fitting the housing 30 is formed of somewhat resilient plastic to allow the required deformation a tab 43 is formed integrally on the element 32 also preferably molded of plastic to facilitate removal for replacement the filter medium is preferably surgical gauze having extremely fine porosity on the order of one micron which typically is made of non woven plastic fiber on a very thin film while relatively expensive only a small amount of such a filter medium is needed in this application in use this material is said to develop a static charge as a result of air flow which forms one barrier in the form of static attraction and then a second barrier is the fine one micron porosity of the filter medium one feature flowing from the use of this filtering material is that after extended use perhaps one year or more in normal use in a normal environment when the filter finally fills it reaches that condition rather quickly going from an air flowing condition to an air blocking condition signals the user to replace the filter by stopping the water flow the valve 35 protects the water during filter replacement and more importantly by preventing use of the cooler if the filter is not properly installed or not installed at all a further feature is to locate.