Radiator Misters

[TomC]

I realize that radiator misters are not the best solution to heating problems.  Like in my situation, I had the radiator rebuilt to the largest core the tank and size would allow, and still had heating issues if the outside temp was over 90 degrees.  I installed 15 misters from Home Depot, and while it helped, I still had to be gentle on up hills and stopping to let it cool-albeit it would cool off in less then 5 minutes.
This summer, I experimented and drilled out two of the misters on the bottom with a 1/16" drill.  I had the misters aimed out and they squirted about 15ft out from the bus! After re-aiming them, the results were dramatic.  I pulled the big hill going up to Shaver Lake in 90 degree weather and didn't have to stop!  I think it flows about a gallon a minute.

The formula for water evaporation is 1lb of water evaporating is 1,000btu's.  So one gallon per minute would be 8,300btu/minute, or 498,000btu's of heat rejection per hour.  Now that's some heat dissipation.  Whenever you read of what an engine puts out for btu heat rejection, it is always in btu/minute.  I know the Allison transmission can put out up to 20,000btu/minute in torque converter mode.

For those that have tried everything but are still getting heating issues, maybe try my trick of drilled out misters, or just plainly install one lawn sprinkler.  Good Luck, TomC

[Mex-Busnut]

Good post.

So a huge amount of the heat problem is due to the automatic transmission? Good thing the buses I am looking at have standard trannies!

How do you activate the misters from the cockpit? How about some pictures?

Thanks in advance!

[Lin]

Tom,

Although from a purist point of view, misters are not an ideal solution, very few solutions are.  If I want a bus, ideally I would spend the million or so and have an ideal coach.  I could also hire a mechanic to run along side too.  I guess that's the difference between here and the afterlife.

[Chopper Scott]

Just be sure and use distilled water in the misters as regular water will lime up the exterior of the cooling fins and compound the problem. I think some guys have stated that they used a condensor cleaner that heating and air places have. After Jack Conrad's advise I installed a seperate tranny cooler and also added a 24 volt fan. It really puts out some heat!!

[zubzub]

not to get too funky here but would it be possible to use the run off from the ACs for "distilled water"?  I'm picturing something pretty, not garden hoses draped along the side of the bus.

[happycamperbrat]

Am I to understand you correctly? You actually use regular patio misters to cool your engine or tranny when driving? Could you please explain how this works and show photos?

[Lin]

I have never examined any mister system up close, but I have read where some said that RV type mister system worked substantially better than most homemade ones.  I think the concept is to cool the air as a swamp cooler does rather than just wetting down the radiator.

[steve wardwell]

the misters are in front of the radiator's

[fe2_o3]

   Our mister system works well now. In the beginning we had calcium issues, but we found a filter that chemically eliminates the calcium. Since then (5yrs.) we've had no issues with buildup on the fins, or plugged misters. We use an automotive fuel pump the push the water through the filter and the misters. It's a fine mist near the top and middle of the rad.
  The biggest difference is on slow inclines. For the passes I just use a lower gear and crawl. I also have a 4 speed manual instead of an automatic which means a lot less heat to deal with...Cable

[kyle4501]

Spraying water on a radiator increases it's cooling capacity because of the energy dissipated by the phase change of the water from liquid to gas.
In high humidity, the misters wouldn't lower the air temp much, but would still have a big impact on the engine temp.

Misters are a cheap solution that can temporarily get you out of a jam, but, for the long term, I'd rather have additional coolers (to take the transmission & engine oil cooling loads off the radiator) & add a remote mounted auxiliary radiator if needed.  

But, that's just me. . . .

[luvrbus]

I know guys that love the HD patio misting systems they own radiator shops ,the fan sucking water through the radiator at 20 to 30 MPH destroys a radiator but radiators are 2 to 3 grand and a engine is around 12 grand on the average it is your call but I never had mister system.


good luck

[steve wardwell]

well when it rains acid rain it's worse than any distilled water! When we run in the hills it might be on 1-2 mins at a time, with 18 tips running we use about 3-4 gals a day  (revised down from an old estimate of 10) ..takes about 1 min to drop the temp 20*......it does make a little mess back there but then again every time we take the bus out it seems to rain somewhere during our trip

[Rick 74 MC-8]

Like Kyle said

           I still have my otr heat I also have a switch to turn off the power to the heat controll valve (defalt is full heat) When pulling a hard grade if temp start to rise. Flip the switch and turn the heat on Temp comes right down. Some times it gets warm in the coach but the DD stays cool. Some day I will cut into the heat duct and open it to the old otr ac compartment (MC-8) But until then only the occupants get warm and that cost less than new 8V71 works for me KISS (Keep it simple stupid) LOL Or just take my foot out of it and enjoy the ride 


                                                                                 Rick 74 MC-8

[luvrbus]

Steve, check with a shop have you ever wondered why a radiator rots faster in wet areas here in the west nothing to see a radiator 25 years old you won't see that in a wet area where you get a lot rain


good luck

[happycamperbrat]

luvr I agree about the wet areas compared to the dry areas. Absolutely! But in a system like this, wouldnt the water evaporate so quickly that nothing has a chance to get wet and stay wet? And it would be used only very infrequently.