Jung Da-hyun is a reporter at The Korea Times, covering social issues in Korea, including foreign residents, education, environment and politics. Driven by a deep interest in people’s stories, she focuses on investigative and feature reporting through direct interviews and field coverage. She received the Amnesty International Korea Media Award for her “Deepfake Crisis at Schools” series. Reach her at dahyun08@koreatimes.co.kr. Always open to hearing your stories.
On or off? Air conditioner dilemma drives up power bills
A customer looks at air conditioners and cooling appliances at a retail store in Seoul, May 25. Yonhap
By Jung Da-hyun
With a record-breaking heat wave gripping the country, air conditioners have become less of a luxury and more of a lifeline.
Yet with rising temperatures come growing worries about the strain on household electricity bills.
In response, social media platforms have been flooded with tips and tricks for using air conditioners more efficiently — offering relief from the heat without delivering a financial shock.
Among the most widely shared energy-saving tips are running the air conditioner continuously rather than turning it on and off, and using the dehumidification setting instead of standard cooling.
Some users upload snapshots of their electricity bills as evidence that these strategies actually trimmed their costs.
Whether it's cheaper to keep the air conditioner running or to turn it on and off depends largely on how the unit’s outdoor compressor operates.
For inverter-type air conditioners — which adjust the outdoor fan speed based on cooling demand — keeping the unit running is usually more efficient. Turning the unit off and back on too quickly can cause indoor temperatures to spike, forcing the system to work harder — and consume more energy — in order to restore a comfortable level.
Older single-speed models, in contrast, are generally more efficient when turned off while not in use. These non-inverter units run at full power until the room reaches the set temperature, then shut off entirely — only to restart once the temperature rises again.
Another widely shared tip is to use the dehumidification mode rather than standard cooling to save on electricity. However, appliance manufacturers note that the difference in energy consumption between the two modes is minimal.
Cooling mode works by rapidly bringing the room down to the desired temperature, then maintaining it with minimal power. Dehumidification aims to lower humidity levels while keeping the temperature steady, adjusting fan speed and compressor output based on indoor conditions.
As for questions of whether cooling or dehumidifying eats up more electricity, it all comes down to how humid the air is that day, according to experts.