Integrating energy simulations and analytical hierarchy process procedure in multi-criteria evaluation of heating systems for industrial buildings

Industrial buildings in Italy are generally aged and widely outdated from an architectural, technological, and environmental perspective. Despite the current limitations affecting both envelope and system installations, enhancement strategies are not frequently debated in the literature or addressed recurring to not adequately comprehensive approaches. This research examines space heating options for integrated retrofit interventions of manufacturing facilities using a novel methodology that combines multi-criteria decision analysis based on the Analytic Hierarchy Process (AHP) with building energy simulations. Interviews with representatives from mediumsized companies in Tuscany provide insights into the exigencies of industrial buildings, while onsite surveys identify common features of industrial buildings in the region leading to the identification of a representative case study building. This facility is examined producing several energy models to account for the different heating system alternatives to be evaluated according to criteria including economic, environmental, comfort, space, and reliability. Both qualitative judgments and quantitative outputs from energy simulations are considered to rank the technological alternatives encompassed in the analysis. In addition, sensitivity analyses are carried out to highlight the impact of boundary conditions on optimal configuration selection. Economic considerations weigh heavily for industrial owners, often outweighing environmental concerns due to higher initial investment requirements for low-impact solutions. Consequently, gas boiler generators and hot-water fan heaters emerge as preferred options for their flexibility, low initial cost, and ease of installation.