This video shows how to reduce or silence the outside noise made by direct vent water heaters, sometimes called power vented water heaters. It shows you how to make a sound suppressor/resonator made of materials costing less than $10 and how to easily install it. This solution works and it does not involve much effort. Simple and effective noise reduction for exhaust vents from your power vented water heater.

This solution is specifically intended for noisy exhaust vents with a 3" diameter over a short run. This video showcased a Bradford White direct vent water heater with about a 4' vertical rise and 3' horizontal run, with one 90 degree elbow. Repairs or modification to systems are at your own risk. Consult a professional if you are unsure of the work.

*UPDATE*
   • Part 2:  RESULTS of quieting a water ...   Hear the results!
Using an app called Sound Meter on my android phone (all I had) I measured the dB drop. I measured inside and outside for 30 seconds with the blower on from about 3 feet away from the vent and blower, and it gave the average dB.
Outside it dropped from 70.5dB to 47.9dB wow!!
Inside it dropped from 62.5dB to 58.4dB