Sizing a Breathing Air Compressor
Many people agonize over - - - "What size breathing air compressor do I need?"
The procedure of choosing a breathing air compressor that will meet your requirements can be simplified by following the four steps below:
- The first task is to determine how many SCUBA or SCBA tanks you need to fill in the worst case scenario. Forget about storage - - - just think about the number of tanks required to meet the "daily" or "sporadic demand" requirement.
- Next you must decide how long you want the breathing air compressor to run each day. The run time is determined by such things as - A) the available operator time, and - B) the time of day you want to run the compressor (filling at night or early morning when it is cooler is always a good idea). A small compressor will fill your tanks just the same as a large one if you don't mind running it 18+ hrs/day. (Storage only affects 'when to run', it does not affect run time)
- How long do you want the breathing air compressor to last? This refers to maintenance intervals as well as compressor overhaul or replacement. Every compressor has a life - - - and that life can be stated as the total number of tanks filled. Get your prospective vendor to tell you approximately what that number is. For example - a 15 CFM compressor of average quality should reasonably be expected to last about 3500 hours before overhaul (assuming normal maintenance such as valve cleaning and replacement). That same compressor will fill an 80 Cu. Ft. SCUBA tank with 750 PSI (left in it) in 4 minutes. Or you can say that compressor will fill 15 tanks per hour (TPH). So if an average 15 CFM compressor has a life of 3500 hours, multiply 3500 by 15 = 52,500 tank fills (at the conditions stated above). Then @ 2000 tanks/year = 26 years.
- The final step in the procedure is "What is the budget?" Obviously if you really need a 50 CFM breathing air compressor and you can only budget $15,000 for the compressor - - - some serious compromises must be made.
Our technicians are always available to assist you with these calculations & decisions, including how to structure the fill profile.