Air conditioning is easily our biggest ongoing environmental impact, and has traditionally been thought essential to maintain the stable conditions necessary for the best care and preservation of physical records in the repository.

The Victorian Archives Centre opened in 1999 with the latest design features at the time. A key feature of the building was a high thermal mass construction to assist temperature and humidity control. Should there be a major power disruption the thermal mass ensures the protection of archive repositories in the central core of the building.

In May 2008 we turned the repository air conditioning off to test whether the building’s thermal mass could maintain constant temperature and humidity. Frequent monitoring ensured the archives were not put at risk, with temperature and humidity readings logged every 15 minutes.

The trial to switch off the air-conditioning achieved spectacular results. There was an immediate decrease in energy use and a reduction of almost 40,000 kW h in the first fifteen days, without disrupting strict air quality standards. The trial was extended and additional equipment has now been purchased to switch on air conditioning units only when trigger points for temperature, humidity and carbon dioxide levels are exceeded.

Combined with other measures, our electricity use has been reduced by 27% – equivalent to almost 30 million ‘black ballon’ and greatly exceeding the Victorian Government’s target of 20% by 2010.