Life cycle analysis methodology for heating, ventilation and air conditioning ductwork in healthcare buildings

The design, modelling and construction of heating, ventilation and air conditioning (HVAC) facilities in healthcare buildings must aim for the users’ maximum comfort and meet sanitary criteria for indoor air quality. The environmental impact of 12 HVAC duct types was subjected to life cycle assessment, with a single-score damage category analysis carried out for the midpoint and endpoint levels. The two most favourable duct types for the different impact categories were aluminium with helical steel wire reinforcement and fibreglass insulation, and also copper sheeting with rock wool and polyurethane insulation. However, although the former presented the best environmental impact values, this type is inadvisable for healthcare buildings. This is due to its nature and the subsequent tendency of the system to lose pressure and efficiency, as well as the difficulty of cleaning this type of ductwork and its predisposition to bacterial proliferation. Thus, the copper duct type with rock wool insulation is the most suitable type for healthcare buildings. This came second overall environmentally (1.06 pt/m 2 ), with values 2.83 times more favourable than the polyisocyanurate solution. Finally, the application of the life cycle assessment (LCA) methodology to HVAC ductwork was demonstrated to reduce the impact by up to 39.88%.