The heating system in my house is the forced air. It works fine but when it turns on it wakes me up (it is noisy). I heard that one cans quite it down by extending the length of the return line (from the grill to the furnace). I would like to know if it works and if does how?

I suspect that there are number of noise sources (air velocity, grill shape, bearing conditions and others) but it is hard, for me, to believe that increasing the length of the return line can have significant effect. I would think that just by increasing the line length, you are increasing the air resistance, and forcing your blower to work harder.

I have only one return grill for the entire house and 11 registers in 4 bedrooms, living, family rooms and utility room. The surface area of grill is much smaller than surface area of the register and I was thinking about making additional return not far from the original (is this a good idea?) to slow down velocity of the air.

G-Tape