I just had a Rheem Power Vent (43V50E2) installed and the sound from the PVC exhaust is extremely loud. The fan sounds like a hair dryer as I suspected but the exhaust is loud enough where it is audible across the street in my neighbor’s yard. It appears to be 2.5″ PCV piping to a 45″ elbow at the end. Would a 3″ adapter with 90 degree elbow muffle the sound? I have attached pictures for reference. What are my options to muffle the sound? A quick google wasn’t promising (e.g. extended the pipe near the ground to muffle the sound)

http://www.shawnaugust.com/PICS/HOME…2Install-1.jpg

http://www.shawnaugust.com/PICS/HOME…2Install-2.jpg

http://www.shawnaugust.com/PICS/HOME…2Install-5.jpg

The Rheem install manual (http://www.rheem.com/documents/power…nd-care-manual) shows this install wasn’t done up to code as it is right below a window and right near the intake/exhaust pipe (see the vent to the left of the PCV exhaust) for the utility room where the furnace gas water heater is installed. Also, they didn’t even put silicone to seal the edge around the exhaust pipe.