is there a way to clean a sealed evaporator coil?
this is a 23 yr old system. yes, i know i need to just replace it. but it runs fine, however inefficiently. you can take the front cover off the case, and the coil is exposed. But there is a triangular panel that keeps you from having access to the underside of the coil for cleaning.
Also be sure to clean the squirrel cage blower also. The slightest amount of dust on the edge of the blades will cause the system not to function anywhere near its ability as compared to when its clean.