Energy
Everyone points at the cooking; the meter points somewhere else. Refrigeration that never clocks off, fryers idling three quarters of their lives, and heat that gets paid for three times - a walk through the building in the order the kilowatts actually leave it.
Energy
Stand in any commercial kitchen at half past three in the afternoon. Nothing is being cooked. The lunch rush is cleared, dinner prep is quiet knife work, and yet the room hums: fryers holding oil at temperature for nobody, a bank of fridges cycling against the heat of the room, the extract fan pulling hard against ductwork it has been fighting all year, heat lamps warming stainless steel. Ask where the kitchen's energy goes and everyone points at the cooking. The meter tells a different story - and it is the meter that pays the bills.
UK metering studies of pub and restaurant kitchens put catering at around 63% of the whole premises' electricity, and the split inside that number is the interesting part. This is a walk through the building in the order the kilowatts actually leave it.
The big three
The single largest draw in the metered day is not a cooking appliance at all. Refrigeration runs at around 41% of a kitchen's daily electricity in the same UK studies - because it never stops, and because it is usually working harder than it should. More than half of the refrigeration units in one fourteen-site study displayed the wrong temperature, which is what chronic strain looks like: dirty condenser coils, perished door seals, cabinets crammed against the cookline soaking up its heat. The upside of a big number is a big lever - one metered site cut a walk-in freezer's consumption 45% with a single service visit. Across the whole estate, roughly 70% of available savings were behavioural and around 45% came from maintenance: the two cheapest categories of fix there are.
Across a typical UK restaurant the whole-site split runs near 30% cooking, 25% refrigeration and 20% ventilation - and the cooking share is less about the food than the idle time around it. Commercial fryers spend roughly three quarters of their operating hours at idle, holding oil hot between orders; in the kitchen-level data fryers draw about 13% of daily electricity, with combi ovens and grills near 12% each and bain maries at 9%. Why fryers cost more to run than their nameplate suggests is a story mostly written between services, which is why staggered ignition and honest switch-off routines beat any equipment upgrade pound for pound.
The quiet losses
The kitchen's real waste is not any single appliance - it is heat changing hands. Every kilowatt an idle fryer or an over-lit cookline throws into the room is bought once at the appliance, fought a second time by the refrigeration working against a hotter ambient, and moved a third time by the extract fan. A grease-loaded extract system makes the whole loop worse: the room runs hotter, the fridges cycle longer, and the fan burns more power to move less air. That is why an energy audit that only lists appliances misses the building-sized machine they all live inside, and why the equipment that quietly wastes energy is usually the equipment nobody watches.
The order of attack falls out of the numbers:
None of this is glamorous, and that is rather the point. A kitchen's energy is lost quietly, in idle hours and dirty coils and ductwork nobody can see - so it is recovered quietly too. The kitchens that pay least are not the ones with the newest kit; they are the ones disciplined enough to follow the kilowatts instead of the flames, week after week, until the bill simply stops arguing back.
Questions
By daily electricity draw, refrigeration - around 41% in UK kitchen metering studies - because it runs around the clock and is often maintained poorly. Across a whole restaurant site the typical split is roughly 30% cooking, 25% refrigeration and 20% ventilation, with catering overall taking about 63% of premises electricity in pub-restaurant metering.
Because most of the load is not cooking. Fridges cycle continuously, fryers spend roughly three quarters of their operating time idling at temperature, holding equipment stays hot through quiet spells, and the extract fan runs from first prep to final cleandown. The hours when nothing is cooked are where most recoverable waste lives.
Behaviour, then maintenance. UK metering work attributes roughly 70% of available savings to behavioural change - staggered ignition, switch-off routines, holding discipline - and around 45% to maintenance such as refrigeration servicing and clean extract systems. Both cost little to nothing compared with equipment replacement.
Yes, twice over. Grease narrows and roughens the ductwork so the fan moves less air for the same power, or burns more power to hold its setpoint - and the heat left behind in the room makes refrigeration work harder too. A grease-loaded system can be down 30 to 50% on design airflow, which is resistance the whole building pays for.
Phoenix Duct Clean · by the numbers
Grease-loaded extraction costs you airflow, fan power and a hotter room. TR19 Grease cleaning restores design performance, with the certificate to prove it.