Coil cleaners are divided into two categories, acid and base (alkaline). Acid types are usually made with hydrofluoric acid. They are typically much more dangerous than alkaline types and not recommended by most equipment manufacturers.
The alkaline group is divided into foaming coil cleaners (caustic)
and non-foaming detergent cleaners. The caustic formulations use sodium hydroxide and tend to be more aggressive than detergent products.
Always match the coil cleaner to type of cleaning required. Have questions? Contact your local HVACR wholesaler for specific answers.