A restaurant chain asked us to investigate why their energy bills had increased by 25% across three London sites. No obvious faults — all the systems were running, all the temperatures were roughly where they should be. But “roughly” was the key word. Every system across the three sites was running 1-2°C warmer than set point, and the compressors were running 30% longer than normal. The cause was the same on all three: slow refrigerant leaks that had been losing charge for months. Nobody noticed because the systems still worked — they just worked badly, and the electricity meter noticed even if the staff didn’t.
Refrigerant leaks are the silent drain on commercial HVAC and refrigeration systems. A system can lose 20-30% of its charge before it actually stops cooling, and in that window it’s consuming significantly more energy, running the compressor harder, and heading toward a failure that’ll cost far more to fix than the leak itself.
Visual Signs of a Refrigerant Leak
- Oil stains around pipework joints — refrigerant carries compressor oil through the system. Where refrigerant leaks out, oil leaks out too. Look for dark oily residue on pipe connections, flare joints, and valve stems
- Ice formation on pipework — a leak at a specific point can cause localised icing as the refrigerant expands through the leak point. A frost line on a pipe where there shouldn’t be one is a strong indicator
- Bubbles in the sight glass — if the system has a liquid line sight glass (common on commercial refrigeration), persistent bubbles indicate low charge
- Oil on the floor beneath the outdoor unit — often the first visible sign of a significant leak from the compressor area
Performance Signs
- Reduced cooling capacity — the system runs but doesn’t cool as well as it used to. Rooms take longer to reach temperature, or never quite get there
- Compressor running longer — longer run times to achieve the same result
- Higher energy consumption — the electricity bill tells the truth even when the thermometer lies
- Ice on the evaporator coil — low refrigerant charge causes the evaporator temperature to drop below freezing, and moisture in the air freezes on the coil
- Short cycling — if the charge drops far enough, the low-pressure switch starts tripping
F-Gas Regulations and Leak Checks
Under UK F-Gas regulations, commercial systems above certain charge thresholds must have mandatory leak checks at specified intervals. The purpose is both environmental (fluorinated refrigerants are potent greenhouse gases) and practical (a leaking system is a system heading for failure). Simply topping up a leaking system without finding and repairing the leak is illegal under F-Gas regulations — and it’s a waste of money because the new refrigerant will leak out the same way.
If you suspect a leak, call 020 3974 1419. We’ll pressure test the system, locate the leak, repair it, and recharge to the correct specification. All F-Gas documentation included.