readiescards Posted September 3, 2017 Share Posted September 3, 2017 So the next project is on the cards - currently in planning - a barn conversion on the family farm for holiday letting. 3 bedroom, 120 m2 However it is 'ear-shot' of our wheat and barley storage sheds: https://youtu.be/H3GRG7_M9uw Any suggestions on how to muffle a large fan? (Only runs later August and early September) Link to comment Share on other sites More sharing options...
PeterW Posted September 3, 2017 Share Posted September 3, 2017 A wall ...... daft as it sounds you need to direct that noise upwards..! Baffles on the front of the shed will help as will ducting the inlet. Got a site layout plan ..? 1 Link to comment Share on other sites More sharing options...
readiescards Posted September 3, 2017 Author Share Posted September 3, 2017 21 minutes ago, PeterW said: Got a site layout plan ..? https://www.dropbox.com/s/zuyg4uc8oy7m83a/LDC1838-04 Block Plans A3.pdf?dl=0 Link to comment Share on other sites More sharing options...
PeterW Posted September 3, 2017 Share Posted September 3, 2017 Is the dryer on the top building on that plan ..?? Link to comment Share on other sites More sharing options...
readiescards Posted September 4, 2017 Author Share Posted September 4, 2017 Yes, see attached A wall could be possible but it would need to be at the edge of shed - approx 8 metres from the fan entrance - would that still help? Baffles on the front of the fan house: what might they look like? Link to comment Share on other sites More sharing options...
Tennentslager Posted September 4, 2017 Share Posted September 4, 2017 (edited) Score a goal? I know. I know but the football is on just now...come on England we need you to win. Edited September 4, 2017 by Tennentslager Explanation of bad joke Link to comment Share on other sites More sharing options...
readiescards Posted September 4, 2017 Author Share Posted September 4, 2017 6 minutes ago, Tennentslager said: Score a goal? I know. I know but the football is on just now...come on England we need you to win. Nope you lost me there! Link to comment Share on other sites More sharing options...
PeterW Posted September 4, 2017 Share Posted September 4, 2017 7 minutes ago, readiescards said: Yes, see attached A wall could be possible but it would need to be at the edge of shed - approx 8 metres from the fan entrance - would that still help? Baffles on the front of the fan house: what might they look like? So you're getting noise from the open door and the blower cage - you need a way of : - Ducting the air into the fan from a baffled source - stopping noise being transmitted across the yard. First one could be as simple as blocking the doorway up and using some big galvanised square ducting to go up and over the fan house roof. Square duct is easier to cover with foam or fibre to also muffle the sound. Second thing is to build a fairly heavy wall about 6ft from the fan house to deflect the noise back away from the house. Sometimes easier to get the pre-made acoustic panels they use on roadsides - you can work out where it works best then by moving it about. Its not a permanent noise source so you need to weigh up cost vs benefit anyway - decent sound insulation in the house would be a good start ! 1 Link to comment Share on other sites More sharing options...
Ferdinand Posted September 5, 2017 Share Posted September 5, 2017 (edited) How much will your rental income be reduced by for those 2-3 weeks per year due to a temporary noisy environment ? £500-£1000 per annum? Or a lot more? Are the works justified? Edited September 5, 2017 by Ferdinand 1 Link to comment Share on other sites More sharing options...
readiescards Posted September 5, 2017 Author Share Posted September 5, 2017 Probably around £4k reduction if we block those weeks. Alternative could be to give reduced rental price with warning about potential noise. Triple glazing better for sound proofing? 1 Link to comment Share on other sites More sharing options...
readiescards Posted September 5, 2017 Author Share Posted September 5, 2017 8 hours ago, PeterW said: Sometimes easier to get the pre-made acoustic panels they use on roadsides - you can work out where it works best then by moving it about. Great idea! 1 Link to comment Share on other sites More sharing options...
PeterW Posted September 5, 2017 Share Posted September 5, 2017 1 hour ago, readiescards said: Triple glazing better for sound proofing? Not necessarily the best idea although @craig can probably help here. There are sound reducing glazing units available that use heavier laminated glass or Optiphon to reduce the noise transmission. Link to comment Share on other sites More sharing options...
Ferdinand Posted September 5, 2017 Share Posted September 5, 2017 1 hour ago, readiescards said: Probably around £4k reduction if we block those weeks. Alternative could be to give reduced rental price with warning about potential noise. Triple glazing better for sound proofing? How bad is it? Will the thing be uninhabitable? Or can the grain dryer run during the day when they will be out (suspect you need the 24x7 ability just in case)? Can you use those weeks as "medium" not "high" season at say 25% less rent, or for "friends and family" at a smaller or nominal charge (which may help you with the availability / occupancy requirements ti to get the tax concessions - others will be better on these than me). Solid chunky wooden fences may be an option for reflecting sound, at perhaps 1/3 the cost of a wall, but the whole thing is a bit of a black art. Or well sealed secondary glazing (or thicker units) is good for sound deadening with a larger air gap of 100mm or so. Ferdinand 1 Link to comment Share on other sites More sharing options...
craig Posted September 5, 2017 Share Posted September 5, 2017 (edited) From memory triple can give you 44db + with the right glazing. Double glazing can perform better than triple, it's down to the glazing and space the sound has to travel. It's also down to numerous other factors around the glazing and how the sash is sealed around the frame (how many gaskets) and how it is installed. No point in sound proof glazing if the window and installation are not up to the job as well. You should be able to get the details from the supplier. Edited September 5, 2017 by craig Link to comment Share on other sites More sharing options...
readiescards Posted December 18, 2019 Author Share Posted December 18, 2019 Well back on with this sound issue,. we've built the Stables holiday cottage and installed triple glazing. Inside the property with all the windows and doors shut the noise from the dryer is difficult to hear ? But it being late summer when the fan is used the guests often want to have the doors and windows open and be outside on the garden bench. Unfortantely one family were unlucky and suffered with the fan running flat out every day from 8 to 10pm (we were very lucky to get the harvest in before the heavy rain and so needed to use the fan to cool the grain) and I fully understood when they complained so I switched the fan off at 4pm when they returned from visiting but is not going to be always possible. I did look at building a wall of straw bales about 10m from the fan intake but by the time the straw had been baled the grain was cool enough not to need airing. I've asked the company who re-wind the motor in 2011 if they can advise why it is so loud. A metal square channel so the air is sucked in from the opposite side to the holiday as suggested might work but that would deflect the noise to a couple of other residences (one of them being my house!) Lourved vents I'll investigate. One question I have is: Would spray foaming the inside of the fan house help to absorb the sound - the fan house is probably 10ft square, mainly brick with absetos sheeting type roof. I wondered if spray all those hard surfaces would absorb some sound before it is reflected internal? Link to comment Share on other sites More sharing options...
SteamyTea Posted December 18, 2019 Share Posted December 18, 2019 I know very little about sound, but have you recorded it and then had a look at the wave forms. There may be a possibility to dampen out some of the worst frequencies. Also how about active noise cancellation. 1 Link to comment Share on other sites More sharing options...
Onoff Posted December 18, 2019 Share Posted December 18, 2019 On 03/09/2017 at 21:02, readiescards said: So the next project is on the cards - currently in planning - a barn conversion on the family farm for holiday letting. 3 bedroom, 120 m2 However it is 'ear-shot' of our wheat and barley storage sheds: https://youtu.be/H3GRG7_M9uw Any suggestions on how to muffle a large fan? (Only runs later August and early September) A guy I knew once asked me a similar question. Turned out he was a weed grower. He and his mate "rented" the spare room in a friends council flat where they had erected a growing tent. The fan was suspended from the tent frame by wires. The flat owner was complaining about the fan noise. His solution was to cut a huge cardboard box to fit round the fan and fill with expanding foam! ? Link to comment Share on other sites More sharing options...
Onoff Posted December 18, 2019 Share Posted December 18, 2019 You can buy cheap acoustic foam panels ex sound studios, look like they're made from foam pyramids. I lined the concealed cistern recess in the stud wall and when it fills it is imperceptible from filling to when it shuts off. Pretty sure it's the geometry of the face as well as the sound absorbing material that combine. It's not resonating off of adjacent walls or roof sheets, maybe loose, is it? You say you had it rewound, dodgy motor bearings can make a lot of noise. I've just stripped a motor at work for the very same issue. (That was a constant extract fan to an underground, bulk (bio diesel) oil storage room). Link to comment Share on other sites More sharing options...
readiescards Posted December 18, 2019 Author Share Posted December 18, 2019 10 minutes ago, Onoff said: solution was to cut a huge cardboard box to fit round the fan and fill with expanding foam Now that is a neat simple, cheap idea at least for the motor! I'd need to check how much heat the fan motor body radiates 18 minutes ago, SteamyTea said: I know very little about sound, but have you recorded it and then had a look at the wave forms. There may be a possibility to dampen out some of the worst frequencies. Also how about active noise cancellation. Good idea, will try with a laptop and Audacity. No idea about active noise cancellation - sounds expensive Link to comment Share on other sites More sharing options...
readiescards Posted December 18, 2019 Author Share Posted December 18, 2019 2 minutes ago, Onoff said: You say you had it rewound, dodgy motor bearings can make a lot of noise I've emailed the company who did the rewind to get their input and will mention that. But I'll go and investigate to see if I can turn the fan by hand some how to check. Link to comment Share on other sites More sharing options...
SteamyTea Posted December 18, 2019 Share Posted December 18, 2019 (edited) 7 minutes ago, readiescards said: I'd need to check how much heat the fan motor body radiates Probably around 10% of the motor power, but you could put in some cooling pipes. Is it actually the motor, or the fan that is making the noise. The extractor fan at our place is noisy, but not as noisy as the the air intakes, and they have baffles in them. 7 minutes ago, readiescards said: Audacity Is a good program. There was this in my favourite comic almost 18 years ago, I still think it was an early April Fools though. https://www.newscientist.com/article/mg17323354-500-sculpted-sound/ Edited December 18, 2019 by SteamyTea Link to comment Share on other sites More sharing options...
Moonshine Posted December 18, 2019 Share Posted December 18, 2019 (edited) 1 hour ago, SteamyTea said: O.k, probably something I can help with.... - Have you got any pictures of inside the fan room? - any pictures of the space between the fan room and housem - do the residents complain about the noise in all rooms of the house, or just a couple? - how is the fan room ventilated? - do you know the make model of the dryer? - what is the construction of the fan room and door? Edit: just watched the video, that is loud! Is it the same now as then? Edited December 18, 2019 by Moonshine 1 Link to comment Share on other sites More sharing options...
Onoff Posted December 18, 2019 Share Posted December 18, 2019 (edited) 1 hour ago, readiescards said: I've emailed the company who did the rewind to get their input and will mention that. But I'll go and investigate to see if I can turn the fan by hand some how to check. Isolate the power first ffs! I really wouldn't recommend the dope fiends idea of covering the motor in foam. Recipe for overheat and failure that is. Also makes maintenance a bitch. His was a plastic encased inline fan. I think he put a bin liner over it first then surrounded by the box and foamed. Edited December 18, 2019 by Onoff 1 Link to comment Share on other sites More sharing options...
dpmiller Posted December 18, 2019 Share Posted December 18, 2019 piccies would help. is there line-of-sight in through either outlets or inlets to the fan/fan room? Ensuring there's no straight-line for the sound to travel on is a good start, a foam lined baffle of some kind would work for this A dodgy fan would certainly need addressing beyond this, yes, absorbant lining of the fan house (especially with proper mass-loaded stuff) would be next... 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted December 18, 2019 Share Posted December 18, 2019 Doesn't this sort of problem need many different solutions. So sound reduction, sound deflection, sound absorption, vibration reduction or isolation etc. I have used an FE program called LISA to do some thermal modelling, it also does acoustic modelling. https://lisafea.com/ Link to comment Share on other sites More sharing options...
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