Does Turning Your Air Conditioning Down Cool a Room Faster?
Does turning your air conditioning down cool a room faster?
No. Setting your air conditioning lower does not work like pressing an accelerator. The number on the remote is your target room temperature. If the system is already cooling at full capacity, choosing a lower setting will not give it extra cooling power. It may simply keep running for longer and use more electricity than necessary.
What Does the Temperature on Your Air Conditioning Remote Mean?
The temperature on your remote is the temperature you want the room to reach. It does not control the temperature of the air leaving the indoor unit.
The system measures the room temperature and works towards your chosen setting. A modern inverter air conditioner can then reduce its output as the room approaches the target temperature.
In simple terms:
- The number on the remote is a target.
- It is not a cooling-speed control.
- The unit can only provide its available cooling capacity.
- A lower setting can keep the system cooling for longer.
So, if you want your room to reach 21ยฐC, setting the air conditioning to 16ยฐC wonโt get you there faster.
Why Doesnโt Setting Air Conditioning Lower Cool the Room Faster?
Suppose your room is 30ยฐC when you switch on the air conditioning.
The system starts removing heat from the room.
If itโs already cooling at full capacity, selecting 16ยฐC cannot suddenly give it additional cooling capacity. It will continue removing heat at the rate the system and conditions allow.
The difference comes as the room approaches the temperature you actually want.
- A unit set to 21ยฐC can ease off as the room reaches 21ยฐC.
- A unit set to 16ยฐC will continue trying to reach 16ยฐC.
- That can result in unnecessary additional running time and electricity use.
Changing the setting also cannot make an undersized or poorly performing air conditioner more powerful.
Controls and operation vary between systems, but the important point remains the same:
The lowest temperature setting should not be treated as a fast-cooling button.
Could Setting Your Air Conditioning Lower More Electricity?
Potentially, but 25% should be treated as an illustration rather than a prediction for your home.
A UK government study of non-domestic buildings reported a potential 5% reduction in energy use for every 1ยฐC increase in the air-conditioning temperature setting.
Applying that rule of thumb across the five-degree difference between 16ยฐC and 21ยฐC gives a rough estimate of 25%.
However, actual energy consumption will vary considerably depending on the air conditioning system, outdoor temperature, room conditions, insulation, sunlight and how long the system operates.
The important principle is much simpler:
If you want your room to be 21ยฐC, set your air conditioning to 21ยฐC.
Setting it to 16ยฐC isnโt a shortcut to getting there faster and could result in the system cooling for longer than necessary.
What Temperature Should You Set Your Air Conditioning To?
There isnโt one perfect air conditioning temperature for every home or every person.
Choose a temperature that feels comfortable and allow the system to work towards it.
If you want your room to be 21ยฐC, for example, select 21ยฐC rather than setting the system to 16ยฐC and planning to turn it back up later.
If youโd like to know more about choosing an efficient and comfortable temperature, read our guide: What Temperature Should I Set My Air Conditioning To?
How Can You Cool a Room Faster?
You canโt give your air conditioner additional cooling capacity by pressing the temperature button.
What you can do is reduce the amount of heat entering the room and help the system operate effectively.
- Close external doors and windows while the air conditioning is running.
- Close blinds or curtains on windows receiving direct sunlight.
- Switch the system on before the room becomes excessively hot.
- Select Cooling Mode rather than Fan Mode.
- Choose an appropriate fan speed.
- Keep furniture and curtains clear of the indoor unit.
- Close internal doors if youโre cooling one particular room.
- Follow the manufacturerโs instructions for cleaning reusable filters.
Fan Mode circulates air but does not provide active cooling. If your room isnโt getting cooler, checking the operating mode is a good place to start.
Can Servicing Help Your Air Conditioning Cool More Efficiently?
Yes. Regular servicing helps an air conditioning system operate as intended and gives an engineer the opportunity to identify problems that may be reducing its performance.
Depending on the system, a service may include:
- Inspecting the indoor and outdoor units
- Cleaning filters and accessible components
- Checking airflow
- Checking condensate drainage
- Testing controls and operating modes
- Checking the systemโs cooling performance
- Identifying faults that may require further repair
Dirty filters, restricted airflow and other maintenance issues can reduce cooling performance.
And no amount of hammering the temperature button down will remove a blocked filter.
If your system hasnโt been serviced recently, get it serviced by an FGAS registered engineer.
Why Is My Air Conditioning Running but Not Cooling the Room?
If your air conditioning runs continuously but the room still doesnโt become comfortably cool, the thermostat setting may not be the problem.
Start with the simple checks:
- Is the system in Cooling Mode?
- Are the doors and windows closed?
- Are the filters clean?
- Is anything obstructing airflow around the indoor or outdoor unit?
If everything appears correct but the system still struggles to cool the room, it may need professional attention.
Poor cooling can be caused by restricted airflow, an incorrectly sized system, component faults or refrigerant problems.
Turning the temperature down further wonโt repair a fault.
If your air conditioning isnโt cooling properly, arrange an inspection.
Set the Temperature You Actually Want
Turning your air conditioning down will not normally make a hot room cool faster if the system is already delivering its available cooling capacity.
The temperature on the remote is a target, not an accelerator.
If you want the room at 21ยฐC, set it to 21ยฐC.
And if the room still refuses to cool properly, the problem may be the system rather than the setting.
Need Help With Your Air Conditioning?
Whether youโre dealing with an existing system that isnโt cooling properly or youโre considering air conditioning for your home, TM Hughes & Son provides air conditioning installation, servicing and repairs across Essex.
Existing system not cooling properly?
Book an air conditioning repair.
Want to keep your system performing properly?
Book an air conditioning service.
Thinking about installing air conditioning?
Arrange a free home survey and no-obligation quotation.
New air conditioning installations start from ยฃ1,300, with servicing and repairs from ยฃ100.

Hi, I’m Terry, the founder and owner of TM Hughes & Son Gas Services
Please get in touch to book an appointment or receive a free, no-obligation quote
Call: 01245 830075
Email: info@tmhughesandson.uk
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