Replies

1. 
   Guest_ | Mar 09, 1999 09:07am | #1

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   Iggy you should contact the manufacturer of the furnaces whether they are gas or oil fired to find out the ventilation requirements for those particular units.

   Any other ventilation requirements should be discussed with your mechanical contractor to ensure the integrity of the balancing or the system if it is forced air.

   Sound proofing insulation and a solid door will go along way in keeping things quiet.

   good luck

1. 
   Guest_ | Mar 09, 1999 10:46pm | #2

   *Soundproofing does not mean making the room airtight. In fact, I recently installed an enclosure around a 30hp high pressure pump (car wash). It dropped the sound from deafening and painful to barely audible. The enclosure is ventilated with duct runs down the sides. The key is that the ducts are lined, and are long enough to dampen any reflected sound inside the duct itself.You will have to install flex joints in the trunks as well. Thin ductwork transmits sound nicely. Insulating the ducts, especially with some heavy foam rubber, will dampen sound through the ducts as well. Insulate them a few feet past the first elbow in each run. This means inside the walls as well. As far as the room goes, it should be possible to ventilate this room and soundproof it. In laymens terms (bout as good as I get on this subject) you need to create a system where the walls have material in them to absorb higher frequencies, but are stiff enough to not transmit low frequencies.I currently have the same problem with my high efficiency furnace. I'm finishing up the ducts this summer, then I'll enclose it. I have to sound proof my new office at work (in the middle of a factory) so I'll get better versed in this real soon. If this thread is near alive in a few weeks I'll post what I learn. Unless someone else posts a good one.-Rob

2. 
   Jeff_P | Mar 10, 1999 04:44am | #3

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   Combustion air must be supplied to any appliance like a boiler, furnace or water heater. This combustion air may take several forms. Easiest to deal with is 50 cubic feet of space for every 1000 btu's input to the appliance. Since you are enclosing the furnaces that is now out of the picture. A lot of newer 90% efficient furnaces have a 2nd PVC pipe that brings in its own combustion. If that is the case here, you need do nothing. It is safe to enclose the furnaces. The other way is to introduce air with ducts to the outside, or holes through the wall. Different code entities will be different but it amounts to (usually) 1 square inch per 4000 btu's of input for the total of the 2 furnaces. And this must be one hole within 12" of the ceiling and one within 12" of the floor. So if you had 2 furnaces, each of 80,000 btu's input you would need 2 fresh air inlets, each 40 square inches. If you can't get the second hole through the wall near the floor because you are partially underground, you can make 1 hole 80 square inches and duct 1/2 to the floor. Hope this helps.

3. 
   iggy_ | Mar 10, 1999 04:44am | #4

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   I'm finishing a basement framing off an area about 15x15 feet which houses 2 4 year old high efficieny furnaces. the client wants the room as tight as possible to reduce noice to the rest of the basement. What in the way of ventilation to the basement area outside of the furnace room do I need to provide.