noisy air compressor
I have 2 pancakes 1 for home the other is at the shop for air tools. Both are loud.
Being small you can build a insulated box to fit over the compressor.
Giving enough space for it to breath. Don't worry about heat. If you time the compressor they only run a few minutes unless you are running a sander that will make them run low on pressure fast.My home one is in a shed.I just close the door. They do make much quieter small compressors but they are way more costly.
Does sound like 10 minutes is way too long to build air. You did right to take it back.