Let's talk procooler

[RonMaxwell]

Hi Everyone,
my name is ron maxwell and i invented the procooler. there seems to be a lot of questions
about the procooler, who we are and how it works.
i have joined the board to hopefully clear up any mysteries. My main business until we introduced procooler was building custom porsches and classic automobile restorations. we now have over 30 years in that business. by the way i am a one man shop building one or two cars at a time while marketing the procooler. i am not sure where to start but here goes.
the most critical problem with any ac system is the inability to condense the high temp vaporized regfrigerant into a liquid and keep it that way until it reaches the metering device in this case a txv. as the outside temp increases this becomes more critical, particulary in slow traffic or idling conditions where you lose airflow over the condensor, this is compounded by the fact that the high side line and the receiver are always somewhere in a climate not conducive to removing heat (ie in porsche the receiver is in the wheel wheel steadily cooking from road heat (here in texas that can be over 125 degrees in the summer)
the normal solution is for more condensor and fans. this has always been the norm and a good solution.
with the procooler we have just taken another approach. by using the refrigerant exiting the evaporator (which stays in the 60-70 degree range)to cool the liquid refrigerant in the receiver, the procooler provides the extra condensing needed and much closer to the txv.

As the temp outside goes up the procooler becomes more efficient because the temps in the inner and outer chambers get further apart. condensors are just the opposite.
its as simple as this if you take a boiling glass of water (condensor and refrigerant) and try to cool it with a heat gun (air here in texas)it does not work well. if you take that same boiling glass of water and set it in another glass of ice water (procooler)improvement.

we are not knocking extra condensors, we are only suggesting procooler as an alternative or at the least a compliment. we have a lot of customers who run both. we have more than a couple of thousand on 911's around the world, plus a long list of shops who sell them as well. you can get them at tweeks or performance products.

we have installed and tested them on just about any vehicle or home ac you can think of. We have tested at the Behr facility in fort worth, texas a&m university and spent 3 weeks in the climate controled wind tunnels at chrysler. i hope i have not confused you anymore, i certainly hope i have not offended anyone by dicussing the procooler on the forum. please email or call me if you have other specific questions.

trying to help you chill out this summer

ron maxwell
830-935-3343
raire19@netscape.net

[ZCAT3]

Ron - I have an 86 930 with the stock AC system. It does not cool at all. We recharged it once and maybe it got a few degrees cooler, but that was all. I have read about your Pro Cooler, but like many 911 owners it just seems like I have so much wrong with the AC system it is not worth messing with. I would really like the AC to work in this car and if I thought that buying your cooler and doing some general AC maintenance would get it up and running I would be all for it.

[RickM]

Does Pelican sell it?

[Jack Olsen]

Ron, clear up the confusion and post a link to independent testing that proves your product works. Every year, when people start to think about fixing their AC system, there's a lot of discussion about the Pro Cooler -- but I've never seen published results from an independent lab that verifies the thing. When I was upgrading my AC, I looked for something -- anything -- to verify the Pro Cooler claims, and I couldn't find anything convincing, so I went with a stock receiver/dryer.

What I see on the site doesn't appear to be very scientific. I get 37-degree output (85 ambient, high fan setting) from my system without a Pro Cooler, and your site claims a stock system is putting out 56-degree output on a 98-degree day. That doesn't seem like a properly functioning system that you're using as a baseline.

And the article on the website isn't much use, either. A guy did a lot of AC upgrades, including yours. He got better AC. I don't know what that tells me.

What I'd like to see -- as a potential customer -- is a fully functioning system, tested blindly, with and without your product, by a completely independent lab. Has that been done?

[LeeH]

I'd be more than happy to offer up my car for a scientific test! Any A/C improvement would be appreciated by those of us who live in Arizona!

Edit: Is this system available for any other make/model? I have a '98 Isuzu Trooper that I really like, but the A/C just doesn't cut it here in AZ.

[88911coupe]

Hey, I am in Dallas and I'd be glad to offer my '88 coupe as a guinea (sp?) pig. I have been looking at adding an underbelly condensor but that seems like a pretty expensive option. The car's a/c works ok but it would be nice to see what quantifiable difference would be made with the ProCooler.
later

[beamonk]

I think we all would like to see some independent testing on the procooler, as I, like many, have to face the total rebuild and replacement of my system this summer. I don't want to spend more money and have my tech say"what is this junk" and toss it in the can. He will too! I think it is a good idea, but we all want facts and want to know also if it works with alternate refrigrants, freeze 12 etc.

[ZCAT3]

What does it cost to get a complete but utterly useless 911 AC system working?

[Sean Hamilton]

Originally posted by JackOlsen
.........What I'd like to see -- as a potential customer -- is a fully functioning system, tested blindly, with and without your product, by a completely independent lab. Has that been done?

Well I've searched too and cannot see anywhere that it's been done.
So I've baulked on purchasing the Pro Cooler to date.

Like John, I'm loath to install something that is later considered to be not much more use than a Cool Collar.

[Jim Sims]

I'm a skeptic but perhaps I don't understand how your system works. If one draws a control volume around the A/C system all the heat still has to exit basically out through the condenser. The marginal 911 systems are condenser limited; does the Procooler work by raising the refrigerant temperature (and pressure) at the condenser (and compressor) inlet thereby increasing the temperature difference (to the air) across the condenser and improving heat transfer? There doesn't appear to be much surface area within the procooler (it appears to be nested shells?) for the transfer of heat between the refrigerant going to the evaporator and that coming off. If there is sufficient contact time this limited area may may work, but if the refrigerant is moving rapidly as it would on a hot day the heat transferred would be significantly reduced. Some test data demonstrating raised condenser inlet temperatures and reduced evaporator inlet temperatures at various ambient temperatures would help illuminate this issue and prove the worth of the Procooler. If the Procooler works by raising the condenser inlet temperature this means the cooling air being feed to the 911 engine (through the A/C condenser) is preheated even more. An auxilliary wheel well or front mounted condenser would not have this effect or at least would do it less. Cheers, Jim

[RonMaxwell]

thanks guys for the interest

Jack, i am trying to gather up some of the testing data that was sent to us, back when i first started, and will post it to our website as soon as possible. As you can imagine back then because we were new every shop had to test before they would sell to their customers. i am sure many of them will still have some of their data around. Its all good by the way or they still would not be selling them to their customers. for all of you guys volunteering your car for testing thanks for the offers.
Jim- actually the refrigerant leaving the evaporator in not fully vaporized it always contains liquid, entering the procooler the refriqerant is vaporized in a major way when it strikes the inner receiver - this causes the outer chamber to become like an evaporator absorbing heat without raising the temperature (latent heat of evaporation)or something like that, with the procooler installed the outer chamber is ice cold to touch, try grabing a receiver on a 95 degree day plus the velocity is increased both of which increases the cop of the compressor. you only need a few degrees drop (less than ten)to help the condensor and to keep the high side condensed and keep a liquid seal at the txv. guys i will try and have some data for you in the next couple of days and a list of some shops you will know who have used the procooler for several years. blessings ron

[Jack Olsen]

Originally posted by RonMaxwell
As you can imagine back then because we were new every shop had to test before they would sell to their customers. i am sure many of them will still have some of their data around. Its all good by the way or they still would not be selling them to their customers.

Thanks for the reply, Ron. But with all due respect, this isn't what I'm talking about. Shops selling your product stand to make a profit if they can make a reasonable case for their customers buying it. This gives them common interest with you that doesn't promote a fair test.

This is the part I don't get. If I had a product like the one you're selling, I would be getting it to an independent lab before I ever even came up with a specific strategy for how to bring it to the market.

Once I had reproducible numbers that I could prove weren't done by someone with an interest in them coming out one way or the other, well, I'd have the greatest piece of marketing a company could ask for. It's got to be a third party with no financial interest in the product, or, basically, you're going to be just offering 'infomercial' style data.

Not too long ago, the guys who make the Isaac head-restraint device went out on the internet BBS circuit. What they had done was gone to Kent State University, and let the guys there test their device in a side-by-side test with the other major head-restraint devices (Hutchens, HAANS, etc.). Once they had done that, and the results were published by a group that didn't share any financial interest with them, they were able to generate a lot of interest in their product.

My opinion (and I know, you didn't ask for it ) is that you need to do something like that. Otherwise, your claims for your product will fall into the same category as the air filter, tornado-vortex, and oil-additive guys, which would be a shame, if it's actually able to improve the performance of a 911's air conditioning.

Like I said, I'm ready to buy it. But I need to see independent testing that I feel I can trust before I put down by money.

[Jim Sims]

While doing some research in preparation for an air conditioning tech session planned by our little local Porsche group in April I ran across this:

www.rparts.com/Catalog/Major_Components/accumulators/accumulators.asp

The Procooler appears to be a specialized version of an accumulator/subcooler although to be very efficient I would expect it would need to look like the heat exchanger versions.
The compressor horsepower ratings for the various subcoolers are an interesting bit of data. It is also interesting that some of these components have patents pending.

Cheers, Jim

[Jack Olsen]

It's also interesting that Ron seems to have disappeared from the board.

I don't mean to come off as hostile, but for the life of me I can't imagine why you wouldn't get an independent lab to test a product like this if you hoped to market it widely.

A response like: "That's a great idea, Jack, but it costs big bucks to get a test done, and the company can't justify that kind of expense right now" would makes some sense, or maybe: "It works great, Jack, and at the shop we have two identical systems operating side by side, one with and one without the Pro Cooler, and you're always welcome to come by and see it working for yourself" or something.

But, no.

Not yet, at least. I'll keep waiting. Like I say, if it can be shown that it works, I'll add it to my system.

[Kevin Stewart]

Jack as we all know money makes the world go round and they may not have enough to have it tested. I too am looking for cold air in my 911, when i sold the 944 years ago my first btch was the air in my 911, Kevin

[Steve W]

It's been years since my college thermodynamics courses, but from what I remember, an AC system is nothing more than a heat extractor, extracting the heat from inside the cabin, and transfering it to something outside of the cabin which will radiate this heat out to the atmosphere - in this case the condensers on the 911 in the front and in the rear decklid. The amount of heat transfered between the condensers and the atmosphere are a function of four factors:

1. Condenser surface area
2. Airflow over the condensers
3. Ambient temperature of the atmosphere
4. Temperature of the condensers

1 and 2 are fixed and beyond the Procooler's control. With 3 and 4, the temperature differental between the two is what determines the amount of heat transfered from the condensers to the atmosphere. Since the atmospheric temperature is also fixed and beyond the control of the Procooler, what left is there to change, the temperature of the condensers? Unless the Procooler is superheating the refrigerant flowing through the condensers, making them hotter than without one, I cannot see how any extra heat can physically be transfered from the condenser fins to the atmospheric air. And unless the Procooler shell also acts as a heat sink, radiating extra heat out to the atmosphere, there still is no additional heat radiating surface area. But Ron has just stated that the outer shell of the Procooler is actually ice cold to the touch, so it cannot radiate any heat, in fact it must be absorbing heat from the outside air, and making the system more inefficient. So tell me where I am wrong.

[Jack Olsen]

I'm with you, Steve.

Kevin, he may be savvy enough to realize that there's more money to be made by not testing it. I don't know.

[Barry2]

It's got to be a third party with no financial interest in the product, or, basically, you're going to be just offering 'infomercial' style data.

That is exactly what I thought the intial post was, an 'infomercial'.

Hummm ...

Later,
Barry

[greglepore]

Well, I bought one as more or less an experiment. I'll report back in the summer. My black/black Targa should be quite a test.

[derkpitt]

What's funny is the claim that the problem lays with the 911's receiver/ drier being mount in the wheel well. Exposed to road temperature. Yet my other cars have no problem with this unit mounted in the engine compartment. Where temperatures are much higher than OAT.