Upon my arrival in Austin, I performed a A/C cooling evaluation on 7 Lennox gas furnaces. Checked system cleanliness, water removal systems and cooling operations. Cleaned outdoor heat transfer media coils. Checked all electrical connections and operations. Found that all systems are clean at this time. Systems 3 and 4 are low on refrigerant. Would recommend adding a hard start kit all all 7 systems. And surge protection and Reme halos. Left all equipment operating at this time.