Challenges and perspectives in time of changing climate for the indoor climate control in Italian archives

A changing climate is impactful for the preservation of cultural heritage both outdoors and indoors. Notwithstanding buildings can have a good buffering effect for short-term fluctuations of outdoor climate conditions, the latter strongly affect the long-term evolution of the indoor climate making challenging its control. Indeed, the control of indoor climate to keep constant specific temperature and relative humidity conditions is becoming less and less sustainable due to the intense use of heating and air conditioning systems, contributing in the glocal carbon footprint. This study investigates the potential changes of the indoor climate control in Italian archives under the low and intermediate Shared Socio-economic Pathways climate scenarios (SSP1-2.6 and SSP2-4.5). The evaluation will be carried out through the application of “degree-days” and “gram-days” using as reference values the temperature and relative humidity thresholds suggested by standards for limiting climate-induced degradation in cellulose-based collections. The expected increase of the outdoor temperatures will be responsible for the decrease in the heating degree days as well as an increase in the cooling degree days and dehumidification gram days at different extent throughout Italy. “Degree-days” and “gram-days” can then be used to derive the energy demands of archives. These outcomes can serve as basis for planning how to leverage and adapt to the expected warming induced by ongoing the changing climate, finetuning the indoor climate control to safeguard library collections while enhancing energy saving, or pathing the way towards novel standards and codes for archives which incorporate the estimates of future warming and climate change adaptation. Further investigations will be needed for an accurate design process aimed at improving the indoor air ventilation to reduce overheating issues at building level and at optimising the re-use of waste heat and other natural-based improvements at neighbourhood level.