Hot gas defrost is one of those processes in an ammonia refrigeration system that can easily become a “set it and forget it” operation. An evaporator may have been programmed for a 30-minute hot gas defrost years ago, and as long as the coil stays clear, nobody questions it. But just because a defrost cycle works does not necessarily mean it is operating efficiently. The challenge with that mindset is that a defrost cycle can be effective without necessarily being efficient.

In ammonia refrigeration, documentation is not just paperwork. It is how operators understand the system, improve efficiency, maintain consistent performance, reduce miscommunication, and comply with industry regulations. That is why SOPs and P&IDs need to be accurate, current, and actively used within your PSM program or General Duty facility. These documents shouldn't just sit in a binder or folder for audits. They should guide training, daily operation, maintenance activit

When asked what the oil in an ammonia screw compressor is responsible for, most people immediately answer, "lubrication." While that's certainly true, lubrication is only one of several critical functions oil performs within the compressor. This oil lubricates bearings and moving components, absorbs heat generated during compression, and creates a dynamic seal between the rotors and compressor housing. This sealing effect reduces internal leakage, improves volumetric efficien