If you’re trying to stay cool in summer or warm up in winter, knowing how to set your air conditioning correctly is essential. Whether using a domestic or commercial air conditioning unit, the right temperature keeps you comfortable without driving up your energy bills, and it also helps prevent overuse, which can lead to wear and tear on the system. It’s important to understand how to get the best out of your air conditioning system all year round so you can stay comfortable whatever the conditions.

Why Temperature Settings Matter

Manufacturers design air conditioners to work best within certain temperature ranges. Pushing them too hard, like setting the temperature very low in summer or very high in winter, won’t cool or heat your space any faster. What it does do is increase energy use, create uncomfortable airflow, and strain the system.

Systems that run too hard for too long will invariably malfunction, which will increase the chances of you making a service call to an air conditioning engineer for a repair or replacement, depending on the damage. Choosing the right temperature from the beginning minimises the risk of this happening, and, more importantly, keeps your space feeling comfortable for longer, without causing excess wear on the system.

Best Temperatures for Summer Cooling

UK summers can feel particularly uncomfortable given that homes and offices built here are inherently designed to retain more heat. In summer, it’s important to stay comfortable inside without wasting too much energy. Setting your AC too cold won’t improve comfort any quicker, but it will use more energy, so it’s best to aim for a balanced setting.

There’s no one-size-fits-all answer when it comes to indoor cooling. While 21-22°C is often recommended for a comfortable and efficient setting, preferences can vary. Some may prefer slightly cooler or warmer temperatures depending on the room, the time of day, or personal comfort.

A fan can help improve airflow, and using this alongside an air conditioning system can help disperse cooler air throughout a larger area.

Best Temperatures for Winter Heating

Modern air conditioning systems often serve dual purposes, offering both heating and cooling as part of an integrated HVAC setup. Heat pumps, in particular, are an efficient, eco-friendly alternative to traditional heating.

In winter, a setting around 21°C is generally considered most comfortable, with 20–23°C suitable for most homes and workspaces. Temperatures above 23°C typically lead to unnecessary energy use. A good HVAC system should maintain this range efficiently without running constantly.

How to Set Your AC at Night

Temperatures for sleep should be slightly different from daytime settings. Aim for a cooler, comfortable temperature between 17-19°C using a unit’s built-in sleep mode.

Remember to avoid very cold air directly blowing onto you while sleeping.

Some air conditioning units adjust temperature automatically during the night. If your system has this feature, use it, it keeps things comfortable without running full power all night.

Improving Efficiency and Comfort

Correct temperature settings are just part of the picture. These steps help your system work more effectively:

  • Use ceiling or floor fans to circulate air
  • Close curtains or blinds during hot days
  • Insulate your space to maintain stable temperatures
  • Clean or replace filters and accessories
  • Avoid blocking vents with furniture

Systems that are maintained regularly are more likely to reach and hold the set temperature efficiently. If yours seems to struggle, an inspection from an air conditioning engineer might be overdue, so you can understand why it isn’t working as it should be.

What If the Room Still Feels Too Hot or Cold?

Sometimes, even with the right air conditioning settings, your space doesn’t feel right. There are a few common causes:

  • Dirty filters or poor airflow
  • Incorrect unit size for the room
  • Low refrigerant levels
  • Blocked or poorly placed vents
  • Insulation issues

These problems are more common in systems that haven’t been serviced recently. Performance often drops in properties where the system hasn’t been checked before the start of a new season.

Expert Temperature Advice from Air Conditioning Experts

For most homes and businesses, setting your air conditioning to the recommended temperature strikes the right balance between comfort and efficiency. The ranges described above suit the systems Climachill installs and supports.

While it’s tempting to crank the temperature down when it’s boiling hot, or hike it when it’s freezing, don’t overdo the settings and focus on maintaining good airflow and consistent, uniform temperatures. If your unit has a sleep mode, use it to maintain comfort overnight without wasting energy, and remember to check your system if you suspect it’s not performing as well as it should.

To keep your system running smoothly year-round, book a service with Climachill’s experienced team, covering homes and businesses across Sussex.

An air conditioning system works by removing heat from indoor spaces and expelling it outside, thereby cooling the interior environment. This is the same fundamental process used in modern central air conditioning and split-system air conditioning units, where heat is transferred through a continuous refrigerant cycle. The process involves several key components:

  1. Evaporator Coil: Located indoors, the evaporator coil contains refrigerant that absorbs heat from the indoor air, causing the refrigerant to evaporate into a gas. This is the first step in how air conditioning systems cool your home.
  2. Compressor: The compressor, situated in the outdoor unit, pressurises the gaseous refrigerant, increasing its temperature and preparing it for heat expulsion. It’s often referred to as the “heart” of the AC system due to its crucial role in the cooling cycle.
  3. Condenser Coil: Also part of the outdoor unit, the condenser coil releases the absorbed heat into the external environment, causing the refrigerant to condense back into a liquid, a key stage in how AC units remove heat and humidity.
  4. Expansion Valve: This component reduces the pressure of the liquid refrigerant, cooling it down before it re-enters the evaporator coil to continue the cycle, allowing the system to deliver consistent, energy-efficient cooling.

This continuous cycle effectively transfers heat from inside your property to the outside, maintaining a cool and comfortable indoor climate.

The Importance of Regular Air Conditioning Service in Sussex

Regular servicing of your air conditioning unit is essential to ensure its efficiency and longevity. Many homeowners book maintenance to keep their systems running smoothly, improve energy-efficient air conditioning performance, and reduce the risk of breakdowns. In Sussex, where seasonal variations can impact system performance, scheduling routine maintenance helps prevent unexpected issues and costly repairs.

Professional servicing typically includes cleaning components, checking for refrigerant leaks, inspecting the AC system components, and ensuring all parts function optimally, the same thorough approach recommended by leading air conditioning service providers.

Understanding the Cost of Air Conditioning Service

The cost of servicing your air conditioning unit can vary based on factors such as the system type, age, and specific maintenance requirements. On average, you might expect to pay up to £150 for a standard service. However, more comprehensive maintenance or repairs can incur higher costs. Investing in regular servicing enhances system efficiency, potentially reducing energy bills and extending the unit’s lifespan—ultimately saving you money in the long term. Routine maintenance is especially beneficial for older or heavily used systems, helping ensure reliable, long-term cooling performance.

At Climachill, we specialise in air conditioning installations, servicing, and repairs across Sussex and the South East. Our team of qualified engineers is committed to providing exceptional service to both residential and commercial clients. We offer flexible payment options and work to ensure your system operates at peak performance, whether you need a new AC installation, emergency repair, or routine air conditioning maintenance.

Contact Climachill

  • Phone: 01273 803820
  • Email: office@climachill.co.uk
  • Address: The Oaks, Lordings Road, Billingshurst, Sussex, RH14 9NA

Investing in regular air conditioning service not only ensures a comfortable indoor environment but also contributes to the system’s efficiency and longevity. Trust Climachill for all your air conditioning needs in Sussex and the surrounding areas.

[Contact us today ]

portable air conditioning
There are 2x modes which allow a temperature set point to be made, cooling mode and heating mode.

The answer to this question is that there is no answer – everyone is different and will therefore like a different temperature, from our experience the general norm setting in cooling & heating mode is around 22C.

Setting Air Conditioning Temperature

Setting your Air Conditioner lower than 21C in cooling mode is normally regarded as too cold and is generally a waste of electric in trying to cool the room this cold, likewise trying to heat a room to higher than 24C is generally a waste of electric – most people set their home thermostat to approx 22C so you should set your Air Conditioner to the same temperature.

You shouldn’t set the Air Conditioner to the lowest cooling setting (generally 18C) – this is far too cold for an office environment and likewise you shouldn’t set the temperature to 30C in heating mode, both of these simply waste electric.

Keep Cool in the Office

Temperature set points can cause arguments within an office environment; we have found that men generally like the temperature lower compared to women, we have one customer whom has a mixed office and on a service visit we found that the women had all moved to one end of the office whilst the men had all moved to the other end of the office, the office had 2x air conditioner units and they found this way the men & women each had their own system – a tad extreme but nonetheless solved the office bickering.

In summary we would recommend a temperature set point of approx 22C.