Air to water heat pumps for heating system retrofit in urban areas: understanding the multi-faceted challenge

Air has an important role to play as a renewable resource to supply heat in urban areas. The implementation of heat pumps in multifamily buildings represents an important and underexploited development potential. Financial comparison of heating costs depending on building size and heat production technology shows how retrofit projects with air-to-water heat pumps compare to gas. Feedback from experience based on pilot projects presents the various challenges faced and proposes solutions.