Furnace intake noise question

joeg679 · 12-08-2009, 11:28 PM

The lower level of my house (below grade) has 3 rooms: a family room with a fireplace, a home office and the boiler room. I recently put in the office and got rid of a slotted door that was in there and replaced it with a solid door, but also added 2 vents in the family room so the furnace could pull air from somewhere. When I am watching tv in the family room and the heat/AC goes on, it gets very loud. I tried putting in a bigger register to 20x20 and tried sound insulation in the inside of the duct, but it is still the same. I laid a piece of drywall up against the intake and the noise was gone. The intake currently takes air from the family room then it goes through a filter system and into the furnace. The furnace in the boiler room is about 4 feet from the family room wall so I would like to know if I could cut the ductwork back then put a 20x20 register on the ductwork in the boiler room. THis will allow me to permanently cover up the hole in the wall and the furnace would still be pulling in air, only it would be pulling in air from the boiler room and the noise would be gone. This may be a stupid question, but I don't know what else to do. THanks a lot for your help.

joeg679 · 12-09-2009, 12:20 AM

I have attached a diagram of another option that I may have. I believe that if I move the 20x20 vent up to high it will be far enough away from the actual fan/blower and I will not hear the noise. I would need a few 90 degree pieces and some 20 inch wide ductwork, which I don't know where to get, but it may work. Please let me know what you think and please excuse my MS paint skills. Thanks a lot

kennzz05 · 12-09-2009, 12:48 AM

cant draw air from furnace room against code and dangerous as combustion fumes can be drawn into system
second idea of moving return is feasible but doubtful its going to make a nite and day differance
pre made duct can be purchased at many supply houses

joeg679 · 12-09-2009, 12:59 AM

thanks. I'll go with the 2nd option, anything has to be better than what it is now.

joeg679 · 12-09-2009, 09:55 PM

I went with the 2nd option and it worked perfectly. I no longer have to turn up the tv when the heat goes on. Hope this helps others.

kennzz05 · 12-10-2009, 10:42 PM

Quote:

Originally Posted by joeg679

I went with the 2nd option and it worked perfectly. I no longer have to turn up the tv when the heat goes on. Hope this helps others.

thanks for letting us know the results

Yoyizit · 12-11-2009, 01:03 PM

I guess I'd check the delta T across your heat exchanger to make sure you're not shortening its life. The CFMs and FPM are all interdependent.

12-08-2009, 11:28 PM	#1
joeg679 Member Join Date: Nov 2009 Posts: 205	Furnace intake noise question The lower level of my house (below grade) has 3 rooms: a family room with a fireplace, a home office and the boiler room. I recently put in the office and got rid of a slotted door that was in there and replaced it with a solid door, but also added 2 vents in the family room so the furnace could pull air from somewhere. When I am watching tv in the family room and the heat/AC goes on, it gets very loud. I tried putting in a bigger register to 20x20 and tried sound insulation in the inside of the duct, but it is still the same. I laid a piece of drywall up against the intake and the noise was gone. The intake currently takes air from the family room then it goes through a filter system and into the furnace. The furnace in the boiler room is about 4 feet from the family room wall so I would like to know if I could cut the ductwork back then put a 20x20 register on the ductwork in the boiler room. THis will allow me to permanently cover up the hole in the wall and the furnace would still be pulling in air, only it would be pulling in air from the boiler room and the noise would be gone. This may be a stupid question, but I don't know what else to do. THanks a lot for your help.

12-09-2009, 12:20 AM	#2
joeg679 Member Join Date: Nov 2009 Posts: 205	Furnace intake noise question I have attached a diagram of another option that I may have. I believe that if I move the 20x20 vent up to high it will be far enough away from the actual fan/blower and I will not hear the noise. I would need a few 90 degree pieces and some 20 inch wide ductwork, which I don't know where to get, but it may work. Please let me know what you think and please excuse my MS paint skills. Thanks a lot Attached Thumbnails

12-09-2009, 12:48 AM	#3
kennzz05 Member Join Date: Nov 2008 Location: palm coast fl Posts: 551	Furnace intake noise question cant draw air from furnace room against code and dangerous as combustion fumes can be drawn into system second idea of moving return is feasible but doubtful its going to make a nite and day differance pre made duct can be purchased at many supply houses

12-09-2009, 12:59 AM	#4
joeg679 Member Join Date: Nov 2009 Posts: 205	Furnace intake noise question thanks. I'll go with the 2nd option, anything has to be better than what it is now.

12-09-2009, 09:55 PM	#5
joeg679 Member Join Date: Nov 2009 Posts: 205	Furnace intake noise question I went with the 2nd option and it worked perfectly. I no longer have to turn up the tv when the heat goes on. Hope this helps others.

Furnace intake noise question