The GREEN-MAC-LCCP is a very good tool, however, it still needs improvement if it is to become a real global standard. Major input data are:
realistic refrigerant leak scenarios across the entire life of the vehicle, including local service habits
required power (fuel) to operate the MAC system to provide comfort inside the passenger compartment at different ambient climate conditions
There are two possible ways to provide the MAC performance input:
Virtual calculation of the system performance in different climate zones and driving cycles, based on steady state bench test results (as in the current version of the GREEN-MAC-LCCP tool)
Fuel overconsumption measurements at a certain driving cycle at varying ambient conditions
Following the latest publications on R744.com, Obrist Engineering has equipped a non-VDA car with an R744 MAC system, again a small car, which represents the car majority on this planet… As shown earlier by Visteon, Behr and Valeo (medium size car), even R744 MAC systems for small cars can outperform current HFC-systems both when considering cooling capacity and fuel efficiency. (Even at ambient temperatures above 40 şC)
Unfortunately, the GREEN-MAC-LCCP tool does not consider this kind of data obtained in vehicle measurements. If these important results could be implemented into the 'to be' standard LCCP tool, the 'bars' showing CO2-equivalent emissions due to MAC would look rather different than they do today, when comparing R744 systems to non-natural alternatives.
everyone knows that you are an expert on LCCP issues having given many presentations over the years.
My question to you is simple. Why is this issue so hotly debated ? why do i get the impression that LCCP is used by different companies to give contradictory arguments depending on whether you support R744, 134a or 1234yf? Is there really a chance for us to have a 'neutral LCCP' methodology with open data that can be cross checked?
Anonymous posted on 2008-05-15 14:48:25: dear Armin,
everyone knows that you are an expert on LCCP issues having given many presentations over the years.
My question to you is simple. ... Jump to Post
I agree, may the best refrigerant win, ..... fact before fiction. it is is everyone's interest that we have the most transparent methodology possible, using the best available 'real life' data regardless of refrigerant
Anonymous posted on 2008-05-15 14:48:25: dear Armin,
everyone knows that you are an expert on LCCP issues having given many presentations over the years.
My question to you is simple. ... Jump to Post
Dear Anonymous,
thank you for opening the 'open' LCCP discussion!
I would like to answer your question in reversed order:
Yes there is a chance, if the input data for every LCCP presentation in open public are public as well; otherwise the results are very close to worthless. The audience should be able to follow and cross check the data applied in a LCCP analysis, a main objective of every scientific presenter or author. A copy or the link, where the file can be downloaded, should be provided.
LCCP is the tool to compare different systems; however, as long as the performance input is limited to bench tests, the model is far from flexible. In addition it is important to be aware of the kind of baseline HFC-134a system which is applied, i.e. Midsize Sedans with a V6 3.1 litre engines are not always representing the majority of cars in certain countries / regions. If the fuel over-consumption of different MAC systems is measured in the same/similar vehicles for a specific driving cycle, no heavy MAC cycle simulations are required and a clear answer can be found with a open LCCP analysis, including total fuel consumption ++ Again, if the input values are open information, the number of contradictory arguments should approach 0, at least after an open discussion.
This is a hotly debated issue since the Green-Mac-LCCP tool is supposed to become a global standard, starting as SAE standard. This then can be applied as the base for carbon trading regimes.
And the question to the MAC society is simple; should it be possible to apply MAC performance data obtained from real vehicle measurements in such a global LCCP tool or do we define these results as unfeasible and rely on virtual calculations based on steady state bench test data?
An international LCCP activity forum with open technical discussions is already in place. The global LCCP Team, lead by Dr. Papasaavva, is known for the: Open, Fair, and Highly Technical discussions that take place on a frequent basis, based on feedback received from the Industry, Academia, National Labs, Governmental and Non-Governmental Organizations.
Dr. Hafner is welcome to forward for our consideration any ideas through the LCCP forums or if he chooses through R744.com.
The model allows the user to enter data obtained by any laboratory bench-test experimental set-up. A global OEM effort, led by Mr. William Hill, came to OEM consensus that bench-test results are the most reliable source for AC system energy consumption. SAE CRP data are now publicly available, and are a fair basis for comparing proposed alternative refrigerants.
The model automatically reports GHG emission totals that can very easily be converted to fuel consumption for the indirect emissions associated with AC operation during driving. The LCCP data obtained from the model are readily available for getting fuel consumption.
Frequent global LCCP meetings are held to further perfect the model and to incorporate vehicle-based test results in future versions of the model. The GREEN-MAC-LCCP team recognizes the need for a common approach to fuel consumption measurement of AC systems and has been discussing this for some months.
The most recent updates to the model also incorporate new direct leak rates by considering not only best refrigerant recycling practices (90% refrigerant recovery) but also attributing a higher end-of-life direct refrigerant emissions when a complete refrigerant charge release takes place. The model actually weighs more heavily (60%) the complete charge release than the 90% refrigerant recovery at service (40%). Furthermore the model estimates direct refrigerant leaks during servicing from professional people and from DIY procedures with much higher emissions than professional service.
Each city is treated differently with respect to both Operating and Service direct leaks using best available data. The LCCP model comprehends the 20% leaks from the banks (old vehicles) but the frequency of service is estimated using a more complex methodology than Dr. Hafner’s two-time per lifetime suggestion. The model takes into account the work by Dr. Denis Clodic funded by the EU and recognized as the state-of-the-art leak rate assessment by the industry and governments around the world. As more data become available the model will update the leakage input spreadsheets.
R744.com acknowledges that the GREEN-MAC-LCCP model is a copyrighted programme hosted by the U.S. EPA, as quoted in several articles published on the website. However, please note that the R744.com Forum was created to allow for an open public debate among members of the CO2 Community about any topic they wish to discuss, with free choice of subject or opinion. This is why we welcome comments from all interested parties about the GREEN-MAC-LCCP.
Please make sure not to post any email addresses or contact details to this forum, since these will be removed by the R744.com website administrator, as explained in our Forum Guidelines.
Dear LCCP friends and colleagues,
I would like to emphasis that I agree that the Green-Mac-LCCP is a very good model to evaluate lifecycle greenhouse gas emissions from MAC. And there is no need for another peer reviewed model, if the current model is flexible and gives the user the freedom to choose what kind of performance input date are applied.
In many cases potential users of the model like OEM’s and Tier 1’s do have reliable and objective road test data, i.e. fuel over consumption measurements. It may be of interests to these users of the model to be able to apply their data to be able to make their own comparison of alternative refrigerants or systems. Isn’t this the case? (Just in case…you are welcome to answer as: ‘Anonymous’)
The main question remains:
Why is an update/upgrade of the Green-Mac-LCCP tool, having the possibility of applying performance input data (fuel over consumption measurement data) as an alternative, such an issue?
Dr. Armin Hafner posted on 2008-05-19 12:47:11: Dear LCCP friends and colleagues,
I would like to emphasis that I agree that the Green-Mac-LCCP is a very good model to evaluate lifecycle greenhouse ... Jump to Post
i support this statement by armin. why can't the Green Mac lccp methodology include latest test data from OEMs and Tier 1 ? especially the ones that have the best CO2 systems.
Dear Armin,
I'm trying to find out a bit more about how end-of life measures are incorporated into LCCP analyses. Do they assume that the refrigerant used is recycled and therefore doesn't enter the atmosphere or do they allow for the possibility that the refirgerant may be vented?
Thnaks for your input
fionnuala
Ms. Fionnuala Walravens posted on 2008-06-02 14:02:56: Dear Armin,
I'm trying to find out a bit more about how end-of life measures are incorporated into LCCP analyses. Do they assume that the refrigerant ... Jump to Post
- Upper part: (HFC-134a): No refrigerant Recycling During Service takes place (‘NO’ in cell: E14 on ‘MAC-Manufacturing-EOL-Input’)
- Lower Part: Baseline HFC-134a
Leakage from EoL is considered to be 10% of the remaining charge with refrigerant capture. First column example (Phoenix, USA baseline HFC-134a) -> 48g leak at proper EoL station (90% or 428g of remaining charge is recovered -> back to service?) However, since not all cars with MAC find their grave via proper EoL stations, the Green-Mac-LCCP model weights the leaks due to EoL to 305g HFC-134a for the Pheonix area. The weighted leaks due to Service are 70g while the total refrigerant losses are assumed to be 652 g HFC-134a / vehicle.
In case of no refrigerant recycling during service and EoL (upper part of the table), the total refrigerant loss is assumed to be two times the original refrigerant charge, i.e. 1104 g HFC-134a / vehicle.
For all other global regions/cities you will find the assumed leakage rates in the table.
Dr. Armin Hafner posted on 2008-06-03 17:13:25: Dear Fionnuala,
I had a look at the Green-Mac-LCCP model (Version 3), more precisely the ‘Leakage-input’ worksheet. Please see the copy of the ‘Le ... Jump to Post
Dear Armin,
Thanks for your response. That does answer my question. Do you happen to know if the orginal LCCP analyses also took EoL leakage into consideration?
Cheers
Fionnuala
Dear Fionnuala,
sorry for my late reply, I have been out of office for some days...
Since this forum is meant to be an open place for discussion, I hope the architects behind the Green-MAC-LCCP tool may help us to find the answers to questions like yours.
I just would like to point out my support to the global LCCP team, and I fully agree that we need a global tool to do this kind of calculations. However, constructive criticism of issues should be allowed and accepted.
An open place like this forum is one way of exchanging information to a wide range of people, and people are visiting this pages... so why not using this platform more actively as an supplement to meetings at events around the globe, which are not accessible to all people interested in the subject. And since the tool is meant to be the baseline for possible Carbon Trading Deals, a real perfectness has to be the common goal, however perfectness requires also flexibility, therefore I would like to repeat my question to the Green-MAC-LCCP architects;
Why is it so difficult to add a worksheet into the tool that allows the user to apply performance data obtained during vehicle testing on rolling benches?
Tests performed at various ambient temperatures at a certain driving cycle, which is one possible way for a fair and scientific comparison of different MAC systems. Such tests (as show earlier on this web site) have been performed from global OEM’s and Tier 1 supplies, i.e. people/companies who know how to build MAC systems in large numbers....
Armin,
Making LCCP analysis should idealy include all facts such as the energy used for the production of the refrigerant. Dr. Stella Papasavva has made a copyright tool but if we have not seen the tool. Wa also need full transperancy of the methods use and where the data come from. Per review is perhaps in an ideal world OK but who are the reviewers. You can select a team to review and they will pass what you want. It does not automatically hold the whole truth because it has been review by a select group. Lets all have a look at the data to see what it holds. The truth can have many facets not included by Dr. Stella Papasavva and her team.
i very much support this last statement by Mr Pachai. Peer review is needed but what happens when it is not open for outside input or different opinions, which based on the previous posts seems to be the case?
is that not the whole idea of this forum, that anyone can post a comment in an open way without the 'politics' of peer review?
Dear All, I received an email from Stella Papasavva about a conference call today. Anyone interested should participate.
--------------------------
Dear All,
Please find attached a revised version of the SAE J2766 standard in which I have incorporated the comments you sent me:
Our next conference call is scheduled for July 30th, at 8:00 - 10:00 AM Detroit time.
Conf. Call Nr. (801) 828-9914 Access Code: 1457273
Please review the standard and send me your comments in advance, so I can prepare a list of the comments with answers to discuss.
In addition to the standard, we will discuss all the new data that have been revised in Version3 of GREEN-MAC-LCCP.
For those of you who have attended the LCCP meeting in Phoenix, based on your request, we have addressed in depth the structure of the model and the leak rates included in the current version.
The new data have not been discussed yet. I will send you the powerpoint agenda presentation later this week.
Best regards,
Stella
Stella Papasavva
Senior Researcher, Ph.D
General Motors, R&D Center
Chemical & Environmental Sciences Lab
Sustainable Automotive Futures Group
MC: 480-106-269, 30500 Mound Road, Warren, MI 48090
Anonymous posted on 2008-07-30 09:17:45:
Dear All, I received an email from Stella Papasavva about a conference call today. Anyone interested should participate.
-------------------------- ... Jump to Post
Does anyone know who this peer group is? Names, emails, etc.... where can we find this 'open' information?
Mr. Alexander Cohr Pachai posted on 2008-07-20 21:26:32: Armin,
Making LCCP analysis should idealy include all facts such as the energy used for the production of the refrigerant. Dr. Stella Papasavva ... Jump to Post
Alex, referring to your comment about ‘who are the reviewers’?
Below are some of the persons involved in the GREEN MAC LCCP.
Stella Papasavva, Bill Hill and Ryan Brown from GM,
Stephen Andersen and Kristen Taddonio from EPA
Ward Atkinson,
Bob Low and Sean Cunningham from Ineos
Mark Spatz and Nacer Achaichia from Honeywell
Barabra Minor and Mary Koban from DuPont
Sephen Lepper and Michael Wallis from Ford
Hans Fernquist from Volvo
Ikegami from Toyota,
Jürgen Wertenbach from Daimler,
Rajendra Shende from UNEP
Armin Hafner and Petter Neksa from Sintef,
Nicholas Lemke from TU Braunschweig,
Plus several from CARB and representatives from Renault, Opel, Audi, Nissan, FIAT, Volkswagen, Visteon, Behr, DENSO and Sanden.
Maybe you know a few of them?
Next question is who are the most active? Maybe Armin Hafner would know?
Thank you Alex and Marc for pointing out some interesting issues.
The methodology behind the Green-Mac-LCCP model is transparent and has been modified during several years. However, we are not talking about an open source code, it’s MS-Excel based tool which theoretically can be used by anybody.
How many active users are out there is a difficult question, I guess the people mentioned by Marc are using the tool frequently.
As presented by the GM team around Bill Hill earlier and as part of their IMAC work, the Green-Mac-LCCP tool will be the base for a new SAE Standard (SAE J2766), regulating the way to calculate LCCP for vehicles. Once a SAE Standard is approved it can be submitted to ISO, i.e. a global Standard. This is than the legal base for CDM – projects.
One question, which I would like to discuss;
Is the current LCCP model and the proposed SAE Standard, which only allows bench test data as performance input values, excluding companies, NGOs or other institutions from performing their own MAC-LCCP analysis in the future? (Background; Not everybody has access to these kind of bench facilities.)
Real vehicle measurements (in wind-tunnels) are challenging and do have many pitfalls, however, they are performed and the industry has to do these kind of tests anyhow for the documentation of the total CO2 emissions from a vehicle. And in the near future, AC has to be a part of this documentation. Of course simulation is one alternative option, however, time will show what EU requires on this subject from the OEMs.
greetings from Norway
and I'm looking forward to your comments!
I got this message from Stella today. For those that belong to the SAE LCCP group, details for the next conference call are below.
Armin, will you be participating?
marc
-------------------------------
This message is to announce that our next global LCCP conference call will take place on:
April 2nd, 8:00-10:00a.m (US Detroit Time)
Dial In Nr: (214) 765-0496 - Access Code: 1457273
The agenda of the meeting will be distributed shortly.
We have updated GREEN-MAC-LCCP - Version 3 to GREEN-MAC-LCCP - Version 3b by considering all comments and suggestions received during the SAE J2766 ballot process
SAE J2766 is now available for purchase through SAE; please check next e-mail
We also plan to have a face-to-face meeting during the SAE Congress week on Monday April 20th, 9:00-12:00pm at the Marriott Renaissance Center, Room Brule b
During our conf. call on Thursday we need to discuss the agenda topics of the face-to-face meeting on April 20th
Best regards,
Stella
Stella Papasavva
Senior Researcher, Ph.D
General Motors, R&D Center Chemical & Environmental Sciences Lab Sustainable Automotive Futures Group
MC: 480-106-269, 30500 Mound Road, Warren, MI 48090 Ph. (586) 986.1620 / Fax. (586) 986.1910
Dear Marc and all other LCCP friends,
Unfortunately I'm not able to join the conf-call tomorrow due to another meeting, I'm looking forward to the MoM...please join it if you have time!
I'm looking forward to the real new model that will accommodate vehicle test results.
As mentioned during the February 5th meeting focus should be given to:
Subgroup is interested in investigating both options as a means for integrating vehicle A/C load results into the LCCP model
–Steady State & –Drive Profiles
•Steady state test should measure fuel economy and not compressor load.
– Compressor load is not realistic option to measure for production vehicles.
•More work is required to show how steady state can be accurately linked to profiles
•JAMA will be consulted to provide starting point based on their work up to this point
I fully support Stella to push for 'to arrive to a consensus on the next steps ' in the development of the real new model that will accommodate vehicle test results.
To be able to get a beta version of it ASAP...
I'm looking forward to see progress on this important issue, support from our side is available.
Either here or in the comment field of the article.
Have a nice summer and we are looking forward to contiune the work with the next generation LCCP tool, which also allows the input of measured vehicle fuel over-consumption values...
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