@bigbunny101
On HVACs in nonresidential property qualify. HVAC for residential rentals does not qualify for section 179.
@MRGREEN
Yes, it is depreciated over 27.5 years. No, you don't keep depreciating it after it is gone. When the old AC is gone, you report that disposition (essentially you sold it for $0) and the undepreciated amount will show up as a loss on Form 4797.
