I make Parallel Flow Micro-Channel Condensers for 911's front and rear

[KelogGes]

Originally Posted by Josh D

My humble opinions.

I started out a couple of years ago just like you have with your smaller dimension rear PFC and the same exact one I bought from ackits and using my OEM tube and fin front condenser, and did all the known a/c tricks and tips and a few more but I could not get constant temps in all driving conditions much lower than you have after a lot of testing but wanted at least 10 degree drop colder air vent temps, and from all this testing I knew the answer was adding condenser more square inches surface area. Because I could not get much better air-vent temps than you have.

I had been trying to buy a PF condenser from anywhere worldwide that would fit my early 911 OEM front and rear factory body cavities for more than 3 years; I knew when I bought ackits PFC it was too small

Thinking as a marine engineer Everything matters; that could be a cause or affect related to the efficiency or the performance of a heat exchanger when the available dimensions are undersize limited as in an older model 911 condensers and your trying to get/gain as much performance as possible for the space you have available to work with!!! From my technical research I learned PF condensers when using R-134A can be approximately 25-30 % smaller in dimensions than any prior technology heat exchanger (which includes tube and fin & serpentine) and yet still achieve a 25-35 +% higher condensation efficiency/performance

I think outside the box and I have spent a lot of time studying every possible affect in my mind I could imagine that could have any kind of effect both negative and positive whither it was radiated engine heat from the engine in the deck lid or the rows of tubes being out of the incoming ambient airflow etc., when I designed my first rear contour deck lid PFC, furthermore I have made and tested several revision prototypes that also keep adapting to newer state of the art PFC micro-channel technologies and have learned by testing experience EVERYTHING MATTERS no matter how small especially when there is not enough room in the first place. From my testing I believe it is a mistake to believe/think having extra rows of TUBE attempting to condense refrigerant not being cooled with ambient air-flow

Moreover I have also studied serpentine technology after doing a lot of technical reading related to PFC for a long time and from much research it only offers approximately about a 6 to 8 % performance efficiency improvement compared to tube and fin technology For Similar Sizes of Tube, but for argument sake let’s say it’s a higher 12 % more efficient than tube and fin; and it’s a proven fact PFC offers approximately in many published scientific studies 25-35+% increase in performance and YET can be further MUCH smaller in all dimensions and this is why all the worlds automotive manufacturers have switched to PFC’s!

Others have had older technology serpentine condensers available for years and they all work a little better then tube and fin and I knew they offered some improvement to tube and fin tube condensers, but the rub is that they Have To Be Made Much Thicker width in diameter and/or longer and taller to match the ,much higher efficiency/performance of a PFC! I.E. I have done a lot of interesting testing comparisons between tube and fin, and serpentine evaporators; that were actually the same dimensions for example that included refrigerant gauge pressures, heat exchanger surface digitally monitored exact temps, and output air vent temps digitally monitored temps and the difference I found was very little performance gain although serpentine evaps are a little better;

Then with further extensive testing about a year ago I compared a plate & fin technology evap I designed as a new product that was about 25 % smaller in length and width and slightly smaller in thickness and it has a MUCH HIGHER performance/efficiency; This further discovery cemented my opinion that serpentine heat exchanges for any purpose for air conditioning IS Obsolete technology!

it’s a fact compared to serpentine, any PFC heat exchanger can be approximately ¼ smaller in all dimensions and still Preform approx. 25-35 % with a higher efficiency!!! And this is why every new automobile manufacture in the world has switched to Newer technology

[kuehl]

Originally Posted by KelogGes

Griffiths and others ........

Reid,

This is a 1.

I have no issue with you tooting your horn, however if you are going use our firm's name or trademark anywhere in a public statement and it is determined to be not factual, think before you write.

[KelogGes]

I have very carefully designed my PFC's to take FULL advantage of every bit of surface area possible in both the front body clip, and the rear deck lid air inlet opening the early 911 body has available even better then Porsche factory did



My front PFC is larger than OEM to get as much PFC surface area as possible



My rear deck lid contour PFC is completely sealed to the deck lid air inlet opening
Note; that there are no extra micro-channel tube rows below the air inlet air-flow
That would allow hot radiated engine heat to reduce the performance of the rear PFC!




NOTE: This rear deck lid in the picture is not a normal 911 Porsche steel OEM deck lid, it is a custom made fiberglass retro look duck deck lid and I had to slightly modify my contour PFC that normally perfectly fits all early model Porsche's 1963-1989 and also add special support brackets and trim the PFC metal a little to make it fit this aftermarket fiberglass deck lid; that my rear PFC normally does not need anything extra done to it to fit on the Porsche factory OEM deck lid

[KelogGes]

Originally Posted by kuehl

Reid,

This is a 1.

I have no issue with you tooting your horn, however if you are going use our firm's name or trademark anywhere in a public statement and it is determined to be not factual, think before you write.

Kuel thank you for pointing this out, I have edited trademark name out this time as a courtesy!

However what I said is/was factual and only a comparison of old and new technology used. Respectfully I know the laws related to what I can say publically or write legally and did not infringe on them related to you.

I noticed you replied to this post within minutes after I posted it, seems you are being overly critical and watching my tread like a hawk do you have a problem with having new competition?

However it might not have been fair to you only using your trademark name, without including all your competitor’s names using similar technology at the same time, so I will try to be more careful out of better respect to you in the future. I would prefer to have a continuing friendly and good relationship with you!

[DG624]

Why does Porsche have two AC condensers? I looked at other AC units and they don't even have a condensor just a compressor. Is there a way to simplify the entire system especially since your new condensor is more efficient?

[Ronnie's.930]

Originally Posted by DG624

Why does Porsche have two AC condensers? I looked at other AC units and they don't even have a condensor just a compressor. Is there a way to simplify the entire system especially since your new condensor is more efficient?

You just didn't see the condenser as there must be one in order to have a/c (auto, home, refrigerators - they all have them as this is the component that dumps, or transfers, heat from the system). The 911s have two condensers because there is no frontal area, like on most cars, to mount one large one.

[DG624]

I am only familar with a few cars but I have an 89 VW that has AC but there is no description of a condensor in the Bently manual. Maybe there is some type of condensor but there certainly is not two and not all of the parts the Porsche has. A simple solution would really help save weight and give the engine compartment more room.

[Ronnie's.930]

The condensor on your VW is probably mounted in front of the radiator (like on most vehicles on the road) and likely has more surface area, and certainly gets far more airflow, than all the 911 condensors combined . . .

[Scott R]

Originally Posted by DG624

I am only familar with a few cars but I have an 89 VW that has AC but there is no description of a condensor in the Bently manual. Maybe there is some type of condensor but there certainly is not two and not all of the parts the Porsche has. A simple solution would really help save weight and give the engine compartment more room.

Condenser on your VW is in front of the radiator and looks very much like a radiator.

[KelogGes]

Originally Posted by DG624

Why does Porsche have two AC condensers? I looked at other AC units and they don't even have a condensor just a compressor. Is there a way to simplify the entire system especially since your new condensor is more efficient?

First answer because the 911 body room available for either condenser is not big enough in cubic feet of surface area! Even with the now 2 condensers that used tube and fin condenser technology it was never big enough when using the original R-12 refrigerant, and when R-134a became the replacement for R-12,
R134a made a bad situation even worse.

The early model 911 Porsche was never designed to have any Air Conditioning whatsoever and was a Porsche design flaw, Air Conditioning was added by Porsche only as an afterthought due to demand from North America owners in the late 60's and early 70's. For these early 911s the A/C system I believe was mostly by only a local dealer option in the USA after the 911 was delivered from Germany! About 1974-75 for the Porsche Silver Anniversary Edition I think, a/c finally became a Porsche factory option besides being a USA dealer option supplied by both Porsche factory or by independent aftermarket USA sources approved and/or licensed by Porsche unless I am mistaken.

FYI All Air Conditioning and refrigeration systems that use a refrigerant gas compressor, (I think I can safely say?) must have a condenser as part of the system coming out of the high pressure side of the compressor as hot high pressure gases, next to force the hot compressed gas to cool (CONDENSE) the gases and go into what is called phase change to liquid,

before the refrigerant stream continues the circuit and is sent next downstream as mostly a liquid by way of and through the filter dryer and next onto or near the evaporator,

and in the case of an early model 911 right before it enters the evaporator, it next enters the thermal expansion valve which causes a radical pressure dropped liquid and from which it next is injected and inters directly into the evaporator inlet as mostly a low pressure liquid,

and inside the evaporator is where there is another refrigerant phase change (the most important for making cold as kind of a liquid mist atomizes as it phase changes) from liquid refrigerant to gas refrigerant and thereby as a product of this phase change greatly expands at the point of the phase change where it is the coldest temp,

thereafter this now low pressure expanded GAS refrigerant comes out of the evaporator expended after doing its work making cold and continues on to the low pressure inlet side of the compressor and the a/c cycle repeats itself

[KelogGes]

Originally Posted by Scott R

There is a well known exhaust manufacturer on this board that does their marketing by sending prototypes out to members, seems to have been very successful.

Scott I agree with you this might be a good idea after thinking about it

I am not sure but I might offer something like this to a few specially selected Pelican members at lower unit cost that live in places places that have high ambient temps?

[Ronnie's.930]

Originally Posted by KelogGes

Scott I agree with you this might be a good idea after thinking about it

I am not sure but I might offer something like this to a few specially selected Pelican members at lower unit cost that live in places places that have high ambient temps?

If you do, I would be game! I have a 1987 930 with OEM front and tail condensers. I do have a Zims fender condenser in the left rear, however.

I live in the Dallas TX area - doesn't get much hotter and more humid than that!

I would be happy to test your bits and report to you on any findings, and in any manner, that you wish.

[brads911sc]

Good Plan. Glad to see your back on track.

Originally Posted by KelogGes

Scott I agree with you this might be a good idea after thinking about it

I am not sure but I might offer something like this to a few specially selected Pelican members at lower unit cost that live in places places that have high ambient temps?

[SilberUrS6]

Originally Posted by brads911sc

good plan. Glad to see your back on track.

+1

[88911coupe]

Very interested to see where this goes. I'm also in Dallsa and have done some mods to the ac on my '88 but still not where I want it to be. I added a large condesor and fan in the left rear wheel well and a Procooler but if the car sits in the sun for any lenght of time about the best I can get is a 30 degree drop from whater the actual temperature is.

[mthomas58]

Originally Posted by 88911coupe

Very interested to see where this goes.

After 550 posts I've lost interest in where this is going.

[KelogGes]

Originally Posted by Josh D

I have measured 43* vent temps at ambient temps of 100*+ with the single decklid condenser. This is with a meat thermometer stuck in the vent and blower on high (upgraded Retro Air evap blower motor) after about 20 min of driving. That's driving during the daytime with direct sun after pulling the car from the garage.

My oil temps range between 180* and 200*. I did see about 210* once when idling in 100*+ waiting for my daughter at school. Temp dropped quickly when I started moving again. I have the 28 row brass aux oil cooler and the temp sender is less than a year old.

The Retro Air PFC rear decklid condenser, as mentioned before, isn't a perfect fit to the opening of the decklid. It leaves a few inches of gap on either side. I fabricated block off's for these gaps with aluminum treadplate. Easy to do and prevents air from diverting around the condenser.


• About Josh D
Location
Gilbert, AZ
• Signature
'80 RoW 911 SC non-sunroof coupe in Guards Red
It's not a Carrera.... It's a Super Carrera!

I want to say something about what Josh has said and where my head is related to 911’s and heat exchangers in the 911 body and also engine oil temps

Josh’s 1980 911 SC engine oil temps running his a/c in 100 plus ambient in the desert while using a PFC in his deck lid and only having normal engine oil temps and him saying “My oil temps range between 180* and 200*. I did see about 210* once when idling in 100*+”, agrees with the extensive PFC testing in my 75 Carrera engine oil temps I get similar negligible higher engine oil temps Josh gets; in Fort Lauderdale with 95 degree ambient temps and very high % humidity, but still get a/c air vent temps lower than Josh”31 F” but thermostatically raised the my air vent temps to 33-34F to prevent freezing in all types of driving conditions because both of my front and rear PFC’s are bigger and therefore have larger PFC surface area coupled with newer state of the art higher performance/efficiency micro-channel tubes, together with they are designed as a matched set to perfectly fit the 911 body to get absolute optimum heat transfer, and the heat dump effect into the engine compartment appears to not raise to within normal safe levels

Having said this, I honestly think/believe that using extra/additional condensers in the fenders are NOT needed at all using ONLY my front and rear PFC’s on normally aspirated 911, unless maybe you live in extreme 110-125 F desert areas; and except maybe on 930 turbos with larger engine later model with the newer much larger intercoolers,

only due to requests & demands for a/c condenser alternate 911 body placement then Porsche Factory OEM stock front and rear body placement, am I in the process of making front and rear fender units both single and duel core PFC’s prototype’s for early model 911’s prior to 2000; I don’t think fender condensers are needed to have a very cold 911 Personally; nonetheless for other than racing applications, or when using supercharged or turbo’s with very large intercoolers, or a few extreme desert extremely high temp cases

I am also currently working as well as rear deck lid PFC’s for 930 turbo’s and also for 911’s manufactured after 2000-2005 front side bumpers units for new 911 PFC products. When I get time to go back to the newer technology evaporator for the smuggles box I want to complete this project; and I have been also thinking about a completely new modernized interior mounted a/c with evaporator/blower unit.

[Josh D]

I need to clarify my oil temps as it appears I was ready my temp gauge wrong. I have type "C" in this picture:



I had always thought that the white line at the top of the warm up zone was 180*. But apperantly it is 194*. When fully warmed up and not running A/C, my needle will go to just above that mark, or 200*. Running A/C I'm in the 220* to 230* range. Still well below the red zone, but probably not ideal either.

[DG624]

I have always felt, due to reading articles, that anything over 210F was not good... 240F is definately bad and that is where my engine wants to go if I push it hard. I would like to get additional cooling if possible, the Elephant cool finned lines seem like the best approach with addiditonal ability to drain oil cooler and and lines when changing oil.

[911 tweaks]

style B...what is the temp if running inbtwn the 2nd & 3rd white line = about 9 o'clock...?? I cannot read the temp #'s on the side of the gage...thx...