Heat soak is an issue, that 250kg of hot metal, when parked, only has one way to get out and that is through the same condenser that was cooling you a few minutes ago. I think it would labour for a while until you got some real airflow through it.

Just checked with Bruce Anderson's book, my fan pulls 1380 litres per second at 6000 rpm, so if one assume linear flow (likely not true, it almost for certain tails off at higher rpm) then at idle one is drawing about 200 litres per second (about 7 cu. ft. per second or 420 cfm) so a decent flow even at idle. Certainly I notice that at dead idle, my AC is not quite as cool ( I have left the thermometer in the vent while I check out the system), I see about 40-45 F in traffic idle, and about 36 F best case while cruising (all temps at 28 c outside temperature).

I started on the math for the heat extraction capacity of this airflow, but ended up needing to know such esoteric things as the temperature of the condenser under load....but it is .569 watts per cfm for a 1 degree C change. So very simplistic calculation ought to show that if the condenser is 10 c over ambient, at idle I came up with about 2300 watts of heat extraction capacity in the air with the air leaving the condenser of course 10 degrees higher than it went in. And then I got lazy....get into transfer efficiencies ...

Empirically it works and the practical side says leave it at that...

D.

Cool.. Now I'm intrigued. I'll hold off on ordering until I see the surprise, then. Glad I haven't pulled the trigger on purchasing the rennaire kit from pelican, yet. And glad you're teamed up with them as maybe I'll be able to get this part of the resto planning locked up.

"...Now I can go back and finish.."

Why bother, By your standards, high-lighted above, your requirements for our understanding most of what you write is beyond our comprehension.

RetroAire system condenser
 

I have one of these same exact condensers and have completely thoroughly tested it on my 911, Then removed it because I was not satisfied with its efficiency or its vey old Parallel Flow condenser technology, after I tried and tested several other newer designed technology condensers , but I will say it works better than anything Porsche and/or Behr has for a 911 which is not saying much, except to say RetroAire’s claims are overblown

THE ONE I BOUGHT DID NOT COME FROM RetroAire <grin>; the condenser is American Made and I bought it strictly for testing purposes, and I was disappointed in it after I tried and tested several others newer ones to say the least before building my own.


This is a “Generic Universal Parallel Flow condenser”, is using rather very old technology called “Multi-Flow technology” compared to today’s much newer Parallel Flow condenser technologies!!!


FYI Parallel Flow “Multi-Flow technology” Condensers is obsolete technology and I DO NOT USE IT!
If you want to save a few dollars you can use it I guess, it definitely works better then what you have but that is not saying much because I have been there and done that and if you want to spend your money on old technologies instead of new technology I leave this up to you

As a courtesy and respect to RetroAire I am not going to rain on their parade and post the link to where this same condenser can be found much cheaper

Reid

...Reid, just a small note of caution. I realize you are passionate about your work and are more than likely correct about the efficiency, but you just want to be careful not to diss people who are otherwise happy. Leave it as being that you are working on a better mouse trap and take care not to cast too many aspersions on other companies or people who knowingly bought from them.

I do hope you are able to get your product well into market and it gets picked up by some of the vendors that you refer to, or perhaps you become a worthy competitor for them.

D.

"..made several of my own..."

If "you" were in charge of making these than why are they not fully form and fit compatible with your target market....?

Isn't it rather ARROGANT to ask ALL your buyers to modify their cars in order to fit something you "made", something that in the end that will prove to be less effective, efficient, and a LOT more expensive, that simply installing 2 12 volt fans at $34...?

Something you found on the Russian internet...?

KelogGes, is your tubing from Brazeway?

looks like it. Brazeway Automotive micro-multiport tubing Â

Just curious... I have designed machines that help them produce the stuff along with other types of aluminum tubing they make.

That's Patent Pending

no

Subscribed, ..........do you ship to Europe?

1975 Carrera

Hello André,

Thank you for asking

Answer unfortunately at least for now I must say NO

I am just starting up what I have invented which is Patent Pending and my patent attorney has advised me not to export outside the USA at this time

For your information;
I have worked on FEADSHIP's on and off for 30 years related to Marine engineering; I have great repect for people in the the Netherlands ( believe you know about FEADSHIP ?)

I like this idea... but the only way I would buy a new front condensor at hundreds of dollars is if it fit the stock location.
There is no point with the crappy fan that is pushing air through it. The limiting factor between yours and the Rennaire Dessert Duty I have already is not the condensor its the amount of air generated by the Bosch Fan.

I would be game on the rear deck condensor. I already have a fender mounted supplemental condensor with a fan.

I disagree. I have a supplemental condensor with a hight output fan... it helps, but the deck lid condensor performance absolutely was NOT mitigated by adding a $34 fan...

".....but the deck lid condensor (poor) performance absolutly was NOT mitigated by adding a $34 fan....

First, $34 gets you TWO fans.

You imply that you TRIED the deck lid fan(s) technique and it did not work to your satisfaction...

How so...?

i am not saying that fan(s) dont help. i am saying that if you want 35 degree vent temps in 96 degree 80% humidity texas weather (it was 106 today)... adding 34 dollars worth of fans isnt going to get you there... been there done that... you need a wholistic approach to AC in the 911 anytime its over 88 degrees.. changing the evap to more efficient type, adding high output evap fan, changing condensors to more efficient models, adding supplemental condensors with fans.. will get you there. What this guy is selling is in fact one peice of the puzzle. Griffiths and Rennaire have proven that. I was merely pointing out that saying that an upgraded superior condensor is a waste of money and all you need is 34 dollars worth of fans... is really oversimplifying the problem for anyone in the southern half of the US.. Wouldnt you agree?

Perhaps in the Paciffic NW that is all you need... I assure you that you would be VERY unhappy in Houston TX if that is all you did...

"..I assure you..."

I hope you don't mind if I don't take your word for that.

IMMHO the proof is in the pudding.

To late to plan for this year but maybe next year, August, we can bring our '88 to "planet" Houston. You do know, do you not, that the Porsche 911 A/C sysetm is ALWAYS in recirculate. If you can deliver a continous flow of liquid refrigerant to the evaporator expansion valve, you're home free.

Oh, looking down into the "cubby" today I couldn't help but think discharging a full can of "Good Stuff" to fill in, isulate, the exterior of the evaporator/blower plenum might be of help.

No disrepect, you made some comments,

My reply is not ment just for you, many people are reading here that do not post post messages in the channel, and there are somethings going on in the background

As such this is my reply
Please note: I will do a long post about condenser blowers/fans soon when i have more time

FYI or anyone who missed this; My patent pending front condenser was specifically designed to fit within the 911 930 stock location!!!

I guess some people don’t bother to read everything I have taken the time to already address and written here, then make comments

I GUESS YOU NEVER READ WHAT I SAID/WROTE HERE A MONTH AGO WHEN SOMEONE SAID BASICALLY THE SAME THING YOU SAID TO ME TODAY? THAT I ANSWERED ALREADY ABOUT A MONTH AGO

However my front condenser ON PURPOSE does not use the original OEM screw holes because MY SPECIFIALLY INTENDED DESIGN IS slightly larger in length and width, but it also mounts far more securely to the front pan underside body then the OEM condenser does. THERFORE if a rock guard is going to be used, the rock guard will need to be modified or be replaced with a new fabrication

When I read some of the posts here by others; You guys just don’t seem to get it sometimes, SOME OF YOU ARE LOCKED INSIDE A BOX OF OLD TECHNOLOGY and attitudes that never worked VERY G-O-O-D ON 911s!

Porsche 911 930 A/C history lesson 101 GENERAL KNOLEDGE
Never forget THIS SIMPLE FACT; Porsche never designed the 1963 to 1989 911/912 930 body to accommodate air conditioning to be used PERIOD!!!

A/C WAS AN AFTER THOUGHT ONLY, caused from Porsche 930 USA American sales demand!!!
AFTER the body HAD BEEN SET IN STONE, and Porsche never changed it, until about the END of 1989; The 930 body was completely redesign for a completely new model, and that for the very first time EVER; the replacement model FINALLY had an air-conditioning system included IN THE NEW MODEL BODY COMPLETELY RE=DESIGNED AS AN INTEGRAL PART OF THE NEW BODY!!!


I am not like most people!
I think outside the box, I have new technology never before used on a 911 and I have used every possible millimeter available that can be found in the body, if I needed too, to enhance its design to the extreme that I can and still allow it to fit if it enhances it, that Porsche engineers overlooked when they gave BEHR original parameters for design their OEM models Condensers, and furthermore I have done things they either never dreamed of or decided to use for whatever reason, and they both made a lot of mistakes what they dumped on their multitude of buyers to give the world a Porsche car with a bad joke for an a/c system.

You would have thought that Porsche with some of the best engineers in the world would have re-engineered the 911 somehow in the early 70s to have a decent A/C but I guess corporate greed just did not care enough to fix it!

Well I HAVE DECIDED TO PERSONALLY DO SOMETHING ABOUT IT TO FIX IT FINALLY THEN JUST TALK;
IN MY OPIONION WITH WHAT I HAVE DONE WITH MY LITTLE CONTRIBUTION FOR THIS FINE CAR;
IT NOW WORKS!

I AM USING R-134A and After I DESIGNED, CUSTOM MADE AND INSTALLED 2 HIGH TECH STATE OF THE ART CONDENSERS’ borrowed a RennAire Serpentine Evaporator from Cab after he read about what I am doing here and messaged me to inquire about my condensers;

MY VENT TEMPS HIT MY TARGET of 41; sometimes I get in the mid 30s F, and I know without a doubt when I make further tweaking of the car and the A/C SYSTEM it will only get far colder’ ( except I have been just too dam busy so far making more condensers to tweak it,)

To the Nay Sayers if there are any my question is;

SO HOW COLD IS YOUR 911 AND WHAT ARE YOUR VENT TEMPS NOW IT’S AUGUST WITH RECORD HIGH TEMP???

""I am not like most people..."

GRANTED..., in spades.

"...I think outside the BOX.."

And therein lies the problem...

A little more thinking inside the box (rock guard box:cool:), common sense, non-degreed shade-tree mechanic thinking, would be of tremendous aid.

"...WHAT ARE YOUR VENT TEMPS..."?

And the price of tea in china is....

As long as the compressor system can deliver a continous stream of liquid refrigerant to the evaporator expansion valve NOTHING else matters on the HIGH side.

Your upgrade is not only useless in that scenerio and therefore extraordinarily costly.

You have a good idea, but why not stop with the rear condensor, properly sized, and fit 2 inexpensive fans....?

TRY IT, you might LIKE IT.

Since you're running trials anyway.

Why do you talk about air-to-air condensors on shipboat when there are so MANY BTUs to be much more easily had in that water...?