Re: New Atwood 2 speed excaliber furnace
Reply #3 –
Yes, those furnaces are loud. That's what would be my biggest reason to look forward to the Aqua hot on my next coach.
What I did some 8 years ago was added some sound absorbing foam under the closet where the furnace resides. I kept it away from the actual furnace but placed it on any surface that I could (I bought foam that had adhesive on one side). Some sound comes from the output ducts of the furnace which is hard to do any thing about but there are intake grills in the cabinetry were a lot of sound can come from. Placing foam between these grills and the furnace helped drop the sound down a notch. I only did it on the rear furnace since it was my sleep that was getting interupted by the furnace cycling.
In "quiet box" designs (like on generators) where you have competing goals between allowing airflow but wanting to block sound there's a trick: make the air flow go through 180 degree turns where the walls are covered with sound absorbing foam. As the sound tries to make it out it has to bounce several times off the foam - each time loosing more intensity. On the air return of my coach furnace I had enough room under the closet to put in a couple of vertical panels to make the air snake through but keep the sound blocked (to a degree). I was careful not to restrict the airflow - the openings of the grill was my guide.
I bought the foam from McMaster-Carr Catalog (my favorite):
http://www.mcmaster.com/#sound-control-insulation/=7ho1mt
item # 5692T49
Don't try regular upholstery foam (I've tried it) - it does nothing for reducing sound.
Topic: New Atwood 2 speed excaliber furnace