What version of Premiere Elements are you using and on what computer operating system is it running?
Edit Menu/Preferences/Scratch Disks has the category Media Cache. At the designated hard drive location that you designate in preferences,
there will be the conformed audio files in the Media Cache Files Folders. You delete them. It is not an automatically timed removal.
The consequences of the removal - the program will automatically generate new conformed audio files (cfa and pek) when needed.
Edit Menu/Preferences/Media takes you to the Media Cache Database area. At an unchangeable default save location,
there will be the conformed video files. See the path to that folder in Edit Menu/Preferences/Media. It is not an automatically times removal.
You can clear the conformed video, but clicking on the Clean Button in the Media Cache Database area in preferences.
The consequences of the removal - the program will automatically generate new conformed video files (.mcdb) when needed.
But keep a watch out for pile ups of preview files in the Adobe Premiere Elements Preview Files Folder.
Please review and consider and then we can discuss this further if needed.
I am currently using PE 12 (PE 13 soon) on Windows 7.
I have found the two files you referenced. The media cache database is set for a size of 5 GB and clean once a month is checked. The media cache contains 166 GB of information, not all PE information and not really identifiable (by me). The media cache files contain about 315 GB of data, and as a result, my 1 TB hard drive is about full (I record a 60-90 minute church video weekly.) So it seems that I can delete all the .cfa and .pek files (at least the old ones that will not be used again - all of them really because they can be regenerated.)
Thanks for your help.
Not to worry about deleting the conformed audio. If it is really needed for the here and now, it will be regenerated almost immediately after you delete it.
As I mentioned, watch out for those preview files pile ups. Every time you render the Timeline to get the best possible preview, the program automatically generates one of those preview files - adds up quickly in GBs. If SD project, the preview file is DV AVI whether you rendered a Timeline video or still. If HD project, the preview file is MPEG2.mpg whether you rendered a Timeline video or still.
Best wishes with your Premiere Elements projects.