Hydronic heating and cooling distribution systems can be supplied from a variety of heat pumps. One specific type is called an air-to-water heat pump. In 2016 there were over two million air-to-water heat pumps installed worldwide, but only a small portion of those were installed in North America. That statistic is expected to change significantly during 2020 and beyond. Air-to-water heat pumps can now challenge geothermal heat pumps based on their return on investment. They are an ideal match for modern hydronic distribution systems. If you’re involved with modern hydronics technology, this category of heat pump represents a growing market opportunity. John Siegenthaler, P.E. presents information on how these heat pumps are installed and how they perform in such applications.