Ammonia refrigeration systems have some advantages over other refrigerants. Ammonia has physical properties that make it well-suited for large industrial systems, as it is 3 to 10% more thermodynamically efficient than some of the other refrigerants. Another plus for ammonia is that it degrades rather quickly if it escapes the system. It lasts less than a week if it is accidently vented out into the air. Another virtue of ammonia is that it has a pungent smell that alerts you to leaks quickly. One caution about ammonia is that it’s not compatible with copper, so it couldn’t be used if there are any copper pipes you would need to run your refrigerant through.
A consideration with an ammonia refrigeration system is whether you have it configured in a “central station” configuration or a “distributed station” configuration. No matter which configuration you have, Sterling Refrigeration engineers can work with you to maximize cooling efficiency. The central station setup requires higher line pressure and larger quantities of ammonia. This can contribute to more frequent leaks, as a 200,000 square foot facility could require a refrigerant charge from 35,000 to 45,000 lbs. This also could lead to more compliance costs as Homeland Security wants to keep track of facilities with charges over 10,000 lbs. On the plus side, all your equipment will be in one room and most of your maintenance will be in one room and not all over the building. With a distributed station setup, each evaporator has its own set of compressors, condensers and vessels that operate with a low refrigerant charge of around 3,000 lbs. You’ll be using less refrigerant in total, and the lower pressure should minimize leaks. One advantage is that each evaporator station can be set up for a critical refrigerant charge without needing to be pumped back to a central location. Not having to pump the refrigerant through the whole facility should also reduce energy costs.