Techno-economic assessment of energy savings and CO2 emission reductions from replacing conventional HVAC systems with ground source heat pumps in Iran

Energy policymakers must develop strategies to promote the adoption of newer and more sustainable systems. It has been demonstrated that ground source heat pump (GSHP) systems are significantly more environmentally friendly than conventional HVAC systems, which remain prevalent in many buildings. Since construction projects are time-consuming, it is essential to consider replacing conventional HVAC systems with GSHP systems in existing buildings. Therefore, supporting a transition toward more sustainable practices to replace outdated systems is crucial. This study aims to explore alternative approaches and appropriate frameworks for replacing traditional fossil-fueled heating and cooling systems with GSHP systems. The current state of the Iranian building sector, a country with substantial oil reserves, is well documented. A techno-economic comparison was conducted between the most common conventional HVAC systems and suitable GSHP systems across Iran’s different climatic regions. The results indicate that purchasing surplus energy at a reasonable price can yield an attractive return on investment when GSHP systems replace conventional HVAC systems. This approach helps offset the additional capital costs, improves system efficiency, and, in some cases, even generates profits, thereby enhancing economic viability and stakeholder acceptance. Furthermore, energy savings and CO 2 emission reductions were evaluated under different scenarios. In the best-case scenario, energy savings of 230.4 MWh and CO 2 emission reductions of 131.5 tons were achieved over the system’s 30-year lifetime. Finally, this study presents a practical procedure for researchers and policymakers to assess the techno-economic feasibility of replacing conventional HVAC systems with GSHP systems under favorable conditions