How cold is your AC at idle? - Page 2 - PeachParts Mercedes-Benz Forum

Graplr · #1 05-08-2009, 09:51 AM

Well, my temps are from last year as my AC is nonfunctional right now. (I poked a hole in my parallel flow condenser when taking the engine out last fall.) I have a new condenser coming in today and may be back up and running this weekend.

I had a parallel flow condenser. I first ran it on r134a. My vent temps with the blower on high were mid 40sF. At a stoplight they rose to ~60F. I wasn't pleased with that so I decided to take out the r134a and put r12 in. I noticed a slight increase in performance with just a few degrees cooler a both idle and on the highway. If I put the blower on low vs high I noticed a substantial decrease in vent temp. About 5F.

The condenser I just ordered is much bigger. The one I had originally was 24.5 x 14. The new one is 26 x 16. I did a bunch of measurements and shuffling my old condenser around and I should be able to make it fit. We'll see how much of a difference this makes. I will be putting r12 back in since I now have a recharge and recycle machine in my garage.

ah-kay · #2 05-08-2009, 10:38 AM

Quote:

Originally Posted by Graplr

I first ran it on r134a. My vent temps with the blower on high were mid 40sF. At a stoplight they rose to ~60F. I wasn't pleased with that so I decided to take out the r134a and put r12 in. I noticed a slight increase in performance with just a few degrees cooler a both idle and on the highway.

Is this fact or fiction that you only noticed a slight increase in performance with R12? Is it true that some members insisted on R12 is superior and is willing to pay the price for it?

JimmyL · #3 05-08-2009, 10:40 AM

It doesn't matter, on a W123, whether you are running R12, Freeze12 or R134a, at idle on an above 90 degree day your vent temps will climb over 60 degrees. If you idle for 10-15 minutes [ trying to eat your lunch for example

] it can approach 70.
The condenser and the aux. fan do not support the AC system in a manner that will get you any better.
BTW, I've had/have W123's with all the freons indicated above, with very sound AC components. It's just what these W123's do......

leathermang · #4 05-08-2009, 10:52 AM

ah-kay,
Your credibility has long since vanished on this subject. You only look silly with these kinds of childish posts. You might as well do the research and figure out how to help people with AC issues by sharing good information instead of wasting bandwidth with more trolling.

The ability of an automobile to continue putting out acceptable cool after being caught in traffic can be helped by increasing the volume of the system between the conversion point in the condenser and the TxValve. This is the part of the high pressure area where liquified refrigerant is stored. A larger condenser or a larger receiver dryer ( or two being my preferred method ) can store up the work done by the system AT SPEED... and utilize it when less than ideal conditions of air passing by the condenser happen afterwards.

ah-kay · #5 05-08-2009, 10:59 AM

Quote:

Originally Posted by leathermang

ah-kay,
Your credibility has long since vanished on this subject. You only look silly with these kinds of childish posts. You might as well do the research and figure out how to help people with AC issues by sharing good information instead of wasting bandwidth with more trolling.

If you have nothing good to day, say nothing. Did you read thee forum rules.

Brian Carlton · #6 05-08-2009, 11:36 AM

Quote:

Originally Posted by leathermang

ah-kay,
Your credibility has long since vanished on this subject. You only look silly with these kinds of childish posts. You might as well do the research and figure out how to help people with AC issues by sharing good information instead of wasting bandwidth with more trolling.

The ability of an automobile to continue putting out acceptable cool after being caught in traffic can be helped by increasing the volume of the system between the conversion point in the condenser and the TxValve. This is the part of the high pressure area where liquified refrigerant is stored. A larger condenser or a larger receiver dryer ( or two being my preferred method ) can store up the work done by the system AT SPEED... and utilize it when less than ideal conditions of air passing by the condenser happen afterwards.

I agree on all points.

SwampYankee · #7 05-08-2009, 01:59 PM

Quote:

Originally Posted by 79Mercy

Today I was stuck in alot of afternoon traffic and the vent temps were like 65 degrees. It was about 92 degrees outside, once moving the vents temps came down to about 45 degrees. So how is your AC at idle?

Ambient temperature + 5-10 degrees. It would probably be cooler if the AC worked.

leathermang · #8 05-08-2009, 02:12 PM

Quote:

Originally Posted by SwampYankee

Ambient temperature + 5-10 degrees. It would probably be cooler if the AC worked.

LOL !!!!!!!

When I first started researching automobile AC stuff... I was surprised at the capacity of automobile systems to cool. A room AC in a house is only expected to change the air from intake to exhaust by 6-8 degrees... but run regularly in order to take out the moisture in the air... and it has the entire room of cool air stored up when the door is opened.. etc...

BUT our cars.....and particular SwampYankee's WAGON are aptly described as ROLLING LEAKING GREENHOUSES with regards to their ability to take in heat...

If this concept were more firmly entrenched I think fewer shortcuts would be offered or accepted in working on automobile AC's...

Matt L · #9 05-08-2009, 09:32 PM

You're right, Brandlj. I didn't have a car with AC prior to 2004. I did ride a lot of miles though, both on motorcycles and bicycles.

Now, I don't want to live without it. That's why I insist on proper service. I want the system to keep cooling me for years to come.

By the way, try this link. Sums up what I think about the crap they sell at Auto Zone.
http://www.google.com/search?q=%22death+kit%22+ac

TheDon · #10 05-23-2009, 11:12 PM

-set to cold-

ohh yeaaaaaah its nice and cold in the SDL at idle

#11 05-23-2009, 11:48 PM

AC is cold? I get 14.1volts at idle.

Neither of my cars have A/C, Colorado isn't hot enough for me to bother getting them working. My 240 has a great heater and my 300D is a summer car so I pulled everything out and have only a $12 ebay blower for ventilation when I can't have the windows down.

leathermang · #12 05-24-2009, 04:16 AM

Remember folks...
no matter how well the rest of the system is working you are going to have less cold air if you do not address the FINS ON THE EVAPORATOR....( UNDER YOUR DASH inside the car)
NOT easy to get to to clean... which is why most of our cars HAVE NEVER HAD THEM CLEANED... DWMorrison had a thread with great pictures of his project cleaning his...
Highly recommended procedure for all of us with 20 plus year old cars...

Mark DiSilvestro · #13 05-24-2009, 08:41 AM

All things considered, if an AC system has no, or minimal leakage I prefer keeping an R!2 system on R12 whenever possible. Othewise, I'm not wasting my limited supply of R12.
In 1990, I cobbled together a "factory' AC for my '87 Isuzu pickup, using salvage-yard components, includina an oversized condenser from an '88 Trooper, some new bits including a new filter-drier, and R12. Cooled great and I had to add maybe 2 pounds in over 15 years.
My '84 Euro 300TD was cooling on R12 when I bought it, and is still coolng satisfactory after a year without any attention from me.
My tired 82 240D AC, converted to R134, without any component upgrades, is definitely inferior, but better tha nothing. I keep it parked in shade and almost never use the car in rush-hour traffic.
If I really need ccld AC, under severe conditions, I'll drive my 98 Altima.

Happy Motoring, Mark

nickofoxford · #14 05-24-2009, 04:02 PM

Quote:

Originally Posted by leathermang

Remember folks...
no matter how well the rest of the system is working you are going to have less cold air if you do not address the FINS ON THE EVAPORATOR....( UNDER YOUR DASH inside the car)
NOT easy to get to to clean... which is why most of our cars HAVE NEVER HAD THEM CLEANED... DWMorrison had a thread with great pictures of his project cleaning his...
Highly recommended procedure for all of us with 20 plus year old cars...

Another important point to address. Im putting that on my to-do list.

Expansion valve is already messing up on mine, are they kind of in the same location?

leathermang · #15 05-24-2009, 04:32 PM

Very close although I am not sure that helps any... the Txvalve is pretty much straight under/behind the glove box...and at the firewall.... and the Txvalve connects pretty directly to the evaporator...but enough over that a whole different set of access procedures are involved.
Be sure ( if you are able ) to take and share pictures and any problems encountered... the more different car types are sampled the better chance of getting people to address this really weak spot in the cooling circus.