Bosch upgraded its SM Series two-stage geothermal water-source heat pump. Vertical and counterflow cabinets were redesigned with a focus on serviceability and reliability, with front water connections and an all-aluminum air coil to resist corrosion. The internal layout has easier access to components through the front panel. The Greensource CDi Series Model SM heat pump comes in cooling capacities from 2 to 6 tons. It meets Energy Star Tier 3 requirements.