supplemental fan idea on AC cars.. Thoughts?

[daeron]

Okay, this thought was stimulated by cooling problems I am having because I need a new headgasket. That being said, I still think its a neat idea, and I am curious to know what you all think of how effective this might be.

 

Sometimes the water runs a little low, and when I turn the AC on, the temp rises. This may be a faulty reading, its a digidash, but whatever.... My thought was to install a small blower fan with the output blowing from one side of the car to the other, providing a point source of "fresh" air to the radiator. IE, air that hadn't already seen the heat of the AC condensor.

 

do you think that would really lower the temperature of the air flowing over the radiator fins dramatically? I was anticipating wiring it to come on only when the AC is on.. my stock electric fan is currently hotwired and running with the key on (got it like that, saw/see no real reason to change it)

 

It seemed to me that with the space between the two, it could make a difference. That, and I've got several ideal little blower fans from nissan 280ZXs.. they had this thingy that blew air up over the top of the cylinder head down over the fuel intake...but the fan would fit perfectly, at least in my head.

 

Any air flow engineers out there care to sound off?

[nipper]

i had this, and beleive it or not it was a tired Radiator fan motor. The bearing was shot, so it was drawing a lot of current, and the temp increase was false. It was a voltage drop that caused the temp gauge to go up, along with a very very tired radiator.

 

So check your cooling fans make sure then spin freely and have no play

Physically remove and inspect the radiator. It may look fine from the engins side, but its possible on the other side all the cooling fins are gone.

The temp going up with the AC gone is the standard sign of a clogged/decrepid radiator.

 

If you do do an auxiliary fan, use a radial not a blower tupe motor. you need to run air over as much as possible of the radiator, not just one spot. One spot wont do a thing.

 

nipper

[daeron]

nipper: replaced fan and radiator both already. my thought was specifically to feed some positive airflow AROUND the condensor whenever the AC was on. i would achieve better results if i could route some ductwork to be blowing fresher air into the gap between the two coils, but thats totally more difficult than simply hanging a little blower fan pushing a little air into that region just behind the condensor.

[NorthWet]

First off, do everything possible not to let the coolant level run low. If my assumptions about the case's transom coolant passage is true, any lowness could risk serious overheating.

 

I would think that blowing air in between condensor and radiator would not do any good, and might cause issues by disrupting airflow through the area (though doubtful with the amount of air that a blower could provide). And this sort of thing is likely to compomise your A/C, so all-in-all you might be better (if sweatier) to turn off the A/C.

 

Do you have the engine driven fan (for A/C) on your car? Could the fan-clutch be malfunctioning? I would consider putting on a second electric fan (an EA81 slim fan, like GD and others have recommended recently) in place of the engine driven fan.

[nipper]

If you can get a hold of a FSM, the FSm tells you exactly how much air moves through that area (its huge) , and there is really no way to match that besides what the factory already has done, unless you squeeze in a radial fan.

Also what you may do can interfer with the normal flow of air, and make things worse. Air flow is not an exact science and flow can be disturbed.

 

nipper

[daeron]

so, a slight addition of positive pressure at one side would not really decrease the temperature of the air flowing into the radiator fins then?

 

once i fix my headgasket, it wont be an issue. however, i was still considering it for the overall efficiency of the cooling system as a whole. the idea occurred to me one night, driving around. since i drive pizzas, i pretty much start the car when i go to work after topping off the coolant.. then drive around all night (50-100 miles) and dont have a chance to top off the coolant until that night, at home, after the engine has cooled off. there have been times when i was forced to carefully open the radiator, and SLOWLY add water while the engine was running in the middle of a shift, but ive tried to minimize that.. and those times were all in situations of "i have some sort of coolant leak, but i havent traced it down yet." my headgasket is bubbling compression into the cooling system, so im slowly popping things that havent been replaced yet... yes the crank fan is installed, yes its functioning properly.. the coolant is going into the combustion chamber....slowly. but 100 miles a day is not slowly, any way you cut it.

 

and yes, i know, i need to do the headgasket. that was the VERY first sentence of the thread. im not trying to fix the problem of my temp going up with this stupid blower fan... im asking a theoretical question about air flow, which is a subject i KNOW to be complex beyond my current awareness of it. my motivation, rather than being a jerry-rig fix, is simply more efficient operation of the system as a whole.

 

thank you nipper, for answering that question.