I performed a maintenance on two gas furnaces Ac units I replaced both 16x25x1 filters I checked all electrical components and checked the temp drop it was not good for both units I cleaned the drain lines on both units I checked the Freon levels and checked the capacitors on both units I found that they both were low on 410A Freon I called the property manager and confirmed that I can put Freon in I got the go ahead from them I put a total of 2 Lbs of Freon in the units which is 99.00$ a Lb. the units are in good working order at this time.