Choosing the Best Quiet HVLS Fan for Your Space

What Factor is Often Overlooked When Finding a Quiet HVLS Fan?

When it comes to selecting a high-volume, low-speed (HVLS) ceiling fan, many people prioritize budget and performance. However, one important factor that is often overlooked is the noise level, specifically the carrier frequency. In quiet settings, the type of HVLS fan you choose can have a significant impact on the overall ambiance.

Understanding Fan Noise and Carrier Frequency

All fans that come with variable frequency drives (VFDs) emit carrier frequencies, which are sounds produced by the motor. The key difference lies in how these sounds are perceived in various environments:

• Loud environments (e.g., warehouses, gyms): The background noise in these settings tends to mask the carrier frequency, making it less noticeable.
• Quiet environments (e.g., offices, museums, schools, libraries, and churches): The carrier frequency stands out more, highlighting the importance of selecting a fan that is quiet.
  

Fun Fact: Did you know that The American Academy of Pediatrics recommends that sound machines be kept at or below 50 dB? A number of MacroAir fans, like the AVD370, operate below this level at max speed. A representative can share more on which models and sizes are below 50 dB, or you can use the chart below.

Gear-Drive vs. Direct-Drive Fans: Which is Best for Your Space? 

When choosing an HVLS fan, it's important to understand how different drive types affect sound levels:

Gear-Drive Fans

✅ Lower carrier frequency (deeper sound) but more noticeable in quiet settings. Capable of high torque and efficient air movement.

❌ Adjusting the fan’s frequency can reduce noise but may also shorten motor lifespan and cause breaker trips. In many cases, frequency adjustments void the manufacturer’s warranty.

Direct-Drive Fans

✅ Higher carrier frequency but typically less noticeable in most environments. Quieter operation overall, making them ideal for sound-sensitive spaces. Requires less maintenance than gear-driven fans.

May have a slightly higher upfront cost compared to gear-driven models.

Adjusting Carrier Frequency – What You Need to Know

Some customers inquire about adjusting the carrier frequency of their HVLS fan to reduce noise. While this is possible, there are trade-offs:

• Adjustments can shorten motor lifespan by increasing electrical stress.
• Breaker trips may occur if the frequency is altered too much.
• Warranty concerns—adjusting carrier frequency often voids manufacturer warranties.

It's important to note that carrier frequency isn’t unique to MacroAir—all gear-drive and direct-drive HVLS fans emit similar sounds. However, the way these sounds are perceived depends on the environment in which the fan is installed and MacroAir works tirelessly to design fan options for a wide range of environments.

Key Terms to Understand

• Decibels (dB and dBA): dB is a common descriptor and measures the loudness of a sound. Imagine playing a piano—striking a key harder increases the volume (higher dB), while a gentle touch lowers it (lower dB). While dBA is a more accurate approach from an engineering mindset. The “A” represents a weighting scale and relates to the way the human ear perceives sound. 
• Frequency (Hz/kHz): Measures the pitch of a sound. Lower frequencies (deep piano notes) are on the left side of the keyboard, while higher frequencies are on the right.
• Carrier Frequency: The frequency emitted by motors driven by variable frequency drives (VFDs). While low in decibel level, high-frequency sounds can be more noticeable in quiet settings.
  

How to Choose the Right Quiet HVLS Fan for Your Space

Consider your environment. If you’re selecting an HVLS fan for a loud environment like a warehouse or gym, carrier frequency is less of a concern, as ambient noise will likely mask any noticeable sounds. You can afford to be more flexible on the level of the carrier frequency and consider the right gear drive fan.

However, if you’re planning for a quiet space like an office, museum, school, or library, you’ll want to prioritize direct-drive fans, like the AVD370, AVDX, or ADV3 for their quieter operation and reduced frequency impact.

Why Choose a Direct Drive HVLS Fan by MacroAir?

MacroAir understands the importance of quiet, effective air movement in all environments. Our AVD370 HVLS fan, for example, operates as low as 45 dBA—quieter than recommendations for a baby sound machine, making it ideal for offices and sound-sensitive areas like schools and places of worship.

Need help selecting the right quiet HVLS fan for your space? Contact our experts today to find the best solution for your environment!