From retrofitting a ranch built in the ’40s to conditioning massive multi-family Passive House developments, air source heat pumps are being selected as the primary method to heat and cool an ever-growing variety of housing stock. While this technology is remarkable in its affordability, efficiency, and ability to offset a major contributor to greenhouse gas emissions, there are often unmet challenges in selecting the most appropriate piece of equipment. This session will explore the equipment options available in 2020 and evaluate design strategies to ensure that the equipment can be successfully deployed in new construction and retrofit applications.