New smart home appliances are taking over the market as sensors that control them evolve: They take care of all you need without a remote control. Three to four years ago, sensors had only on and off functions for overheated motors. Now, they are so sophisticated they auto-control operation modes by detecting the nearby atmosphere.

Jeong Sun-ah, 25, recently got sick from being exposed to air-conditioning that she kept on while working out at home for the past two months. Jeong always kept the temperature low because she sweats so much, but she repeatedly coughed and shivered right after getting out of shower.

“It was cumbersome to change the temperature with a remote control after getting out of shower because I get busy drying hair and putting lotion on,” she said.

It doesn’t happen since she purchased one of Samsung Electronics’ smart air-conditioners two weeks ago, because an attached camera sensor tracks her activities. It keeps the temperature low while she works out, automatically turns off when she gets into the shower and turns on again with a nice natural breeze when she sits in the living room.

According to Samsung, twice as many home appliances with so-called smart sensors sold during the past 12 months as those without the function.

“We plan to expand the sensor function to most of our products,” a source at the company said.

Dishwashers also have started to detect grease spots. A Miele model automatically gauges the amount of detergent and rinses several more times for dishes with heavy grease. It even estimates the murkiness of already-circulated water to minimize usage.

LG Electronics’ Dios Dishwasher includes a DD motor sensor, which controls the pressure of water streams when there are more dishes or they are very dirty. It also uses about 22 percent less water than older products.

German company Miele’s Honeycomb Drum and Samsung’s Bubble Shot 3 weigh laundry and automatically use an appropriate amount of detergent.

“With too much detergent, the washer usually spends more water and electricity to clean it out,” said a Miele Korea employee. “Our product was certified by a German ecology research institute for a 30 percent reduction in detergent use.”

This year’s new Samsung vacuum cleaner, the Motion Sync, includes a sensor that estimates the amount of dust on the floor. The robotic vacuum cleaner’s key auto-cleaning technology was integrated into the regular cleaner’s sensor technology. The vacuum turns a red light on when floor dust is heavy and green when it is clean. A sensor in the filter assesses the level of dust and controls the function.

Smart Kimchi refrigerators mean better taste. Samsung’s Zipel Asak includes 10 sensors inside and outside the body of the fridge. Asak in Korean is the sound of someone biting a crisp piece of kimchi. Like the name, the fridge adjusts temperature and humidity when the door is open and closed to maintain the best conditions for fermentation. Once the kimchi is aged, the storage mode helps maintain the already-set condition for longer-lasting taste.

BY CHO HYE-GYUNG [jiyoon.kim@joongang.co.kr]