By now, most of you have either installed inverter-driven variable speed heat pumps that can deliver their nominal rating output at temperatures well below 0° F without any backup heat source, or at least have become familiar with the technology. The most efficient models rival the COP (Coefficient of Performance) ratings of geothermal heat pumps, but without the expense of installing the boreholes, or wells, for the heat exchanger.
With tax credits now reduced from 30% to 22% in 2021, and 0% in 2022, geothermal systems will have to compete against inverter air-to-water systems installed cost, which were already less expensive back when geothermal systems enjoyed the full 30% federal tax credit. Based upon my own cost analysis between inverter-driven air-to-water and geothermal heat pump systems, customers were easily swayed to selecting the air-to-water systems. Fortunately, John Siegenthaler’s “Picking Winners” column has done the heavy lifting where numbers crunching is concerned with well-defined costs for both systems along with extended payback.