Running the Cold Plant Well
Suction and head pressure, defrost on demand, door discipline and the operating habits that decide any food or drink site's refrigeration bill.
10 min read · Jacob Willis, Net Zero Lead · Last reviewed July 2026
The refrigeration plant is the biggest electrical machine on most food and drink sites, and unlike the cookers it has no recipe card: how it runs is decided by setpoints, timers and habits that were configured at commissioning and have often never been questioned since. Whether the plant chills a brewery's fermentation cellar, a factory's spiral freezer or a dairy's ice-water loop, the same four operating levers decide its bill, none of them exotic: pressures, defrost, doors and load. This lesson teaches them once, for the whole sector.
In this lesson
- 01Lever one: suction pressure (the cold end)
- 02Lever two: head pressure (the warm end)
- 03Lever three: defrost discipline
- 04Lever four: doors, infiltration and load
- 05Where the process courses take this
- 06Sources and further reading