Adaptive Climate Control Strategy

The practice of maintaining tightly controlled temperature and relative humidity levels for artwork preservation within building structures that have large open spaces results in high energy consumption by art museums. It is estimated that over 60% of energy use in art museums is required to operate HVAC (heating, ventilation, and air conditioning) systems to maintain these controlled environments.

There is increasing awareness that the energy use of these preservation environments should not be at the expense of longer-term environmental impacts. The NGV is looking at ways of optimising the building plant and HVACHeating, ventilation, and air conditioning systems to ensure they operate efficiently in response to changing climate. We are also working closely with gallery and museum colleagues in Australia and abroad to look at ways of modifying museum practices for the beneficial outcomes of reduced environmental footprint and energy costs. These include:

• endorsing the Bizot Green Protocol (BGP) along with 50+ other leading art institutions globally. We are currently in the third and final phase of the BGP rollout at NGVI.
• engaging an NGV Energy Performance Contract as part of the Victorian Government’s Greener Government Buildings Initiative, a project which has already delivered a 16% reduction in NGV greenhouse gas emissions.
• collaborating with national, state, and regional art museums to support an industry wide transition towards more flexible settings by adopting wider settings as standard in loan agreements.

These activities, along with ongoing research in this area, will ensure the NGV is positioned to meet the effects of a changing climate with a sound understanding of the risks and consequences of the different display and storage solutions used to care for the Collection.

Phased implementation of the Bizot Green Protocol (BGP) at NGV International

Bizot Green Protocol

In 2014, the NGV’s Director Tony Ellwood moved to endorse the Bizot Green Protocol (BGP) along with other signatories of the Bizot Group (NMDC 2015). The Bizot Group, also known as The International Group of Organizers of Major Exhibitions, represents some 50 of the largest art museums globally, providing a forum to discuss museum issues and exchange ideas.

The BGP outlines standard environmental parameters and guiding principles to encourage museums to reduce their carbon footprint while maintaining care of objects for long-term preservation. Policy and practice should be tailored to a museum’s building, local environment, and collection needs. Energy-reducing considerations include passive low-energy environmental control methods, adoption of realistic target conditions given the building envelope and exterior climate, and support for broader environmental parameters for many classes of objects. Whilst recognising that more sensitive materials may require particular environmental settings, general environmental guidelines given are a stable temperature in the range 16–25°C and stable relative humidity (RH) in the range 40–60% and fluctuations of no more than ±10% RH over a 24-hour period (NMDC 2015). Previously, the NGV galleries maintained much tighter parameters, with temperature at a set point of 21.5 ±2°C and RH at 55 ±5%. These narrower settings required more energy to maintain and resulted in more mechanical wear compared to BGP settings.

The NGV Facilities team led the engagement of the Energy Performance Contract (EPC) as part of the Victorian Government’s Greener Government Buildings Initiative. This led to energy saving improvements building-wide, including upgrades to the Building Automation System (BAS) essential for testing and rollout of the BGP. These improvements reduced greenhouse gas emissions at NGVI by over 16% before the BGP rollout, with more reductions expected with the building operating at wider environmental settings.

Honeywell Building Automation System (BAS) diagram for one of the NGVI galleries programmed to Bizot Green Protocol settings

The rollout of the BGP environmental parameters has occurred in three phases at NGVI:

Phase I – Research, consultation, and testing
NGV conservation staff attended the Getty Conservation Institute’s Managing Collection Environments workshop, and began planning for Bizot implementation strategies at NGVI. The NGV Facilities team began researching and implementing building improvements, including energy-reducing changes to the HVAC system.

Phase II – ‘Soft Bizot’
Initial trials of a transitionary ‘soft Bizot’ setting – temperature between 20°C and 23°C with 24-hour fluctuations of no more than ±1.5°C and relative humidity between 46% and 56% with 24-hour fluctuations of no more than ±4% – demonstrated reduced energy use.

Phase III – BGP rollout
Following successful trials of ‘Soft Bizot’ settings, the BGP was rolled out in full across galleries on level 2 at NGVI.

Collections Monitoring

To ensure the safety of the Collection as we transition to the more energy efficient BGP, objects are monitored using multiple techniques. The NGV has partnered with scientists from the Los Angeles–based Getty Conservation Institute (GCI) to use acoustic emission (AE) technology to monitor the Carved Retable of the Passion of Christ. This technique detects ultrasound waves produced by microscale changes in the hygroscopic (moisture responsive) wood found in the altarpiece’s many parts (learn more here).

Photomacrograph of the wooden Card table (1345-D4), documenting a pre-existing crack for monitoring

Detail of Triptych with the miracles of Christ (1247-3) (left) with RTI image showing surface texture, providing a record of condition (right)

The highly sensitive AE monitoring is complemented by monitoring objects using imaging techniques. These include macrophotography, RTIreflectance transformation imaging – a photo-based technique for modelling surface characteristics, and 3D scanning. Each technique captures different object features that add to the data obtained from AE monitoring and can be used on several objects on display in the galleries. By repeating image capture at regular intervals, they can be compared to determine if any change has occurred. By combining AE and imaging techniques, we can gain both sensitivity and breadth when monitoring our collections.

Loan Practices
Loan agreements contain climatic requirements for works being lent from one institution to another, and conventionally these requirements stipulate tightly controlled environmental conditions. There has recently been a coordinated effort between major Australian lending institutions to change lending and borrowing practices nation-wide to reduce the environmental impact of exhibitions. In September 2018, in a meeting of the Heads of Conservation from Queensland Art Gallery and Museum of Art (QAGOMA), Art Gallery of New South Wales (AGNSW) and the NGV, it was agreed that the BGP and the nationally-developed Australian Institute for the Conservation of Cultural Materials environmental guidelines (AICCM 2018) would be adopted for collections and loans. This was later submitted to, and approved by, the Council of Australasian Art Museum Directors (CAAMD) meeting held at the NGV.

A one-day roundtable inviting facilities, registration, conservation, and collection management staff from CAAMD members was hosted by the NGV in late 2019 to facilitate open dialogue on: what parameters members were setting and achieving across their exhibition and storage areas; whether options for widening environmental parameters had been implemented or considered; what issues members had to address to be able to implement these changes; and the sharing of relevant case studies. The roundtable was a useful forum in which to exchange ideas, review requisite amendments to loan documentation and identify areas in which resources and future research might be shared.

References

Learn more about the NGV’s Sustainability Initiative: https://www.ngv.vic.gov.au/about/sustainability/

Read a paper co-authored by NGV conservators and GCI scientists on Bizot implementation at the NGV: Michael Varcoe-Cocks, Michal Łukomski, MaryJo Lelyveld, Vincent Laudato Beltran, Caitlin Breare and Cecilia Winter ‘Developing an Adaptive Climate Control Strategy and Programme Monitoring Micro-change in Wooden Heritage Objects’ Studies In Conservation 2022, VOL. 67, NO. S1, 183–292

AICCM. 2018. Environmental Guidelines. Australian Institute for the Conservation of Cultural Material. www.aiccm.org.au/conservation/environmental-guidelines/

NMDC. 2015. ‘Bizot Green Protocol’ In Environmental Sustainability: Reducing Museums’ Carbon Footprint. National Museum Directors’ Council. www.nationalmuseums.org.uk/what-we-do/contributing-sector/environmental-conditions/