How to sound proof the furnace closet

[nisryus]

So the furnace is on the second floor next to the master bedroom. I am wondering if I could use this Acoustic Panels ( http://smile.amazon.com/gp/product/...ue&ref_=ox_sc_act_title_1&smid=A24BVQ69RJOKWH ) by gluing them to the furnace closet door. Think that might work to reduce the noise?

 

[boomerang]

So the furnace is on the second floor next to the master bedroom. I am wondering if I could use this Acoustic Panels ( http://smile.amazon.com/gp/product/...ue&ref_=ox_sc_act_title_1&smid=A24BVQ69RJOKWH ) by gluing them to the furnace closet door. Think that might work to reduce the noise?

Gotta ask, it's not a louvered door, correct?

 

[NetWareHead]

The best way to do it would be to stuff soundproofing insulation inbetween the studs of the furnace room. Is the room drywalled/finished? If the furnace was enough for me to complain about, I'd consider removing the drywall in a room that nobody ever sees to properly insulate. I like Roxul safe and sound insulation

 

[DrPizza]

The things in that room need air. You cannot block the air flow. So, no. You cannot make it a soundproof room.

 

[NetWareHead]

The things in that room need air. You cannot block the air flow. So, no. You cannot make it a soundproof room.

It wont be a true soundproof room in the sense of an acoustic studio. I bet there is a louvered door that will allow combustion air to pass through. Even if you isolate the room entirely, a furnace will still convey its sound through the ducting.

I still beleve you can knock a huge portion of the sound out with the proper batt insulation. Maybe not all of it but if you can put a layer between the furnace room and the bedroom, it will be far better than nothing.

https://www.youtube.com/watch?v=hQq594MEah0

 

[DrPizza]

Yes, but I noted that he specifically said "gluing them to the furnace closet door." If the appliance was an electric water heater, then he could probably do as he suggested. Then again, electric water heaters don't make noise. There are some scenarios where he probably could. E.g., air is provided to that closet via a duct from unoccupied space, rather than through a louvered door, and perhaps I should have asked first,

OP, is your door louvered? Pictures please?

 

[boomerang]

And combustion air may be provided from outside if it's a modern HE furnace. But I asked if the door was louvered in case the system does not have cold air returns. Our condo does not. It relies on the louvered door to provide a path for return air. I wanted to make sure the OP knew that covering up those louvers would be a bad thing to do.

 

[Humpy]

The linked foam product barely works for it's stated purpose of absorbing/reducing sound reflections. It will do essentially nothing in preventing sound transmission.

If the mechanical closet door can't be swapped for a solid core, then the bedroom door could be. If you also go as far as opening up a wall, then installing staggered studs to decouple the new sheetrock is well worth the minimal effort. If you go this route, filling with plain old fiberglass insulation performs as well (potentially better) as any "sound" specific product.

 

[TheSlamma]

It wont be a true soundproof room in the sense of an acoustic studio. I bet there is a louvered door that will allow combustion air to pass through. Even if you isolate the room entirely, a furnace will still convey its sound through the ducting.

I still beleve you can knock a huge portion of the sound out with the proper batt insulation. Maybe not all of it but if you can put a layer between the furnace room and the bedroom, it will be far better than nothing.

https://www.youtube.com/watch?v=hQq594MEah0

This is the route I would go

Rockwool is superior to fiberglass in every way possible, mold, fire, heat, sound, rodents and insects hate it, easier to cut, less harsh and itchy to work with, doesn't sag after time like fiberglass always does. Run from foam like crazy, the stuff burns quickly and easily and puts off deadly smoke fumes when it does. Rockwool you can hold a propane torch on it for an hour and nothing will happen.

I do have to say though, I don't get newer houses where they put the utility rooms on the second floor. Is this just architects and builders getting bored and trying new things? Keep those gas lines, water heaters, furnaces in the basement safely away from the human beings and out of areas where the sq footage is worth more.

 

[nisryus]

It doesn't has a louvered door. There is a pipe on on the side that connect to the roof, maybe that is how the air returns.

It is also gas, not electric.

Hmm...I need to open the wall to check how good the insulation is. Wife might not like that idea.

 

[Red Squirrel]

Is the hot water tank in there too or just the furnace? If it's a furnace from the past 2 decades it will most likely be a closed combustion system so you don't need to worry about fresh air. You can confirm this if it has two ABS or PVC pipes going outside. If yours is not it may actually be worth while looking at replacing it as the old style furnaces are very inefficient, not only do they suck cold air in the house as you are trying to heat it, but the actual heat process is not as efficient. Most water heaters unfortunately don't use this principle though so they do need fresh air and arn't as efficient.

But either way if you do insulate it what you could do is just have an air intake going outside, then it will suck air from there. you can buy them they look like a dryer vent but instead of lovers they just have a grid and let air in. Then pipe it near the source that needs fresh air.

Make sure you use a fire rated insulation as well, I would go with the roxul as suggested. I think fibreglass is acceptable too. Don't use foam. Not sure about those acoustic panels, You could buy one and try to set it on fire outside to see how it burns.

Just make sure you don't compromise the accessibility of the furnace for any repairs/maintenance.

Oh and drywall alone is actually pretty good at absorbing sound. If there is room you can always double the drywall when you install it.

 

[Humpy]

Rockwool is superior to fiberglass in every way possible, mold, fire, heat, sound, rodents and insects hate it, easier to cut, less harsh and itchy to work with, doesn't sag after time like fiberglass always does. Run from foam like crazy, the stuff burns quickly and easily and puts off deadly smoke fumes when it does. Rockwool you can hold a propane torch on it for an hour and nothing will happen.

Rockwool has a lot of things going for it. Reducing sound transmission through a typical wall assembly is not one of them though. Increased insulation density does have an effect in open air of increasing absorption but within a wall cavity it provides no benefit. Basic, inexpensive fiberglass does just as well.

 

[TheSlamma]

Rockwool has a lot of things going for it. Reducing sound transmission through a typical wall assembly is not one of them though. Increased insulation density does have an effect in open air of increasing absorption but within a wall cavity it provides no benefit. Basic, inexpensive fiberglass does just as well.

I would never trade the 10 other benefits I listed for cost, saying that ONE benefit is on par with the cheaper material and then tossing out all the other things I listed is one of the worst internet argument tactics there is.

I have pulled out and replaced way too much sunk fiberglass that had mouse droppings and stolen material for nests then I will ever find acceptable. You get what you pay for.

and actually I got Roxul for cheaper than any of their on shelf fiberglass product they had.

 

[NetWareHead]

I have pulled out and replaced way too much sunk fiberglass that had mouse droppings and stolen material for nests then I will ever find acceptable. You get what you pay for.

Agreed. Roxul is a better insulation that wont degrade with moisture and is structurally stable. If you want to put an insulation up and forget about it, choose roxul.

Also, the graphic posted is interesting. The sound transmission class rating is nearly the same. The densest "rockwoool" insulation is listed as being 2.4 lb/ft3 density (dont know how to write superscript for cubic foot).

According to Roxul's data here: http://www.roxul.com/files/RX-NA_EN/pdf/Technical Data Sheets- updated/SafenSound.pdf the safe and sound insulation is 2.5 lb/ft3 and can be packed even denser if needed.

Basically Roxul performs equal or better than fiberglass in SCT ratings (and potentially better than fiberglass if compressed before installing). Given roxul's other benefits, I cant see a situation where I would choose fiberglass ever again.

 

[Humpy]

I would never trade the 10 other benefits I listed for cost, saying that ONE benefit is on par with the cheaper material and then tossing out all the other things I listed is one of the worst internet argument tactics there is.

Being that the problem needing to be solved is entirely related to sound transmission most of your post was irrelevant BS.

Because the type of cavity fill material has such a small effect on the overall outcome (i.e. compared to decoupling the assembly), it is misdirection to focus on as a primary solution.

To be clear, the internet argument tactic I am using is to point out the absurdity of claiming better insulation leads to a more desirable result while at the same time completely ignoring far more effective methods of attaining the goal.

 

[Humpy]

Agreed. Roxul is a better insulation that wont degrade with moisture and is structurally stable. If you want to put an insulation up and forget about it, choose roxul.

Also, the graphic posted is interesting. The sound transmission class rating is nearly the same. The densest "rockwoool" insulation is listed as being 2.4 lb/ft3 density (dont know how to write superscript for cubic foot).

According to Roxul's data here: http://www.roxul.com/files/RX-NA_EN/pdf/Technical Data Sheets- updated/SafenSound.pdf the safe and sound insulation is 2.5 lb/ft3 and can be packed even denser if needed.

Basically Roxul performs equal or better than fiberglass in SCT ratings (and potentially better than fiberglass if compressed before installing). Given roxul's other benefits, I cant see a situation where I would choose fiberglass ever again.

Unless contact with the wallboard is prevented, compressing insulation within a wall cavity has the negative effect of increasing sound transmission as it begins to couple the two leafs of a wall together. Increased density is simply not a benefit (the chart I posted demonstrates this) for the type of wall construction it is assumed the OP is dealing with.

Though fiberglass products exist that match nearly all of the claimed benefits of Rockwool/Roxul this isn't a discussion about which is a better insulation overall. Roxul is pretty good, no question. Not sure what that has to do with the OP though.

 

[TheSlamma]

Being that the problem needing to be solved is entirely related to sound transmission most of your post was irrelevant BS.

Because the type of cavity fill material has such a small effect on the overall outcome (i.e. compared to decoupling the assembly), it is misdirection to focus on as a primary solution.

To be clear, the internet argument tactic I am using is to point out the absurdity of claiming better insulation leads to a more desirable result while at the same time completely ignoring far more effective methods of attaining the goal.

What is more effective about putting vermin nesting material in your house? as opposed to a material they absolutely hate that has as I stated the same or in my case a lesser price. And ignoring the fact that fiberglass can't make 20 years without sinking in a wall cavity.

"irreverent BS" in your opinion it's irreverent, nothing you can say would ever convince me to put that inferior product anywhere in my house. I have pulled fiberglass out of multiple places in multiple houses where it was either sunk, had black mold on it, had vermin droppings in it, was torn up for bedding by them or when it was stuffed in a cavity it couldn't expand to full the gaps.

 

[TheSlamma]

Though fiberglass products exist that match nearly all of the claimed benefits of Rockwool/Roxul this isn't a discussion about which is a better insulation overall. Roxul is pretty good, no question. Not sure what that has to do with the OP though.

Those are my typical experiences of replacing Fiberglass, if I'm going to buy a product, why would I not opt for the one that accomplishes the same thing but doesn't have all the downsides.

No no no, take off the disk brakes, I prefer drum brakes.. they still stop the car.

 

[no surprises]

I have a similar issue. My furnace is in my basement rental suite and I believe a ton of sound is travelling through the ill-fitting folding door between their kitchen and the HVAC system. The suite has electrical heat so the sealing off the HCAV is worth doing IMO. I was thinking that since it's just a closet I don't go into much I could hang a heavy curtain or some thick plastic on the inside of the furnace closet to stop sound transmission. I was thinking that instead of replacing the door with something airtight because it would be cheaper.

Do you think this would work? Maybe it would only work if it's 100% airtight?