Misters completed

[Iceni John]

I've just finished making a radiator mister system, and early tests indicated I'm getting about five degrees cooler (less hot?) engine temperature on climbs.   It uses distilled water to prevent mineral buildup on my expensive new radiator, and I'm using a separate SHURflo 8000-series continuous-duty 60 PSI pump and some 0.012" mister nozzles that flow only half a gallon per hour each.   Like all my projects it's taken way more time and effort (and money) than I would have ever dreamed possible for such a seemingly-simple project.

I originally had two 2.5 gallon jugs of distilled water on a new shelf above the radiator to supply the pump, but immediately ran into a problem with the pump cycling on and off because the mister heads use so little water.   The solution was to have a return line into each water jug, with most of the pump's output returning through a bleeder valve that keeps the pump working at just below its 60 PSI cutoff pressure.   Next problem was all the water slowly siphoning out when the pump was not running  -  the pump allows water to flow through it when it's off, so that meant adding a solenoid valve that shuts off flow to the heads when the pump is off.   In order to test the system and adjust the mister heads I also added a test switch near the radiator, so now I can test-run the pump without needing to switch it on at the front.   Because the wire from the front switch is only 16 AWG with a 3 A fuse, I use one of my old Cole-Hersee solenoids that I replaced from my rear start panel  -  there was nothing wrong with it, but why take a chance on something critical that's almost 30 years old?   The solenoid has its own 10 AWG feed from the rear start panel with a 15 A fuse.   The pump, solenoid and bleeder valve sit on a small shelf I made next to the radiator, out of the way but easily accessible if needed.

With five mister heads I was seeing about five degrees drop when climbing Highway 138 here last month.   Pretty good, I thought.   Well, having the water jugs above the radiator wasn't good  -  the heat there weakened their plastic and they started leaking, so back to the drawing board.   Because I've now used almost every nook and cranny (WTH is a cranny anyway?   Is it bigger than a nook?) under the bus, I had to get imaginative to find a better place for the water jugs.   Behind my driver-side rear wheels I have a few inches of space, so I made a fancy fold-down shelf there from stainless and aluminum that keeps the jugs out of harm's way and cool, and most importantly they're easily accessible unlike before.

I remade my mister heads' mounts using Sch.80 PVC pipe, and now I'm using eight heads, so maybe I'll see slightly more temperature drop?   Even with eight heads I can get just over an hour of misting from five gallons of water.   One last thing, because I just can't ever leave anything alone, was to make a feedback system to know if everything's working OK.   I added an adjustable pressure switch that closes at the full operating pressure of about 50 PSI, and it controls a relay that powers a warning light and a buzzer in my gauge panel.   When I turn on the misters, for the first two seconds the buzzer sounds, then when pressure builds up the buzzer stops and the light comes on to remind me the misters are on.   If anything goes tits up, like the pump stopping, or running out of water, or a head or hose blowing off, or a fuse blowing, then pressure will drop, the switch opens, the light goes out, the buzzer starts, and I know there's a problem instead of blissfully driving along thinking it's working when it's not.

Simple it ain't, but it works well, and if it gets me up the hills with less risk of Bad Things happening, then it's worth it.

John   

[chessie4905]

Glad to hear you installed a system. Too many here haven't bothered. Way too cheap of insurance to dismiss on the older coaches with cooling systems that could be larger or better.

[Bill Gerrie]

I've used a misting system for many years and it is definitely a good insurance when it comes to a hot engine. My system is very simple. I used a underground sprinkler system valve that gets its water from the fresh water supply. It is 24 volts ac but it works well on 12 volts dc. I put a switch on the dash to activate it when needed. The fresh water system has to be on all the time to supply water to the misters when needed. The spray system is just ridged 1/2" plastic pipes in an "H" configuration in front of the rad. I drilled 1/16" holes in it to spray the rad. It works well and was cheap to do. I don't use it enough to worry about the minerals in the water system bothering the rad.

[lvmci]

Hi John, congrats on your misting system, I too used distilled water (for the same reason) in 2 1/2 gallon jugs, but ran out of water before the end of Baker grade. Same with Cajon Pass. I also drilled out the mister holes from HD to 1/16th" on Tom Cs recomedation, connected to my fresh water tank, now, thru my manifold, turn my house pump on/off with a cordless fob, lvmci...

[GnarlyBus]

Anybody willing to share pics of their system?

[TomC]

If you read about the cooling capability of straight water, you need to dump lots of water on the radiator to get any affect. I have a 15 mister system and have drilled out two of the nozzles with a 1/16" drill. Now it dumps lots of water-can go through 30-50 gallons on a hot day. It works off my regular water system (130gal tank). If any calcium does build up, I just spray with CLR and off it comes. Good Luck, TomC

[Iceni John]

While putting the finishing touches to my mister system today I discovered something weird.   Electricity can flow in both directions simultaneously!   OK, I'm not an electrical guru, and if I were this may not be so surprising, but I'm not, so it is.   I installed a small LED panel lamp for testing the mister's adjustable pressure switch that grounds a relay in the front for the idiot light and buzzer, but this LED lamp was not doing what I expected.   The wire from the front going back to the pressure switch is to ground the front relay, but it was also simultaneously grounding the LED lamp to the front relay through its coil, in other words the wire was grounding two separate things in opposite directions.   After much head scratching and experimenting I just put a diode in the wire so it can only pass current in one direction  -  voila, problem solved.   Who'da thunk it?    Ain't science wonderful!

So now, after this little hiccup today, everything works the way I want.   I switch on the misters from the front, a buzzer sounds for a second or two while pressure builds up, when pressure is good the buzzer stops and an idiot light instead comes on to remind me they're working OK and to not forget they're on.   If anything should go wrong, pressure will drop, the light goes out and the buzzer buzzes, and I say " Oh Bollocks, what's wrong now?"   Electronic guys would call this a positive feedback loop, but I'm just a busnut with too much time on his hands, so who knows what it is?

John

[luvrbus]

Nice system John,I saw a MCI DL yesterday with a 500 hp DDEC 8v92 that had 2 big radiators across the rear with 2 -32 inch 2 speed fans from the factory looked like MCI got that one right.
The owner told me he has never saw over 195 even on the pull from Laughlin to Kingman @ 119 degrees and that is a tough pull for 10 miles .
That was the 1st time I ever saw that setup up close,on my DL3 with the series 60 I only have 1 radiator with a intercooler and both have large fans   

[windtrader]

Must be getting old(er) lol. So, what is the consensus on which system is more effective -- spraying misted air or heavier amounts of water for wetting the rad?

[lvmci]

For the southwest, I think the sprayer in the dry climates and mountains, with substantial spraying works best. but hybrid mist/sprayer works also, lvmci...

[chessie4905]

Maybe a second set of misters or sprayers hooked to a separate water control solenoid. Then a third solenoid hooked to a fire hydrant when that doesnt do it.....

[lvmci]

And a real long hose on a reel!

[boxcarOkie]

Last time I put up something with water misters in it, some shovel humper in AZ called me an A**hole.  So here goes nothing.  My desert cooling is hooked straight to the water tank with 1/4" PVC that runs to a small Shure-flo pump with an inline fuse and its own dedicated circuit. 

The pipe has holes drilled in it to shoot water directly onto the radiator. 

That is it.  Simple.  Uncomplicated.  This NOT Rocket Science.  All of this discussion here, seems to be over-engineered and for the most part ...  Random Speculation (just like the thread on Louvers). 

It doesn't take huge amounts of water to remedy the situation.  A short duration hit will do the job.  Hit it for about fifteen seconds and then turn it off, nature will do the rest, the system as is doesn't take oceans of water to make it all work. 

The best piece of advice is to put a spring loaded toggle on it, so you do not forget they are on (because at some point you will).  When this happens, you will find yourself on the narrow shoulder of #95 South, bailing water out of the Ice Chest with a coffee can and throwing it on the fins, in order to get your dumb ____ up the hill. 

BTDT got the T-Shirt.

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[chessie4905]

One pipe on radiator?  Top, bottom, or front? Number of holes? Hole size? Thanks.

[Dave5Cs]

Just like the thread on Louvers? Do you use Delo 100 or 10W50 Shamsaville oil Company, oil to lube the Louvers and if so do you want them horizontal or corner to corner. Do yours have the darsomvega bullistic vent opulators or pulltrain versa station regulator orindas? Thanks in advance.