U.S. production of CFCs stopped in 1996, although there was no hard cutoff date for manufacture or installation of CFC-based equipment. So if your building was built in the late 1990s or later, your HVAC systems are less likely to contain CFCs and you are a step ahead with this prerequisite. However, it’s still a good idea to inventory all equipment to verify the refrigerant information, especially if you’re not completely sure. You’ll need that data to document the credit, anyway.