Alternative Heating and Cooling Systems for the Retrofit of Medium‐Rise Residential Buildings in Greece

Abstract

The European Union recently set the target of doubling building retrofit rates through the European Green Deal. Currently, more than half of the households’ energy consumption is accounted for space conditioning, with southern European countries experiencing increasing demand for cooling systems over the past decade. Herein, the performance of market‐available heating and cooling systems that can replace the existing low‐efficiency systems in multiresidential buildings in Greece is compared. The study's objectives are to minimize the operating greenhouse gas emissions and the life‐cycle cost. Results demonstrate that air‐to‐air heat pumps have the lowest life‐cycle cost. In areas where natural gas is not available, the replacement of the diesel‐oil boiler with a biomass boiler leads to a 48% to 73% decrease of the operating greenhouse gas emissions. In areas where natural gas is available, the gas absorption heat pump has the lowest operating greenhouse gas emissions, demonstrating a reduction between 40% and 54% when compared to a conventional gas boiler; however, it dramatically increases the life‐cycle cost, making it less attractive than heat pumps and condensing gas boilers. The findings are in line with the current residential space conditioning market, while indicating the potential of biomass boilers and gas absorption heat pumps.