The Rising Importance of Latent Cooling in Swedish Multi-Family Apartments Under Future Climates.

Paper i proceeding, 2026

Climate change is expected to increase the heat and moisture load indoors in cold climates. While Sweden has historically had low to no demand for cooling in dwellings, recent climate model projections indicate a rise in both temperature and absolute humidity. This study explores how much additional cooling energy will be needed for a representative 80m2 apartment in Gothenburg, Sweden. Hygrothermal simulations of the apartment with 25°C set-point temperature for cooling, and a target of 35-65% RH show that from the 2020s to the 2080s, the total summer cooling load could increase substantially. If only mechanical cooling is used, the sensible and latent cooling could increase by 5 kWh/m2 and 1.9 kWh/m2 respectively. Combining mechanical cooling with demand-controlled outdoor air cross-ventilation, may limit the increase in sensible cooling load to 1.5 kWh/m2 and the latent cooling load to 1.25 kWh/m2. Even then, results suggest that the total cooling load could be more than double in the future. Moreover, the impact of cross ventilation on latent cooling load is highly variable, since favourable outdoor temperature do not necessarily coincide with favourable outdoor humidity conditions. Besides, the share of annual latent cooling nearly doubled, rising from approximately 15-20% in the 2020s to 30-40% in the 2080s. Such increase in latent cooling, if not addressed, directly indicates a higher indoor moisture load impacting the building envelope. This study highlights the need to explicitly consider latent cooling in design, renovation and policy, showing that carefully integrated passive strategies can substantially reduce future cooling loads.