STUDY BY

WT&A Engineering

WT&A Engineering (a specialist in high-rise HVAC acoustics) found that upgrading to a modern retrofit fan coil unit typically results in a noise reduction of approximately 5 dB.To put a 5 dB reduction into perspective, in the logarithmic world of sound:

• 3 dB is the smallest change clearly noticeable to the human ear.
• 5 dB is a significant, "clearly quieter" improvement.
• 10 dB is perceived by humans as a 50% reduction in volume.

The noise reduction isn't just because the parts are "new"; it's due to three specific technological shifts in fan coil design over the last 15-20 years:

• EC Motors (Electronically Commutated): Legacy units use PSC (Permanent Split Capacitor) motors that typically run at fixed speeds (High/Med/Low). Modern EC motors are brushless and DC-powered, allowing for "soft starts" and variable speeds. They eliminate the "hum" and "thump" of older motors.
• Closed-Cell Foam Insulation: Older units often used fiberglass insulation, which degrades, peels, and loses its sound-dampening properties over time. New units use high-density, anti-microbial closed-cell foam that acts as a far superior acoustic barrier.
• Vibration Isolation: Modern chassis are often mounted on neoprene pads or spring isolators, preventing "structure-borne" noise - the vibration you feel in the walls or floor when the unit kicks on.