desmophile

If I run 95%water/5% water wetter (more or less) in the Z06 at the track this summer, and use the air conditioner, is it possible to freeze the heater core by running frigid air through it? (since water wetter has no antifreeze property)


I read that on the Redline Oil products (water wetter folks) website. This seems really unlikely to me because the system would be taking in 100 degree air and cooling it to 70, and then it would go through the heater core. Or the AC heat exchanger could even be downstream of the heater core. Couldn't find a diagram of the system on the net, or answers in a forum search, so I thought I would toss it out and see if someone could help me.


thanks, paul

davepl

OK, but a few things would have to happen:

- The discharge from the AC has to be super cold, like 25F, which I've never seen on a hot day
- The water flow valve must be off and must be a tight seal
- No antifreeze in the coolant
- The heater core must be right downstream of the evaporator

With those four things being true you could freeze your heater core.

383vett

desmophile

Thanks, that pretty much puts that question to rest. Glad you know how that system is arranged, I could not figure it out.

My 2017 Z06 A8 coolant will be changed to 95% distilled water/5% water wetter for the track season

back to regular antifreeze for the next winter.

thanks, paul

JHundertmark

Agree with others that you should have no issues.


In general, the A/C system has controls to maintain the evaporator just above freezing to aid in not having very moist air freeze on the evaporator core. In addition, the compressor will generally not run if ambient air is below freezing.


#3 - Side note is that air that goes through the evaporator will pass through the heater core if your inside car temperature setting requires some warming of the air. All of the air goes through the evaporator & subsequently the temperature control door will modulate how much air flows through the heater core depending on conditions.

davepl

If you look at the airflow diagram of a 1969 C10 pickup (or Camaro or Impala) it's pretty ingenious, particularly with fresh air and recirc built in with just two vacuum cans.

Normally air from one (heat or cool exchanger) does not flow through the other, but they're post-mixed after heating or cooling. I don't have a diagram of the C7 HVAC handy though!

Bill Dearborn

I agree. They don't want the evaporator freezing. That reduces air flow through the evaporator and causes ice flecks to be thrown out of the AC vents. At some point the AC shuts down and the ice on the evaporator shuts down and you get water spraying out of the events as the ice melts. Then you go through the cycle again. Been there and had the problem on my first Air Conditioned car back in 1966.

Bill