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Kitchen deep cleaning - energy
You might expect a kitchen's energy bill to fall in summer - less heating needed - but often it rises. The main reason is refrigeration: fridges and freezers work much harder in the heat to stay cold, using more energy. A hot kitchen makes it worse. Understanding why summer costs more shows how to soften the rise. Here is why your energy bill is higher in summer. This is general commentary.
The short answer
It seems counter-intuitive: in summer you need no heating, so you might expect a lower energy bill - yet many commercial kitchens see their energy bill rise in summer. The main reason is refrigeration. How refrigeration works and why heat matters: a fridge or freezer keeps its inside cold by removing heat from inside and shedding it (via the condenser) to the surrounding air. How hard it has to work depends partly on the surrounding temperature: when the air around the fridge (and its condenser) is warmer - as in summer, and in a hot kitchen - the fridge has to work harder to remove heat and shed it, because there is more heat coming in and it is harder to shed to warmer air. So in summer, refrigeration compressors run harder and longer to keep the same cold temperature, using more energy. Because refrigeration runs 24/7 and is a major energy user, this summer increase in refrigeration energy is significant - often enough to raise the overall bill despite no heating being needed. What makes it worse: a hot kitchen (kitchens get very hot in summer) means the fridges and their condensers are in hot air, working even harder; poorly-sited condensers in hot spots; dirty condensers (that already struggle) struggling more; and poor door seals or doors opened more in the heat. And air-conditioning (if any) adds its own summer energy use. So the summer bill rises chiefly because refrigeration works harder in the heat (plus any air-conditioning), and a hot kitchen worsens it. How to soften it: keep refrigeration efficient - clean condenser coils (so they shed heat efficiently even when it is warm), good door seals, not overloading, and keeping the fridges and especially their condensers out of the worst heat (well-sited, ventilated, and the kitchen as cool as practical) - so the refrigeration copes with the summer heat with less extra energy. So the bill is higher in summer mainly because refrigeration works harder in the heat, and keeping refrigeration efficient softens the rise. This is general commentary on kitchen energy.
Key points
The summer surprise
It seems back to front: in summer you need no heating, so you might expect a lower energy bill - yet many commercial kitchens find their energy bill goes up in summer. The intuition is understandable: heating is a big energy use, and in summer you are not heating the space, so surely the bill should fall. But in a commercial kitchen, other energy uses rise in summer enough to outweigh the heating saving - chiefly refrigeration, which works much harder in the heat. So rather than falling, the bill often rises, catching operators by surprise.
Understanding why reveals something important about where a kitchen's energy goes. Unlike a home (where heating dominates and summer is cheaper), a commercial kitchen has large, constant refrigeration and cooling loads that are sensitive to heat - and these rise in summer. So the summer bill is a window onto the kitchen's refrigeration energy, and how much the heat affects it. The main driver is refrigeration working harder in the heat (the next section), worsened by a hot kitchen, and added to by any air-conditioning. Knowing this explains the summer surprise - and points to how to soften it (keeping refrigeration efficient). So the summer surprise is a higher, not lower, bill - driven by refrigeration in the heat. So higher, not lower, is the summer reality. This is general commentary.
Refrigeration in the heat
The main reason the bill rises in summer is refrigeration working harder in the heat - fridges and freezers have to use more energy to stay cold when the surrounding air is warmer. How refrigeration works: a fridge or freezer keeps its inside cold by removing heat from inside and shedding it (through its condenser) to the surrounding air. How hard it has to work depends partly on the surrounding temperature. In warmer conditions - summer, and a hot kitchen - two things happen: more heat leaks into the fridge from the warmer surroundings (so it has more heat to remove), and it is harder to shed that heat to the warmer air (the condenser sheds heat less easily to warm air). So the refrigeration system has to work harder and run longer to keep the same cold temperature.
The result is that in summer, refrigeration compressors run harder and longer, using more energy - to achieve exactly the same cooling. And because refrigeration runs constantly (24/7) and is a major energy user in a kitchen, this summer increase in refrigeration energy is significant - often enough to raise the overall bill despite no heating being needed. So the counter-intuitive summer rise is largely refrigeration: the warmer it is, the harder the fridges and freezers work to stay cold, the more energy they use. This is the core reason a kitchen's energy bill is higher in summer - the constant, major refrigeration load rising with the heat. So refrigeration working harder to stay cold in the heat is the main driver. So working harder to stay cold is why refrigeration costs more in summer. This is general commentary.
What makes it worse
Several things make the summer refrigeration rise worse - chiefly a hot kitchen and hot condensers, plus dirty condensers, poor seals, and any air-conditioning. A hot kitchen: commercial kitchens get very hot in summer (cooking heat plus the warm weather), and the fridges and freezers sit in that hot air - so they work even harder than the outside temperature alone would cause. The hotter the kitchen, the harder the refrigeration works. Hot condensers: the condenser (which sheds the fridge's heat) needs to shed heat to its surroundings, so if it is in a hot spot (a hot part of the kitchen, an unventilated space, near heat sources), it struggles to shed heat in summer, making the fridge work harder. So a hot kitchen and poorly-sited, hot condensers worsen the summer rise.
Dirty condensers make it worse still: a condenser clogged with grease and dust already sheds heat poorly - and in summer, when it most needs to shed heat efficiently, a dirty condenser struggles more, so the fridge works much harder (a dirty condenser and summer heat compound each other). Poor door seals and doors opened more (in the heat, or with more activity) let more warm air in, adding to the load. And air-conditioning: if the kitchen or premises has air-conditioning, it uses more energy in summer (cooling against the heat) - adding directly to the summer bill. So the summer rise is worsened by a hot kitchen, hot and dirty condensers, poor seals, and air-conditioning - all compounding the basic effect of refrigeration working harder in the heat. So a hot kitchen and hot condensers make it worse. This is general commentary.
Softening the rise
The summer rise cannot be eliminated (refrigeration will always work harder in the heat), but it can be softened - chiefly by keeping refrigeration efficient, so it copes with the heat with less extra energy. The biggest lever is clean condenser coils: a clean condenser sheds heat efficiently, so the fridge copes with the summer heat with much less extra energy than one with a grease-and-dust-clogged condenser (which struggles badly in the heat). Keeping condensers clean is therefore one of the most effective ways to soften the summer refrigeration rise - and it matters most exactly when it is hot. Good door seals and not leaving doors open reduce the warm air getting in. Not overloading, and good internal airflow, help the fridge work efficiently.
Keeping the fridges and their condensers out of the worst heat helps too: siting condensers in cooler, ventilated spots (not hot corners), keeping the space around them clear and ventilated, and keeping the kitchen itself as cool as practical (good ventilation and extraction, which also helps the staff) - so the refrigeration is not working in excessive heat. Together, these keep the refrigeration coping efficiently with the summer heat, softening the energy rise. The single most impactful and controllable step is keeping the condensers clean - because a clean condenser sheds heat efficiently in the heat, while a dirty one struggles most when it is hottest. So softening the summer rise means keeping refrigeration efficient - clean condensers above all, plus good seals and keeping the fridges out of excessive heat. So keep refrigeration efficient to soften the rise. This is general commentary.
Manage the summer load
So a commercial kitchen's energy bill is often higher in summer mainly because refrigeration works harder in the heat - fridges and freezers using more energy to stay cold when the surroundings are warmer - worsened by a hot kitchen, hot and dirty condensers, poor seals, and any air-conditioning. The rise cannot be eliminated, but keeping refrigeration efficient (clean condensers above all, good seals, and keeping the fridges out of excessive heat) softens it. So manage the summer load by keeping refrigeration efficient.
This is where keeping the refrigeration condensers clean connects directly to the summer bill. The condenser is how a fridge sheds its heat, and it has to work hardest in summer - so a clean condenser (shedding heat efficiently) copes with the summer heat with far less extra energy than a dirty one (clogged with grease and dust, struggling to shed heat exactly when it most needs to). Keeping the condensers clean - through the periodic cleaning and deep cleaning that removes the grease and dust build-up routine cleaning misses - is therefore one of the most effective, controllable ways to soften the summer energy rise. It is worth having refrigeration condensers cleaned before or during summer, so they cope with the heat efficiently. And keeping the kitchen cooler through a clean, working extraction helps too (less heat around the fridges). So managing the summer energy load comes down largely to keeping the refrigeration efficient - and clean condensers coping with the heat is the heart of it. So clean condensers cope with the heat, softening the summer bill. This is general commentary on kitchen energy.
Questions
Because in a commercial kitchen, refrigeration (and any air-conditioning) works much harder in the heat, and this rise outweighs the saving on heating. It seems counter-intuitive - no heating needed in summer, so surely a lower bill - but unlike a home (where heating dominates), a commercial kitchen has large, constant refrigeration loads that are sensitive to heat. Refrigeration keeps food cold by removing heat and shedding it to the surrounding air; when the surroundings are warmer (summer, and a hot kitchen), the fridges have to work harder and run longer to stay cold, using more energy. Because refrigeration runs 24/7 and is a major energy user, this summer increase is significant - often enough to raise the overall bill despite no heating being needed. Add any air-conditioning (which uses more in summer), and the summer bill rises. So the bill goes up in summer mainly because refrigeration works harder in the heat, outweighing the heating saving. So it rises because of refrigeration (and cooling) in the heat. This is general commentary.
Because it has to remove more heat and shed it to warmer air, so it works harder and longer to keep the same cold temperature. A fridge or freezer keeps its inside cold by removing heat from inside and shedding it (through its condenser) to the surrounding air. In warmer conditions (summer, a hot kitchen), two things happen: more heat leaks into the fridge from the warmer surroundings (so it has more heat to remove), and it is harder to shed that heat to the warmer air (the condenser sheds heat less easily to warm air). So the refrigeration system has to work harder and run longer to achieve exactly the same cooling - using more energy. Because refrigeration runs constantly and is a major energy user, this extra summer energy is significant. So refrigeration uses more energy in hot weather because it has more heat to remove and a harder time shedding it - working harder to stay cold. This is why keeping refrigeration efficient (especially clean condensers, which shed heat efficiently even when warm) matters most in summer. So it works harder to stay cold in the heat. This is general commentary.
Yes - a hot kitchen makes refrigeration work harder still, worsening the summer rise. Commercial kitchens get very hot in summer (cooking heat plus the warm weather), and the fridges and freezers sit in that hot air - so they work even harder than the outside temperature alone would cause, using more energy to stay cold. The condensers (which shed the fridges' heat) also struggle more in a hot kitchen, especially if sited in hot spots or unventilated spaces - making the refrigeration work harder still. So the hotter the kitchen, the harder the refrigeration works and the more energy it uses. This is why keeping the kitchen cooler helps the summer bill (as well as the staff): good ventilation and extraction keep the kitchen and the air around the fridges cooler, so the refrigeration works less hard. Keeping the fridges and condensers out of the worst heat (well-sited, ventilated) also helps. So yes - a hot kitchen worsens the summer bill, and keeping the kitchen cooler (and refrigeration efficient) softens it. This is general commentary.
Yes - a dirty condenser struggles most in summer, when refrigeration most needs to shed heat efficiently, so it costs more then. The condenser sheds the heat a fridge removes, and it has to work hardest in summer (shedding heat to warm air). A clean condenser sheds heat efficiently even when it is warm; a condenser clogged with grease and dust already sheds heat poorly, and in summer - when it most needs to shed heat - it struggles far more, so the fridge works much harder and uses much more energy. So a dirty condenser and summer heat compound each other: the inefficiency that a dirty condenser causes year-round becomes worse in the heat, because the condenser cannot cope with the extra summer demand. This makes keeping condensers clean one of the most effective ways to soften the summer energy rise - and it matters most exactly when it is hot. It is worth having refrigeration condensers cleaned before or during summer, so they shed heat efficiently through the heat. So yes - a dirty condenser matters more in summer, costing more energy when it is hottest. This is general commentary.
Chiefly by keeping refrigeration efficient - clean condensers above all - and keeping the kitchen and the fridges out of excessive heat. Because the summer rise is mainly refrigeration working harder in the heat, the savings come from helping it cope efficiently: keep the condenser coils clean (a clean condenser sheds heat efficiently in the heat, while a dirty one struggles most when hottest - the biggest, most controllable lever); keep door seals good and do not leave doors open (less warm air in); do not overload, and keep good internal airflow; and keep the fridges and their condensers out of the worst heat (site condensers in cooler, ventilated spots, keep the space around them clear, and keep the kitchen as cool as practical through good ventilation and extraction). Together these keep the refrigeration coping with the summer heat with less extra energy. The single most impactful step is keeping the condensers clean, so they shed heat efficiently through the heat. So reduce the summer bill by keeping refrigeration efficient - clean condensers, good seals, and keeping the fridges out of excessive heat. This is general commentary.
By keeping the refrigeration condensers (and the extraction) clean, so refrigeration copes with the summer heat efficiently and the kitchen stays cooler - both of which soften the summer rise. The condenser is how a fridge sheds its heat, and it works hardest in summer - so a clean condenser (shedding heat efficiently) copes with the heat with far less extra energy than a dirty one (clogged with grease and dust, struggling exactly when it most needs to shed heat). Keeping the condensers clean - through the periodic cleaning and deep cleaning that removes the grease and dust build-up routine cleaning misses - is one of the most effective ways to soften the summer refrigeration rise. And keeping the extraction clean and working keeps the kitchen cooler (clearing the heat), so the fridges are in cooler air and work less hard. So cleaning helps the summer bill by keeping refrigeration efficient (clean condensers coping with the heat) and the kitchen cooler (clean, working extraction) - both reducing the extra energy the heat would otherwise cost. It is worth having condensers and the extraction cleaned before summer. So cleaning helps by keeping refrigeration efficient and the kitchen cooler. This is general commentary.
Refrigeration works hardest in summer, and a clean condenser copes with the heat far more efficiently than a grease-and-dust-clogged one. Our kitchen deep cleaning and equipment cleaning keep condensers clear, and a clean extraction keeps the kitchen cooler - so refrigeration uses less extra energy in the heat. Ask us about cleaning before summer.
