When my furnace comes on, it feels like U are sitting in an aircraft getting ready for take off.

The basement is not done, only the walls are waterproofed & the floors sealed.

Is there some kind of sound absorbtion material available in the market that I can buy and install it, to absorb/ dampen the noise

In new construction houses, There is a hollow sound from the furnace, especially if you have hard wood floors. "Inshoot Burners" will be typical of this sound. If you can give a Make, Model and Serial # I can give you more Info. There may or may not be a problem, but I know exactly what you are talking about.

I have a Rudd-Silhouette II Gas Furnace

Rheem prestige. It sounds like a vibrating column and must be at least 80 dB. If I restrict the flow it goes away, but I'm afraid I'll damage the furnace or ruin the efficiency. The installer just shrugs, but he's not going to shrug if I make him take it out.

If you restrict the flow of what? No gas furnace is purposely made to make a sound that loud, there is something seriously wrong.

www.heatpro.us energy businessmen's knowledge

Yes, you really have to find out the MAKE and MODEL to get good answers. There IS more than one machine made.

The make is Rheem, the model is Prestige. I have the "high efficiency" option (95% as stated on the yellow tag affixed to the unit). There are two PVC tubes, about 2" in diameter, which leave the furnace and go outside. One of them, the one which makes the noise, has noticeable, wet air flow, coming from it. If I restrict this flow the noise goes away. The noise sounds like a vibrating air column at resonance.

When the exhaust tube is restricted, the furnace should stop firing, something wrong with the setup.

www.heatpro.us energy businessmen's knowledge

Yes, you really have to find out the MAKE and MODEL to get good answers. There IS more than one machine made.