels.

Air transition winterIn the winter cold air is pulled into the tunnel system and warms as it passes through. The air then passes into an energy centre above the lecture theatre and heated to a comfortable temperature before being circulated into the theatre. In the winter the solar chimney is closed and the expelled warm air is used to aid the heating of the air arriving from the tunnel system.