Why shouldn’t you set the air conditioner to 26°C at night?

Why Setting Your Air Conditioner to 26°C at Night Isn’t a Good Idea

1. Why Avoid 26°C at Night?

In hot summer months, it’s tempting to crank the AC to the lowest setting for quick relief. But doing this can actually weaken your immune system, raise the risk of respiratory issues, and waste energy. A better approach is to set your air conditioner in line with the outside temperature.

For instance, if the day’s peak temperature is 34°C, keeping your AC around 26–27°C is ideal. This keeps the indoor–outdoor temperature difference to about 7–8°C — helping you stay healthy while saving on electricity.

During the day, 26°C is comfortable for most people. But at night, it’s not the best choice. Once you fall into deep sleep, your body naturally cools down as metabolism slows. You might feel fine at first, but later in the night you could wake up feeling chilled, needing to grab a blanket — or worse, catching a cold. That’s why experts recommend avoiding 26°C while sleeping.

2. The Best AC Temperature for Sleeping

Most AC technicians suggest setting your air conditioner to 28°C at night. It’s warm enough to prevent a nighttime chill, yet cool enough for comfortable rest. Plus, it uses less electricity.

If 28°C still feels too warm, you can keep it at 26°C but turn on Sleep Mode. This setting increases the temperature by 1°C after the first hour, and by another degree the following hour, eventually reaching 28°C. This gradual change prevents early-morning cold spells while still keeping you comfortable.

3. Why Your AC Might Not Feel Cool at 26°C

Some people think 26°C doesn’t actually cool the room. If that’s the case, there may be underlying issues:

Undersized Unit: If your AC’s cooling capacity is too small for the room, even setting it to 18°C won’t make much difference.
Dirty Air Filter: A clogged filter restricts airflow and reduces cooling performance. Clean it regularly.
Blocked Air Vents: Obstructions in front of vents can disrupt air circulation. Keep them clear.
Low Refrigerant: Without enough refrigerant (due to leaks or underfilling), cooling efficiency drops. Only a technician should check and refill it.
Compressor Problems: A faulty compressor severely impacts cooling. This requires professional repair.

If your AC doesn’t cool properly at 26°C, first check the settings, clean the filter, and make sure vents are clear. If that doesn’t solve it, call a qualified technician.