Hello All.
I'm a little board. I "pulled" my back a bit standing backwards on a step ladder while using a 14" air board to sand the "Bondo" I applied to my wooden bus barn door in hopes of resurrecting it. Not an unusual sort of thing for me to do----but----my chiropractor is on vacation and I'm afraid to try someone new so I've been enjoying that stiletto in the back feeling for the last week. As an amusement I've been watching utube videos of ways to lower the noise level of generators. Laughing finally causes me to cough which kills my back.
I'm happy with the noise level of my bus's generator though it be stuffed away in a slide out drawer but I was reminded of the problems folks have with trying to keep their boxed up gennys cool. I have a constant "pusher" fan blowing air over my enclosed jenny and a thermostatically controlled "puller" fan that kicks in as needed at 60 degrees C. I also have a kill switch to shut the genny down at 91 degrees C (about 200 degrees F) It has never shut down yet.
So here's where my board mind went. What if I installed a mister in the area of the pusher fan that turned on when the puller fan engaged? Would that serve to chill the incoming air enough to promptly shut down the puller fan? Enquiring minds want to know. Any thoughts? Jack
Jack,
On our real buses ;) many people put misters on the radiators to cool them down primarily on hills. I have heard numbers something like a 10F+ degree drop almost immediately. Some people used distilled water to prevent calcium (I think it is) buildup on the radiator fins.
Your problem will be you have a pretty small water tank on your unit, but you may have room for another freshwater tank in your engine compartment.
English John has done a lot of research on this and did something interesting on his bus but I forgot what it is. Maybe he can chime in on this subject.
Gary
My radiator mister system isn't especially noteworthy or different than most others - I use distilled water, a SHURflo 8000 pump, and eight 0.5GPH fogger nozzles. I don't know exactly how much difference it makes, but it's a few degrees, and that's usually all I need. What makes my system slightly different to most others is the way it tells me when it's working correctly or when it's kaput because something's not right. If you're interested in incorporating something like that, PM me and I'll tell you all the juicy details.
John
Jack,, it sounds like your OVERDUE for another major project.!!>>>Dan
Some truth in that Dan. Jack
Is the generator head downstream of these imagined misters?
THAT would be a funny video to watch on YU TUBE.
For others...
Happy coaching!
Buswarrior
Bw, I'm not thinking of Niagara Falls pouring through my windings but rather the moist air like one would find in a house cooled with a swamp box in Tucson in August. I'll give the potential problem some thought (like what is the RH in that house in Tucson) though at first blush I don't really see a problem. If you run across something that would indicate a problem with the idea we'd all like to get a heads up.
Thanks, Jack
Seen lots of corosion in mobile aplications... I would be afraid to purposely put moisture in there. Seems more than enough damp gets in there on its own?
Bw, you got me looking at the science and from what I learned I'll not be misting my genny. In a long term study (2008-2017) of the effects of heat/humidity on 250 portable gennys there was a failure rate of 30% all related to moisture and corrosion of the windings. The studies were done in Nigeria in a climate with average temps of 80 degrees F and 85% relative humidity. I originally trained as a scientist (became a cop don't ask why) and the test methods are sound.
Anyway, thanks for the prod and here is the study:
http://www.ajsc.leena-luna.co.jp/AJSCPDFs/Vol.7(2)/AJSC2018(7.2-01).pdf
Jack
Interesting study Old Runt. :-)
However, these do not look like very high-quality generators in the photo IMHO, so they may not represent something like a Wrico generator, but there may be something to be said for humidity getting into the windings as they may in a very humid climate, especially if they are not used much. A generator is not something I would want to leave out in the elements. However, if you are misting the radiator, you should be fine as long as you do not the windings wet.
You can wash the engine all you want but you need to be careful not to get the generator part of the genny wet and if you do, you want to let it dry for a couple of days before you start it up.
Half joking on this. but why not tap into your ac duct to divert some ac to it? :)
Jacks A/C is open windows.>>>D ::)
If a generator is even close to needing a mister system to keep it from overheat, it needs redesigned. Increase the radiator size, or if it is air cooled, add a squirrel cage blower to the enclosed compartment. If the squirrel cage blower isn't enough, either gear it to run faster or go with a larger squirrel cage. Maybe something here:
https://www.globalindustrial.com/c/hvac/blowers/centrifugal
I think the cooling air ductwork is most likely the critical factor in keeping the generator temp down. Here it is probably best to work with thermal principles rather than against them, in other words, draw the cool air from the shaded area beneath the bus and exhaust it high, preferably out the top of the bay door. Make sure the area of all ducting and openings well exceeds any and all ducting in the genset, and if wanted or needed, baffle the ductwork to exclude road spray. I'd suggest the new ductwork exceed any existing by at least a factor of 2:1 to avoid restriction, and this would include any baffles. Avoid turns in the airflow wherever possible, and minimize eddies, which can create a far greater restriction than you might think. Just fitting a simple tin-built air horn to any blunt opening, particularly on the suction side, can increase airflow.
The fan in the genset should be adequate for this but if not, in some cases a more aggressive fan may be fitted. I'd try to stay away from auxiliary fans and exotic solutions just for the sake of reliability.
Jim
Also, if watercooled, a larger radiator. Our Kohler 12kw diesel was fitted with a larger cross flow automotive radiator when it was installed, along with a squirrel cage blower. Nice thing about radiators, there are millions in salvage yards for those on a budget, or check a site that lists dimensions and inlet and outlet sizes if you would rather buy new. If you go with the newer aluminum ones, you wont have to deal with calcium build up at ends of tubes.
If rad size is an issue, have a look at some racing websites that sell aluminum rads. They have some high efficient ones in a small foot print.
The radiator in our Perkins/Kohler 12.5kw generator is discussed in the Custom Coach manual as "basically a Chevrolet core with custom top and bottom tanks". It certainly looks larger than the average generator radiator. The squirrel fan pulls an enormous amount of air through the radiator - in through a hole in the opposite side door and out through a hole in the floor. You don't want to pull air through the floor, unless you're keen on clogging your radiator with grass and dust almost immediately.
Assuming that the genset has been installed in the bus for a long time, my first thought on it overheating would be to check the radiator and see if it needs to be rodded. Generator radiators probably get even less love than our bus radiators, and it wouldn't be surprising to see one clogged internally and in need of a good cleaning.
And some don't get a work out near their rated capacity till it is close to 100 degrees out and they run all the ac units. Units had received little love till their is an issue. How many check regularly check for tight secure connections on the big wires and cables?
Quote from: chessie4905 on July 23, 2019, 01:49:40 PM
And some don't get a work out near their rated capacity till it is close to 100 degrees out and they run all the ac units. Units had received little love till their is an issue. How many check regularly check for tight secure connections on the big wires and cables?
I was told minimum of 30 minutes run time a month with a substantial load on the generator to ensure that the windings stay dry through the change in seasons. Motor also benefits from the run time, but drying out the generator was explained to be the biggest reason. I try to run ours year round at least a couple of times a month, but in the winter it's a challenge. It's easy to apply a load once started (electric heat) but getting it started when temps go near zero is a chore since we don't have a block heater.
Have you considered installing a larger radiator like this on your bus Jack? I think this should keep it cool.
;D
Even if you avoid sucking air from under the bus it'd be a good idea to place the inlet low and the outlet high, preferably on opposite sides of the bus, although I realize that raises a noise issue. However, a household furnace filter on the inlet can keep the grass and rocks out, and a larger opening means lower velocity to pick stuff up. If you've augmented the airflow enough though I suppose it makes little difference how you route it, and if the genset is big enough you'll never notice the additional current draw. Sorta like Gary's suggestion. Might eat into your mileage figures though.
Jim
If the radiator is properly sized and the fan is moving enough air with positive flow, it should make no difference whether you're blowing up or down - we're only talking about a few feet of lift here, and the natural convection isn't the concern since there is a fan.
In addition to many generator installs, OTR a/c condensing unit pull in from the side and out through the floor of the bay. Not sure if there is a reason to reinvent things. Just make sure things are up to snuff and carry on.
Small differences add up. You can ignore them but it'll cost you. You've seen the size of those motors on the AC fans, they weren't the least bit concerned with an economical solution. The goal was massive overkill. If that's what you want with your generator system it's easy enough. Fit a massive genset with an oversized radiator and an excessive fan. And don't concern yourself with the cost.
BTW, Summit sells generic aluminum radiators for a very reasonable cost. One for a V8 Camaro runs about $200 which is a pretty good deal.
Jim
Guys, all I have is a little air cooled Yamaha 3000iSEB air cooled genny. I'd need a trailer bigger than my bus to carry all the gear that has been suggested. For me the bottom line is don't up the RH in your genny box---it'll corrode the windings and spoil your fun. I wish I had space for a nice diesel genny etc but that is way out of my league. Still, it's fun to read all the suggestions. Jack
Just go get one from a salvage yard. 35 bucks and get the electric fan that is attached to it. If you have a you pick it yard, even better. I love walking a salvage yard occasionally. Trip down memory lane and see things that are useful for other ideas.
On my '74 MCI, I recently relocated my 13 KW Kubota genset from an enclosed bay (it was mounted in there, but never hooked up... I bought the bus that way), to the screened bay behind the front driver's side tire. I've run the coolant lines to the spare tire compartment where I'll install the radiator and fan. I'm in the middle of this project, but so far it looks good, but it is somewhat of an experiment at this time. I'll let everyone know how it works (or if it works).
Quote from: Glennman on July 23, 2019, 10:02:51 PM
On my '74 MCI, I recently relocated my 13 KW Kubota genset from an enclosed bay (it was mounted in there, but never hooked up... I bought the bus that way), to the screened bay behind the front driver's side tire. I've run the coolant lines to the spare tire compartment where I'll install the radiator and fan. I'm in the middle of this project, but so far it looks good, but it is somewhat of an experiment at this time. I'll let everyone know how it works (or if it works).
How are you routing the airflow for the spare tire compartment?