Temperature and relative humidity have been clearly identified as the major determinants in the rate of chemical deterioration of both film bases and images. Tools such as the Time Weighted Preservation Index are useful in predicting the potential life expectancy of film materials under changing conditions. However, to improve the accuracy of these predictions and to spot any potential problems in the air handling plant, regular monitoring of the environmental conditions inside each storage area is essential.
Long term collection of data can be used to plot energy usage on a seasonal basis and to identify improvements that can be made to the physical storage location to improve energy efficiency.
Another aspect to environmental monitoring is that of pollutants within the storage environment. Continual sampling and analysis of air is a very expensive option. However, since most air handling systems introduce less than ten per cent fresh air to reduce energy costs the levels of pollutants may build up to levels where, in the long term, they have an affect on the film. So examination of the effectiveness of any activated charcoal filters that are part of the air handling system is essential.