Nordyne Receives Patent on Heat Pump Defrost Board

ST. LOUIS, Mo. — NORDYNE, a subsidiary of Nortek, Inc., recently received a patent for their defrost process on split-system heat pumps with Micro-Channel condensing coils. U.S. patent 8,869,545 makes thorough defrosting possible on heat pumps that use all-aluminum coils.

Traditional tube-in-fin heat pumps have coil headers on the sides and defrost horizontally. But in a Micro-Channel heat pump, the coil is rotated 90 degrees so 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 never defrost completely.

The NORDYNE patented process adds a hot gas bypass so hot gas goes from the top-down as well as the bottom-up, ensuring the entire coil gets defrosted.

Contractors and distributors who would like to see this defrost process in action can view a video at