Completed AC inspection on systems in home. Overall all systems meet manufacturer specifications and are running properly. Units labeled #3 and #5 are not currently operating due to low refrigerant charge. #3 is so low the condenser turns itself off due to low pressure cut out switch. #5 has been freezing and thawing trying to operate. Other systems are good on charge and appear to be running great. Most equipment is Lennox date coded from 2007, there is one newer system that was installed roughly two years ago. Field supervisor has already contacted customer in regards to the systems that are not performing and will be following up with him later.