Need second opinion on AC condenser to radiator placement on a '65

[Cannoball888]

Need second opinion on AC condenser to radiator spacing on a '65

Today I was making custom fan brackets and removing the bottom radiator support on my '65 to fit a fat Griffin radiator. I was thinking about what the guy at Griffin told me. He told me that the radiator will cool better if I move my AC condenser right up against it. This makes absolutely no sense to me, and when asked he couldn't explain the reasoning behind this advice he said he just knows it works better. But I know for a fact that more air is drawn through the radiator if the condenser isn't right up against it blocking it. Anyone think he's right, and if so why?

 

[Tim65GT]

I added the Vintage Air kit with the brackets that came with it and it had overheating issues. I removed the condenser brackets and bent them so it mounted about a inch and a half more away from it.

It now doesn't overheat, but it still gets hot. Once it starts clinbing past 210, it won't drop unless I turn the AC off. A bigger aluminum radiator is in my future. Of course my AC is probably less efficient now, but it blows cool pretty damn good anyway (yes it is R134)

Your right, what he said doesn't make sense. The more room between them, the more flow of air to the radiator that hasn't been "preheated" by the condenser.

There might be a more scientific reason for what he says, like maybe the air flows smoother or faster through them as one unit.

 

[xoxbxfx]

i was thinking its because air would cavitate between the 2 whereas if they were together, it would act as one

 

[fastdave]

I was told the same thing. Something about some of the air will go around the condenser not through it resulting in less heat transfer in the a/c condenser. Be carefull about getting a fatter radiator because it reduces some of the air flow through the radiator. less air flow,more of a chance of getting hot. Look at ANY brand newer car. The A/C condenser is very close (1/4") to the radiator. Also the radiator is thin and wide. This is why I am going to modify my opening to fit a wider radiator that is alumminum,and 2-1" rows and a cross flow w/ electric fan(s). Ever wonder why the smaller (narrow) radiator was only on 65 & 66 mustangs? Also they usually had overheating issues. (not always tho). In 67 they changed it to a wider one. wa-laaa! No more overheating issues. At least that is what my little mind thinks.

 

[Cannoball888]

I was told the same thing. Something about some of the air will go around the condenser not through it resulting in less heat transfer in the a/c condenser.

The Griffin guy was talking about the radiator cooling better if the AC condenser were closer to it, not the AC condenser cooling better. Anyhow, I guess if my car still overheats, I'll try his advice.

 

[reenmachine]

The condenser should be as close as possible to the radiator. If it's spaced too far away, the air flow becomes turbulent between the two and the efficiency of the radiator is reduced. Warm air flowing cleanly through the radiator removes more heat than cooler air that's turbulent. If you're overheating you don't have enough radiator or somethng else is wrong.

 

[Cannoball888]

The condenser should be as close as possible to the radiator. If it's spaced too far away, the air flow becomes turbulent between the two and the efficiency of the radiator is reduced. Warm air flowing cleanly through the radiator removes more heat than cooler air that's turbulent.

I just found a post on another forum that this is correct and the explanation is, as reenmachine wrote, to reduce turbulence. So, Griffin guy was correct after all. Therefore, the AC condenser should be mounted as close as possible without touching (only because touching will cause rubbing).

Here is the other post I found with a detailed explanation if anyone is interested in reading it:

Posted: 12/23/2001 10:04 EST

Lost and Found and I have a little bit of a healthy disagreement on this subject, whereas a 3/8 inch space vs a 3 inch space is a lot of difference. He is correct, they do ideally need some space. I run them frame to frame with rubber spacers and depending on radiator or AC coil design, this leaves about 3/8 to 1/2 inch in between.

My friend (actually a part time rodding buddy) here in town who owns 5 differing FROSTEMP locations across the southeast, a company specializing in all kinds of automotive and truck airconditioning needs and installations, says no more than 3/4 inches for the best or ultimate positive transfer of airflow from front to back for the entire coil and radiator unit. But this depends somewhat on speed and design of course.

Ideally, the coil can be run up against the radiator, but it won't be as effective. I know of alot of them that work fine but I would be afraid of core to core rubbing and eventual problems on that front than anything else.

The air coming thru the AC coil will be set up or straightened to an extent when flowing past the fins and tubes of the AC coil. Because the fins and/or tubes of the radiator do not match exactly the same spacing and line up correctly with the AC coil, it is advised to design a space in between the AC coil and the radiator to let the air move in semi straight/deflected lines, but not eddy or build unorganised pressure to any extent behind the AC coil. If this happens, the air that was coming thru the AC coil that was all formed and mostly straightline becomes disarrayed, (the more space the more eddys and unorganised it gets...kinda like walking away from a floor fan....close up its very forcefull and organised...but the further you get from it it becomes unnoticeable and not moving due to eddys and air friction....same principle here) and bogged down and doesn't enter the radiator in effective straight line motion and creates a dead zone of trapped air. This produces two problems. One is that it traps conducted heat from the AC coil in front and diminished the airflow CFMs greatly.

By having the coil no more than 1/2 to 1/4 inches, the incoming air will permeate the radiator in a relatively organised and straight line matter and result in more CFM. The heat conduction from the AC coil (when in turned on) WILL take place in ALL systems. Your radiator and cooling system has to have the capacity to take on what the industry design standard is of around 15 degrees higher ambient temperatures going into the radiator. This is why if you have overheating problems in any car, the turning off of the air conditioning helps enormously to help cooler air get to the radiator.

This is also why Griffin (and the OEM boys install larger radiators for AC cars) recommends most applications without air to use their 1 inch tubed radiator and with air their 1.25 incher, for increase in cooling capacity expecting the incoming air to be higher. Their combo unit by the way is spaced 3/8 to 1/2 inches depending on design from the factory if that's any help.

 

[95 cobra clone]

well can anyone tell me why my 96 mustang with 5.0 heats up whil driving 85-90 mph.the bottom radiator hose isn't squeezing cause it has a spring in it,the condenser was removed because it wasn't letting enough air threw while sitting in traffic and it was clogged up with bugs so once I fixed that problem by removing the condenser its starting to heat up while driving at high speeds .I bought new radiator and twin fans with aluminum fran strod new water pump plus the system was flushed before installing new parts.I kind of think my problem is with the condenser removed and me running high speeds like that,the wind comming threw the radiator is stopping the fans from spenning properly so I'm going to purchase a new condenser.