How to monitor a directory without indexing file contents and alert when files in the directory are 3 hours hold and greater than 200KB?

I want to monitor only files that are 3 hours old in a particular directory and DON'T want to index content of the files. Also, monitor the size of the files. I want to set up alert for files in a directory that are more than 3 hour old and with size more than 200KB. Please let me know the possibilities.