DIY radiator water sprayer
 

|I have an idea|

Given the propensity by eco modders to close the airflow that feeds the radiator, why not look for a simple solution to prevent an overheated cooling system?

I gave it a quick brainstorming session (the only session I can do, :D ), and remembered the water spraying systems used i n the intercoolers of turbocharged cars.

Such a system would be:

- simple
- cheap
- light

It could be made to turn on automatically, but that would need an arduino (a microcontroller) or equivalent, and a temp sensor.

Just imagine the same thing, but using it for the radiator. Would it make a difference?

Does anyone have any experience with this?



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System would be like:

reservoir of water ------ windshield washer pump ------- windshield nozzle ---- radiator.

i understand you refere to something that would spray water on outside on the radiator?

i suppose one could hook this up to the fan relay, the water stray being a "wet fan" alternatively you could use water injection into the engine.

water injection has little benefits for FE in a NA engine. It was however initially used as "internal cooling" on early gasiline engines, at times when radiators where unreliable. It also prevented predetonation with the low octane fuel, wich was discovered when radiators replaced WI on the low octane fueled engins and they suddenly started nocking...

Yes, external water spraying.

As in spraying the radiator fins area with water.

It might be helpful in a few situations, but:

*a variable grille block would be simpler, lighter, and more effective. It's the holy grail of grille blocks, and I think a simple, universal, easily duplicated automatic variable grille block should be our focus.
*you'd need a large, heavy reservoir for continuous operation of a water sprayer
*if you really need cooling in a hurry, the small amount of heat an ecomodder's engine produces can be easily dissipated by the heater core
*dropping a few mph is usually adequate to bring me back to nice and cool operation

...back in the '40's & '50's, when driving through the deserts of the southwest, people used to hang a canvas water bag in front of the grille to accomplish the samething, ie: evaporative cooling.

http://4.bp.blogspot.com/_p4PkoeXYyO.../bag23e3_3.gif

...anybody remember them?

It seems like it would be a simple mod if you have the room under the hood:
-A windshield washer tank w/pump from a junk yard
-A relay
-A toggle switch
-some wire
-hose and a sprayer of some type

I have a second cooling fan for A/C, which my car no longer has, so I'm going to rig it up to a manual switch. Blasting the heat works well, but in the summer it's really not ideal. I don't have a grill block installed right now, so this project will come after I get that together...

one thing that could cause problems is corosion... i suppose the radiator itself might stand up quite well, but all the firrings and underlaying structurs that otherwise are pretty well shielded from water would not get soaked... most of the water on the rad, might vaporise, but it could still pool in areas underneath

We use evaporation cooling at work to keep some storage tanks cool.


Cars basicly have everything you need at hand: a water reservoir and a spraying system

It's just a matter of repositioning the spraying nozzle. :)

Most engine bays get soaked in the rain.
Water gets through the grill, through the radiator, through the various seams, through the holes in the bottom, ...


Driving through big puddles can kill your engine if it gets into the air intake.
And it does on some cars.

I'm just keeping my mind busy. ;)

Cars do have everything needed to do this, but a separate system would be simpler in terms of not joining 2 systems in one (windshield washers and the radiator sprayer).

Corrosion is not a problem, unless you drive a toaster. =P


I would use the system at EOC, with the fans at full blast.

The water pump isn't turning during EOC.

It can be, if you convert to an electric water pump (only available for some engines).

Somebody sells a system similar to this for use on home a/c units. I believe the someone here tried it. It was reported that the a/c unit ran less than without it. The issue was there is mineral build up as the water evaporates. It used tap water (or whatever you push through a hose at it). This mineral build up would decrease heat transfer out of the radiator. I don't know if collected rain or distilled water would prevent this.

I wouldn't keep the water under the hood, I would keep it away from engine heat so there is a bigger delta T°.

I would also consider a nozzle that makes more of a cone pattern that a washer nozzle does. This would more evenly cover the radiator.

Good luck.
Don

You would'nt be able to carry enough water to make much differance.

Rick

You don't need that much water for evaporation cooling.

Actually, a common error at work is to use far too much water.

...Swamp Cooler Theory 101:

eqn 1: E(s) = ( DBD / WBD ) = (T1 - T2) / (T1 - T3)

...where:
E(s) = Saturation Efficiency, actual change divided by maximum possible change.
DBD = Dry-Bulb Depression, air temperature change from HOT to COOL, actual.
WBD = Wet-Bulb Depression, air temperature change, HOT to COOL, maximum possible.
T1 = Outside (or inlet) HOT air temperature.
T2 = Inside (or discharge) COOL air temperature.
T3 = Wetbulb temperature, maximum adiabatic air cooling possible.

...for example, if T1 = 105°F and T2 = 73.9°F and T3 = 66.1°F, then the saturation efficiency E(s) would be 0.80, or 80%:

E(s) = (105.0-73.9)/(105.0-66.1) = 0.80 x 100% = 80%

...unfortunately, that E(s) value is for Aspen Excelsior, not a FRAM™ paper automotive air filter, which probably has an E(s)-value of ~ 0.5 or less...but "mister spray" can approach 0.95.

...never the less, let's backsolve the above equation to see how "cool" the air going into the engine (ie: T2) would be with E(s) = 0.5:

eqn 2: T2 = T1 - E(s)*(T1 - T3) = 105.0 - 0.5*(105.0 - 66.1) = (105.0 - 19.4) = 85.6°F ...a (theoretical) temperature reduction of 19.4°F.

...if you know the relative humidity (RH%) values of T1, T2 and T3, Eqn 1 becomes:

eqn 3: E(s) = SQRT[ (rh2 - rh1)/(rh3 - rh1) ]

...where:
rh1 = relative humidity at T1 of the inlet (outside) air.
rh2 = relative humidity at T2 of the discharge (after the wet filter) air.
rh3 = relative humidity at T3; theoretically 100%, but practically less than 80%.

...so, because of the HUGE volume of air drawn by the engine through the air filter, a large amount of water is required to raise rh2. For instance, in the first example above, the outside air would be: T1 = 105°F @ rh1 = 12% and the inside air (going into engine) would be: T2 = 73.9°F @ rh2 = 68%.

...unfortunately, THAT's gonna take a LOT of water, especially if you're driving at freeway speeds (higher RPMs) for any appreciable time...literally, gallons-per-hour!

...and, here's the equation for calculating "how many" gallons-per-hour (GPH) of water you'd need:

eqn 4: GPH = [CFM*WBD*E(s)] / 8700

...where, 8700 is a conversion factor based upon (a) 8.34 lb. water-per-gallon and (b) 1043 BTU-per-pound of water. CFM is a function of engine displacement (CID), volumetric efficiency (~ 80%) and RPM:

eqn 5: CFM = (CID*RPM*0.8) / 3456

"...Swamp Cooler Theory 101:..."

"...unfortunately, THAT's gonna take a LOT of water, especially if you're driving at freeway speeds (higher RPMs) for any appreciable time...literally, gallons-per-hour! ..."

what if you captured the H2O to re use it? Maybe a radiator in the bottom of a stainless steel box. Water vapor condenses on the walls and drips down to the radiator. Seems like trying to take advantage of the phase change from liguid to gas could yield some really impressive results. Some of you engineering/scientist types may be able to explain what I'm thinking of (or why it wouldn't work).

:)

You can't spray enough water on a radiator to cool it w/o a continuous flow of water.
You are beating a dead horse.

Install an electric fan in front and set on a push instead of a pull function. install a manual switch or a temp comtrolled switch.
put a shroud around the fan to keep the airmoving thru.

You can dance all around this water issue but it is impractical.

someone mentioned the sprayer on the a/c. remeber this system is runnung off a water hose that is 'on' providing a constsance source of water

never seen a water spray bar on an intercooler before, though i have seen plenty of CO2 spray bars, same general concept, but the science behind it is completely different

The idea was to use the sprayer for emergency cooling. Why doesn't anyone read the whole thread anymore?

Kind of interesting - use a windshield washer pump, or something like that? Puts out quite a good flow of water.

A racer on another forum said they had variable grille blocks, but didn't offer many details. Do you have any ideas on where to buy or how to build one? Here in Florida, I definitely couldn't do a full-time radiator block of any appreciable size.

Oh, and if you want to make a radiator water sprayer--whether the idea is practical or not--you probably can't do much better than the autospeed intercooler sprayer--search their site for "World's Best Intercooler Water Spray"

i'm a cheep ba5+ard & i'm unemployed at the moment. so i can not afford the systems on the market. i fashioned a spray system from a chrome water fire extinguisher i had, and 4 of nozzles from a patio mister set up & a few fittings & hoses from a box store. just 10 psi and it starts to mist. it works best at 40 psi so i only full the tank to 50psi. i used an old lawn mower throttle cable to pull on the squeeze valve. i can then cool my truck pulling the hills outside of los angeles. This is on my 64 Chevy pu with the old inline six. the temp rises just a tad over my comfort range when pulling my trailers. i pull the Castaic grade in second gear and that slows the speed so i'm not getting very much air through the grill.

the system works to my satisfaction and brings the gauge down to just over level driving range. remember, the factory gages have no numbers, just a cold; hot; and a "normal range" painted line... C |______| H so i'm just eyeballing it :)

There was a similar item sold through the late 1980's (prior to the advent of FI) where the radiator temps would spike on hill-climbs for tow vehicles [RV's]. Severe heat spike. It used a windshield washer pump, that reservoir made common (and/or enlarged) and distilled water recommended (for reasons above: corrosion and mineral build). IIRC it was four spray heads mounted so as to cover the entirety of the first heat exchanger (generally the A/C condenser).

By report this worked best -- the temporary increase in surface area -- in dry, hot, higher altitude climbs.

.

Hi GrapeApe,
Excellent, how much water do you use per trip?
-mort

yea it would be nice to live in a place where i could do some kind of grill block, here in central arkansas we push into the 100-110 range. any kind of block in the front will instantly lead to a rising temp gauge. im still trying to figure out if i cover the front of the car under the engine if it will affect cooling. air is coming in it has to go somewhere there will have to be an outlet. this belongs in a different thread so im gonna shut up now.

You mean prior to the return to forced induction. There had been supercharged road cars dating back to at least the 1920s, and turbocharging first was utilized in mass production in the early 60s at General Motors, ex the Corvair Monza flat six turbo, and the turbocharged version of the Buick 3500 V8 as installed in the Oldsmobile Cutlass Jetfire variant of the Buick Special/ GM Y-body in 1962

The variable grille block to which you're referring is called a shutterstat~ been used on bigrigs for quite some time. This combined with extra thermostatically controlled fans is the best option, BUT is designed for HUGE cooling systems. As previously stated to hose the rad core you'd have to carry so much waterweight that it is impractical. If emergency cooling is in order enough to warrant such concern, then modifying driving conditions and increasing cooling capacity is in order.

At the risk of getting flamed, you're overthinking this. The reason newer cars run so hot's because they're designed to~ it increases the thermal efficiency of the motor. Every pound of pressure held by that fancy rad cap increases the boil point 3 degrees, raising the overall to 240-270 degrees running temps. If modifying driving conditions isn't in the plan, go for as big a radiator as you can fit, add thermo-fans set at different temps, and then MAYBE add that shutterstat if you can add enough capacity to the system.

No, sorry, I meant Fuel Injection, or, more carefully, digital engine controls. It became much harder for a car to go "out of tune" on top of problems with towing and altitude changes that made carburetors hard put.

In that case the 80s was only the advent of the modern electronically controled fuel injection systems, however direct injection dated back to at least world war two on fighter air craft, and mechanical fuel injection was used by Mercedes on the 300SL and GM on some sub models of the Corvette in the post war era.