42nd Annual Meeting – Collections Care + HVAC Session, May 31, "The Road to Sustainable Environmental Management of Storage Conditions at the National Archives by Kostas Ntanos"

The National Archives is the official government archives of the UK and Wales. The Archives has two buildings: Q1, a building built in 1978 with three main repositories in three floors, and Q2, a newer building built in 1996 with twelve repositories over four floors.
Ntanos started by looking into records from 1973-75 to see the decision-making of how the Q1 building was designed. During this time from 1973-75, the staff discussed the requirements of environmental control and determined that temperature was more important than relative humidity and felt that if you kept temperature at mid-range, the RH would be controlled, too! Seven to eight years of mold growth prompted investigation into this building. Intensive climate-mapping was done using data loggers to determine the differences in the environment, and they saw a big difference between the center of the room (50-55%) and the ends of the room (70%).
Ntanos also used environmental assessment permanence maps to demonstrate how the environment changes through the year (he gave a poster at this AIC meeting on the mapping of material types). Once they had collected 1-2 years of information, they started making changes.
They used Energy Plus Software and put in as much information as possible about the environment and the building. They also used HAMT (Humidity and Moisture Transfer) and saw a difference with and without HAMT because of the large collection of hygroscopic material. The aim of the model was to examine options in maintaining a sustainable preservation environment for the collection. They were able to reduce energy consumption in line with sustainability targets, build resilience in light of climate change predictions, and inform ongoing capital investment. Powering down the HVAC over the weekend saved up 22% without affecting the preservation environment.