Understanding Decibels (dB)
Sound intensity is measured in decibels. Each 10 dB increase sounds roughly twice as loud to human ears.
Reference Sounds
- 0 dB: Threshold of hearing
- 30 dB: Whisper
- 40 dB: Library
- 50 dB: Normal conversation
- 70 dB: Vacuum cleaner
- 80 dB: Heavy traffic
Typical AC Noise Levels
Indoor Unit
- Quiet AC: 22-26 dB
- Average AC: 26-35 dB
- Loud AC: 35-45 dB
Outdoor Unit
- Quiet: 50-55 dB
- Average: 55-65 dB
- Loud: 65-75 dB
AC Types and Noise
Inverter ACs
Generally quieter (22-30 dB indoor) due to variable-speed compressor running smoothly without constant on/off cycles.
Non-Inverter ACs
Noisier (28-40 dB indoor) due to frequent compressor start-ups which create noise spikes.
Tips to Reduce AC Noise
- Use high-quality wall-mounted units (quieter than window ACs)
- Place outdoor unit away from bedrooms
- Ensure proper installation and support to minimize vibration
- Use soundproofing foam around outdoor unit
- Regular maintenance (clean fans, lubricate bearings)
For Sleeping
Choose ACs under 25 dB for bedrooms. Inverter ACs at this level let you sleep peacefully even with AC running all night.
Conclusion
For bedroom use, prioritize quiet operation. Look for inverter ACs with noise ratings below 25 dB. A slightly more expensive quiet AC is worth the comfort.