Utility room with the gas furnace & blower is right beside the family room.
Intervening wall is built with 2x4s with thin wood paneling on the family
room side.

Someone had put peg-board on the utility room side, but we ripped it out to
give the electrician access for some rewiring work. There is no insulation
in the wall.

To decrease the noise of the furnace I'd like to put something in the wall
space.

Will R-13 fiberglass make any significant difference?

Any better suggestions?

Sam