Talk:Vapor-compression refrigeration

Merge

A vapor-compression refrigeration system and a phase-change heat pump seem to be the same thing; the article on vapor-compression refrigeration even states, "a vapor-compression refrigeration system may sometimes be referred to as a phase change heat pump," which indicates we don't need an article for each. The same suggestion to merge has been made on the talk page for the phase change heat pump article. Tobinmarcus 16:01, 6 July 2006 (UTC)

Tobinmarcus, I strongly disagree with merging the two articles. Yes, vapor-compression refrigeration and a heat pump are simply two sides of the same thermodynamic cycle. However, refrigeration and heat pumps are, in the common and widely accepted usage, two distinctly separate techniques. The articles have been written for a wide range or readers ... and not just for thermodynamic purists (not to say that that was your motivation). This article's inclusion of the statement "a vapor-compression refrigeration system may sometimes be referred to as a phase change heat pump" is simply for the purpose of explaining that there are other names for vapor-compression refrigeration ... it is not a reason for merging. . Again, I strongly believe they should remain as separate articles and therefore I am going to take the bold action of removing the merge tag. - mbeychok 18:37, 6 July 2006 (UTC)

I agree that heat pumps and this article should not be merged. However, Phase change heat pump should be merged into this VC article, but maybe with some content going to heat pumps. The phase-change heat pump's figure is colorful and might make a nice intro to this article, but I do have a problem with the blue 'coolth' arrow shown on it ... 129.237.114.171 21:41, 8 November 2006 (UTC)

I disagree that Phase change heat pump sould be merged with this article. Phase change heat pumps (with reversing valves so that they can function as air coolers or as air heaters) are, to a large extent, primarily used in HVAC applications in residential homes and other buildings. On the other hand, vapor-compression refrigeration is very widely used in large-scale industrial processes as well as in air conditioning and I strongly believe it deserves to be a stand-alone article. As for the image in the Phase change heat pump article, it is indeed colorful but it also simplistic. It is a nice "logo" type image but it does'nt adequately depict the vapor-compression system. In my opinion, it would be much better to merge Heat pump and Phase change heat pump. mbeychok 23:19, 8 November 2006 (UTC)

Ozone depletion

The "Disadvantages" heading states that many vapor-compression refrigeration systems are "still" using HFCs (true) and that HFCs contribute to ozone depletion (huh?). The point of switching to HFC refrigerants (like R-134a and R-410A) is that they don't contain chlorine. By my understanding, it's only chlorine and bromine that affect the ozone layer. According to the article on ozone depletion, fluorine reacts with water so quickly that its effect on the ozone layer is trivial. Was HCFC meant here instead?

Mind you, the entire haloalkane family has massive Global warming potential compared to CO₂. But that's a separate problem. Chronos Tachyon 12:58, 26 May 2007 (UTC)

Chronos Tachyon, if you believe that the change should be made, then be bold and make the change in the article. - mbeychok 15:54, 26 May 2007 (UTC)

Done. I think whoever wrote that section got confused by the Coca-Cola press release, which was talking about global warming and not ozone depletion. Chronos Tachyon 05:15, 9 June 2007 (UTC)

Minor Change

I added HVAC to the "see also" section, and alphabetized the list johntindale 20:06, 6 June 2007 (UTC)

3rd world

R12 never took over in the 3rd world like they did here, highly flammable hydrocarbon gases have long been the standard refrigerant, butane, propane etc. Article seems to ignore this at the mo. Tabby (talk) 04:45, 6 January 2008 (UTC)

Refrigerants

This section introduces references to "CFC"s without really explaining or linking to this topic. I think some revision is in order. Ericnoel (talk) 00:45, 9 September 2008 (UTC)

Expansion valve

I would think that the description should mention the irreversibility of the pressure drop through the expansion valve, and the efficiency loss that entails. I'm not sufficiently expert to be comfortable writing that in--hence this encouragement for someone else to take that one. Or at least encouragement to anyone who wonders about it and finds this note to go read a book about it rather than stopping with this article (always a good idea anyway).Ccrrccrr (talk) 20:10, 14 December 2008 (UTC)

Removal of Ozone Depletion Propaganda

I removed a bunch of unsourced ozone-depletion science propaganda from the section on Freon and replaced it with a reference to ozone depletion where discussion of that topic belongs. John Chamberlain (talk) 15:18, 9 September 2009 (UTC)

I'm not sure what you mean by "science propaganda". Usually propaganda is criticized if it's unscientific... Were there components of that you thought were dubious and in need of sources? I found it useful as a very concise summary of ozone depletion, staying to the well established non-controversial components of that article.Ccrrccrr (talk) 21:19, 9 September 2009 (UTC)

Seeing no reply I'm proceeding with a revert. Then if we can identify specific problems with that material, we can address those. Ccrrccrr (talk) 19:57, 13 September 2009 (UTC)

Other features and facts of interest

I think this section heading is almost verging on 'miscellaneous' and as such I would like to re-title to something like 'refrigeration system design and components', and expand and rearrange the text to better describe the aspects of typical refrigeration system design Pahazzard (talk) 21:44, 12 September 2010 (UTC)

Empty section?

The "Thermodynamic analysis of the system" section is completely empty, but for a single image, (Adding insult to injury, at least on my browser, this image is formatted to show mainly in the next section). The image is also used in the Heat pump and refrigeration cycle article, along with some actual text. Should the section just be removed? Tøpholm (talk) 23:10, 9 December 2010 (UTC)

Replaced the original text for this section which somehow got removed by someone. mbeychok (talk) 03:08, 12 November 2011 (UTC)

Plz here give the this topic in Hindi. Radha Tiwari (talk) 16:26, 27 March 2016 (UTC)

About the pressure vs. temperature diagram added to this article on May 24, 2012

The subject diagram adds nothing to the article and creates much confusion because the diagram's caption is incorrect. The caption reads:

"The gas is compressed which increases the temperature and turns the gas into liquid. Temperature cools through equalization with the ambient environment."

That is incorrect, The compressor does NOT turn the gas into a liquid nor does the temperature cool through equalization with the ambient environment. The compressed gas is routed through a condenser (water-cooled or air-cooled) where it is cooled and condensed into a liquid.

Figures 1 and 2, which have been in this article for a number of years, are correct and very adequately explain vapor-compression refrigeration. The subject pressure vs. temperature diagram with its incorrect caption is not needed here and has therefore been removed. mbeychok (talk) 17:11, 25 May 2012 (UTC)

How does the pressure vs temperature diagram for Vapor-compression refrigeration look like? Electron9 (talk) 01:00, 28 May 2012 (UTC)

Hi, Electron9:

I have just reviewed about 75 articles (obtained by a Google search) devoted to explaining the vapor-compression refrigeration cycle. About 98% of them used a temperature-entropy (T-S) diagram to characterize the cycle. About 70% of them also included a pressure-enthalpy (P-H) diagram of the cycle. Not a single one of them even mentioned a temperature-pressure (T-P) diagram for the cycle.

The point being made is that the T-S diagram in this article (i.e., Figure 2) is all that is needed to characterize the cycle. What a T-P diagram of the cycle would look like is neither here nor there. This article is not meant to be a thermodynamics textbook and a T-P diagram would add nothing of benefit to the explanation of the vapor-compression refrigeration cycle. Regards, mbeychok (talk) 03:03, 28 May 2012 (UTC)

That it's possible characterize the cycle with a temperature/pressure-entropy isn't a contradiction to that a temperature-pressure (T-P) diagram would increase the understanding. That this would constitute a thermodynamics textbook seems far fetched. Electron9 (talk) 23:36, 28 May 2012 (UTC)

I repeat what I said above: Not a single one of the 75 articles explaining the vapor-compression refrigeration cycle that I reviewed made any mention of a T-P diagram. A good many of the 75 articles (about 35 to 40 of them) were obtained from university websites which certainly indicates that a T-P diagram is not needed to provide a good understanding of the cycle by university students.

I would suggest that perhaps you could upload your version of a T-P diagram into Wikipedia's Phase diagram article ... assuming that you can find some credible, verifiable references documenting that your version is correct. Also, make sure that the caption of your image does not include the erroneous statements pointed out in my original comments above (dated May 25, 2012). Regards, mbeychok (talk) 02:55, 29 May 2012 (UTC)

Adding a third-party perspective:

• It is not acceptable to have a diagram with errors in it. The errors need to be corrected before we consider including it.
• The fact that it is possible and adequate for university students to understand on the basis of a T-S diagram does not necessarily mean that is it adequate for all of wikipedia's audience. It is possible to develop a basic understanding of vap-comp refrigeration without understanding the relation to entropy, and I expect many readers would appreciate that.

If there is a corrected version of the diagram made, I suggest that a link to it be posted on this talk page before it is added to the article, so that it can be discussed before addition to the article. Ccrrccrr (talk) 17:37, 1 June 2012 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Vapor-compression refrigeration/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

I rated this article as Class A and High Importance. Class A because it meets all the requirements of that classification. It includes all the sections that a good Wikipedia article has, it is very well written and organized, and is well referenced. It is of very high importance to chemical engineers, refrigeration engineers and HVAC engineers.

Last edited at 00:30, 5 December 2006 (UTC). Substituted at 09:49, 30 April 2016 (UTC)

WHY?

- Is this page locked from editing? The subject seems fairly non-controversial.

- Is there a blatant commercial advertisement included (Danfoss)? 200.68.142.11 (talk) 19:24, 7 January 2019 (UTC) baden k.

"Seems fairly non-controversial", yes, but last year we had some serious problems with an editor who had some, shall we say idiosyncratic ideas about what should be in the article. DS (talk) 04:41, 8 January 2019 (UTC)

Siemens cycle

What is relation to Siemens cycle? (c.a. 1852) 2A02:168:F609:0:5F8:C25A:2F16:ECD5 (talk) 03:42, 26 June 2019 (UTC)

Reverse Ranking cycle?

Hi, I was wondering how Vapor-compression refrigeration really differs from Reverse Ranking cycle or Reverse Brayton Cycle. It looks identical to me. 2A02:168:F609:0:5F8:C25A:2F16:ECD5 (talk) 20:05, 26 June 2019 (UTC)

Heat being "rejected"?

The article repeatedly uses the word "reject" to refer to heat being transferred. This word choice strikes me as rather odd. Is that a common way to describe this? —BarrelProof (talk) 23:21, 17 November 2019 (UTC)

Requesting edit in Description of vapor-compression refrigeration

The last line of the first para states, "This is where the circulating refrigerant rejects heat from the system and the rejected heat is carried away by either the water or the air (whichever may be the case)." What does " this is where" indicate? It is not specified. So, I suggest an edit in this section with mentioning about the Condenser or making another para explaining the step involving the condenser before this line. Unanimous350 (talk) 18:14, 26 March 2021 (UTC)

AS USUAL - THE ARTICLE IS TOTALLY INCORRECT - AND CANCEL CULTURE DELETES EDITS

THE ABOVE IS TOTALLY INCORRECT:

The fan is used to cool vapor so that it condenses in the condenser line. The fan alone is not sufficient: the radiator is also radiative and can operate without a fan. The heat of vaporization, AMAZINGLY NEVER MENTIONED, is imporant part of the heat transferred in the evaporator: the heat of expanding gas alone does cool but not suffiencly (beer bottle cool with serious moisture issues). Without a cooling the condensing coil the PSI needed for vapor to liquid phase change (which adds heat of vaporization necessary for target cooling) would be absolutely impractical. — Preceding unsigned comment added by 2601:143:480:a4c0:4ecc:6aff:fe8e:47d (talk • contribs) 15:46, 18 July 2021 (UTC)

Firstly: Please look up acceptable editing practices, this is an absolute mess. I added a mention of the evaporation absorbing heat since that was a little unclear, I'm having trouble parsing the rest though. MasterTriangle12 (talk) 09:38, 19 July 2021 (UTC)

PERFORMANCE

The COP is just a bad equation which the article doesn't explain correctly.

THE THING TO MENTION FIRTS IS THE BIGGEST PERFORMANCE FACTOR, THEN THE MINOR ONES.

THE BIGGEST PERFORMANCE FACTOR IS: the design of the G.E. motor / patented motors. The PSI or "design PSI" is set to match the power band (rpm, load efficiency) of the electric motor in question. It is the biggest factor in efficiency.

Other factors, such as increasing the condenser cooling or cheapening the cost of the condenser, are factors but are no where near as important as to TOTAL COST = PRICE OF UNIT + ELECTRIC BILL / YEARS SERVED (i emphasize the electric bill can be a major factor, but that over-design about minutia can also kill total cost)

Economic effects

Air conditioning:

. protects buildings from moisture

. protects health in many ways ie, rids mold

. is used in FOOD DISTRIBUTION

. is used in MANUFACTURING

Office and Home "air conditioning" are the BIGGEST ENERGY USERS IN THE USA, the Energy Department found. The Jimmy Carter Administration asked the nation to set their dials on "78" in a large campaign to be green and conserve USA's energy costs. Yes more than heating and lights, yes. Air conditioning is a power user.

AIR CONDITIONING FAILURE

While manufacturing have been known to fail: the chief cause of failure is improper installation, dissimiliar metal contact or vibrating overlaps, improper maintenance, and well known "wear items" (capacitors).

Life of units are intended to be 20 years, but too often 10 or less years are achieved.

Lesser causes of failsures include:

. manufacturing leaving pipes overlapped where they rub (yearly checkups are supposed to catch these and fix them) , or dissimilar metal contact (some of which is absolutely un-avoidable)

. setting thermostat too low , getting greedy

. improperly adjusting vents to "get one room cooler" (starving the evaporator of air), or bad air filter.

. lack of cleaning / service / inspection

I emphasize a great number of problems and potentia for failure are due to: the installer and then service person.