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I am investigating various means to quiet an on board diesel generator installation that I am designing for my motorhome. I would like to design/fab an aluminum enclosure that will work in my application. I am a fan of Cummins power but not a fan of Onan RV side mount sets. Typical truck APUs are too noisy and don't really put out enough power for my application. I am looking at Yanmar, Kubota or Perkins powered 1800 rpm generators that will fit in a side box installation. These sets tend to be a bit portly. The hush box extends the overall size of the total package size quite a bit, so I am looking for hush box design techniques/tricks that are space efficient and quiet. I have looked at a few studio generators and a couple of military Deutz generators (European military sets seem to be much quieter than US sets) for ideas. I have been looking into what the boat/yacht and high end motorhomes folks use but haven't really found practical approaches or materials. I have seen various several NASCAR transporter solutions from afar. Quiet but wasn't able to get close enough for a detailed look. Lead clad acoustical foam insulation seems to be the ticket for inside enclosure surfaces. Rubber isolation mounts for conducted vibration induced noise are a given. Critical grade mufflers appear to effective on exhaust noise. The real question that I have is how to design/fabricate an aluminum enclosure that effectively manages the cooling air flow and keep the radiated sound to acceptable limits (i.e. as quiet as possible). Do any of the WeldingWeb experts have any practical design suggestions or fabrication suggestions on hush boxes? Anyone aware of any technical resources that address hush box design.Regards, KevinKevin Morin - I can't get your direct email address to work. I sent you a PM.
Reply:With the brands your talking about, seems like you have some money to spend. If you have the money, go with a Honda generator for your first priority. These are the QUIETEST gennys on earth. Next, build maybe an aluminum housing on slider rails to easily pull out the generator for servicing. Make sure to install a cooling fan that runs continuously and has its own air intake/exhaust port for the generator. That's the .02 cents worth of info I can recommend. I have no plans, but a simple "box" with a circulating cooling fan and exhaust outlet are the only two things to consider when welding up your genny's home. You need easy access for fuel and oil too.Lincoln Power Mig 216Lincoln AC/DC-225/125Miller 625 X-Treme PlasmaMiller 211 Forney 95FI-A 301HF 91110Victor Journeyman O/PMilwaukee DaytonMakita Baileigh NRA Life Member
Reply:I second the Honda. Not a quieter genny anywhere!
Reply:I agree, love my honda!
Reply:Nix the Hondas.They are a great piece of equipment (I own a 5.6KW one, love it!), but they are air cooled and run at 3600RPM.Like you mentioned, an 1800RPM, water cooled engine is going to be MUCH easier to hush-up.How big a generator are you planning on?You mentioned sound deadening mats. Good start. The entire inside of the engine enclosure should be covered. Use assymetrical bracing to minimize simpathetic resonence between the case and the engine.The radiator with an electric fan should be OUTSIDE the engine enclosure (the fan cycling shouldn't be annoying). An overkill muffler. The exhust pipe tip should have an extra spark arrester/heat shieldThe engine's air intake should be well inside the enclosure. The double-louvered vent with a very fine screen in between should be as far from the air intake as possible to both limit noise and be the bit of cooling inside the enclosure.PM me if you would like to discuss more.Be wary of The Numbers: Figures don't lie,. but liars can figure.Welders:2008 Lincoln 140 GMAW&FCAW2012 HF 165 'toy' GTAW&SMAW1970's Cobbled together O/A
Reply:Hondas are great products. I have several but they don't put out the power that I am looking for. Goal is 15 - 20 KW. Typical diesel gen set in this class is 50" long, 24" wide, a36" tall, and just under 1000lbs. Good power but still small enough to fit a side box chassis mounting. I am very familiar with the gen sets available in this range, their capabilities, and features. A trailer mounted gen set is not in the plan. Costco specials in a simple box with a big *** muffler won't provide the sound attenuation required. Gen set will most likely have the mechanical fan replaced with electrics to control air movement and noise matched to the cooling load required. Asymmetrical bracing is a good idea that I had not considered. Thanks for the tips. Your comments are appreciated.Regards
Reply:Nice long extension cord attached to the RV next door!
Reply:36" tall genset + mounting + insulation + enclosure floor + enclosure ceiling = (do you have enough height in the RV's 'basememt')?I'm thinking of the small Diesels (18 & 20 HP) in my compact tractors and how big the 4-5 KW alternators are. I think you may be able to get a 15 KW diesel genset (without fuel tank or radiator) in under 48L x 18W x 24H. I may be getting a bit impertinent here, but why do you want 15KW of electricity when you are away from civilization? I ask because I routinely do wilderness camping with my small travel trailer. The water tanks (fresh, grey & black) will hold us for several days (5 maxed things out). Cooking, heating, hot water and refrigeration are all propane. The 12V battery has enough electicity for lighting, circulating the heat and to pump all the water for those several days. At first I carried a small (1KW) genset because the previous owner had replaced the original fridge with a 110V bar fridge. Since deciding to lean heavily on propane, carrying a spare bottle and setting up for quick swaps, I haven't needed to carry a genset when camping. The tow vehicle charges the trailer's battery because it powers the brakes in the event of a breakaway.Be wary of The Numbers: Figures don't lie,. but liars can figure.Welders:2008 Lincoln 140 GMAW&FCAW2012 HF 165 'toy' GTAW&SMAW1970's Cobbled together O/A
Reply:One thing to be aware of on the cooling is that if you switch to an electric fan the engine won't notice, but the generator head might. Typically the cooling fan on the engine helps draw the air that the generator head expels into the enclosure, out of the enclosure and across the radiator. So not only should you design to allow cool air in at the generator head intake, but also ducting or some other means for the warm air to be expelled out of the enclosure rather than into it. Also keep in mind that the engine and generator head will reject heat into the enclosure.MikeConstans Fides et IntegritasLincoln Weldanpower 150 ACAirco Aircomatic MIGet CAV II w/ spoolgunMillermatic 30a wirefeeder
Reply:Originally Posted by tackitSounds like an expensive overkill project that leads to nothing but unforeseen troubles.
Reply:Originally Posted by Brink, M.E.One thing to be aware of on the cooling is that if you switch to an electric fan the engine won't notice, but the generator head might. Typically the cooling fan on the engine helps draw the air that the generator head expels into the enclosure, out of the enclosure and across the radiator. So not only should you design to allow cool air in at the generator head intake, but also ducting or some other means for the warm air to be expelled out of the enclosure rather than into it. Also keep in mind that the engine and generator head will reject heat into the enclosure.
Reply:Originally Posted by rlitmanAgreed. That, and not motorhome has a need for "15 - 20 KW". That's just nuts.
Reply:Yeah, I concur. I spit out me coffee when I read that he wants "15-20K" genny power for a motor home. No offense, but WTF? That's nuts and I respectfully believe that the OP has absolutely no clue as to what he needs for a "PRACTICAL" motorhome set up. This is akin to saying one is going to put a Chevy 454 into his Nissan Sentra. 15-20K!!!! Are you kidding me??? Lincoln Power Mig 216Lincoln AC/DC-225/125Miller 625 X-Treme PlasmaMiller 211 Forney 95FI-A 301HF 91110Victor Journeyman O/PMilwaukee DaytonMakita Baileigh NRA Life Member
Reply:Originally Posted by SuperArcYeah, I concur. I spit out me coffee when I read that he wants "15-20K" genny power for a motor home. No offense, but WTF? That's nuts and I respectfully believe that the OP has absolutely no clue as to what he needs for a "PRACTICAL" motorhome set up. This is akin to saying one is going to put a Chevy 454 into his Nissan Sentra. 15-20K!!!! Are you kidding me???
Reply:Originally Posted by mike837goAgreed. Unless AMillerUser wants to run multiple A/C units and a clothes dryer.
Reply:Originally Posted by mike837goCheck post #5:The engine's combustion air intake has to be INSIDE the enclosure. That should draw plenty of cool, outside air to keep the alternator's heat buildup in check.
Reply:Marathon Coach puts 20 kw gensets in their coaches and mount them on airbags to isolate vibration. They have 4-15k btu ac units, many large TVs, mood lighting, etc...http://www.marathoncoach.com/invoice/1211-invoice.pdfhttp://www.marathoncoach.com/invento...908&coach=1211Millermatic 200Hobart Handler 120Victor O/A & Ramco BandsawLincoln 225 ACSnapOn AD HoodMiller XMT304/22AHypertherm Powermax 1650 G3Lincoln Idealarc DC600 w/Extreme 12 VSMiller Digital Elite "Joker"
Reply:Guys, you are a bit off in left field. This diesel Kenworth "motorhome" is not an RV. Home back up generators and a truck load of Honda's EU6500s are not going to meet the need. Currently, 12KW of connected electronics will be housed in the 24 foot custom box with multiple operator positions, and a head. The electronics generate a fair amount of heat, and the cooling required to keep the electronics happy is significant. The "motorhome" is specd to operate in ambient temps up to 120F and alititudes of up to 10,000 feet. Solar load on the box adds to the problem. This ain't your grandparent's Winnebago, nor is it a 454 in a Nissan Sentra. Add the heat of a few warm bodies in small spaces and the generator load can be significant. Connected load, operational environment, length of continous operation, and altitude derating of the gen set pushes the need out of the range of RV solutions or emergency home gen sets. The truck, box, gen set, and air conditioning are dirt cheap compared to the on board electronics.Recognizing that this is Welding Web and the opinions provided are worth what you pay for them, can we get back on topic? While many of the comments are entertaining, many of the gen set sizing and sanity opinions are not particularly useful. But if it makes you feel good, go for it. The two primary questions were about practical design and fabrication tips regarding hush boxes. I was hopeful that some of the very experienced folks here at Welding Web might have been involved with the development and/or build of a ruggedized commercial quality hush boxes, similar to those used in high end motorhomes or marine applications. Baring that, I was hopeful that someone might be able to provide a referral to source of practical noise control techniques of truck mounted gen sets. Most of our previous experience has been with trailer mounted gen sets. Parking a trailer mounted, studio quality generator 100 feet away did the job efficiently and economically. The problem is the trailer. This application requires a self contained, on board system. The space available in the lower bay is tight. The gyrations to get everything to fit and operate reliably with a variety of hush enchancements is a nontrivial problem. Off the shelf enclosures from gen set OEMs won't fit the volume available on board. The genset radiator will most likely remoted for air flow and fit, driving the need for electric fans. 10 lbs of **** in a 5 lb bag comes to mind.So, anyone built one, or been involved in the design of commercial grade, ruggedized hush boxes? Have any lessons learned that can be shared? I am willing to bet that q240z with his Chris Craft project might be interested in what you folks have to say.Regards
Reply:My little eu2000 runs the AC on my TT. What I love about it is when I am not using it for camping I can carry it anywhere and use it for power tools/work. |
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发表于 2021-8-31 22:43:15