Decided to just record my fridge that i needed for a project, sharing here for anyone else who needs a fridge!. Recorded with a zoom f6, 2 x rode nt55s set to cardioid, xy coincident recording24 bit, 96 khz.
This is a recording of a natural gas furnace for a home air heating system. Rode k2 microphone pointed at the piolet light of the furnace about 3 inches away.