Eco mode: when it saves the most and when it is not advisable

At this point, it is clear that the air conditioning's Eco mode is the most efficient when it comes to cooling a room. By activating it, the unit avoids the spikes in consumption that occur when the compressor starts up at maximum power.

So, when should you use it to save the most? When the room has already reached a reasonable temperature and you just want to maintain it, or during the middle of the day if you are working from home.

When is it not advisable? If you have just arrived home after a hot day and the room is at 35°C, Eco mode will take a long time to give you any relief. In that case, it is better to use Cool mode or even Turbo for a few minutes to cool the room down initially and, once you are comfortable, switch to Eco mode to maintain the coolness while spending as little as possible.

Cool mode: cools quickly, but can send consumption soaring

If Eco mode is the most efficient, the air conditioning's Cool mode has the greatest potential to send your consumption soaring. It is the standard cooling function, the most widely used, selected with the snowflake symbol.

A very common mistake during a heatwave is setting Cool mode to 16°C, thinking it will cool the house down faster. This is false: the air will come out at the same temperature, but the compressor will not stop working, straining the unit and sending costs through the roof. As indicated by the Institute for the Diversification and Saving of Energy (IDAE), the most efficient approach is to set the thermostat between 24°C and 26°C.

For every degree you lower it below 24°C, your consumption can increase by approximately 8%.

Auto mode: comfort without worrying about the remote

Auto mode is the preferred choice for those seeking absolute convenience. In this setting, the unit itself uses its internal sensors to measure the room temperature and decides for itself whether it should cool, heat (if it has a heat pump), or simply ventilate.

Automatic mode prioritises comfort and speed to reach the selected temperature, which can mean the compressor works at a higher power than necessary. Therefore, consumption in this mode will largely depend on the environment, meaning it will generally tend to be higher than in Eco mode, which limits energy usage, even if it takes a little longer to cool down.

If there are sudden temperature changes and you do not want to keep touching the remote, Auto mode can be a good option, but choose Eco if your absolute priority is your bill.

Fan mode: consumes the least, but does not cool

There is only one mode that consumes less than Eco: Fan mode. This air conditioning setting consumes less because it completely turns off the compressor, which is the part that demands the most energy. For this very reason, it does not cool. It simply works like a conventional fan, circulating the air that is already in the room.

It is ideal for nights when the outside temperature is pleasant or to prevent the air from feeling stagnant. During a heatwave, Fan mode will not lower the temperature and you might feel even hotter and more bothered if the air it circulates is warm.

Sleep mode: the best option for sleeping while spending less

The air conditioner's Sleep mode is designed to work with your sleep cycle. It is usually represented by a moon symbol.

When activated, the unit adjusts the temperature gradually. For example, in summer, it will raise the temperature by one degree every hour (usually up to a maximum of two degrees) to adapt to the drop in body temperature we experience when sleeping. This not only prevents you from waking up cold, but also significantly reduces the strain on the compressor during the night.

Furthermore, it usually reduces the fan speed to the minimum so it is much quieter.

FAQs about air conditioning modes

What is Dry mode on an air conditioner?

Its function is dehumidification. Dry mode generally uses less energy than Cool mode because the compressor runs at a lower, constant speed just to condense the moisture in the air. It is perfect for rainy days or coastal areas where the feeling of heat is caused by humidity rather than the actual temperature.

Is it better to leave the air conditioning on Auto or turn it off and on?

Maintaining a constant temperature is the key to saving money. Compressor start-ups are the moments of highest energy consumption. It is better to leave the air conditioning running at a stable temperature (or in Auto/Eco mode) than to constantly turn it on and off every time you feel a little cold.

Which mistakes drive up your air conditioning's energy usage?

• Dirty filters: these can increase consumption by up to 20% by restricting airflow.
• Selecting extreme temperatures: setting it to 16°C uses a lot of energy and does not speed up the cooling process.
• Not using the timer: Forgetting to turn the air conditioning off in empty rooms is an avoidable waste.
• Not closing windows: Letting the cold air escape forces the appliance to work non-stop.

To ensure your unit is always efficient, we recommend an annual maintenance check that includes cleaning the filters and checking the refrigerant gas, which can prevent costly breakdowns and keep your bills under control.