[Smart Electronics Story] Longest Rainy Season and 100% Humidity... Best-Selling 'Dehumidifiers' This Summer

[Asia Economy Reporter Ki-min Lee] ‘Agile Electronics Stories’ is a column that keenly examines small details about electronic and mechanical products and devices. From hot new products frequently appearing in advertisements and news, to nostalgic items, and puzzling products and industry terms, we will kindly cover them all with a beginner’s mindset.

Contrary to expectations of an intense heatwave this summer, record-breaking heavy rains that make one wonder if there is a hole in the sky have been hitting the entire country day after day. This year, especially in the central region, the monsoon rains have lasted for over 50 days since June. Even when it’s not raining, humidity reaches 100%. Staying indoors still feels like being soaked in water, causing discomfort and fatigue, which raises the discomfort index.

As the gloomy weather continues, air conditioner sales have been sluggish, while dehumidifiers are gaining attention. When did dehumidifiers, which make indoor air dry and comfortable, start being used? Ironically, dehumidifiers have a history alongside air conditioners. The earliest place in Korea where the principles of dehumidification and temperature control were introduced is known to be Seokguram Grotto, built during the Silla Dynasty.

Our ancestors constructed the entrance of Seokguram in a cave style, with the inner chamber built as a granite dome. This structure is effective in preventing water damage. To prevent corrosion caused by moisture and frost that could occur due to temperature differences between the outside and inside, the dome was covered with soil. Additionally, channels were made under the floor to allow water to flow, maintaining cool and dry conditions inside Seokguram.

The person who first developed modern machines that control humidity and temperature was Willis Carrier from the United States. Carrier created the first dehumidifier in the early 1900s to control moisture in a publishing warehouse. Later, to eliminate heat inside factories, he introduced the air conditioner, which combined dehumidification and cooling systems.

Then, you might ask why use a dehumidifier separately when you can just use an air conditioner. The reason is that air conditioners do not perfectly dehumidify. When the air conditioner reaches the temperature set by the user, it switches to fan mode to maintain that temperature. At this time, moisture inside the air conditioner cooled by refrigerant or water that cannot drain through the air conditioner’s drainage pipe is blown back into the room through the airflow. Therefore, the indoor air can become humid again during fan mode.

Different dehumidifiers apply various methods, but the basic operating principle is as follows. When the dehumidifier is turned on, humid air passes through it and meets refrigerants or cooling devices inside. As the air cools, condensation occurs, turning moisture into dew. The collected dew falls into a water tank, and the previously humid air is expelled in a dry state.

The dehumidifier market, which had annual sales of about one million units in the early 2010s, dropped to 200,000 units last year due to repeated dry monsoons that did not feel like typical rainy seasons. However, due to the continuous monsoon rains following the scorching heatwave in mid-June this year, sales until this month have far exceeded the usual levels. According to recent data from E-Mart, dehumidifier sales increased by 104.3% from July 1 to August 11 compared to the same period last year. On the online shopping mall Auction, dehumidifier sales in the recent month (July 10 to August 9) surged by 114% compared to the same period last year.