What is Daikin Auto Mode: A Comprehensive Guide for Optimal Comfort and Energy Efficiency

Daikin Auto Mode is a cutting-edge feature in Daikin air conditioning systems that automatically selects the appropriate operation mode (COOL or HEAT) based on the indoor temperature. This mode is designed to provide enhanced comfort and significant energy savings by dynamically adjusting the system’s operation according to the room temperature and the user’s lifestyle.

Understanding the Intelligent Eye Sensor

At the heart of Daikin Auto Mode is the INTELLIGENT EYE sensor, which detects human movement within the room. If no occupancy is detected for more than 20 minutes, the system automatically switches to an energy-saving operation mode, reducing energy consumption when the room is unoccupied.

The INTELLIGENT EYE sensor utilizes a highly sensitive infrared (IR) detector to monitor the room’s activity. It can distinguish between human presence and other heat sources, ensuring accurate detection and efficient energy management.

Technical Specifications of the INTELLIGENT EYE Sensor

  • Sensor Type: Passive Infrared (PIR) Sensor
  • Detection Range: Up to 7 meters (23 feet) in front of the indoor unit
  • Detection Angle: 100° horizontal, 80° vertical
  • Response Time: Less than 0.5 seconds
  • Sensitivity Adjustment: 3 levels (High, Medium, Low)
  • Energy-Saving Mode Activation Time: 20 minutes of no occupancy detection

Comfort Airflow Function

What is Daikin Auto ModeImage source: Daikin Air Conditioner Outdoor by Dinkun Chen

The COMFORT AIRFLOW function in Daikin Auto Mode adjusts the airflow direction based on the current operation mode. In COOL and DRY modes, the airflow is directed upward, while in HEAT mode, the airflow is directed downward.

This feature helps to prevent cold or warm air from blowing directly on the user’s body, providing a more comfortable and pleasant indoor environment. The airflow adjustment is achieved through the precise control of the motorized louvers within the indoor unit.

Technical Specifications of the Comfort Airflow Function

  • Airflow Direction in COOL/DRY Mode: Upward (0-30° from horizontal)
  • Airflow Direction in HEAT Mode: Downward (45-70° from horizontal)
  • Louver Adjustment Range: 0-80° from horizontal
  • Louver Motor: Stepper motor with 0.9° step angle
  • Louver Control Precision: ±1.8° from target angle

Outdoor Unit Quiet Function

The OUTDOOR UNIT QUIET function in Daikin Auto Mode ensures a low noise level of the outdoor unit, which is particularly useful for maintaining a quiet neighborhood environment.

This function is achieved through the precise control of the outdoor unit’s fan speed and compressor operation, reducing the overall sound output while maintaining the desired cooling or heating capacity.

Technical Specifications of the Outdoor Unit Quiet Function

  • Noise Reduction: Up to 3 dB(A) compared to normal operation
  • Fan Speed Reduction: Up to 3 steps lower than normal operation
  • Compressor Speed Reduction: Up to 10 Hz lower than normal operation
  • Noise Level Measurement: Conducted at 1 meter (3.3 feet) from the outdoor unit

Auto Fan Setting in Daikin Ducted Systems

In Daikin ducted systems, the auto fan setting in Daikin Auto Mode decides the fan speed based on the controller’s logic. The system typically uses higher fan speeds when the temperature difference (delta-T) between the setpoint and the room temperature is greater, and gradually ramps down the fan speed as it approaches or reaches the desired setpoint.

To stop the fan from running once the thermostat is satisfied, a field setting change is required. This is not something the user can select from the controller’s menu, but different preferences for heating and cooling can be defined.

Technical Specifications of the Auto Fan Setting

  • Fan Speed Control: Varies based on delta-T between setpoint and room temperature
  • Higher Fan Speeds: Used when delta-T is greater
  • Lower Fan Speeds: Used as delta-T approaches or reaches setpoint
  • Fan Stop on Thermostat Satisfaction: Requires field setting change
  • Heating vs. Cooling Preferences: Can be defined separately

Cooling and Heating Mode Fan Operation

In cooling mode, the fan in Daikin Auto Mode keeps running continuously, and the compressor cycles on and off to control the temperature. However, in heating mode, the fan stops running once the target temperature is reached.

To enable the fan to run continuously in heating mode, a specific field setting change is required. The exact setting may vary depending on the Daikin model and controller.

Technical Specifications of Cooling and Heating Mode Fan Operation

Cooling Mode:
– Fan Operation: Runs continuously
– Compressor Operation: Cycles on and off to control temperature

Heating Mode:
– Fan Operation: Stops when target temperature is reached
– To Enable Continuous Fan: Requires field setting change
– Exact Setting Varies by Model and Controller


Daikin Auto Mode is a highly advanced and intelligent feature that optimizes the performance of Daikin air conditioning systems. By automatically selecting the appropriate operation mode, adjusting airflow direction, reducing outdoor unit noise, and managing fan operation, Daikin Auto Mode provides enhanced comfort and significant energy savings for users.

The technical specifications and detailed explanations provided in this guide offer a comprehensive understanding of the inner workings of Daikin Auto Mode, empowering users to fully leverage this feature for maximum comfort and efficiency in their homes or commercial spaces.

– OPERATION MANUAL – daikincomfort.com
– https://www.reddit.com/r/hvacadvice/comments/ujlqem/how_does_daikin_auto_fan_work/
– https://hvac-talk.com/vbb/threads/2217181-Daikin-Mini-Split-won-t-stop-cooling