Energy demand and indoor climate control in non-residential buildings: challenges and perspectives in time of a changing climate

The climate projections estimated by the Intergovernmental Panel on Climate Change (IPCC) and their impact on energy demand and indoor climate control in existing buildings may help public and policymakers to understand future dynamics and to define proper mitigation and adaptation strategies. The energy demand related to projected climate can be considered valid if building envelope properties will be assumed invariant over the whole projection period. Heating and cooling degree days (HDD/CDD) are here used to assess heating/cooling energy demands (EDheat and EDcool) in buildings housing movable cultural heritage (CH). As CH preservation is a priority in the management of such buildings, HDD/CDD were calculated as the difference between outdoor day's average temperature (T) and the indoor T threshold suggested by European norm for cultural property conservation. Outdoor T projections were extracted from the Copernicus Climate Data Store (CDS) for two scenarios based on two Shared Socio-economic Pathways (SSP), namely SSP2-4.5 (i.e., the radiative forcing is stabilized at approximately 4.5 W∙m-2 after 2100) and SSP5-8.5 (i.e., the radiative forcing reaches 8.5 W∙m-2 after 2100), as defined in the Sixth Assessment Report (AR6) of IPCC. HDD/CDD projections were used both to calculate future energy demand and to show geographical areas in Europe most affected by future T increases. In all projections, T increase will be likely responsible for a decrease in HDD and an increase of CDD at different magnitude over Europe, causing a shift of climate zones at global level and thus affecting mitigation strategies at local level. Consequently, EDheat and EDcool should be expected to decrease in EDheat – especially in mountainous regions – together with an increase in EDcool – especially in proximity of coastlines in Mediterranean region. However, the decrease in EDheat might be not sufficient to balance the increase of EDcool, especially considering the unpredictable evolution of electricity cost. It follows that the indoor climate control in such buildings will be more challenging especially when it comes to preserve collections vulnerable to temperature-induced degradation. These outcomes show the complexity of the issues associated with defining operative strategies at EU level for the preservation of buildings in the twofold role of immovable cultural heritage and container of movable cultural heritage.