Which of the following is a reason to not mix your own refrigerants?

• A. It can cause equipment failure
• B. It is illegal
• C. The resulting mix has unpredictable temperatures
• D. It is quick and easy

Answer: (A)

Mixing refrigerants creates an unknown blend whose properties aren’t matched to the system. Each refrigerant has specific boiling points, pressures, and lubrication needs, and the oils and materials in a machine are chosen for that exact combo. When you blend refrigerants, the resulting mix can have unpredictable pressures, temperatures, and chemical interactions. That can push the compressor and other components beyond their design limits, cause oil incompatibility or loss of lubrication, and even promote corrosion or acid formation. All of this raises the risk of equipment failure, which is why you should not mix refrigerants yourself.

The other options are not as direct a reason. Legality and regulatory handling are important, but the core danger is the chance of damaging the equipment. Saying the mixture has unpredictable temperatures is true but describes a symptom, not the full, primary risk. And calling it quick or easy is simply incorrect.