Evolution of A/C condensor fans

[mechtech2]

Overall, I prefer the electric system.
But a working clutch fan DID cool well.
Who can forget the start up roar of GM vehicles as the fluid in the clutch was redistributed?

 

[ltslimjim]

An example of a man-made evolutionary process...ironic to say the least.

 

[CBR.worm]

So here is a question that I thought of today, as I watched top gear.

Mechanical fans used to frequently be directly connected to the water pump. If at highway speed the fan belt broke, would the air moving through the radiator spin the fan fast enough to keep some water moving through the engine?

 

[RH+G]

Quote:
Plus R12 was more efficient than todays R134a.



Yeah but todays AC systems are more efficient than yesterdays R12 systems

The main reason they wasnt more electric fans around was cause of the lack of alt power.

A proper working clutch fan can cool just as well as a electric fan setup. The difference is an electric fan requirers more alt power and the clutch fan is robbing engine power.

 

[Nick R]

Originally Posted By: RH+G
Quote:
Plus R12 was more efficient than todays R134a.



Yeah but todays AC systems are more efficient than yesterdays R12 systems

The main reason they wasnt more electric fans around was cause of the lack of alt power.

A proper working clutch fan can cool just as well as a electric fan setup. The difference is an electric fan requirers more alt power and the clutch fan is robbing engine power.



And in the end, more load on the alternator robs less power from the engine than air drag on a clutch fan.

 

[lexus114]

Originally Posted By: Chris142
Originally Posted By: meangreen01


how much did having only a fan clutch driven fan effect A/C performance before electric fans became the norm?



A mechanical fan and a working fan clutch will move more air through the radiator and condenser at all engine speeds than electric fans could ever hope for.

Plus R12 was more efficient than todays R134a.

Todays AC systems get you cooled off in a couple of blocks. The old R12 with a fan clutch got you cooled off before you got out of the parking lot.



+1! Absolutely!!

 

[antonmnster]

I have a hard time accepting that electric fans are more efficient than a clutch fan.

Let's assume that you have two fans that are moving equal amounts of air; they're generating the same physical load. Making electricity is not 100% efficient, and using electricity to turn a motor is also not 100% efficient. The heat losses in the alternator and the electric fan motor can't be completely insignificant.

But the mechanical fan is directly driven; some heat loss will occur through the friction in the silicone, but it can't be as bad as making and using electricity.

 

[SteveSRT8]

But you're forgetting all the time where you do not need a fan.

Then your mechanical one looks like the dinosaur it is.

Sounds like a few of us need some AC work. Our Silverados (electric fans) and Savanas will all get cold before you can get out of the parking space. The difference comes when sitting still at idle. Other than the fans they are identical AC setups.

The electric fan vehicle wins every time in 100+ degree heat sitting still.

 

[mechtech2]

Originally Posted By: CBR.worm
So here is a question that I thought of today, as I watched top gear.

Mechanical fans used to frequently be directly connected to the water pump. If at highway speed the fan belt broke, would the air moving through the radiator spin the fan fast enough to keep some water moving through the engine?


Interesting. I believe there would indeed be water pump movement by the fan - no doubt at speed. Enough? Probably not. And all the dash lights would make you pull over anyway.