Review on 💨 AC Infinity AIRCOM S7: Top-Exhaust 12'' Quiet Cooling Fan System for Receivers, Amps, DVRs, AV Cabinet Components by Brian Sage

This unit is much louder than the advertised 20dB at the lowest fan setting. I hear a constant hum coming from a medium sized room with the fan on the lowest speed. I thought it was a piece of junk with cheap fans, but it's worse than I expected. Since those cheap fans get louder with age, I'll be replacing them with the 120mm Noctua fans I have in my CPU case, which are barely audible from a few feet away. They certainly don't make a piercing noise, but rather a quiet wind noise. Another major design flaw with this unit is that it is raised off the top of the receiver by four 1/4 inch high angled feet. How efficient is this for removing heat from the top of the receiver when the fans bypass the receiver? receiver air outlet and sucking in ambient air from all sides of the open bottom of the fan unit? My solution was to wrap 1/4" strips of Styrofoam around the bottom edge to create a seal at the top of the receiver (see photo). Because this unit is only 12" wide, some of the remaining vent areas on each side were left open , and when I put my hand on these spots, it became apparent that air was entering the bottom of the fan, so I covered the vent areas on each side of the fan box, which forces the box to only bleed cool air out of the side vents of the receiver case This company obviously doesn't understand the basic principles of cooling design lol 12v power supply with a switch but I figured it would take a few hours to order everything and get it looking decent and cost me more work.