Question:
Ok, here is what I have… A 8ftx10ft elevated (8ft) generator shed with a 48inch porch that I need to sound dampen as much as economically possible. It has a 3×4 plywood floor unfinished and 5/8 RBB plywood siding. I have 8 inch I beams in the ceiling with a trolley that allows raising and lowering the genset to the ground by pushing it along the trolley to the outside and using a chainfall. I want to support the generator at a comfortable working height on a wooden platform.The roof is 3×4 plywood with metal roofing fastened to the top with screws. The diesel generator has a1/2 inch steel plate platform. I need ideas about what to place between the steel base of the generator and the wooden platform to dampen vibration/noise transmission. I also need suggestions about the insulation, sound dampening, etc for the walls,ceiling and subfloor. I have not finished the inside walls, subfloor bottom or ceiling yet so I am open to wonderful ideas from the group. The generator is water cooled and I will cut a opening away from the cabin for the radiator to vent to the outside through. I will install a furnace fan below the generator shed to bring cooling air into the shed via a wooden duct. I will also have a exhaust gas heat exchanger I found a used marine heat exchanger that only needs a couple of ells welded to it to route the exhaust gas through. It will be easy to brush clean and really easy to connect. I will replace the rubber gashets with durabla gaskets in it. This will provide a secondary method of heating the hot water for the cabin. A battery box, inverter,and propane hot water heater will be located inside the shed. I know a block building would have been better but I live in a flood area and it would be underwater sometime and I really did not want to deal with seeing my pet diesel generator underwater. I have not decided on how much I want to spend so don’t hammer me about it. I will spend what it takes, it will just take longer. Thanks Offgridman
Response:
Back in my radio engineering days, I had to soundproof, as much as possible, some new studios. One way is through the use of two separate walls, each framed with normal 2×4 lumber, and constructed with a product called Homosote. It’s similar to drywall (gypsum board) material but made from paper and cardboard. Usually it’s a gray color, not quite as heavy as drywall material, and installs, cuts, and tapes up the same way. Build the two walls so the studs are interleaved (i.e. on 8 inch centers from one wall to the other) and separate the walls by an inch or so. Put fiberglass insulation in the space between the walls, weaving it between the offset studs. Use some sort of rubber membrane between the walls at the floor and ceiling joints. You can buy some foam soundproofing material and line the inside walls with that. My little 12kw Onan genset has 1 inch thick foam throughout the inside of the enclosure. It seems to have some sort of shiny paper or plastic layer on the inside. Every possible surface is covered by this foam. The unit is very quiet. Your biggest problem is likely going to be vibration from the generator to any piece of plywood. This will act as a loudspeaker and will be difficult to eliminate. Isolating the floor from the generator any way you can will be a big help. Obviously you need something springy yet strong enough to support the weight. What about hanging it from several pieces of rubber tires, or making legs from the floor that can raise the support position and cradle the generator? You may be able to use several pieces folded together under the generator between it and the floor. The more you have, the better, but obviously if you get it too high and movable, it could walk off the supports, so you may need to strap it into place in all directions. Even though it’s up in the air, surrounding it with some evergreen trees or shrubs will also offer some soundproofing to the rest of the neighborhood, as will some sort of fence. Let us know what you end up with. Bob M. ======
– Hide quoted text — Show quoted text -> Ok, here is what I have… A 8ftx10ft elevated (8ft) generator shed with a > 48inch porch that I need to sound dampen as much as economically possible. > It has a 3×4 plywood floor unfinished and 5/8 RBB plywood siding. I have 8 > inch I beams in the ceiling with a trolley that allows raising and lowering > the genset to the ground by pushing it along the trolley to the outside and > using a chainfall. I want to support the generator at a comfortable working > height on a wooden platform.The roof is 3×4 plywood with metal roofing > fastened to the top with screws. > The diesel generator has a1/2 inch steel plate platform. I need ideas about > what to place between the steel base of the generator and the wooden > platform to dampen vibration/noise transmission. I also need suggestions > about the insulation, sound dampening, etc for the walls,ceiling and > subfloor. I have not finished the inside walls, subfloor bottom or ceiling > yet so I am open to wonderful ideas from the group. > The generator is water cooled and I will cut a opening away from the cabin > for the radiator to vent to the outside through. I will install a furnace > fan below the generator shed to bring cooling air into the shed via a wooden > duct. I will also have a exhaust gas heat exchanger I found a used marine > heat exchanger that only needs a couple of ells welded to it to route the > exhaust gas through. It will be easy to brush clean and really easy to > connect. I will replace the rubber gashets with durabla gaskets in it. This > will provide a secondary method of heating the hot water for the cabin. A > battery box, inverter,and propane hot water heater will be located inside > the shed. > I know a block building would have been better but I live in a flood area > and it would be underwater sometime and I really did not want to deal with > seeing my pet diesel generator underwater. > I have not decided on how much I want to spend so don’t hammer me about it. > I will spend what it takes, it will just take longer. > Thanks > Offgridman
Response:
- Hide quoted text — Show quoted text – >Back in my radio engineering days, I had to soundproof, as much as possible, >some new studios. One way is through the use of two separate walls, each >framed with normal 2×4 lumber, and constructed with a product called >Homosote. It’s similar to drywall (gypsum board) material but made from >paper and cardboard. Usually it’s a gray color, not quite as heavy as >drywall material, and installs, cuts, and tapes up the same way. Build the >two walls so the studs are interleaved (i.e. on 8 inch centers from one wall >to the other) and separate the walls by an inch or so. Put fiberglass >insulation in the space between the walls, weaving it between the offset >studs. >Use some sort of rubber membrane between the walls at the floor and ceiling >joints. >You can buy some foam soundproofing material and line the inside walls with >that. >My little 12kw Onan genset has 1 inch thick foam throughout the inside of >the enclosure. It seems to have some sort of shiny paper or plastic layer on >the inside. Every possible surface is covered by this foam. The unit is very >quiet. >Your biggest problem is likely going to be vibration from the generator to >any piece of plywood. This will act as a loudspeaker and will be difficult >to eliminate. Isolating the floor from the generator any way you can will be >a big help. Obviously you need something springy yet strong enough to >support the weight. What about hanging it from several pieces of rubber >tires, or making legs from the floor that can raise the support position and >cradle the generator? You may be able to use several pieces folded together >under the generator between it and the floor. The more you have, the better, >but obviously if you get it too high and movable, it could walk off the >supports, so you may need to strap it into place in all directions. >Even though it’s up in the air, surrounding it with some evergreen trees or >shrubs will also offer some soundproofing to the rest of the neighborhood, >as will some sort of fence. >Let us know what you end up with. >Bob M.
Good ideas, but homosote wouldn’t be the best choice in a flood area. Sound is dampened by isolation, mass, and avoiding resonance. Suspending the generator is good, perhaps different length straps or attaching lead to near the midpoints would help reduce resonance in the straps. Staggered stud walls with snaking fiberglas insulation is an amazingly good sound insulation, especially if the plates aren’t linked to a common floor. The walls can be covered with homosote or corkboard but a double layer of 5/8 gypsum board, taped and mudded both layers is more common. The four layer total reduces even bass notes to a whimper. The gypsum board has mass which dampens the energy of the sound, but the material doesn’t react well to water or dampness much better than homosote. Concrete board (used in tub and shower enclosures) would work but would be expensive. Stucco over foamboard might be another alternative. I’ve seen exterior walls made of this. That metal roof will probably need some damping. Even the undercoating used on cars would help some, but fiberglas batting pressed against the metal would be better. – Hide quoted text — Show quoted text ->====== > Ok, here is what I have… A 8ftx10ft elevated (8ft) generator shed with a > 48inch porch that I need to sound dampen as much as economically possible. > It has a 3×4 plywood floor unfinished and 5/8 RBB plywood siding. I have 8 > inch I beams in the ceiling with a trolley that allows raising and >lowering > the genset to the ground by pushing it along the trolley to the outside >and > using a chainfall. I want to support the generator at a comfortable >working > height on a wooden platform.The roof is 3×4 plywood with metal roofing > fastened to the top with screws. > The diesel generator has a1/2 inch steel plate platform. I need ideas >about > what to place between the steel base of the generator and the wooden > platform to dampen vibration/noise transmission. I also need suggestions > about the insulation, sound dampening, etc for the walls,ceiling and > subfloor. I have not finished the inside walls, subfloor bottom or ceiling > yet so I am open to wonderful ideas from the group. > The generator is water cooled and I will cut a opening away from the cabin > for the radiator to vent to the outside through. I will install a furnace > fan below the generator shed to bring cooling air into the shed via a >wooden > duct. I will also have a exhaust gas heat exchanger I found a used marine > heat exchanger that only needs a couple of ells welded to it to route the > exhaust gas through. It will be easy to brush clean and really easy to > connect. I will replace the rubber gashets with durabla gaskets in it. >This > will provide a secondary method of heating the hot water for the cabin. A > battery box, inverter,and propane hot water heater will be located inside > the shed. > I know a block building would have been better but I live in a flood area > and it would be underwater sometime and I really did not want to deal with > seeing my pet diesel generator underwater. > I have not decided on how much I want to spend so don’t hammer me about >it. > I will spend what it takes, it will just take longer. > Thanks > Offgridman
Response:
I dunno if this will help or not. Pix of sound dampening chambers. http://images.google.com/images?q=anechoic+chamber&hl=en – Hide quoted text — Show quoted text – > Ok, here is what I have… A 8ftx10ft elevated (8ft) generator shed with a > 48inch porch that I need to sound dampen as much as economically possible. > It has a 3×4 plywood floor unfinished and 5/8 RBB plywood siding. I have 8 > inch I beams in the ceiling with a trolley that allows raising and lowering > the genset to the ground by pushing it along the trolley to the outside and > using a chainfall. I want to support the generator at a comfortable working > height on a wooden platform.The roof is 3×4 plywood with metal roofing > fastened to the top with screws. > The diesel generator has a1/2 inch steel plate platform. I need ideas about > what to place between the steel base of the generator and the wooden > platform to dampen vibration/noise transmission. I also need suggestions > about the insulation, sound dampening, etc for the walls,ceiling and > subfloor. I have not finished the inside walls, subfloor bottom or ceiling > yet so I am open to wonderful ideas from the group. > The generator is water cooled and I will cut a opening away from the cabin > for the radiator to vent to the outside through. I will install a furnace > fan below the generator shed to bring cooling air into the shed via a wooden > duct. I will also have a exhaust gas heat exchanger I found a used marine > heat exchanger that only needs a couple of ells welded to it to route the > exhaust gas through. It will be easy to brush clean and really easy to > connect. I will replace the rubber gashets with durabla gaskets in it. This > will provide a secondary method of heating the hot water for the cabin. A > battery box, inverter,and propane hot water heater will be located inside > the shed. > I know a block building would have been better but I live in a flood area > and it would be underwater sometime and I really did not want to deal with > seeing my pet diesel generator underwater. > I have not decided on how much I want to spend so don’t hammer me about it. > I will spend what it takes, it will just take longer. > Thanks > Offgridman
– I don’t like spam. Remove it to contact me. Somewhere in Wisconsin.
Response:
I once worked in a yard that built motor yachts, and we insulated the engine room with sheets of 1" thick stiff fiberglass insulation, covered with thin (about 1/16") sheet lead. Sheet lead is wonderful for damping out resonance. You can buy a wide variety of shock-absorbing mounts for equipment. Small air-inflated rubber mounts would be a good choice for a generator, I think. Check with a company that makes mounting racks for electronic gear. That’s where I have seen such stuff used. Volvo cars used to achieve some sound deadening with heavy rubber matting beneath the carpets in the engine-transmission area of the interior floor. These mats are heavy in that they weigh a lot for their size (i.e. high specific gravity). I think the rubber is filled with barite. Barite is a naturally-occurring mineral composed of barium sulfate, and it has a specific gravity of 4.5, if I remember correctly. I wonder if it would be possible to make "heavy" sound-deadening wallboard with a high barite content. Barite is quite cheap, readily available, and safe. I don’t even know how easy it is to get sheet lead these days, but it takes relatively little to get a good degree of sound deadening. Because it is very soft, it doesn’t resonate like sheet steel or aluminum is wont to do, and its mass tends to damp out resonace in the surface to which it is attached. It’s worth looking into. Simply stapling it to the walls of your generator shack should help a bit. Gordon Richmond – Hide quoted text — Show quoted text – > Back in my radio engineering days, I had to soundproof, as much as possible, > some new studios. One way is through the use of two separate walls, each > framed with normal 2×4 lumber, and constructed with a product called > Homosote. It’s similar to drywall (gypsum board) material but made from > paper and cardboard. Usually it’s a gray color, not quite as heavy as > drywall material, and installs, cuts, and tapes up the same way. Build the > two walls so the studs are interleaved (i.e. on 8 inch centers from one wall > to the other) and separate the walls by an inch or so. Put fiberglass > insulation in the space between the walls, weaving it between the offset > studs. > Use some sort of rubber membrane between the walls at the floor and ceiling > joints. > You can buy some foam soundproofing material and line the inside walls with > that. > My little 12kw Onan genset has 1 inch thick foam throughout the inside of > the enclosure. It seems to have some sort of shiny paper or plastic layer on > the inside. Every possible surface is covered by this foam. The unit is very > quiet. > Your biggest problem is likely going to be vibration from the generator to > any piece of plywood. This will act as a loudspeaker and will be difficult > to eliminate. Isolating the floor from the generator any way you can will be > a big help. Obviously you need something springy yet strong enough to > support the weight. What about hanging it from several pieces of rubber > tires, or making legs from the floor that can raise the support position and > cradle the generator? You may be able to use several pieces folded together > under the generator between it and the floor. The more you have, the better, > but obviously if you get it too high and movable, it could walk off the > supports, so you may need to strap it into place in all directions. > Even though it’s up in the air, surrounding it with some evergreen trees or > shrubs will also offer some soundproofing to the rest of the neighborhood, > as will some sort of fence. > Let us know what you end up with. > Bob M. > ====== > Ok, here is what I have… A 8ftx10ft elevated (8ft) generator shed with a > 48inch porch that I need to sound dampen as much as economically possible. > It has a 3×4 plywood floor unfinished and 5/8 RBB plywood siding. I have 8 > inch I beams in the ceiling with a trolley that allows raising and > lowering > the genset to the ground by pushing it along the trolley to the outside > and > using a chainfall. I want to support the generator at a comfortable > working > height on a wooden platform.The roof is 3×4 plywood with metal roofing > fastened to the top with screws. > The diesel generator has a1/2 inch steel plate platform. I need ideas > about > what to place between the steel base of the generator and the wooden > platform to dampen vibration/noise transmission. I also need suggestions > about the insulation, sound dampening, etc for the walls,ceiling and > subfloor. I have not finished the inside walls, subfloor bottom or ceiling > yet so I am open to wonderful ideas from the group. > The generator is water cooled and I will cut a opening away from the cabin > for the radiator to vent to the outside through. I will install a furnace > fan below the generator shed to bring cooling air into the shed via a > wooden > duct. I will also have a exhaust gas heat exchanger I found a used marine > heat exchanger that only needs a couple of ells welded to it to route the > exhaust gas through. It will be easy to brush clean and really easy to > connect. I will replace the rubber gashets with durabla gaskets in it. > This > will provide a secondary method of heating the hot water for the cabin. A > battery box, inverter,and propane hot water heater will be located inside > the shed. > I know a block building would have been better but I live in a flood area > and it would be underwater sometime and I really did not want to deal with > seeing my pet diesel generator underwater. > I have not decided on how much I want to spend so don’t hammer me about > it. > I will spend what it takes, it will just take longer. > Thanks > Offgridman
Response:
So far good sugestions… The only thing I would add, is to make a platform that the generator sits on. Do not let this platform touch the shed, have it anchored to the ground directly. So what you end up with is a platform that is 8′ off the ground, and a separate shed building that is ‘around’ the generator, but not supporting it. so all the sound that you have to get rid of is acoustic to the building, not mechanical of the building shaking. CAP – Hide quoted text — Show quoted text – > Ok, here is what I have… A 8ftx10ft elevated (8ft) generator shed with a > 48inch porch that I need to sound dampen as much as economically possible. > It has a 3×4 plywood floor unfinished and 5/8 RBB plywood siding. I have 8 > inch I beams in the ceiling with a trolley that allows raising and lowering > the genset to the ground by pushing it along the trolley to the outside and > using a chainfall. I want to support the generator at a comfortable working > height on a wooden platform.The roof is 3×4 plywood with metal roofing > fastened to the top with screws. > The diesel generator has a1/2 inch steel plate platform. I need ideas about > what to place between the steel base of the generator and the wooden > platform to dampen vibration/noise transmission. I also need suggestions > about the insulation, sound dampening, etc for the walls,ceiling and > subfloor. I have not finished the inside walls, subfloor bottom or ceiling > yet so I am open to wonderful ideas from the group. > The generator is water cooled and I will cut a opening away from the cabin > for the radiator to vent to the outside through. I will install a furnace > fan below the generator shed to bring cooling air into the shed via a wooden > duct. I will also have a exhaust gas heat exchanger I found a used marine > heat exchanger that only needs a couple of ells welded to it to route the > exhaust gas through. It will be easy to brush clean and really easy to > connect. I will replace the rubber gashets with durabla gaskets in it. This > will provide a secondary method of heating the hot water for the cabin. A > battery box, inverter,and propane hot water heater will be located inside > the shed. > I know a block building would have been better but I live in a flood area > and it would be underwater sometime and I really did not want to deal with > seeing my pet diesel generator underwater. > I have not decided on how much I want to spend so don’t hammer me about it. > I will spend what it takes, it will just take longer. > Thanks > Offgridman
Response:
I have some rather strange suggestions…more based around stereo equipment than anything else… a buddy of mine loved records…old vinyl records problem was with his picky batlike hearing he could hear the shake of the speakers in the needle of the turntable he placed his speakers on sharp metal cones that were filled with lead shot points down to the floor…I think a rubber sheet was involved as well…this solved his shaking floor problem. as for the sound itself I once wired some car speakers wrong….or one of a pair was wired wrong…the net effect was a muffled din as one speaker pushed the other pulled and they got nowhere.all it took was switch + and – on one of the two speakers… it seems that if you have a microphone feeding an amp and you reverse the polarity of the speaker(s)and put the speakers in your gen shed you could get the same effect…an adjustable capacitor would let you tune the lag so the effect could be maximized something similar is used on the headsets used in airplanes to cancel out the engine noise if you want to hear the in-flight movie strange but true,good luck Peter
– Hide quoted text — Show quoted text -> So far good sugestions… The only thing I would add, is to make a platform > that the generator sits on. Do not let this platform touch the shed, have it > anchored to the ground directly. So what you end up with is a platform that is > 8′ off the ground, and a separate shed building that is ‘around’ the generator, > but not supporting it. so all the sound that you have to get rid of is acoustic > to the building, not mechanical of the building shaking. > CAP > Ok, here is what I have… A 8ftx10ft elevated (8ft) generator shed with a > 48inch porch that I need to sound dampen as much as economically possible. > It has a 3×4 plywood floor unfinished and 5/8 RBB plywood siding. I have 8 > inch I beams in the ceiling with a trolley that allows raising and lowering > the genset to the ground by pushing it along the trolley to the outside and > using a chainfall. I want to support the generator at a comfortable working > height on a wooden platform.The roof is 3×4 plywood with metal roofing > fastened to the top with screws. > The diesel generator has a1/2 inch steel plate platform. I need ideas about > what to place between the steel base of the generator and the wooden > platform to dampen vibration/noise transmission. I also need suggestions > about the insulation, sound dampening, etc for the walls,ceiling and > subfloor. I have not finished the inside walls, subfloor bottom or ceiling > yet so I am open to wonderful ideas from the group. > The generator is water cooled and I will cut a opening away from the cabin > for the radiator to vent to the outside through. I will install a furnace > fan below the generator shed to bring cooling air into the shed via a wooden > duct. I will also have a exhaust gas heat exchanger I found a used marine > heat exchanger that only needs a couple of ells welded to it to route the > exhaust gas through. It will be easy to brush clean and really easy to > connect. I will replace the rubber gashets with durabla gaskets in it. This > will provide a secondary method of heating the hot water for the cabin. A > battery box, inverter,and propane hot water heater will be located inside > the shed. > I know a block building would have been better but I live in a flood area > and it would be underwater sometime and I really did not want to deal with > seeing my pet diesel generator underwater. > I have not decided on how much I want to spend so don’t hammer me about it. > I will spend what it takes, it will just take longer. > Thanks > Offgridman
Response:
It’s important to distinguish between an attempt to prevent sound energy from reflecting back to the inside of a space (e.g. recording studio) and an attempt to prevent sound energy from escaping a space. For example, lining the walls with egg crates (as we did in the early days of budget home recording) may help slightly to reduce internal reflections in the mid/upper end of the spectrum, but won’t do a darn thing to keep the thump from the kick drum from leaking into the rest of the house. This isn’t to say that a some treatments don’t help with both issues, just that the distinction is important. -smw > I dunno if this will help or not. Pix of sound dampening chambers. > http://images.google.com/images?q=anechoic+chamber&hl=en > Ok, here is what I have… A 8ftx10ft elevated (8ft)
generator shed with a > 48inch porch that I need to sound dampen as much as
economically possible. > It has a 3×4 plywood floor unfinished and 5/8 RBB
plywood siding. I have 8 > inch I beams in the ceiling with a trolley that allows
raising and lowering – Hide quoted text — Show quoted text -> the genset to the ground by pushing it along the trolley to the outside and > using a chainfall. I want to support the generator at a comfortable working > height on a wooden platform.The roof is 3×4 plywood with metal roofing > fastened to the top with screws. > The diesel generator has a1/2 inch steel plate platform. I need ideas about > what to place between the steel base of the generator and the wooden > platform to dampen vibration/noise transmission. I also need suggestions > about the insulation, sound dampening, etc for the walls,ceiling and > subfloor. I have not finished the inside walls, subfloor bottom or ceiling > yet so I am open to wonderful ideas from the group. > The generator is water cooled and I will cut a opening away from the cabin > for the radiator to vent to the outside through. I will install a furnace > fan below the generator shed to bring cooling air into
the shed via a wooden > duct. I will also have a exhaust gas heat exchanger I found a used marine > heat exchanger that only needs a couple of ells welded to it to route the > exhaust gas through. It will be easy to brush clean and really easy to > connect. I will replace the rubber gashets with durabla gaskets in it. This > will provide a secondary method of heating the hot
water for the cabin. A > battery box, inverter,and propane hot water heater will be located inside > the shed. > I know a block building would have been better but I
live in a flood area – Hide quoted text — Show quoted text -> and it would be underwater sometime and I really did not want to deal with > seeing my pet diesel generator underwater. > I have not decided on how much I want to spend so don’t hammer me about it. > I will spend what it takes, it will just take longer. > Thanks > Offgridman > — > I don’t like spam. > Remove it to contact me. > Somewhere in Wisconsin.
Response:
There are three types of noise that you will need to deal with. Here are my thoughts on what "might" work. 1. Vibrations directly coupled to the structure where the generator is mounted. A previous post had a good idea of supporting the generator by a separate set of legs all the way to the ground. While that would be very effective, it sounds like a lot of work to accomplish, especially since you already have the building in place. A less effective, but probably easier method would be to use rubber motor mounts to isolate the vibration from the floor (or table). I’d look for the softer types of rubber motor mounts like they use to mount generators to their metal frames. Perhaps rubber motor mounts for a motorcycle or ATV could be found inexpensively as well. Another thought is the foam (not Styrofoam) that is sometimes used in industrial (mostly electronics) pallets. My guess is that the direct coupled vibration will be amplified by the structure unless you can isolate it effectively. I’d put most of my effort into eliminating direct coupled vibrations. I think I’d eliminate the table because it would seem to make it more likely to induce additional vibrations. If it is something that you would really prefer, then build a very heavy and solid table, perhaps with 4×4’s and use more rubber motor mounts to mount it firmly to the floor. Those would be in addition to mounts between the table and the generator base. 2. Vibrations radiated to the inside walls floor and ceiling of the structure. I would try something simple, like hanging remnants of scrap carpeting from the ceiling. You could use some tie-wire or tie-wraps to hang multiple pieces from the ceiling to the floor as with a foot or two of each side of the generator. Nail a couple of sections to the ceiling over the generator. On any side that you need access for maintenance, you could hang the carpeting from a track, of a type that is used for a sliding door and which is available at hardware and building supplies. One or two layers of heavy c arpet should deaden most of the air radiated noise. 3. Exhaust noise. You will want to run your exhaust outside of the building for safety reasons and to avoid heat buildup in the building. One idea from another poster was to run the output from a lengthened exhaust pipe into a larger stack pipe that exits vertically from the roof. That sounded like it would work quite well. Perhaps a 12′ section of 4" galvanized vent pipe with a cap on top would serve this purpose. Whatever you do, please report back on how it worked. Generator noise is a common problem that many readers of this noise group are interested in.
Response:
Thanks for all the ideas. I will post my results just as soon as I finish and test run the system. The weather has me held up as it is cooold and wet now. I hope to see it warm up soon. Thanks again, offgridman
– Hide quoted text — Show quoted text -> There are three types of noise that you will need to deal with. Here are my > thoughts on what "might" work. > 1. Vibrations directly coupled to the structure where the generator is > mounted. > A previous post had a good idea of supporting the generator by a separate > set of legs all the way to the ground. While that would be very effective, > it sounds like a lot of work to accomplish, especially since you already > have the building in place. A less effective, but probably easier method > would be to use rubber motor mounts to isolate the vibration from the floor > (or table). I’d look for the softer types of rubber motor mounts like they > use to mount generators to their metal frames. Perhaps rubber motor mounts > for a motorcycle or ATV could be found inexpensively as well. Another > thought is the foam (not Styrofoam) that is sometimes used in industrial > (mostly electronics) pallets. My guess is that the direct coupled vibration > will be amplified by the structure unless you can isolate it effectively. > I’d put most of my effort into eliminating direct coupled vibrations. > I think I’d eliminate the table because it would seem to make it more likely > to induce additional vibrations. If it is something that you would really > prefer, then build a very heavy and solid table, perhaps with 4×4’s and use > more rubber motor mounts to mount it firmly to the floor. Those would be in > addition to mounts between the table and the generator base. > 2. Vibrations radiated to the inside walls floor and ceiling of the > structure. > I would try something simple, like hanging remnants of scrap carpeting from > the ceiling. You could use some tie-wire or tie-wraps to hang multiple > pieces from the ceiling to the floor as with a foot or two of each side of > the generator. Nail a couple of sections to the ceiling over the generator. > On any side that you need access for maintenance, you could hang the > carpeting from a track, of a type that is used for a sliding door and which > is available at hardware and building supplies. One or two layers of heavy c > arpet should deaden most of the air radiated noise. > 3. Exhaust noise. > You will want to run your exhaust outside of the building for safety reasons > and to avoid heat buildup in the building. One idea from another poster was > to run the output from a lengthened exhaust pipe into a larger stack pipe > that exits vertically from the roof. That sounded like it would work quite > well. Perhaps a 12′ section of 4" galvanized vent pipe with a cap on top > would serve this purpose. > Whatever you do, please report back on how it worked. Generator noise is a > common problem that many readers of this noise group are interested in.
Response:
http://avtinc.net/outline.asp
– Hide quoted text — Show quoted text -> It’s important to distinguish between an attempt to prevent > sound energy from reflecting back to the inside of a space > (e.g. recording studio) and an attempt to prevent sound > energy from escaping a space. > For example, lining the walls with egg crates (as we did in > the early days of budget home recording) may help slightly > to reduce internal reflections in the mid/upper end of the > spectrum, but won’t do a darn thing to keep the thump from > the kick drum from leaking into the rest of the house. > This isn’t to say that a some treatments don’t help with > both issues, just that the distinction is important. > -smw > I dunno if this will help or not. Pix of sound dampening > chambers. > http://images.google.com/images?q=anechoic+chamber&hl=en > > Ok, here is what I have… A 8ftx10ft elevated (8ft) > generator shed with a > > 48inch porch that I need to sound dampen as much as > economically possible. > > It has a 3×4 plywood floor unfinished and 5/8 RBB > plywood siding. I have 8 > > inch I beams in the ceiling with a trolley that allows > raising and lowering > > the genset to the ground by pushing it along the trolley > to the outside and > > using a chainfall. I want to support the generator at a > comfortable working > > height on a wooden platform.The roof is 3×4 plywood with > metal roofing > > fastened to the top with screws. > > The diesel generator has a1/2 inch steel plate platform. > I need ideas about > > what to place between the steel base of the generator > and the wooden > > platform to dampen vibration/noise transmission. I also > need suggestions > > about the insulation, sound dampening, etc for the > walls,ceiling and > > subfloor. I have not finished the inside walls, subfloor > bottom or ceiling > > yet so I am open to wonderful ideas from the group. > > The generator is water cooled and I will cut a opening > away from the cabin > > for the radiator to vent to the outside through. I will > install a furnace > > fan below the generator shed to bring cooling air into > the shed via a wooden > > duct. I will also have a exhaust gas heat exchanger I > found a used marine > > heat exchanger that only needs a couple of ells welded > to it to route the > > exhaust gas through. It will be easy to brush clean and > really easy to > > connect. I will replace the rubber gashets with durabla > gaskets in it. This > > will provide a secondary method of heating the hot > water for the cabin. A > > battery box, inverter,and propane hot water heater will > be located inside > > the shed. > > I know a block building would have been better but I > live in a flood area > > and it would be underwater sometime and I really did not > want to deal with > > seeing my pet diesel generator underwater. > > I have not decided on how much I want to spend so don’t > hammer me about it. > > I will spend what it takes, it will just take longer. > > Thanks > > Offgridman > — > I don’t like spam. > Remove it to contact me. > Somewhere in Wisconsin.
Response:
offgridman, Great. By the way, where is your place located where you have to place the generator up so high to avoid flooding? Just curious. bughunter
– Hide quoted text — Show quoted text -> Thanks for all the ideas. > I will post my results just as soon as I finish and test run the system. The > weather has me held up as it is cooold and wet now. I hope to see it warm up > soon. > Thanks again, > offgridman
Response:
Maybe to break your paradyme… When I was in the Army, we had to bury our generator set underground at every setup. Once you lower the noise level below the ground, it kills the sound totally. Quite a cheap, solid method. I have used it at the bluegrass festival and people cannot even hear it until they stand over the hole. Dig a big hole and build up a concrete wall. (maybe a septic tank would be quicker) Extend the walls up higher than any flood level. At the bottom of the hole put in a sump with a battery sump pump. Take your shack and put it over the hole for weather coverage. Cut out the floor of the shack. When you need the generator, start up the pump and pump out any standing water. Now lower the generator into the hole with your tracks and start it up. If you wish to guarantee your generator won’t get wet, then put it on pontoons. A couple of plastic barrels would do the job. If not, then buy raft floation. Carl
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Mon Louis island in Theodore Alabama when get some real hurricanes down here. I am about a mile south from Bellingrath Gardens if you know where that is.
– Hide quoted text — Show quoted text -> offgridman, > Great. By the way, where is your place located where you have to place the > generator up so high to avoid flooding? Just curious. > bughunter > Thanks for all the ideas. > I will post my results just as soon as I finish and test run the system. > The > weather has me held up as it is cooold and wet now. I hope to see it warm > up > soon. > Thanks again, > offgridman
Response:
At a previous company, we used to ship machinery with air-filled isolators underneath. They were heavy-duty inflatable donuts about the same size and shape of inner-tubes for a small tire. I would think you could find them looking around shipping supplies companies. Alternatively, I would maybe try some partially inflated inner-tubes arranged under the platform and filled to give about an inch of cushion. I also once saw a picture where an inertial mass was isolated by sitting on *lots* of little erasers (the kind kids get for school). – Hide quoted text — Show quoted text -> The diesel generator has a1/2 inch steel plate platform. I need ideas about > what to place between the steel base of the generator and the wooden > platform to dampen vibration/noise transmission. I also need suggestions
Response:
> At a previous company, we used to ship machinery with air-filled isolators > underneath. They were heavy-duty inflatable donuts about the same size > and shape of inner-tubes for a small tire. I would think you could find them > looking around shipping supplies companies. Alternatively, I would maybe > try some partially inflated inner-tubes arranged under the platform and filled > to give about an inch of cushion.
We used these in high school to isolate an optical-bench we were making holographs on. Basically whoopee-cushions. Isolated the table-top from the floor very well. If you think about it, that’s not real different from what motor mounts do in a car – isolate the noise of vibration from the engine, from transmitting to the structure of the car. Dave
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