Nordyne’s top-down, bottom-up defrost receives patent

Nordyne, a subsidiary of Nortek, Inc., has received a patent for its defrost process on split-system heat pumps with micro-channel condensing coils, which makes thorough defrosting possible on heat pumps that use all-aluminum coils. In a micro-channel heat pump, the coil is rotated 90 degrees so that the headers are on the top and bottom, not the sides. If the defrost started from the top down, the bottom of the coil would not defrost completely, according to Nordyne. The patented process adds a hot gas bypass so that hot gas goes from the top-down, as well as the bottom-up. Click here to see this defrost process in action.