Viper Heavy Duty is a concentrated version of our popular Viper aerosol product. Use Viper HD instead of a hazardous acid or alkaline cleaner for unbelievable performance. Viper HD is a multipurpose cleaner/degreaser that can be used to clean just about anything. Use it as a non-rinsing evaporator coil cleaner. When diluted above 20:1, no need to rinse condenser coils if a water source is not available. Apply it through our foam gun or in any type of high or low pressure spray equipment.