A heat exchanger and a water heater incorporating same

摘要

A heat exchanger (10) for a water heater. The heat exchanger (10) has a first part (12) and second part (14). A heat exchanging medium flows through the first and second parts. The majority of the length of the first part (12) is in direct heat exchanging contact with a substance to be heated and the majority of the length of the second part (14) is encased in an insulative material or substantially thermally isolated from the substance to be heated.