Found system low on charge. Added for 10 a to manufacture specs visibly inspected for leaks where I could see. Didn’t see any signs of oil. Can’t get the door off the evaporator coil due to a humidifier that’s blocking it. Customer wanted to add the refrigerant and see if that holds and not do the leak search. 147/309 SH-6. SC-10 Delta T was 14° relative humidity in the return was 70% I recommend we do a spring tuneup in May or June to see if this refrigerant held over the winter