| abstract |
A cleaning agent suitable for cleaning the inside of a system of a heat exchange system using a working medium made of HFC and a cleaning method are provided. After extracting the working medium and the lubricating oil from the inside of the system in which the working medium of the heat exchange system circulates and enclosing the working medium and the lubricating oil, the fluorine-containing ether represented by the formula 1 is put inside the system. A cycle cleaning method for cleaning the interior of the system by introducing a cleaning agent containing, and removing the lubricating oil remaining in the system. R 1 —O—R 2 Formula 1 However, R < 1 >, R < 2 > shows a fluorine-containing alkyl group each independently. The number of fluorine atoms contained in R 1 and R 2 are each 1 or more, and the total number of carbon atoms contained in R 1 and R 2 are 3-8. [Selection figure] None |