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CDNLAO Newsletter

No. 85, February 2016

Special topic: Preservation and Conservation of library materials

Broadening Parameters at the National Library of Australia

By Denyl Cloughley, Manager, Preservation Services and Erin Dampney, Sustainability Project Manager of the National Library of Australia

Table of Contents


< Stack Areas in the National Library of Australia, Greg Power >

1. Background

The National Library of Australia has not conducted a review of collection storage parameters for 15 years. In light of recent research supporting broadened parameters, and the development of revised parameters internationally, a review of parameters was undertaken. This article will address the Library’s recent decision to broaden its environmental storage parameters in line with the Australian Institute for the Conservation of Cultural Materials (AICCM) Interim Temperature and Relative Humidity Guidelines for acceptable storage and display of general collection material. This information was first presented at the November 2015 AICCM National Conference held in Hobart, Australia.

Latest research into collection storage guidelines has seen a general shift towards broader parameters. This is paired with an international acknowledgement that museums and collecting institutions have a responsibility to reduce their carbon footprint and operate in a more sustainable manner. The International Institute for Conservation (IIC) congress in Hong Kong and the International Council of Museums Committee for Conservation (ICOM-CC) conference in Melbourne developed a joint declaration in September 2014 for the international conservation community.

The AICCM parameters are broad. The recommended AICCM guidelines are temperatures of 15-25°C with allowable fluctuations of ±4°C per 24 hours, and relative humidity between 45-55% with an allowable fluctuation of ±5% per 24 hours. Where storage environments experience seasonal drift, relative humidity changes can be managed gradually across a wider range limited to 40-60%.

2. The National Library of Australia’s environment

For the AICCM parameters to be successful, the Interim Guidelines acknowledge that institutions need to work within these guidelines in a manner that suits their collection and organisation. They are guidelines for the acceptable storage and display of general collection material. The AICCM defines ‘general collection material’ as items that are not particularly vulnerable, or are known to be stable under standard conditions. For the purposes of this project, in relation to the Library’s collections, ‘general collection material’ may include printed documentary materials such as books, maps, sheet music, newspapers and manuscripts. As such, the Library’s tape stores, cold store, freezer and exhibition galleries fall outside the scope of this project.

The Library’s collections of predominantly paper based materials are densely packed in closed access storage in the main building and two offsite storage spaces, with many materials enclosed within containers such as archives boxes. The buffering nature of these stored paper-based collections enhances the capacity of stacks to drift gradually within parameters and create a stable environment, which is more important than sharp changes in temperature or relative humidity in a short time period. In addition, the thermal mass of the main building and Canberra’s mild and dry climate contributes to gradual drifting. Recent seasonal trials of turning off air conditioning to a number of stack areas, and the ongoing passive climate at the Library’s offsite repository, have demonstrated that the buildings and collection lend themselves to a stable environment when allowing seasonal drift.

The Library’s ageing main building has a very complex air conditioning system that means some air handling units service both collection and staff areas, whilst some units service only stack areas. For this reason, a staged approach was proposed, beginning with stand-alone stacks that do not share air conditioning units with staff areas.

3. Implementation of new parameters

In June 2015, the Library’s Corporate Management Group agreed to a four stage implementation of new parameters across the Library’s stack areas.

3.1. Risk assessments

Preservation Services staff, in consultation with stacks staff and collection managers, undertook risk assessments for each space prior to the change in parameters, particularly to identify mixed collection materials to ensure that the proposed parameters are appropriate for all materials. A concern emerging through this process was the risk of damage to collection material caused by changing relative humidity conditions. Risk of mould damage does not increase until the relative humidity reaches 65%. This high relative humidity is beyond the upper limits of the revised parameters. Sharp fluctuations in Relative Humidity are also a concern and the Building Management System will alarm if the Relative Humidity exceeds 65% or fluctuates more than 5% within a 24 hour period, allowing immediate rectification.

3.2. Implementation of Stage One

Stage one commenced on 1 July 2015. Parameters in the Stage one spaces were 20±2°C and 45±5% RH. With the revised parameters, these stacks run at 17-23°C with broadened RH of 40-60%. Drift is allowed within these parameters. These parameters apply to the air in the stacks and are measured by the Building Management System. Importantly, there is continuous ventilation to the stacks, rather than the air conditioning being off as had been the case during earlier trials. Staff consultation was an important part of the implementation, with general and detailed information sessions held with effected staff.
Implementation and monitoring work was largely carried out within existing roles and did not require additional resources. As we had done in previous air conditioning trials in stacks, data loggers were placed inside mock-up boxes and books and on shelves in order to monitor and record the conditions as they affect the collection and downloaded as necessary. Hollowed out mock-up books are used to measure the effects inside the book. Building Services staff provided ongoing monitoring of conditions through the use of dataloggers and the Building Management System and the ongoing management of the HVAC (Heating, Ventilation and Air Conditioning) system to ensure conditions in stacks remained stable.

3.3. Results of Stage One Implementation

In each of the stacks involved in Stage one, conditions have remained stable and within the revised parameters. Temperature and relative humidity changes occur gradually and within parameters, with no significant fluctuations. As expected, the air conditioning system is turning on as conditions get close to falling outside of parameters. At the beginning of July, there were short periods of being approximately 1°C below the nominated parameters, but a small adjustment to the air conditioning system has corrected this situation. Datalogging within collection material continues to indicate more stable conditions than datalogging on the open shelves.

There are variations between the storage spaces, with two spaces sitting at the lower end of the revised parameters, at about 17°C, while the third storage space is sitting at the higher end of the parameters, at about 22-23°C. While this is an unexpected result, particularly during winter when it would be expected that the stacks might be naturally inclined to be cooler, the air conditioning is working to stop conditions exceeding parameters and it does not pose a risk to the collections. Building Services and Preservation staff agree that while temperatures between the stacks are different, this is acceptable provided that they remain within parameters with only small fluctuations. Subsequent to the first week of the implementation, no problems or issues were reported through staff consultation channels.

3.4. Implementation of Stage Two

The data indicated that the Library could safely progress to Stage two and it was successfully implemented in mid-September. Conditions have remained stable and within the revised parameters. Interestingly, the conditions within the housing material of various boxes and ziplock bag combinations were often quite dry, which may require further investigation.

4. Issues Raised During Implementation

A few issues have been identified as the project progressed. During the trials earlier in the year, the air conditioning was turned off. It confused the staff, created stuffy spaces and set up negative expectations about the new parameters. In future, as we look to trial spaces prior to Stage three implementation, and now that we know how the Building Management System responds to the revised parameters, we will replicate the proposed conditions more closely by maintaining the air conditioning system at the broader parameters rather than turning it off.

The review raised several broader issues for the Library in relation to storage planning and a review of the HVAC system. The new parameters will be informing a broader HVAC review across the Library, together with the Collection Storage Master Plan 2015-2025. This is the first time that we've been able to review the master plan for collection storage and the HVAC concurrently, thus ensuring that the objectives are aligned. The project also identified the need to agree on standard terminology when categorising the collection for reporting, security and valuation purposes. Another issue that was raised in the risk assessments for the second stage of the project was the identification of digital media in some stack areas and ensuring appropriate planning for its long-term storage is completed.

This work also raises a question to be researched, how dry is too dry for collection material? Most work around the effects of humidity are based around high humidity; however in our case, spaces often get very dry and we need to look into what effect this may be having on collection material.

5. Next Steps

Stage three is due to start in April next year and the consultation and planning for this stage will start early in 2016. After consultation with collection managers and staff, as well as the thorough completion of risk assessments for the collection material in the spaces, these spaces will need to be trialed to see how they respond to the parameters. In addition to this, we will continue to monitor the conditions in both Stage one and two spaces, particularly over summer.

6. Financial Implications

Minimal financial resources were required for this project. While this has not been required to date, there is the potential for different stacks to behave differently and require specialist engineering intervention. Running the air conditioning in a different way may result in energy and potential financial savings.

7. Conclusions

This trial supports other trials conducted by the Library and other collecting institutions that show that conditions within the collection material, particularly tightly packed paper-based collections, or well housed collection materials, are more stable than the ambient conditions. The buffering nature of paper based collections and the stability of the stack areas at wider parameters lends us to believe that passive management of some stack areas in the Library may be possible (that is, we may not need to rely on air conditioning in some stacks). This will be further investigated through the upcoming HVAC review, and follows an earlier Library project which has led to us turning off the air conditioning in our largest offsite storage repository and maintaining it passively for the majority of the year.

Good stakeholder engagement, together with reliable data collection, has been the key to reassuring collection managers and senior management that broadening parameters will not put the collection at risk, and in the case of the Library, will not adversely affect staff working conditions in storage areas.

Although early in the project, it does appear that there will be some energy and financial savings from broadening parameters. Because the Library does not currently have extensive metering in place, the exact energy savings will be hard to quantify; however the Library's electricity consumption and bills have been reduced since the commencement of the project when compared to the same period last year. It is expected that these savings will increase as we commence the new parameters in more stack areas.

Hopefully it is possible for other institutions to trial the AICCM broadened parameters for minimal to no cost, as has been the case for the Library. It would be particularly useful for larger institutions to trial the new parameters thereby providing case studies to assist the smaller collecting institutions that are seeking to reduce the amount of limited resources devoted to air conditioning. Managing our collections in a more sustainable and financially viable way comes back to the original intent of the IIC and ICOM-CC acknowledgement that "collecting institutions have a responsibility to reduce their carbon footprint and operate in a more sustainable manner."


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