Your Fridge and Freezer Are Working Harder This Summer — Help Them
Your Fridge and Freezer Are Working Harder This Summer — Help Them
One appliance in your kitchen is running 24 hours a day — and hot weather makes its job even harder.
When people think about reducing household energy use, they usually look at the obvious things: heating, hot water, washing machines, tumble dryers and perhaps air conditioning.
The refrigerator is rather different.
You never switch it off.
It sits quietly in the corner of the kitchen, hour after hour, day after day, attempting to maintain a little artificial winter while the rest of the house gets hotter.
And during a hot summer, that becomes increasingly difficult.
If the kitchen reaches 28°C or 30°C, the refrigerator is still trying to keep milk, cheese and vegetables at perhaps 4°C, while the freezer next door may be trying to maintain -18°C.
That means moving heat across a temperature difference of nearly 50°C.
So perhaps, before worrying about buying another energy-saving gadget, it is worth spending ten minutes helping one of the appliances we already own.
Your Refrigerator Doesn't Actually "Make Cold"
This is one of those wonderfully simple pieces of everyday science.
A refrigerator doesn't really manufacture cold.
It removes heat from inside the cabinet and dumps that heat into your kitchen.
A refrigerant circulates through the system. It absorbs heat inside the refrigerator, the compressor raises its pressure, and a condenser releases that heat into the surrounding room.
That explains something extremely important:
The back and sides of the refrigerator need to be able to get rid of heat.
If the appliance cannot lose heat efficiently, the compressor has to work harder and often run for longer.
In winter, when the kitchen might be 18°C, that may not be particularly difficult.
During a summer heatwave, with the kitchen approaching 30°C, it becomes considerably harder.
And sometimes we make the situation worse ourselves.
1. Give the Heat Somewhere to Go
Have a look at where your refrigerator is installed.
Is it pushed tightly against the wall?
Is it wedged into a cabinet with virtually no ventilation?
Are boxes, shopping bags or other objects blocking ventilation openings?
Manufacturers specify clearance requirements for a reason.
A fridge needs airflow around the parts that reject heat.
This is particularly important with integrated appliances, where ventilation usually depends on carefully designed openings at the bottom and top of the cabinet.
Blocking those openings can effectively wrap an energy-consuming appliance in a warm blanket.
A simple summer check
Put your hand near the ventilation area while the compressor is running.
You will often feel warm air.
That heat has come from inside the refrigerator.
You want it to escape.
2. Clean the Dust — Where the Design Allows It
Older refrigerators often have an obvious condenser coil on the back.
Some modern appliances hide much of this equipment within the casing, so don't start dismantling your fridge looking for it.
But where coils or ventilation grilles are accessible, they may gradually accumulate:
- dust;
- pet hair;
- grease;
- fluff;
- cobwebs.
Dust acts as insulation.
The condenser is supposed to transfer heat into the surrounding air. A thick layer of dust makes that more difficult.
So one of the cheapest energy-efficiency upgrades available may be nothing more sophisticated than a vacuum cleaner and soft brush.
Switch the appliance off first and follow the manufacturer's cleaning instructions.
This isn't something that needs doing every week.
But checking it occasionally could become part of a household energy MOT.
3. Check the Door Seal
This is possibly one of the easiest faults to overlook.
The rubber gasket around the door should form a good seal.
If it doesn't, warm, moist kitchen air can continuously leak inside.
The refrigerator then has two jobs:
- cool that incoming warm air;
- remove some of the moisture that enters with it.
That is why damaged seals can also contribute to excessive condensation or frost.
Try the paper test
Place a piece of paper between the door and the seal and close the door.
You should feel resistance when attempting to pull the paper out.
Try it at several points around the door.
If the paper virtually falls out at one particular point, inspect the seal.
Sometimes it simply needs cleaning.
Food residue can prevent a proper seal.
Other times the gasket may be damaged or distorted.
Replacing a seal could be considerably cheaper than replacing the refrigerator.
4. Stop Opening the Door to Think
I suspect most of us do this.
Open refrigerator.
Stand looking inside.
Consider possibilities.
Reject possibilities.
Move something.
Look behind something else.
Eventually decide what we want.
Close door.
Meanwhile, much of the cold air that the refrigerator has spent electricity cooling has spilled into the kitchen.
And warm, humid air has entered to replace it.
The occasional door opening isn't going to bankrupt anyone.
But repeated unnecessary opening certainly increases the work the appliance has to do.
The freezer can be even worse because frost may form from moisture entering with warm air.
There is a surprisingly simple solution
Know what you want before opening the door.
And organise the fridge sufficiently well that you can find it.
Energy efficiency occasionally comes down to knowing where the cheese is.
5. Is Your Fridge Actually Too Cold?
There is little benefit in running a refrigerator significantly colder than necessary.
A sensible target for many domestic refrigerators is around 3°C to 5°C, with the freezer around -18°C.
Yet refrigerator thermostats are not always particularly accurate.
A dial marked:
1 — 2 — 3 — 4 — 5
doesn't necessarily tell you the actual temperature.
In fact, people sometimes aren't even certain whether 5 means "colder" or "warmer".
Buy an inexpensive refrigerator thermometer.
Or, even better, use a small temperature logger and see what happens over 24 hours.
You may discover that your supposedly 4°C refrigerator is actually sitting at 1°C.
The compressor may therefore be doing unnecessary work.
6. Don't Put the Fridge Beside a Heat Source
Sometimes kitchen design works against energy efficiency.
Imagine placing a refrigerator:
- beside an oven;
- beside a radiator;
- beside a dishwasher;
- beside a sunny south-facing window.
Every time the neighbouring appliance heats up — or the sun shines directly on the fridge — the refrigerator has to dispose of its own heat into an even hotter environment.
Obviously, most people aren't going to rebuild their kitchens to save a few pounds of electricity.
But if you are designing or replacing a kitchen, appliance position deserves some thought.
And if afternoon sunlight shines directly onto the refrigerator, something as simple as a blind may help.
7. Hot Food Creates Another Cooling Job
Imagine cooking a large saucepan of food and putting it straight into the refrigerator while still extremely hot.
All that thermal energy has to go somewhere.
The refrigerator eventually moves it into your kitchen.
So allowing very hot food to stop steaming and cool somewhat before refrigeration reduces the immediate cooling load.
There is an important qualification here.
Don't leave perishable food sitting at room temperature for hours merely to save electricity.
Divide large quantities into smaller containers so they cool more quickly and refrigerate them promptly and safely.
Energy saving must never become an excuse for poor food hygiene.
8. Don't Completely Block the Airflow Inside
A refrigerator doesn't just cool the shelves.
It needs cold air to circulate around the food.
Stuffing every available centimetre with containers can obstruct that circulation.
The situation is slightly different in a freezer.
A reasonably full freezer has useful thermal mass. Once everything is frozen, all those frozen packages help keep temperatures stable when the door is briefly opened.
If your freezer is almost empty, containers of frozen water can provide additional thermal mass.
But don't pack either appliance in a way that blocks vents or prevents the manufacturer's intended airflow.
9. Defrost the Freezer If It Needs It
Some modern freezers are frost-free.
Others aren't.
If thick ice gradually develops around the internal surfaces, drawers or cooling elements, efficiency can suffer and storage space certainly disappears.
A small amount of frost isn't a disaster.
Several centimetres of ice deserves attention.
Follow the manufacturer's defrosting instructions rather than attacking the ice with a screwdriver — puncturing refrigeration pipework can turn an energy-saving exercise into the sudden purchase of a new freezer.
10. Summer Is a Particularly Good Time to Check Everything
The refrigerator experiences something rather like an examination question that gets progressively harder.
Suppose the refrigerator interior is maintained at 4°C.
With a kitchen at 18°C, there is a 14°C temperature difference.
With the kitchen at 30°C, that difference becomes 26°C.
More heat also travels through the refrigerator's insulation from the warmer room.
Meanwhile, the condenser has to reject heat into warmer surrounding air.
The appliance therefore tends to run for longer.
You may notice this yourself during very hot weather.
The compressor seems to be running almost continuously.
That doesn't automatically mean something is wrong.
But it makes good ventilation, clean heat-transfer surfaces and good door seals even more important.
So How Much Money Could a Poorly Operated Fridge Cost?
This is where things become interesting.
Rather than pretending every refrigerator behaves identically, let's build a simple example.
Suppose a fridge-freezer normally consumes:
200 kWh per year.
Now imagine a combination of:
- poor ventilation;
- excessive door opening;
- unnecessarily low temperature settings;
- dirty accessible condenser surfaces;
- damaged seals;
- a particularly hot location.
Suppose those things increase consumption by 30%.
Extra consumption would be:
200 kWh x 0.30 = 60 kWh per year
If electricity costs 25p per kWh, that means:
60 x £0.25 = £15 per year
That isn't enough to transform the household finances.
But remember what caused it.
Perhaps ten minutes of maintenance.
Now consider an older appliance using 350 kWh annually and operating 40% less efficiently than it might:
350 x 0.40 = 140 kWh
At 25p per kWh:
140 x £0.25 = £35 per year
And that continues year after year.
The exact amount will vary enormously between appliances, household habits and electricity tariffs.
The more useful equation is simply:
Annual cost = annual electricity consumption in kWh x electricity price per kWh
If you know the appliance's actual consumption, you can calculate your own figure.
Better Still — Measure It
This could make an excellent little home-energy experiment.
Use a plug-in electricity monitor, provided it is suitable for the appliance and used in accordance with its instructions.
Record refrigerator consumption for several days.
Then make one or two changes.
For example:
Week 1
Normal operation.
Week 2
Clean accessible ventilation areas and check clearance.
Week 3
Check the thermostat with a thermometer and correct the setting if necessary.
Week 4
Make a deliberate effort to reduce unnecessary door opening.
You may need to collect data for several days because refrigerator consumption naturally varies with:
- kitchen temperature;
- food added;
- door opening;
- cooking;
- weather.
But this transforms a rather boring appliance into something much more interesting.
You begin to see exactly how your house uses energy.
Try the 10-Minute Fridge and Freezer MOT
This weekend, do the following:
- Check the fridge temperature.
- Check the freezer temperature.
- Inspect the door seals.
- Clean around the seals.
- Check ventilation openings.
- Vacuum accessible dust where the manufacturer permits it.
- Make sure the appliance isn't unnecessarily close to a heat source.
- Remove excessive frost if appropriate.
- Check that internal vents aren't blocked.
- Make sure everyone knows where the cheese is.
The final item may turn out to be surprisingly important.
A Small Lesson in Going Green
One of the difficulties with environmental discussions is that they can become dominated by very large decisions.
Should I buy solar panels?
Should I install a heat pump?
Should I replace the car?
Should I completely renovate the house?
Those things matter.
But going green also consists of hundreds of extremely mundane decisions.
Cleaning something.
Repairing a seal.
Moving an appliance.
Changing a thermostat setting.
Closing a door.
Maintaining equipment we already own.
None of them makes a spectacular photograph.
But millions of refrigerators and freezers are operating continuously across the country.
If each one consumes slightly more energy than necessary, those small inefficiencies become significant.
Conclusion: Help the Appliance You Already Own
Your refrigerator may be one of the least exciting pieces of technology in your house.
Until it stops working.
Then it suddenly becomes extremely important.
It runs through winter nights, summer afternoons, holidays and heatwaves without attracting much attention.
Perhaps it deserves ten minutes of ours.
Check the temperature.
Clean what can safely be cleaned.
Give the heat somewhere to escape.
Inspect the seal.
And stop standing in front of the open door wondering what you came looking for.
Because sometimes going green isn't about buying something new.
Sometimes it is simply about helping the equipment we already have do its job properly.
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