PhotoVette1

The much maligned late c3 factory auxiliary radiator fan does a pretty good job of increasing a/c efficiency at idle.

Here is some readings I took last night on my a/c condenser coil:

Ambient temperature = 75F

Engine speed = 800 rpm

Refrigerant entering condenser coil = 121F

Refrigerant leaving condenser coil = 103F

Refrigerant leaving condenser coil with auxiliary fan on = 90F

The temperature of the refrigerant drops almost immediately after the auxiliary fan is switched on.

I have a 7-blade fan with a new hd fan clutch and even so, the auxiliary fan made a significant difference to refrigerant subcooling. I plan to wire the auxiliary fan to also come on when the brake pedal is pressed and the compressor is on--that way it will engage at idle.

I did measure evaporator discharge temperature and saw a 3F drop in temperature at idle, but there are too many variables to get a good indication of the effect on discharge temperature.

ESU

Photo,
I've heard of these fans but never saw one, do you have a picture? Is this a stock factory option or an aftermarket add-on? I have a new 7 bladed fan, new hd clutch and I'm awaiting two new 10 inch flex a lite pusher fans from Summit today to help with a running hot problem. Have an a/c relay to turn them on. Just curious about your set up.
ESU

blackcorvette1980

1979 L82 with AC had auxilliary fan from the factory
1980 L82 All had auxillary fan from factory, but then all had AC since it was standard eq in 80
1981-82 All had Auxillary Fan

ESU

Where did this fan mount???
ESU

PhotoVette1

This is a fan shroud and auxiliary fan from an '81 Vette installed in my '77. I run a high rpm fixed race fan during the summer to keep the cockpit cool while the t-tops are off. No noticable decrease in mpg running the fixed fan. I put the 7-blade fan/clutch back on in the Fall.

I wonder how many CFMs I'm pulling with this fan setup?!

ESU

So the fan mounts in front of the mechanical fan and is used as a puller. I couldnt fit the #118 16 incher in there but at least one of the tens should fit just fine. Does the aux fan turn all the time or just with increased temps or the a/c on? I guess it doesnt impede air flow at all. Thx for the photo. Maybe I'll try mounting 1 of the 10 in on the inside first, I have the a/c relay and I'll hook it up that way for starters. Thx again for the photo,
ESU

ESU

Mounted a 10 inch puller from flex a lite tonite. Just finished the wiring , hooked it up to an a/c relay unfortunately with the car running in my very small garage I couldnt tell if it turned on but it looks good anyway.
Thx to All for the help and suggestions, gotta luv this forum, ESU