"ECO-JOZU" is the nickname for the highly efficient latent heat recovery-type water heaters that captures and reuses latent heat that was normally exhausted through ventilation in conventional water heaterss, achieving a high heat-efficiency rate of 95%. As of FY 2009, there were 1.6 million units (including city-gas units) in general use, and with the aim of the industry to see 20 million units (including Eco-Will) installed by the year 2020, endeavors are being made at toward standardization in the Eco-Jozu production stage.

Recently, design focus has been on meeting consumer needs leading to the development of light weight and compact types. Furthermore, high-efficiency types are materializing through development by combining with solar water heaters or heat pumps, and widespread usage is looked forward to from the perspective of environmental mitigation measures.