anti-freeze

[gaC5]

I recently had a new radiator put in my 78. When I checked the cooling system it was just showing 10 below protection. I want it to be a little higher so i drained out a gallon and put in a gallon of anti-freeze. It now seems like when I have on my a/c that it is cooler.

 

[lnirenberg]

I recently had a new radiator put in my 78. When I checked the cooling system it was just showing 10 below protection. I want it to be a little higher so i drained out a gallon and put in a gallon of anti-freeze. It now seems like when I have on my a/c that it is cooler.

Not to rain on your parade and keeping in mind its a 50/50 shot that I could be wrong, to the best of my knowledge anti-freeze only serves 2 purposes that can't be done by plain water--rust inhibition and the obvious, lowers the temp at which our engines would freeze to death. From what I have read, water is a better cooling agent especially when treated with water wetter, and in perpetually warm climates this is the better alternative. Does is it get colder than -10 in KY?

 

[gaC5]

Very seldom.

 

[bill81vette]

the antifreeze system has nothing to to with the a/c system.
What Inirenberg said.. that is all the cooling system does.


bill

 

[WayneLBurnham]

Antifreeze also greatly increases boiling point....BUT....

ethylene glycol does carry and transfer less heat than water, both per mass and volume.

Worse still is propylene glycol...the active ingredient in "low tox"....I hate that I have to use it, but I have one severe allergy - oddly, to regular antifreeze!

 

[Tom73]

I recently had a new radiator put in my 78. When I checked the cooling system it was just showing 10 below protection. I want it to be a little higher so i drained out a gallon and put in a gallon of anti-freeze. It now seems like when I have on my a/c that it is cooler.

Is there a question in there or is it just a statement?

 

[gaC5]

I guess the way I stated it it was actually a statement. But actually I was trying to get some coment on whether adding more anti-freeze to my cooling system would make the a/c cooler.

 

[WayneLBurnham]

Generally not. The whole working "guts" of the A/C

is in front of the radiator - so, aside from some radiant heat from the radiator going FOREWARD against air flow, there should really be no impact of engine cooling system on A/C system.

That being said, however, since the whole car is the system and C3's love to send engine bay heat into the cabin, if you do manage to reduce engine temps substantially, you probably will be cooler in the cabin so the A/C will seem to working better.

 

[gaC5]

Good point. Maybe that's it.

 

[Tritium007]

Adding anti-freeze should slightly reduce the heat removal capacity of the cooling system until the heat in the system exceeds the boiling point of plain water at the saturation point for a given system operating pressure (whew). The extra anti-freeze only extends the boiling point for the same pressure that the water would vaporize (and it also provides corrosion resistance). Which means you can run a little hotter. Theoretically, the thermostat controls the temp and the anti-freeze just provides a buffer to overheating and also serves as a form of back-up protection. Somewhere in between, the idiot light is supposed to come on. The other factor is that the A/C compressor requires more engine work to operate (ie, horsepower taken away from the rear wheels to drive a belt instead). This extra work creates more engine heat load for the same vehicle speed (higher RPM). I could be wrong about the specific heat capacity of anti-freeze, but if it were greater than water, why wouldn't we use 100% anti-freeze? Of course, any changes in air temp, flow, or volume can have an effect on your cooling system. Just my opinion, comments always welcome. I consider it a wasted day if I don't learn something.

 

[WayneLBurnham]

Goes along with everything I've heard...

Ethylene glycol carries substantially less heat than water, propylene glycol ("low tox" a/f and Evan's waterless coolant) even less. That I can testify to as I always change my heaps over to low-tox since I found out I am so damned allergic to the normal a/f. I usually notice a slight but definite increase in temp afterwards.

The site for Evans waterless coolant I believe even lists the specific heats of a lot of potential coolants, including theirs. (Evan's changes your water pump and deliberately runs engine temps to the 300-375 range and makes use of the super high BP of pure propylene glycol.) I wish somebody would experiment with that stuff on their engine so I could try it!