Diesel generator set

[Don]

Hello,







I'm installing a new 15kw/32 HP/1300 pound water-cooled diesel generating set in an open garage area behind my house. Needless to say, it's very loud. Besides exhaust noise, there is also a lot of mechanical noise. I plan to route the exhaust up and out with a stack arrangement and build a roll-off enclosure around it with the side facing away from the house being a full-width door.  Dimensions of the box will be roughly 72Lx48Wx54H. I plan to use 3x5 beams for framing and 1x8 full-cut heart pine for the siding and door. I will build with 1-1½ feet of airspace around the set in all dimensions.





In the open, the thing runs very cool. Water temperature barely gets off the peg and after an hour of operation, the radiator water is barely more than warm when I stick my finger in it.



It seems as though some sort of closed cell foam is the ticket for sound barrier but I have questions in two basic areas.



1) Air exchange. I like the method presented in your generator house drawing and will go with something similar. In your experience, how much flow capacity/vent area do you think I should provide and do you think auxiliary fan circulation may be a necessity?



2) Sound reduction: I don't know the decibel level of the unit but what general level of soundproofing (thickness and type) would be necessary for a 30% reduction at 20 feet? For the sake of argument, let's say the db level is currently at 110 and I want to reduce it to 75.



Thanks,

Don

[Don]

Cancel question 1. I built ducted ends as shown in the site drawing and the radiator fan moves air through the house like it's a wind tunnel.

Question 2 is still very much an interest. Does anyone ever look at this forum but me?

[Don]

Cancel question two now. I still don't know the detailed answer but after routing the exhaust, caulking the cracks between the siding boards with silicon and insulating the walls and ceiling of the shed with plain ol' R-19, what used to be a roar is now a whisper. I acheived much more than a 30% reduction in noise and did it with dirt cheap materials rather than spending the ridiculous amount of money for the materials being pushed by the soundproofing company that hosts this useless forum.

Don

[supersoundproofing]

Thanks for your input, Don.  

We always offer suggestions on how to use common materials and don't "push" expensive materials.  Professional materials are available because their performances are well known and pro's don't want to take the time and spend the money on labor to experiment.  (And risk the chance it will not work and have to be done over or torn out!).



Here we offer advice that is designed to equip you with the knowledge of how to taylor your specific problem/needs to what materials are available and raise your level of expertise to be able to deal with that problem.



We have offered many types of inexpensive materials here on the forum as well as discussions with folks with many different types of problems, always looking for the best solution for them.  Some of the materials we have offered are hay bales, rolled roofing, concrete board, etc.



We don't jump in and answer every question instantly, because many times the info is available with a little looking around, either here on the forum or on the site.



The site info is there for everyone and it certainly appears to helped you in your search..

I'm very glad you took the time to give us your report.

BJ Nash

Super SOundproofing CO

[Don]

Thank you for your reply BJ. Indeed, professionals cannot afford to make mistakes but amateurs cannot afford to wait forever for answers to basic questions. Amateurs, likewise, cannot afford to throw unnecessary funds at a project just because the product is available.



In reading through this forum I find that questions regularly go unaddressed for extended periods of time and in some cases, are never addressed. Even when something is addressed, you tend solicit a phone call from the potential customer rather than concentrate on building an archive of useful information here. Unlike most forums, there seem to be no user experts or contributors  here, leaving all the work to the administrators. There is no group discussion of subjects. As such, it is a useless forum. That's a shame because soundproofing is an interesting and elusive area.



Yes, I did derive benefit from your site and incorporated some of your information into my design. I do appreciate that but I could find no information at all regarding other areas of concern.  This cost you a sale for the simple reason I did not know what or how much to buy. If you don't know the answer to a question, I think it's better to say so up front or try to refer someone on to a resource rather than leave it lay.  Admittedly, I didn't spend a whole lot of time looking for calculators on sound pressure level reduction but it would have been nice to get a general idea of what's required for a 30% reduction.



Don

[supersoundproofing]

We don't "jump on" questions here, especially when they have been answered many times and such answers are easily found, either on the forum or on the website.  When the subject is obviously beyond the scope of a quick, concise answer, we do ask the person to demonstrate their actual and sincere interest by making the effort to call, whereby we take the time and energy to help them with their question.

We try to foster discussion here by letting some questions go, but manytimes seeing amateurs leading amateurs is not productive, but enlightening.

A "useless forum"?  I'm sorry we have created such animosity by providing up our forum and I hope others don't have your views.

BJ Nash
Super Soundproofing Co