Short Refrigerant Cylnders

Recently Mr. Simmons, one of our air conditioning instructors at Athens Technical College, noted that a new cylinder of refrigerant felt light compared to the others. A quick check with a scale confirmed his suspicion – the “30 lb” cylinder only weighed 22 lbs including the cylinder and outer cardboard packaging. However, it had never been used. The plastic seal was still intact.  It made me wonder if there were other cylinders that we have used and did not catch. We checked a few others, and it seemed that one cylinder was the only “short” cylinder. Obviously, a cylinder that holds 30 lbs of refrigerant should weigh more than 30 lbs. How much more should it weigh? Generally, the whole package including the box should weigh around 36 lbs. The empty DOT 39 cylinder weighs around 5 lbs and the box weighs approximately 1 lb. I don’t know if our experience is unique, or if it is common for refrigerant cylinders to be short, but I will most certainly be checking from now on. I recommend that you weigh your cylinders before opening the seal to make sure you are getting what you are paying for. A great deal on refrigerant is not a great deal if they don’t actually give you the full amount you are paying for. In our case, I called the company that we purchased the refrigerant from and they quickly replaced the cylinder with a full one. I weighed it to make sure.