Performed chemical coil cleaning on three indoor units. Utilized Nu-Calgon Nu-Brite coil cleaner with 1:4 dilution ratio. Applied solution using low-pressure sprayer, allowed 5-minute dwell time. Rinsed thoroughly with Clean-N-Safe neutralizer. Measured airflow post-cleaning: increased from 330 CFM to 412 CFM per unit. Inspected drain pans and cleared condensate lines. Units now operating at optimal heat transfer efficiency.
