To provide a technological means capable of improving energy efficiency (coefficient of performance) of a heat pump using, as a refrigerant, an alternative for chlorofluorocarbon (HCFC and HFC) used for an existing air conditioner, refrigerator, freezer or the like by inexpensive and simple work.

Silicon carbide powder is attached to refrigerating piping of the heat pump using the alternative for chlorofluorocarbon as the refrigerant, in particular piping between a heat release side heat exchanger (condenser) and an expansion valve, particularly preferably, copper piping immediately before the expansion valve. The silicon carbide powder is mixed with a coating material serving as a binder and is coated, or can be attached by filling the silicon carbide powder in a container and attaching the container to the refrigerant piping.