Coolant and refrigerant, at least in the automotive industry, are two different things. Coolant goes in the radiator and refrigerant goes in the A/C.
R-22, commonly used for years in household appliances, is very expensive and is being fazed out of production.
Don't charge the system on your own without some knowledge and a gauge set to see what is going on.
So, like they already told you, call a professional.
By the way, I have a working refrigerator, circa 1934, that uses sulfur dioxide as refrigerant.