how many cars are on the road now with ONLY electric fans?

Many, and I've had to repair replace 6 of them on step-daughters friend's cars.

Never mind how many in the auto industry have had to replace.

I wouldn't trust a thermo-sending unit as far as I could throw one.

That's the thing that turns the fan on and off.

 

An subjective atmosphere has grown around this electric fan debate. It's all relative to what each of us have witnessed with cooling fans period. I have had zero electric fan failures in at least a million plus miles. On the other hand I have had conventional belt driven fan failures for various reasons. By the standards of of observation and conclusion set here, I conclude that belt driven fans are more prone to failure.

If any fan on any vehicle runs off of an electric circuit it is possible to have some sort of electrical failure someday and your personal experience is relative to it and not an absolute of all fans like it. I see people with their cars setting and running ALL THE TIME during the summer in order to keep dogs cool in the summer. I'll bet their fans fail sooner than later. Remember it's all relative.

Anyway, an almost always forgotten point is that most people spend the majority of their driving time moving at speeds fast enough to eliminate the need for any fan at all. How does an electric fan's efficiency fall to and stay at a best of 45%?

If no fan is needed during engine warmup and at high enough speeds, then an electric fan is more efficient.

If you don't like them don't use them and stop exaggerating the pitfalls of them.

 

No exaggeration here. I am glad you have had good luck with your electric fans. Please don't exaggerate the failure rate on mechanical fans. Remember the mechanical failures often will give indications of pending failure and will get you home or down the road to help, -electrics just fail...

Read the post. -The alternator's efficiency is at best 45%.

I have had both electrics and mechanicals fail. Given the fact that mechanicals are much more prevalent in the vehicles I have worked on I would expect more mechanical failures and I have witnessed that, but not at the same ratio.

The electrical failures have fallen into several categories:
-Cheesy aftermarket mounting systems.
-Sloppy mounting workmanship even given the crap they were given to work with.
-Worn out bearings, gives advanced warning.
-Cheesy aftermarket wiring.
-Sloppy wiring installation.
-Burned up motors.
-Burned and failed controllers.
-Shorts and opens in the wiring.
-Failures that took out other expensive components also (radiator, alternator, wiring, controls).
-Broken belts.
-Broken blades.
-Alternator failures.
-A bad OEM motor design.
But OEM wiring and installations are orders of magnitude better than aftermarket junk.

Mechanical failures fall into several categories:
-Worn out bearings, gives advanced warning.
-Silicone fluid leakage, -visible and gives advanced warning for a LONG time.
-Failures that took out other expensive components also (radiator).
-Broken belts.
-Broken blades.

As you pointed out this is relative. Some do and some don't.

Mechanical fans de-clutch and freewheel when they are not needed also saving power and fuel. Admittedly not to the same degree but then the electric does not operate with the same efficiency when it is running due to mechanical-electric-mechanical drive inefficiency (36% or less).


The fact remains that the OEM at present will always use a mechanical fan if possible even given the fact that they are looking for dyno HP numbers and fuel efficiency. They have to take into account reliability also and they warranty their product for years and stand behind it with a parts AND labor guarantee. They have done a ton of testing that we can not possibly do.


Use an electric for an auxiliary fan or "bling value" but keep the mechanical for reliability and efficiency.

Remember for the price of an aftermarket fan you can buy a lot of gas.

 

I don't think you're considering this though, does a ford GT-40 have a clutch fan? They must have more then enough HP to move that? How bout a ferrari? Porsche 911 Turbo?

And don't tell me, "Well your truck is not a Porsche." Well you are right, my truck ISN'T a porsche, but it also does alot less work then a porsche does. Lets think about the ways OEM think, aproximately 5hp to move a vehicle at highway speeds, the only time they have to worry about fans is in the summer. So we have a clutch fan that's cheap, and efficient (at keeping the engine temps down). Does the extra 5-6hp that that clutch fan takes up really matter? Not to them. It's the same reason they don't put lightweight pulleys or ground kits in their vehicales, it's not cost effective. The average truck buyer doesn't worry about reving a little quicker, or 5 more miles per gallon, that's the point of an aftermarket. But these things are tried and true.

Point in case being, electric fans ARE more effcient, but not cost effective if you're going to build 100,000 vehicles with them instead of a clutch fan that costs $100 less. ($100 x 100,000 = alot of money for an electric fan)

 

Apples and Oranges here... The Ford GT and those others don't have the room or the configuration to run mechanical fans and they are limited production vehicles, -no comparison.

This is off topic but the OEM does not use those light aluminum pulleys because they will not last long enuf and they would be replacing thousands under warranty. They also don't drive the accessories at the speeds they consider optimum for most vehicles. BUT the bragging rights to 3 more HP than a chebby DOES matter to marketing so they look for HP and fuel economy everywhere they can. They are looking at high $$ materials, and cutting ounces. Unfortunately E-fans are NOT more efficient at present with 12V electrical systems. If they thought an electric fan would save them 3 HP and 0.05MPG it would be on there.

Go ahead and use an electric fan if you want bling but they are a waste of $$, and time, unless you use one as an auxiliary pusher fan. It is certainly your money.

There is a more efficient fan setup at the moment that uses the wasted power from the PS pump to run the fan. That system will probably be used more often until they get the high voltage electrical systems perfected and then everything will run off electricity and most vehicles will be diesel-electric hybrids.

 

http://www.lorencook.com/pdfs/cookbook.pdf

http://www.lightruck.com/other_cyclo...stallation.asp

 

Nice info on AC fans Dennis. I have a similar book around here somewhere but mine is a mite more technical. Fans are still considered somewhat of a black art but computer simulations are improving design tremendously.

The cyclone electric clutch fan is a nice idea and has advantages and disadvantages. Kind of a semi compromise. Too bad they can't combine one with a RPM limiting clutch. They do mention it helps slow the vehicles on down grades when engaged. -Don't doubt that at all!!! Unfortunately their marketing department is not comparing apples to oranges, and doing some creative figuring, -but it is typical marketing hype.

 

im liking my electric fan allot so far, but as its the first one ive personaly used i saved the old clutch fan just incase. the problem i had with the clutch fan was it took forever for the motor to get up to operating temp. So i opted to try a electric fan. So far my results with the electrif fan are it kicks on at an idle and usualy going down the road it never needs to kick on. Course i also have a 4 core radiator the biggest the truck can take. Thats my results atm, so far i like it, as far as reliability ill have to wait and see