This summer, the debate over 'air conditioning electricity bills' has begun again. Some say that 'dehumidifying' mode saves more electricity than 'cooling' mode, but this is incorrect. Using the dehumidifying mode incorrectly can actually lead to a spike in electricity bills. With the help of the Korea Consumer Agency (KCA), Samsung Electronics, and LG Electronics air conditioning experts, we have compiled tips for air conditioner usage.

◇ Dehumidifying function may increase electricity bills

To conclude, the key to saving electricity on air conditioning depends on 'how much the outdoor unit's power consumption is reduced.' The compressor inside the outdoor unit, which is the heart of the air conditioner, compresses the refrigerant to produce cold air, consuming most of the electricity in this process. Both cooling and dehumidifying modes require this compressor to operate, so how effectively the outdoor unit's compressor is operated according to the situation is crucial.

During sweltering heat, turning on the cooling mode strongly to quickly lower the indoor temperature is advantageous for energy efficiency. The cooling mode prioritizes reaching the temperature set by the user. Once the target temperature is reached, the outdoor unit minimizes its output to maintain the temperature, reducing the overall operation time of the outdoor unit. In this process, the humidity in the air is naturally reduced to some extent.

On the other hand, when the indoor temperature is not high but the humidity is sticky and uncomfortable at over 80%, the dehumidifying mode is effective. This is because it avoids wasting unnecessary energy on 'overcooling.' The dehumidifying mode focuses on removing moisture by lowering the speed of the indoor fan and allowing humid air to stay on the cold cooling fins longer instead of strong cooling. Therefore, if the goal is to lower the indoor temperature, the dehumidifying mode may need to operate for a longer time, which can lead to greater energy consumption.

◇ Inverter type, don't turn it off and on

Whether it is better to turn off the air conditioner briefly when the indoors cool down or leave it on has been a long-standing debate. The answer to this question depends on whether your air conditioner is an 'inverter' type. Since 2011, most air conditioners have utilized smart inverter technology. An inverter air conditioner initially operates the compressor vigorously to significantly lower the indoor temperature to the desired level, and upon reaching the target temperature, it moves with minimal power to maintain it. This is similar to how a car consumes less gas while cruising at a steady speed.

Therefore, it is efficient to set the airflow to strong when first turning it on to rapidly lower the temperature to the target, and once the indoors are sufficiently cool, set the temperature around 26℃ and reduce the airflow or switch to fan mode. Lee Sang-woo, a researcher at Samsung Electronics' air solution technology lab, noted, "If you frequently turn the air conditioner on and off in short intervals due to worries about the electricity bill, you may end up using more energy to lower the indoor temperature again, which could actually result in a higher electricity bill."

According to experiments conducted by developers of Samsung Electronics air conditioners, generally, if you are going out for less than 90 minutes, it is more effective to leave the inverter air conditioner running, while if it's more than 90 minutes, it is better to turn it off and turn it back on when you return. When the air conditioner was turned back on after being off for 30 minutes, electricity consumption increased by 5% compared to leaving it running, and after being off for 60 minutes, electricity consumption was also seen to be 2% higher. It wasn't until the off time exceeded 90 minutes that the power consumption became less than continuous operation.

In contrast, older models built before 2011 or 'fixed-speed' air conditioners that are rated 5 for energy consumption efficiency operate differently. Fixed-speed air conditioners run the outdoor unit at maximum until they reach the desired temperature, then turn off and turn back on when it gets warm again, also running at maximum. Therefore, in these cases, it is more efficient to turn it off when cooled down and turn it back on when it gets warm.

Graphic=Jeong Seo-hee

◇ Cleaning filters increases cooling efficiency

Though it may seem minor, habits that affect electricity bills also exist. Using an air conditioner alongside a fan or circulator doubles the cooling effect. This helps to quickly circulate the cold air throughout the house, serving as the best partner to reduce outdoor unit operation time. Positioning the air conditioner so that the airflow spreads in the direction away from it maximizes effectiveness.

Managing the outdoor unit, which is the heart of the air conditioner, is also important. The outdoor unit must expel hot air; if objects are piled up in front of the air outlet, blocking the passage, efficiency decreases. A shade that blocks direct sunlight can lower the temperature around the outdoor unit, increasing cooling efficiency, but it is important to install it without hindering air circulation.

Cleaning the filters should not be overlooked. Filters blocked with dust hinder air intake and are the main culprits behind reduced cooling efficiency. Cleaning them at least once a month can increase the amount of air intake, improving cooling performance and helping save on electricity bills.

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