Heat and humidity can take a huge toll on the life of your oil. In tropical conditions your oil will breakdown before some factory recommendations. Understanding the compressor size, oil system and operating conditions will allow you to choose an oil change interval that works best for your compressor. We generally recommend the below for high pressure air systems used in breathing air applications:
Portable compressors like the Bauer JRII or Bauer Oceanus we suggest every 50 hours
Standard compressors 13 to 26 CFM units like the Bauer Vertecon 13 we suggest every 150 to 200 hours
Large compressors 30 + CFM units like the Bauer K42 or Bauer K60 we suggest every 300 to 350 hours
Always contact your service center with your system information and they will help ensure you are using not only the right lubrication, but changing it at the correct intervals.