Circular approaches to HVAC components : A comparative life cycle and cost assessment of Reuse, Reapplication andRecycling

The building and construction sector faces increasing pressure to reduce greenhouse gasemissions and improve resource efficiency, highlighting the need for effective circularstrategies for technical building installations. This degree project aimed to develop an apply adecision-support model to determine under which conditions reuse, reapplication orrecycling of HVAC installation products constitute the most environmentally andeconomically beneficial option. The study integrated Life Cycle Assessment (LCA) and LifeCycle Costs (LCC) within harmonized system boundaries, focusing on embodies climateimpacts and life-cycle costs at both component and system level.The model was implemented in Python and applied to a counterfactual office renovation casestudy in Sweden, where all HVAC components were replaced with new products in thebaseline scenario despite technical feasibility for reuse. Environmental impacts werecalculated using manufacturer-specific Environmental Product Declarations (EPDs) inaccordance with En 15804 and EN 15978, while economic inputs were derived from theWikells construction cost database following ISO 15686-5. Sensitivity and break-evenanalyses were conducted for key uncertain parameters, including transport distance,replacement fraction, testing and reconditioning emission and recycled content fraction.The results show that reapplication yields the lowest life-cycle climate impact and life-cyclecost, followed by reuse, while recycling provides inly moderate improvements compared tobaseline replacement. Avoided manufacturing emissions dominate life-cycle climateperformance, and no break-even points were observed where recycling outperforms reuse orreapplication under the tested conditions, Component-level analysis revealed that high masscomponents, particularly chilled beams, dominate both environmental and economicoutcomes.The study concludes that prioritizing reapplication and reuse of HVAC components candeliver substantial climate and cost benefits and that the proposed decision-support modelprovides a transparent and practical framework to support circular decision-making inrenovation projects.