Lowering AC Temperature Doesn't Cool Faster! Daikin's Test Shows 'One Button' Trick for Faster Cooling and Energy Savings

Summers in Taiwan are always sweltering, making air conditioning an essential household appliance. Many people instinctively lower the AC temperature to cool their rooms quickly. However, tests by air conditioning manufacturers show that setting a lower temperature doesn't actually cool the room faster. Instead, switching to 'auto fan' or 'high fan mode' achieves better cooling efficiency and saves energy.

Daikin Air Conditioning, a major Japanese manufacturer, conducted real-world tests published on its official website. They compared lowering the temperature by 1°C versus switching to high fan mode. The results showed that high fan mode provided a cooler perceived temperature and used only about 0.52kWh of electricity, while lowering the temperature by 1°C consumed 1.13kWh—nearly double the energy.

This is because human perception of coolness depends not only on temperature but also significantly on airflow. Increasing fan speed circulates cold air more rapidly, enhancing the cooling effect. Faster air circulation means the room reaches comfort levels quicker, reducing compressor runtime and saving power.

Many people set their AC to low fan speed to save energy, but Daikin's tests found the opposite: low fan speed forces the compressor to run longer to achieve the desired temperature, resulting in higher overall energy consumption. The most energy-efficient approach is to set the fan to 'auto'—using high fan speed initially to cool the room quickly, then allowing the system to reduce fan speed automatically. This method reduces energy consumption by approximately 30% compared to using low fan speed continuously.

Source: Daikin Air Conditioning official website Responsible Editor: Li Yi-Qing