Bored, been thinking--a dangerous combo

[oltrunt]

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

[Gary Hatt - Publisher BCM]

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

[Iceni John]

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     

[Utahclaimjumper]

Jack,, it sounds like your OVERDUE for another major project.!!>>>Dan

[oltrunt]

Some truth in that Dan.  Jack

[buswarrior]

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

[oltrunt]

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

[buswarrior]

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?

[oltrunt]

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

[Gary Hatt - Publisher BCM]

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.

[Ed Hackenbruch]

Half joking on this. but why not tap into your ac duct to divert some ac to it?   

[Utahclaimjumper]

Jacks A/C is open windows.>>>D

[chessie4905]

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

[Jim Blackwood]

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

[chessie4905]

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.