In the middle of our living room is a return-air vent. It goes straight up to 2 of the bedrooms upstairs also. When the furnace kicks on, the noise coming from the vent down here is rediculously loud, almost to a point where nothing else is distinguishable above the wind sound. The furnace's turbine is probably a foot away from the vent on this side of the wall so is there anything I can do to quiet it without lowering the speed of the fan? I've read about using mattress foam to create a "maze" for the air but essentially that's just slowing it down too, correct? I'm not sure if a baffle would take away from the efficiency or if I should just suck it up and go deaf haha... any help is appreciated. Thanks!

That happens a lot when the return air duct is installed in the wall or floor right above the furnace. Not too much you can do about it other than see if a HVAC installer could re-route the return ductwork to another location in the main area. Sometimes cutting a small return in the ductwork in the basement will alleviate some of the noise. You don't want to do anything to impede the airflow, such as the baffle idea. You may want to check with a pro to see if your blower speed is corrrect, along with the proper size return duct. If too small, they will howl...

Sometimes cutting a small return in the ductwork in the basement will alleviate some of the noise.

You mean on the side of the wall that the furnace is on (opposite of where the return air vent is)?

Thanks for your help :)

The first thing I would do is look around at the other vents. Make sure they are all open, clear, and drawing air. If the furnace isn't getting the air it should from the other vents, it will have to draw excessive air through that one.

Yes, the ones upstairs are pulling air but obviously not nearly as much (or as loudly) as the one that's right on the other side of the wall as the furnace... sounds like it might just be something I deal with...

I have a similar problem. The central return air vent in the first floor is noisy, which, when the grille is open, diminishes to almost no noise. This must be caused by the spaces between grille effecting a low pitch whistle noise when air passes through it. I am waiting to see my HVAC guy can offer me a better grille.