Double system CTU- Washed both Condensers and Changed filters for both systems New system is working quite well with a good delta T about 20 degrees Older system had a 15 degree delta, same as last time but no leak found Recommended Refrigerant to help lubricate compressor and reduce wear and tear and upgrade efficiency and lower run time After adding 2 pounds, I had a 20 delta T Systems are ready for Summer time Thank You for choosing Comfort Experts, have a great day