Loud furnace: can I quiet it down?

General Questions
#1

I live in a 1-story house that was built in 1960. As there is no basement, the furnace is located in a utility closet in the center of my house. That closet is surrounded on two sides by the living room. The furnace itself is about 6 years old.

There are two cold air intakes. The smaller one opens to the hallway on one side, through a tubular duct about 8" in diameter. The larger one opens to a wall in the living room, and the furnace is built right up against that opening, so the fan is just inches from the vent grating. The problem is that when the fan is running, it’s very loud. It makes it a pain to watch TV in the living room. It’s that cold air return that is the sole source of the noise. The vents that exhaust into the other rooms are quiet as can be.

The very loud “whoosh” of air being sucked into the intake vent is beyond obnoxious. It does this with the A/C, of course, but the A/C never ran as much as the furnace does. Now that the weather is getting chilly and the firnace spends an appreciable amount of time blowing, I’m getting desperate for a solution.

Any tricks that can keep the blower quiet? Help me before I decide that freezing to death is better than listening to it.

Thanks

#2

You might try lifting of the vent covers and cleaning them out, and then go to the intake fan and clean up the vanes.

#3

My intial thought would be to try some different types of filters. We use a foam one. There are quite few types. This might cut down on the air noise.

#4

Sounds to me like the solution would be a filter in the main intake that would absorb some or most of the sound. However, most materials used for acoustical absorption aren’t particularly porous. Tectum makes a range of somewhat porous acoustic panels, though, so you might try emailing them to ask if they have a product that might be workable. It’d be pricier than a generic furnace filter, though, so you might just go to a store specializing in heating supplies to see what kind of filters might do something for you first.

Actually, now that I think of it, something with a non-porous panel might even work. If you placed a panel substantially larger than the intake grill about an inch from the wall and parallel to it (maybe build it into a piece of furniture?), it should cut down on the sound a lot without impeding airflow. Really low frequencies will refract around it, but you’d be getting quite an acute angle of refraction, so most of the audible spectrum would be absorbed.

#5

IF the noise is caused by too much air comming through you might try restrictign the filter either by obstructing it, letting it get dirty or by getting one of those hepa-type fliters.