Talk:Heat pump/Archive 2

pictures added
1 pictures as added in this article, hope its not removed:



KVDP (talk) 18:38, 7 April 2008 (UTC)


 * I'm sorry, there are two major issues with this picture:


 * 1) It does nothing to further one's understanding of the subject matter.


 * 2) It is incredibly unencyclopedic (seriously, do you think there'd be a picture like this in Brittanica or World Book?)

--K10wnsta (talk) 05:16, 28 December 2009 (UTC)
 * Either issue alone would warrant removal of the image, yet it suffers both and has persisted in the article for over a year. :(

Physics of slowly changing the temp of your ground/water source/sink
This is coming from zero background in physics or much of any science, so please forgive if this is an obvious and/or stupid question. If it has some value, however, perhaps it might also be addressed in the Entry.

If your ground-based system keeps pumping cold refrigerant into the buried pipes, and the adjacent soil is giving up heat to bring that liquid back up to 55 degrees, then the adjacent soil must also be cooling down.

I certainly understand that the great mass of the planet will not be bothered by one gallon of ice water dumped on the ground. But what about a home (or huge commercial building) system, where the heat is being extracted and the adjacent soil is being cooled CONSTANTLY, CEASELESSLY.... my question is, is the Earth able to re-heat the soil adjacent to the pipes instantly, or does the adjacent soil actually get cooler and cooler, therefore less and less efficient for heat pump purposes?

Seems to me that the area around the pipes will cool, until the system shuts off and the planet can warm it back to normal. Seems to me that an installed and ever-running ground installation will just get less and less useful. By the way, ditto for the reverse, when heat is being pumped into the ground. (If I'm correct, the system will be in balance just twice a year, for a short time when the system reverses for the opposing cycle.....).

Thanks!! 66.82.9.74 (talk) 05:38, 21 March 2010 (UTC)
 * The answer to that can be considered by asking yourself the following question: Where are you dumping the energy? You are dumping it into the house, which then leaks it back into the atmosphere, which then equilibriates with the ground. User A1 (talk) 12:28, 21 March 2010 (UTC)


 * Measured data and simulations confirm that the ground cools significantly (~10F iirc) each winter, and, in cold climates, only partly recovers before the following winter. So there is some long-term asymtotic cooling.  Some engineers therefore recommend only using ground source heat pumps in climates where the annual heating and cooling requirements are similar.  How much of a problem this is in practice is not setteled.  Dmbergey (talk) 01:47, 7 August 2010 (UTC)

Woolly
This article goes off the rails in the very first paragraph.

A heat pump is a heat pump: it pumps heat from cold to hot. Full stop.

Only later talk about what 'heat pump' is taken to mean in (e.g.) the US, i.e. a clever box of tricks that with the aid of two-way valves can heat and cool, according to the season. (In both cases it is pumping from cold to hot).

86.183.10.80 (talk) 14:54, 30 November 2010 (UTC)


 * I was about to put a comment in here after getting confused by the first two paragraphs of the article, but I see that the anon user above commented on the same point. In the lead of this article, it says a heat pump is a device that pumps heat from cold to hot. Then it says a normal A/C is not a heat pump because it can't go both ways (can't be used to heat as well as to cool a house). Then it says a refrigerator is a heat pump, despite it only going one way. Perhaps there's an issue here with a difference in language between scientists (who see a normal A/C as a heat pump) and the heating/cooling industry (who don't call a normal A/C a heat pump). I'm just guessing though - can someone who knows more about this stuff correct this inconsistency? For the moment, since the last comment on this (above) was about 3 months ago and hasn't been addressed, I'm going to just remove the inconsistent sentence from the lead. --Abc-mn-xyz (talk) 23:55, 21 February 2011 (UTC)

Mix of heat pump types
This article starts by describing a vapour compression heat pump. It then moves on to "Heat Pump Types" in which it also describes an absorption heat pump. Apart from the broad definition of a heat pump, very little of the preceding description applies to the absorption heat pump, which is described in its own page. — Preceding unsigned comment added by 217.155.41.163 (talk) 08:00, 17 July 2011 (UTC)

Heat Pump Effect in Nature?
Many people who do not have a technical background are mystified, or at least ambiguous, in their understanding of the heat pump concept. Ironically they accept the concept of refrigeration almost intuitively. Yet saying that a heat pump is a referigerator in reverse does nothing to help the situation.

So I thought, is there an example of the heat pump effect in nature?

Best that I could do to date is consider that there is a hidden ("latent" is too ambiguous) air standard cycle (Based on the Brayton/ Reverse Brayton cycle) action in a Chinook wind.

If dry air were to approach a mountain range during the night at atmospheric pressure and 20 degree C, cool by expansion to one half an atmosphere, to a temperature below ground temperature, then the heat content of that air mass should increase. Then if that air mass were to compress back to one atmosphere, over this ficticious mountain range, the temperature should be greater than the 20 degree starting temperature.

This can't be considered for the main article unless some citations can be located - no luck so far.

Pete318 (talk) 15:16, 31 January 2012 (UTC)

Heat sources
Most commonly, heat pumps draw heat from the air (outside or inside air) or from the ground (groundwater or soil). The heat drawn from the ground is in most cases stored solar heat, and it should not be confused with geothermal heat, though the latter will contribute in some small measure to all heat in the ground. Other heat sources include water; nearby streams and other natural water bodies have been used, and sometimes domestic waste water which is often warmer than the ambient temperature.

In some commercial applications there are water source heat pumps that use a closed loop system where a boiler and heat exchanger add heat to the loop in the winter (or when needed), and a cooling tower removes heat in the summer (or when needed). 208.6.2.24 (talk) 17:26, 26 July 2010 (UTC)

Water-source heat pumps that use a closed loop (as mentioned in the previous paragraph) are important, and unaddressed in the article. And they are used in residential applications in apartments and condominiums. 108.18.246.47 (talk) 12:51, 23 April 2012 (UTC)

K°Air Energy Inc
Perhaps K°Air Energy Inc may be mentioned in either the See also section or at the external links section ? 109.133.71.85 (talk) 12:28, 10 June 2013 (UTC)
 * Please read WP:SPAM. We aren't here for commercial promotion. Vsmith (talk) 15:52, 10 June 2013 (UTC)

Nerdy opening paragraph
The introductory paragraph should be understandable by a person of average education, a standard which wasn't being adhered to by this article. I've attempted to clarify it. --gilgongo (talk) 14:47, 17 November 2013 (UTC)

Noise and popularity in residential areas
I'm pretty sure that one of the reasons more people don't use heat pumps for private use (apart from installation and initial outlay) is because of the noise these things create (which does seem to have improved lately). Would it be a good idea to include approximate decibel levels and/or reasons why heat pumps are not more popular despite their performance over other types of heating? --Skytopia (talk) 22:34, 24 February 2010 (UTC)
 * Noise from these devices is not a problem. You will have at least one heat pump (maybe two) in your house already. User A1 (talk)

Noise nuisance from air conditioners of all sorts certainly is a problem. And many heat pump installations may have similar issues.-71.174.188.43 (talk) 23:04, 9 January 2014 (UTC)

window-mounted air conditioner as heater
If you turned around a window-mounted air conditioner, you would have a local heat-pump heater. But, how well would it actually work, under various conditions?-71.174.188.43 (talk) 23:06, 9 January 2014 (UTC)

Performance when temp difference is negative?
According to theory, a heat pump can have unlimited efficiency (approaching infinity) as the temperature differential approaches zero.

So, if you are trying to warm an area, using a remote source that is at a higher temperature, in theory it would require very little (zero or negative) additional energy.

In the real world of actual heat pumps, how well do they work as the temp difference becomes very small, or negative? Are there heat pumps optimized for these conditions? -71.174.188.43 (talk) 23:08, 9 January 2014 (UTC)

Efficiency of cooling
The "efficiency" section gives COP relevant for heating applications, or for freezer/fridge applications if you read them backwards, but not for A/C: maybe add a row/column for going from 20C using air cooling? I don't have those numbers off hand -- I was coming here hoping to find them.

I'd argue the table is also excessively technical, but then the entire article can't decide whether its audience is general or specialist. Bhudson (talk) 13:30, 8 August 2014 (UTC)

"Heat pump inverse mode" and "Heat transformer"?
The explanation of these terms in the article is very vague and confusing, and Googling the jargon doesn't turn up anything that looks useful, either. Unless somebody can clarify these concepts and supply some WP:RS, I suggest that they be deleted rather than lending pseudo-credibility to unexplained jargon from this Wikipedia article. Any suggestions? Reify-tech (talk) 22:30, 2 December 2013 (UTC)


 * -simply put: the heat pump contains a gas/liquid with a low boiling point inside a closed tubing circuit. this gas/liquid is allowed to evaporate and decompress outside of the building and then is pumped and compressed by an electricity powered pump into the indoors part of the tubing, where it is put under higher pressure by the pump and this pressure causes it to go from gas state into liquid state. this process has a side effect: while compressing into liquid state, the fluid heats its surroundings. this heat is used to heat the building. then the process is repeated, untlil the indoors temperature reaches the desired level, or until winter ends. this is the heating part.


 * when you reverse it, you use the heat pump instead of heating the indoors environment and therefore cooling the outdoors environment just the opposite way. this is practical when it is summer and hot outside and you want to cool the inside of the building. this time you need to compress the gas into liquid state when it is in the part of its tubing that is outside of the building and then allow it to evaporate into gas state when it is inside the building. so in one mode you heat the indoors part and in the opposite or inverted mode you are cooling the indoors part. (80.98.212.141 (talk) 21:33, 14 April 2015 (UTC)).


 * Thank you for attempting to explain the classic refrigeration cycle, which is already covered in the article. The questionable terminology I complained about over a year ago has long since been removed from the article. Cheers! Reify-tech (talk) 21:47, 14 April 2015 (UTC)

Better summary of terminology is needed
I'm looking into heatpumps for heating/cooling houses, not for refridgerators, and I look specifically at ground source heat pumps. So below some examples may only make sense in this context.

There are no definitions / explanations of terms such as: inlet temperature, outlet temperature, heating cycle, brine cycle, forward flow, return flow (not sure if the latter two are even correct terms). So when I read stuff online they often have very simple explanations of what a heatpump is, and then suddenly use terms as above. It's not always obvious what they are, but I'm sure people working with this think they are obvious, otherwise they would not just casually and suddenly use them :) See examples of why it's not obvious below:

1) "inlet". Yes, I know what inlet means. But is it the inlet to the heatpump, or the inlet to the radiator cycle?

2) "brine cycle". I know what it means, but it was not obvious while learning. It just means salt water. But maybe both cycles have saltwater? If the heatpump is for cooling, perhaps the cycle leading to the fan in the house is below zero and is saltwater, while the other is not? In some illustrations the other cycle is called the heating cycle. But what if it's used for heating at some times, and at others for cooling? Then again, it's confusing. There must be better words. I call the medium that we extract cold/heat from, typically the ground, the source medium, or the reservoir. But I don't know if these words are used, or if there is a better. I think mine are better than brine cycle, well maybe not ;)

3) "heating cycle". This is the one inside the house. But again, when used for heating the house, it's confusing.

I think all of these terminologies should have clear definitions and explanations, and there should be an illustration to them as well.

MadsSkjern (talk) 08:11, 21 May 2015 (UTC)


 * Your criticisms are valid overall, and I've made some related comments in the past. The entire cluster of HVAC-related articles is in need of rewrites and reorganization. Unfortunately, there haven't been enough knowledgable editors on this subject, and some of the editors who actually work in the industry haven't been able to write clearly enough so that copyeditors can make sense of it. Still worse, other editors just try to inject advertising buzzwords, proprietary  jargon, and spam links, which have to be removed.


 * What I have done is to put together a Template:HVAC which gathers together all the HVAC-related articles I and other editors were able to find. At least it helps reveal some of the gaps and duplication in coverage that exists, as well as the handful of articles in relatively good condition. I also have done a bit of copyedit cleanup and correction/clarification, using my background in physics and engineering.  The scarcity of good introductory textbooks or online tutorials makes it difficult to find good references.  The peculiar jargon and measurement systems used in HVAC make it harder to understand things, even with a general physics background.  The article Glossary of HVAC terms barely makes a dent in the problem.


 * In summary, more help is needed to get a critical mass of knowledgeable editors to work in this area. A WP:WIKIPROJECT dedicated to HVAC or Building Science might be useful, but I don't know much about setting up or running one. Any ideas on how to recruit more editors for such a project?  Reify-tech (talk) 18:45, 20 May 2015 (UTC)


 * Thank you for your swift and elaborate answer. I don't even have an engineering background, and don't really understand thermodynamics. I don't think it's that essential for the questions I addressed. I do agree that explanations for the thermodynamics are important though, also in this article. Despite my limited knowledge/expertise, maybe I can still help point out the issues that are unclear or what is / could be helpful, for novices as myself. I have little experience with editing Wikipedia, but out of interest and curiosity, I will try to follow this and related articles, to learn, and to help out if possible. Heat pumps are exciting and the process of improving the articles sounds very interesting too :) MadsSkjern (talk) 08:11, 21 May 2015 (UTC)

COP and lift
Someone requested a citation for the first paragraph in the "COP and lift" section. I disagree with a need for citation in that part. The first paragraph explains a concept that is considered common knowledge for anyone who deals with heat pumps or understands them, and the concept also simply builds on what the reader ideally should have already understood from the rest of the article or any extra research on heat pumps. The paragraph is simply making logical conclusions based on what we already know, and giving some examples to further clarify. No citation is needed for that in my opinion. Wisdawn (talk) 10:38, 26 August 2011 (UTC)


 * if the concept is ONLY known to those already in the know, then a citation IS required! Matt Whyndham (talk) 19:12, 24 January 2016 (UTC)

In this section, it goes "One observation is that while current "best practice" heat pumps (ground source system, operating between 0 °C and 35 °C) have a typical COP around 4, no better than 5, the maximum achievable is 8.8 because of fundamental Carnot cycle limits. This means that in the coming decades, the energy efficiency of top-end heat pumps could roughly double"

This is making a claim about the future performance gains of pumps. Is this justified? If so, please cite. If not, rephrase to state in terms of the maximum theoretical performance. Matt Whyndham (talk) 19:15, 24 January 2016 (UTC)

'Efficiency' section vagueness ("mild", "very cold")
I have removed: "On the other hand, ground-source heat pumps (GSHP) are dependent upon the temperature underground, which is "mild" (typically 10 °C at a depth of more than 1.5m for the UK) all year round. Their year-round COP is therefore normally in the range of 4.0 to 5.0." Instead, I have written: "On the other hand, ground-source heat pumps (GSHP) are dependent upon the temperature underground. Their year-round COP is therefore normally in the range of 2.5 to 5.0."

It is simply wrong that the temperature is mild all year round. See: Baker & Baker. Long term ground heat flux and heat storage. The yearly temperature variation in the Minnesota site ranges app. from 4 to 13 degrees C in 3,2 m depth. A study from Southern Finland yields similar results (Lemmalä et.al, Annual variation of soil temperature at depht 20 cm to 7 m. It is a myth that the soil temperature is app. constant already in 1.5 m depth. There is no scientific foundation for this assertion. See what is written about "ground-source heat pump". — Preceding unsigned comment added by 95.166.91.203 (talk) 07:13, 14 August 2012 (UTC)

The "Efficiency" section mentions "a mild day" and "a very cold winter day" with no mention of actual temperature ranges to define these (very relative) concepts.

It would be really helpful if what the writer means by "mild" and "very cold" was specified by including actual temperature ranges.

Thanks --TyrS (talk) 08:15, 5 August 2010 (UTC)

I renamed this whole section, since it was about a range of Performance issues, not just Efficiency. Matt Whyndham (talk) 20:13, 24 January 2016 (UTC)

The whole section is non-encylopaedic, and reads more like a how-to guide. IMHO it should be trashed and re-written from the ground up. Matt Whyndham (talk) 20:13, 24 January 2016 (UTC)

Merge concepts of "air conditioning" and "refrigeration"? Comments requested
Please see I think that descriptions of "air cooling" are all the same concept but somehow started to be described in multiples places. I am seeking advice on what can be merged together and where.  Blue Rasberry  (talk)  16:24, 6 March 2017 (UTC)
 * Comments requested on merging "air cooling" process descriptions from multiple Wikipedia articles

Early {{pagename}} television commercials
Of historical interest: Me and my brother Bobby commercials Jidanni (talk) 12:17, 6 August 2017 (UTC)

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Temperature limits
It would be good to add what the limits are to this technology. For instance, if I have 2 water supplies at ≈80°C, can I use a heat pump between them to raise the temperature of one of them to 100°C? If not, what are the limiting factors? FreeFlow99 (talk) 15:22, 4 October 2018 (UTC)

Very few references
After skimming through this article, there seems to be a severe lack of references and citations (only seventeen, which seems crazy for an article of this size). At the moment, I'm most likely going to tag this article as needing additional citations for verification. 3er40 (talk) 19:30, 15 August 2012 (UTC)


 * I don't think 17 references is "very few" (and now there is 19 already). In fact, just two references would be enough if they contain all the information. More references are needed if some statement in the article is not backed up by any reference. --PauliKL (talk) 15:39, 5 November 2012 (UTC)

WHAT IS THE USAGE PERCENTAGE OF GROUND AND AIR SOURCE HEAT PUMPS IN THE UK AN ABROAD  — Preceding unsigned comment added by 81.130.1.11 (talk) 12:52, 25 January 2013 (UTC)

Tag: is now more than six years old and is therefore somewhat self defeating. I removed it. It can be renewed if necessary. It can't really be a B article with a tag indicating lack of references. --Michael Goodyear ✐ ✉  13:30, 9 November 2018 (UTC)

Removal of entire section
A new editor,, added new content in a section with a expand tag for a long time. reverted the whole addition, first citing "self promotion", than disputing the references because they "cite Wikipedia" (they do not). I think this is close to disruptive editing, discourages any good faith additions, and goes against WP:BITE. The added content is not perfect of course, but it is better than (almost) nothing and can be improved instead of erased. I propose to reinstate the version previous to the revert. Also notifying. --Ita140188 (talk) 12:17, 17 August 2020 (UTC)
 * It's not bitey to revert content that doesn't comply with our policies and guidelines. Stop WP:ABFing. Please also read WP:NOR. The primary sources do cite Wikipedia, repeatedly if you read them. They also don't appear to be peer reviewed and there's no evidence that Zogg is an expert in their field, so it also fails WP:V. It's also not bitey to discourage WP:SPS in an article such as this which is highly prone to self promotion. Praxidicae (talk) 12:19, 17 August 2020 (UTC)
 * I am no assuming bad faith, I am just trying to understand your position. Can you specify where the main source cites Wikipedia? Also, the source seems to be published by the Swiss Federal Office of Energy, so it's not a self published source (although probably not peer reviewed). I don't think this qualifies for WP:OR. In any case, there are 8 other sources too. As I mentioned, I am not saying the content is perfect, but erasing it completely is extreme and not constructive. --Ita140188 (talk) 12:29, 17 August 2020 (UTC)
 * as I have not received any response to my claims, and as I think the text does not go against any Wiki rule, I will reinstate the section. I will also try to address its shortcomings and check with other sources too. --Ita140188 (talk) 03:28, 19 August 2020 (UTC)
 * Unfortunately not an improvement, to the extent it would be better to start with a blank section than to try to fix. Main source really isn't suitable; it self-references the author and sources back to Wikipedia at least for media and the glossary reference. It may not be in violation of WP:CIRCULAR, but it certainly is pushing it and clearly superior sources exist. WP:EW, etc. VQuakr (talk) 05:18, 19 August 2020 (UTC)
 * I disagree with 'better blank', but in any case, about your points: linking to Wikipedia as a glossary for terms (another way to say 'Google it') is not citing Wikipedia. Same with images, they are just citing the source of the images and they do not influence content in any way. Moreover, the source is not self published, it is a document published by the Swiss Federal Office of Energy. How is it not a reliable source? It would normally be considered as such. I agree that superior sources exist, but by these standards, we would need to delete the great majority of Wikipedia right now. --Ita140188 (talk) 05:27, 19 August 2020 (UTC)
 * Also, can you specify which point of WP:NOTPROMOTION you think applies here? Thank you. --Ita140188 (talk) 05:30, 19 August 2020 (UTC)
 * As for the edit warring accusation, I would appreciate some further explanation, as I have always engaged in the talk page, and I did not go against the 3 revert rules or any other rule as far as I know. --Ita140188 (talk) 05:33, 19 August 2020 (UTC)


 * It was published by the 'Swiss Federal Office of Energy', but as we see below the author was employed by that office, so the the document is still effectively self published - we have no evidence that any independent fact checking or editing was done before publication. - MrOllie (talk) 14:13, 21 August 2020 (UTC)


 * I honestly don't understand this position. How can it be published by a reliable source and at the same time be self-published? Any text from a reliable source is written by someone (most likely employed by that source). How are you deciding that in this case the text is not reliable? It seems like a completely arbitrary decision. --Ita140188 (talk) 03:14, 23 August 2020 (UTC)

Dear colleagues I was blocked while editing and completely surprised by your first reaction to my post. I have completely rewritten the previously unsatisfactory text in the chapter "Heat pump", Section 2 "History" on 2020-08-17 for the following reasons: It consisted of some accidentaly and partly false statements. Some statements did not contain any references and/or were of little or no relevance to the heat pumping technology. This section is not about a history of refrigeration.

The repetition of the reference to my history of the heat pump https://www.aramis.admin.ch/Default.aspx?DocumentID=65074&Load=true in each section is intended to ensure that the readers can find more information in the right document and that my texts remain meaningful even after further entries.

I headed the research program “Ambient Heat, Waste Heat, Combined Heat and Power” of the Swiss Federal Office of Energy (SFOE) from 1993 to 2002 and subsequently carried out numerous scientific expert reports for this Federal Office. I have no commercial interests in heat pump technology. As part of a mandate, the Federal Office of Energy commissioned me to compile a comprehensive history of the development of the heat pump. In addition to several papers, this led to the book Geschichte der Wärmepumpe (out of print) and History of Heat Pumps as an English translation (link above). Best regards, Martin Zogg Martin Zogg (talk) 12:29, 18 August 2020 (UTC)

Dear colleagues, I encountered a number of formal objections to my edit. The unsatisfactory text on the history of heat pumps in sector 6 (history) has not been replaced. The reference to my comprehensive “History of Heat Pumps” is not at all intended for self promotion but for an easy access to more detailed information in a relevant context with a few mouse klicks. There 297 references will help those who have any doubts or want to know even more. If you still refuse my text, I advise you to submit my text to an independent specialist in the field of heat pumps. Best regards, Martin Zogg (talk) 10:40, 31 August 2020 (UTC)

Suggestion for improvement
The operation of heat pumps is highly counter-intuitive to anyone with a modicum of understanding that heat cannot flow from a colder place to a warmer place. It would seem theoretically impossible to obtain any heating benefit from a colder outside environment. This article presently is no help in explaining, conceptually, how this is possible. An explanation in layman's terms would be very useful. Btw, the oft-repeated analogy that heat pumps are like refrigerators in reverse, with the implication that if you understand a refrigerator then you should understand a heat pump, is no help at all. It is "obvious" that input of energy, e.g. electricity, can force heat to flow from cold to warm, the opposite to what it wants to do, like pumping water uphill. It is entirely UNobvious how anything can be gained out of "pumping water uphill" over and above the energy that one puts in. 2A00:23C8:7B08:6A00:54C5:46FF:27B1:F30B (talk) 17:30, 19 October 2021 (UTC)


 * I think the answer to your question is that the heat pump in that scenario is using a different heat reservoir than you're imagining. A Ground source heat pump can be a source of heat (or cool!) even in situations when the outside air is not the right temperature.
 * If you go far enough below the frost line, the ground temperature is basically the year-round average temperature. In many places, that's ideal for a heat-pump.  ApLundell (talk) 04:45, 23 October 2021 (UTC)
 * This is irrelevant to the question. 2A00:23C8:7B08:6A00:15E5:2AA5:F4D3:2978 (talk) 19:04, 23 October 2021 (UTC)

Have you looked at Heat pump and refrigeration cycle? It provides significantly more explanatory material than this article. Dolphin ( t ) 11:53, 25 October 2021 (UTC)


 * I have inserted a new section titled "Principle of operation" that is intended to simplify the layman's task in understanding the concept of the heat pump. See my diff. Dolphin ( t ) 13:11, 26 October 2021 (UTC)

Scope of article?
What should the scope of this article be? Is it every application that uses the Heat pump and refrigeration cycle, or should it focus on heat pumps used for the heating and cooling of buildings together with associated hot water?

Personally I think it may be better for it to have the widest scope showing the many uses to which they are put (including fridges and freezers, HVAC and also notable industrial purposes) and then leave linked articles, such as the one on the fridge, the air source heat pump the Geothermal heat pump etc to provide more detail on each type.

I also suggest that we trim the amount of information provided on the refrigeration cycle itself to avoid repetition of the content of that article.

Thoughts? --

PeterEastern (talk) 20:08, 10 March 2021 (UTC)


 * Having worked with the article for more time now and having reordered the sections it is becoming clearer to me that the scope should probably be more limited and focus on devices used for: HVAC, potable water heating (domestic hot water), heating swimming pools, and some industrial processes. Other heat pump types and uses (solid state, absorption etc) can then be referenced at the end of the article with sign-posting to more relevant articles. This more limited scope both matches the existing content better and with the growing interest in these uses by the public and government. Thoughts? PeterEastern (talk) 09:53, 11 March 2021 (UTC)


 * I have now completed a major review of the article. I have trimmed back to volume of text considerably trying to get back to the core of the article. Content I have removed has either been repetition, excessive detail which duplicates content in a 'main' linked article, many dubious incited claims, some out-of-date information (such as that air pumps don't work at temperatures of less than 5C), and other statements which I considered to be original research. I have also created a Heat pump (disambiguation) article with links to all possible articles that could be associated with the term 'heat pump' allowing this article to focus on a the more specific use of the term and allowing me to remove references to these other heat pump technologies. Thoughts? PeterEastern (talk) 21:42, 11 March 2021 (UTC)


 * These edits are a travesty. Heat pump is a general term and if you want an article with less scope that's what articles for specific kinds of heat pumps are for. 100.19.146.213 (talk) 03:32, 17 March 2022 (UTC)

Brown University EEPS1960X course assignment
This article is or was the subject of a class project aimed at updating IPCC references to the most recent report (AR6). More details can be found on the course page. Student editor(s): JF726. Updates will be made according to the IPCC citation guide. — Preceding undated comment added 20:16, 10 May 2022 (UTC)

Expansion valve
I note that all descriptions of a heat pump have a simple expansion value; a throttle that obstructs flow of the refrigerant so as to lower its pressure. Theoretically this is wasteful, as it is possible to extract energy from the expansion which can then be used to offset the energy requirements of the compressor. You have to do this if you want to achieve the theoretical maximum efficiency (of about 6:1). Does anybody know why most designs don't do it? Is it because the liquid has a very low volume relative to the gas? I don't know much about how these things are designed. --Alistair

That's interesting... I didn't know there was a theoretical maximum. Some refrigeration cycles don't have an expansion valve(or AKA a throttling valve. I beleive most refrigerators only use so many feet of small diameter tubing.  The length and diameter of the tubing controls the expansion.  Generally the expansion valve seperates the high pressure/low pressure sides of the system. Best design practices control exactly where the refrigerant expands in the evaporator and absorbs heat.  In refrigerator design the tube is sized so that all the refrigerant has evaporated at 2/3 the total length of the evap tube.  If all the  liquid does not evaporate, it can enter the compressor as liquid and damage the seals or something.

Generally design is equally guided by Operation and Maintenance (O&M) costs and efficiency. user:tom2146

Most designs don't extract energy from the high pressure refrigerant side of the system by doing work (valves do not do work) because this requires an additional part. This part is not trivial, as it must be something that takes work out of the high pressure refrigerant. These parts can be expansion turbines or compressors that are run 'backwards' (i.e. they are expanding the gas by making it do work on a piston or rotating vane turbine wheel.), however either way they must provide resistance to extract work from the refrigerant and thus cool it down. Due to the locations of the system's parts (the air handler and the typical expansion coil and joule-thompson expansion valve are typically located here) necessarily being physically separated by some significant distanc (one is inside, and the other one outside the conditioned space) the ability to run the compressor with the expander is moot. If both expander and compressor were located inside the condenser unit (outdoor half of the system) the heat gain on the cooled refrigerant going to the air handler would drastically reduce the system efficiency by cooling the attic instead of the air running through your air handler. This is in addition to being a reliability and cost issue. TX, or thermostatic expansion valves, are a tiny fraction of the cost of a reciprocating compressor, and a turbine would be even more prohibitively expensive.

I have not seen any design that uses the refrigerant piping for anything other than conveying the liquid or vapor to the active elements of the system. My understanding of system design is that the 2/3 length of the evap tube is typically 2/3 of the height of the indoor coil. Limiting the level of boiling refrigerant (for AC operation) in the coil is necessary to ensure that the refrigerant is sufficiently warmed up (called "superheat") before going into the compressor to prevent damage as tom2146 pointed out. —Preceding unsigned comment added by 74.202.188.254 (talk) 20:25, 7 December 2010 (UTC)


 * For future reference (Alistair) is referring to https://en.wikipedia.org/wiki/Thermal_expansion_valve . This is one of the core components that makeup Heating and Airconditioning systems my text book would reference as a "Metering Device".
 * Reversing valve is the important element in heat pumps. This is their defining quality, especially when talking about Air Source Heat Pumps.
 * I think it should be noted that heat pumps are no differen't than air conditioning systems other than AC can only move heat in one direction. A heat pump is a refrigeration system (with a reversing valve) that can move heat in two directions ShortSirKitz (talk) 12:52, 30 September 2022 (UTC)

"rejects"?
There's a couple places in the article where the text talks of heat being "rejected". This is an unusual use of the word "reject". Is this a technical term? I would have used "transferred". --Pseudo-Richard (talk) 16:06, 5 August 2011 (UTC)


 * No it's apropriate when referring to Air conditioning (cooling). Aka, raising the temperature or lowing the temperature... But the "rejecting" heat is taken out of context in relation to Air Con by Refrigeration, and applied to heat pumps here. In fact air source heat pumps have only 1 main diffrence between it and an air conditioning system. "A heat pump is a refrigeration system (with a reversing valve) that can move heat in two directions
 * Johnson, W. M., Tomczyk, J., Whitman, B., Johnson, B., Silberstein, E. (2017). Refrigeration and Air Conditioning Technology. United States: Cengage Learning. ShortSirKitz (talk) 13:09, 30 September 2022 (UTC)

Conventional, Single-stage, 2-Stage, Multi-stage
I have been searching for an indoor thermostat for my residential heat pump. There are different thermostat models available and the selection decision is dependent upon specific system attributes. i.e. - "works with conventional systems or heat pump systems up to 2H/2C" or "Heat Pumps Multi-Stage" or "2-Stage Heat Pump Programmable Thermostat designed for a 2-Stage Heat Pump systems only." If somebody could add clarification about some typical commercial heat pump attributes, it would be of great service. 10:42, 15 May 2006

Extra pictures + schematics link

 * Dutch Useful publications on heat pump systems with drawings and explications of practically set-up systems). Notable publications with pictures include: "Warmtepompen voor woningverwarming" and "Warmtepompen- de natuur als bron van verwarming".

The diagram with advantages of the different systems should also be taken over from the publication noted above. The diagram is on page 18; (translation first required + wikification of table)
 * Or see the direct link 1 and direct link 2

Include pictures of the different systems + schematics mentioned + info and pric info, ... in article. Thanks.


 * UPDATE: following 2 sections have been updated with info from the brochures/folders:

Heat sources
A number of sources have been used for the heat source for heating private and communal buildings. Most commonly, heat pumps draw heat from the air (outside or inside air)or from the ground (groundwater or soil)

Ground-source heat pumps typically have higher efficiencies than air-source heat pumps. This is because they draw heat from the ground or groundwater which is at a relatively constant temperature all year round below a depth of about eight feet (2.5 m). This means that the temperature differential is lower, leading to higher efficiency. Ground-source heat pumps typically have COPs of 3.5-4.0 with little seasonal variation. The tradeoff for this improved performance is that a ground-source heat pump is more expensive to install due to the need for the digging of wells or trenches in which to place the pipes that carry the heat exchange fluid. When compared versus each other, groundwater heat pumps are generally more efficient than heat pumps using heat from the soil.

New rewrite
Following update has been done to make the article way more clear:

Performance
The revert done by (72.140.145.227) on  19:14, 3 April 2023‎ requires some justification at the very least, otherwise it's just throwing a tantrum, which doesn't do any favor to Wikipedia.

The section on performance is poor because of incorrect statements and insufficient editing. First of all, EER,COP and their seasonal variants are DIMENSIONLESS quantities. The fact that, say, (S)EER is usually shown as Btu/Wh is only due to the fact that industry/ad prospects tend to provide this metric in non-reduced form. From a physics point of view it expresses Energy divided by Energy. Furthermore, as the last editor stubbornly stated 1Btu/Wh = 0.293 W/W. But what is W/W?? Well, obviously that's watts divided by watts, hence it's 1 (one, yes a number!), as it should be by definition of this metric. Btw, in case someone doesn't know, the reason for that peculiar number 0.293 comes from the fact that 1Btu ~= 1055 J (Joules) and that 1Wh = 3600 J (Joules), thus 1Btu~=(1055/3600)Wh.

In comparison, the edit before follows a clear and neat structure for this section, where it starts with some general information (there are several metrics available -with reference-, these are the most common, both indicate higher performance the higher values they show, one is used for heating while the other is used for cooling) and the goes to explain the same details as before with only some minor edits relative the false units. Even the example I left is nothing but the example that user is trying to give, except is more clearly explained.

These changes cannot be dismissed by simply claiming they are non-constructive. Structuring a text (aka editing) and streamlining the logic is more constructive that simply regurgitating some text that hasn't been clearly understood.

Hence, we should accept the edit from 19:09, 3 April 2023‎ as the one providing a higher quality for this section 72.140.145.227 (talk) 20:09, 3 April 2023 (UTC)


 * The information may have been accurate (unverified), but is too detailed for an encyclopedia's common user, WP:NOTTEXTBOOK #6-8. Zefr (talk) 21:22, 3 April 2023 (UTC)
 * Ok, so we went from "non-constructive" to "unverified" and "too detailed for a common user" (the latter again extremely subjective and showing what seems little understanding of the content of this section. Let's see.
 * Verify: But verify what??The information is basic physics&math as at Grade12. From physics it follows trivially that a ratio of two magnitudes with the same basic units is dimensionless. Another trivial (for editors) information is the *fact* that both Btu and Wh measure Energy. The situation is the same as when dealing with the aspect ratio of a monitor: a screen 45cm high and 80cm wide has a ratio of 16:9, which is obviously dimensionless. However, if someone decides to keep the width in mm, then they end up with a non-reduced expression of 16cm/450mm. Both quantify the same ratio! Of course, the second is whimsical at best. The same happens with Btu/Wh. Hence, you cannot claim the information in unverified. Otherwise, following that logic of yours we would require references for things like log 10 = 1 or 2+2=4.
 * "Too detailed for a common user": My editing of the section provides a better structure precisely for those users that really can't follow the details of what you left: the new structure adds two new parts and improves the last paragraph, where the first is simply the same sentence that was earlier dumped in the middle of the text, the second paragraph is new and guides the "common user" to understand that there are two basic units and where/what-for are they used; last but not least, the last sentence is again one that had been simply thrown around without much thought on where. With these first two paragraphs thus one can learn quickly that "there are two ways to measure it", that "both mean more performance the higher the value" and that "there is more to it than simply these two metrics". Please, argue that the edit you reverted to is that clear that soon.
 * Finally there is the third edit affecting the last paragraph. My edit brings a rational justification for why we see expressions like Btu/Wh or worse W/W that are totally unintuitive for a physicist's pov. Can this edit of mine be improved? Most likely. But does that deserve a judgement of "non-constructive", "unverified" or simply be totally rejected?
 * I think you rushed into reverting my edits without proper understanding of the content, which in such case I can see how at first glance the edit may seem inconsequential for you. This reply of only reinforces this view.
 * Wikipedia benefits from the wealth of honest, accurate and mindful *small* edits of many. My edit is one such edit and thus it deserves a comment for improvement perhaps, but hardly a complete disqualification. Please, undo your revert. 72.140.145.227 (talk) 22:53, 3 April 2023 (UTC)
 * This edit restored part of your text with additional copy edits. A Wikipedia article is a dynamic document which may have numerous editors and challenges contributing. The goal is to have a simple, clear presentation of sourced facts. Zefr (talk) 00:15, 4 April 2023 (UTC)
 * It's also worth noting that when units of Btu/Wh are used, the EER is no longer dimensionless (unfortunately). VQuakr (talk) 21:56, 3 April 2023 (UTC)
 * That is exactly what my edit is clarifying, and I mention it in my reply to zefr: The situation is the same as when dealing with the aspect ratio of a monitor: a screen 45cm high and 80cm wide has a ratio of 16:9, which is obviously dimensionless. However, if someone decides to keep the width in mm, then they end up with a non-reduced expression of 16cm/450mm. Both quantify the same ratio! Of course, the second is whimsical at best. But you cannot claim it has dimensions. That would be a travesty of a description. The same happens with Btu/Wh. We have to deal with the latter because the industry forces us, not because it makes logical/physical sense.
 * Like many other measures in the consumer market, this one is extremely confusing as different manufacturers may display different such metrics and in different ways ("units"). It took me the effort of checking several wikipedia entries and comparing several manufacturers's specs to understand how I can use these units in my next purchase and also that I need to consider both COP and EER, or there seasonal averages. My edit clarifies this with almost the minimum amount of new stuff.  72.140.145.227 (talk) 23:06, 3 April 2023 (UTC)
 * The partial restore looks much better in sourcing, content, and tone. Thanks! VQuakr (talk) 00:42, 4 April 2023 (UTC)

More efficient than electrical?
In the lead it says "When used for space heating, heat pumps are typically much more energy-efficient than electrical and other heaters". But a heat pump uses electricity. I'm confused. HiLo48 (talk) 08:53, 9 June 2023 (UTC)


 * Have a look at Heat pump. It will help ease the confusion. Dolphin ( t ) 14:07, 9 June 2023 (UTC)
 * It's still electrical. HiLo48 (talk) 00:36, 10 June 2023 (UTC)
 * If we want to add 1 kilojoule of heat to a cold space using electric resistance heating it requires 1 kilojoule (or 1 kilowatt-hour) of electricity. But if we want to do it using a heat pump operating at a coefficient of performance of 10 it only requires 0.1 kilojoule (or 0.1 kilowatt-hour) of electricity; the other 0.9 kilojoule of heat comes from the surroundings, leaving some of the surroundings at a lower temperature. The greater efficiency referred to in the lead is seen by contrasting 1 kJ and 0.1 kJ. The cost in dollars using the heat pump is only 10% that of electric resistance heating and, over time, the heat pump will justify its significantly greater initial cost. Dolphin ( t ) 01:18, 10 June 2023 (UTC)
 * You seem to have missed my point. It was simply that a heat pump IS a form of heating that uses electricity, so a sentence comparing a heat pump with electrical heating is a poor choice of words. HiLo48 (talk) 03:46, 10 June 2023 (UTC)
 * The sentence you are challenging is not talking about a heat pump versus electrical heating. It is talking about the “energy-efficiency” of the two modes of heating. My edits here are focused on the relative merits of the two forms of heating. If you think the lead should simply tell readers that most heat pumps use electricity, such a sentence could go anywhere in the lead; you don’t need to challenge the existing sentence about the relative energy-efficiency. Dolphin ( t ) 03:58, 10 June 2023 (UTC)
 * You are still missing my point. I give up. HiLo48 (talk) 23:20, 10 June 2023 (UTC)
 * heat pumps aren't generally called "electrical heaters" in practice, even though they are a generally electric-powered device that can be used to heat a space. Did my change mentioned below not address the concern? VQuakr (talk) 16:18, 11 June 2023 (UTC)
 * Your statement that "heat pumps aren't generally called "electrical heaters" in practice" may be true for aficionados, in your particular part of the world (wherever that is), but they need electricity to run, rather than any other energy source. They are heaters. They run off electricity. That makes them electric heaters. The average consumer isn't going to know what an electric resistance heater is. I'm pretty the labelling on consumer products doesn't say that. Our article must be written for the average consumer, not industry specialists. HiLo48 (talk) 22:29, 11 June 2023 (UTC)
 * Hence the wikilink. It sounds to me like your concern has been addressed. VQuakr (talk) 05:33, 12 June 2023 (UTC)
 * I changed the pipe description to "electric resistance" to be more precise. VQuakr (talk) 16:09, 9 June 2023 (UTC)

How to reduce duplication with the air source heat pump article?
Possibly excerpts - if so how -if not what do you suggest? Chidgk1 (talk) 11:12, 11 September 2023 (UTC)

COP variation with output temperature
I moved the below table here for discussion because the sources are more than 10 years old so I suspect it is not really useful for readers;


 * I noticed the multiple edits you made to the article, concluding with removal of the above Table on the grounds that the sources are more than 10 years old. Wikipedia has no guideline or recommendation that text or other information should be removed when the supporting sources reach 10 years old.
 * There are likely to be many Users who have an interest in this article, and an interest in this Table. By removing the Table you are showing that you think the views of such interested Users are irrelevant. Wikipedia doesn’t work that way. That is the reason we have a Talk page for each article.
 * I suggest you restore the above Table to the article, and use this Talk page to explain your view as to why you think removal of such a large amount of information is warranted. You might be pleasantly surprised at the views expressed by others. If nobody comments, or nobody objects after, say a couple of days, you can remove the Table with some justification because you gave interested Users the opportunity to see your point of view, and to give you their point of view. Dolphin ( t ) 06:09, 14 September 2023 (UTC)
 * If you or anyone else wishes to restore the table of course you are welcome to do so to do so under the principle of WP:BRD.
 * The table may well have been useful when it was first added, but here are a few reasons why I think it is no longer useful:
 * 1) In many Wikipedia articles a table with sources over 10 years old would be fine, so you are correct that "Wikipedia has no guideline or recommendation that text or other information should be removed when the supporting sources reach 10 years old" and I am fine with that. However in this case the technology has advanced quite a lot since those days, so the numbers in the first 6 rows of the table are no longer reliable.
 * 2) The rest of the table (last 4 rows) are theoretical limits but it is difficult to check whether those rows are correct as it is hard to find out how they have been calculated as they are not cited.


 * 3) The refrigerant propane is not mentioned in the table.


 * I would be happy to discuss this further with you or anyone else as I am not an expert on the subject Chidgk1 (talk) 06:32, 14 September 2023 (UTC)
 * Thanks for your response. I will comment on your three observations:
 * 1) Wikipedia is not a design manual so no professional engineer should be using this Table for the purposes of designing a space heating system in a home or building. The first-mentioned COP in the Table is 2.2 and this is valuable information. The latest technology may have changed that to 2.7 or 3.2 but that is of secondary importance. The primary information is that an ASHP taking air from -20 to +35 has a COP of around 2. It isn't zero and it isn't 5, whereas other COPs in the first six lines in the Table are as high as 7.2. If you believe it would be useful for this article to provide more current data, the appropriate step would be to update the Table, not remove it.
 * 2) Three of the rows in the Table are theoretical limits associated with a Carnot cycle operating between the nominated temperatures. You have written that it is hard to check this information because the method of calculation is not cited. That is incorrect. The method of calculating these Carnot COPs is presented at Coefficient of performance. For example, COP of the Carnot cycle that goes from -20 to 35 is calculated as follows: The temperature range is -20 to 35; a difference of 55 degrees C (55 Kelvin). The output temperature is 35 degrees C or 308 Kelvin. Dividing 308 by 55 yields 5.6 as shown in the Table.
 * 3) I agree that propane is not mentioned in the Table. Neither is ammonia or any of the fluorocarbon refrigerants. At least theoretically, the COP of a heat pump is not altered by the choice of refrigerant. I agree that the Table mentions carbon dioxide in the context of transcritical systems but this information would be equally valid for any transcritical system regardless of the choice of refrigerant. Dolphin ( t ) 13:23, 15 September 2023 (UTC)
 * Thanks for that useful info but I still think the average reader would just be confused by this table. For example it seems pointless having ancient numbers for "Two-stage" as readers won't know what "Two-stage" means without searching the term, and anyway I understand nowadays "variable speed" is more efficient. Such confusion might put them off reading the rest of the article. Also "In general, coefficient of performance (COP) of heat pump is determined from physical and thermal properties of the selected refrigerant....." according to https://www.sciencedirect.com/science/article/pii/S2352484720313500Chidgk1 (talk) 13:59, 15 September 2023 (UTC)
 * I would like a 3rd opinion - could anyone else comment? Chidgk1 (talk) 14:01, 17 September 2023 (UTC)
 * There is a process for requesting a third opinion - see Third opinion. Dolphin ( t ) 14:05, 17 September 2023 (UTC)
 * Have requested - by the way https://www.technologyreview.com/2023/02/14/1068582/everything-you-need-to-know-about-heat-pumps/amp/ says R410a more efficient in cold Chidgk1 (talk) 10:45, 18 September 2023 (UTC)
 * You have quoted "In general, coefficient of performance (COP) of heat pump is determined from physical and thermal properties of the selected refrigerant....." Sadly, this sentence is highly misleading. It suggests the choice of refrigerant is a primary determinant of the COP. Properties of the refrigerant may have a minor effect on the COP but the primary determinants are the temperature of the heat source, and the temperature in the space being heated - that is why, with any heat pump, the COP reduces as time passes and the temperature rises in the space being heated. See Heat pump where it says "As the temperature of the interior of the building rises progressively to 300 K (27 °C) the coefficient of performance falls progressively to 9." (The COP changes even though the refrigerant in the heat pump never does.)
 * Carnot's theorem includes the sentiment that every reversible heat engine operating between the same heat reservoirs has the same thermal efficiency, regardless of the working fluid. A corollary of this theorem can be applied to heat pumps and it would say that every reversible heat pump operating between the same heat reservoirs has the same COP, regardless of the refrigerant. The reason that the choice of refrigerant has a small influence on the COP of a real heat pump is simply that real heat pumps are not reversible; they have irreversibilities that render their COPs slightly lower than the COP of the equivalent Carnot heat pump. <i style="color: green;">Dolphin</i> ( t ) 12:21, 18 September 2023 (UTC)


 * The above Table was first inserted on 29 March 2008 by User:Ralph Purtcher. See the diff. The Table was then substantially expanded on 19 April 2008, again by Ralph Purtcher; see the diff. Purtcher has not edited on Wikipedia since November 2022. <i style="color: green;">Dolphin</i> ( t ) 07:33, 22 September 2023 (UTC)


 * As you are obviously more expert in the subject than me perhaps you would like to update the table? Chidgk1 (talk) 07:18, 2 October 2023 (UTC)
 * I have deleted it for now. Anyone thinking of updating it please consider the useful comments by Dolphin51 and Rublamb above - thanks Chidgk1 (talk) 12:59, 4 October 2023 (UTC)
 * The third opinion did NOT recommend or condone removal of the Table. User:Rublamb wrote that they recommended “either updating the table or removing it ....” Particularly notice the use of the word “either”. I will restore the Table to the article.
 * This thread began when Chidgk1 wrote “sources are more than 10 years old so I suspect it is not really useful for readers.” Chidgk1 provided no explanation or clarification to support this claim. The suggestion that Chidgk1 suspects it is not useful for readers invites several obvious questions for which Chidgk1 provides no answer. For example, if the Table provides no useful information for readers, what are these readers using the Table for? Are they designing the air conditioning systems in high-rise buildings and they need up-to-date information on which to base their designs? Are they delivering lectures to classes of engineering students in the field of ventilation and air conditioning? Obviously NO to these.
 * When Rublamb provided the third opinion they copied and pasted Chidgk1’s description of the Table as being out of date etc. Sadly Rublamb did not notice that Chidgk1’s claims were entirely unsupported. Rublamb repeated Chidgk1’s claims the way a parrot repeats the suggestion that Polly wants a cracker. Rublamb’s opinion shows little or no inquisitiveness about Chidgk1’s claims that the Table is no longer useful to readers.
 * The Table shows trends in the typical values of COP across each row: as temperature difference increases COP decreases and that is a very useful observation for readers. New technology won’t change that. Similarly trends are evident in the vertical columns; these trends are very useful and technological changes won’t alter them. The ideal COPs associated with the Carnot cycles are timeless and will never be altered by changes in equipment.
 * Who are these readers who need up-to-date information on heat pump equipment, and why are they coming to Wikipedia to obtain it? How does Chidgk1 know what they need with such authority that he can decide on their behalf that they are best served by removing the Table? <i style="color: green;">Dolphin</i> ( t ) 15:25, 4 October 2023 (UTC)


 * Chidgk1 wrote “more than 10 years old so .... it is not really useful for readers.” There are several obvious questions that come to mind after reading that claim. eg who are the readers and what are their objectives in looking at this Table?


 * Sadly Rublamb did not see the need for any answers, or at least did not ask any questions. Rublamb, in their opinion, wrote “Technology data that is over ten years old is rarely going to be helpful” This is the same sentiment. Instead of being curious about the validity of Chidgk1’s sentence, Rublamb just repeated it, leaving the obvious questions unanswered. Ideally, a third opinion is an incisive, critical response, demonstrating some penetrating thought processes. <i style="color: green;">Dolphin</i> ( t ) 15:49, 4 October 2023 (UTC)
 * So does that mean you or someone else is going to update the table? Chidgk1 (talk) 17:03, 4 October 2023 (UTC)
 * I am not an expert on heat pumps or readability but I do have some knowledge of both so if you have any questions I will be happy to answer them to the best of my ability. Or should we ask for a 4th opinion which is an "incisive, critical response, demonstrating some penetrating thought processes"? If so I think it would be best if and I agreed beforehand to accept the 4th opinion to avoid wasting the time of your group. Chidgk1 (talk) 17:13, 4 October 2023 (UTC)
 * @Dolphin51, As someone who volunteered their time and spent well over thirty minutes researching and reviewing this topic in order to provide a third opinion, I find your comments offensive and completely against the spirit of this dispute resolution process. It is fine to disagree with my opinion but it is not appropriate to turn this into a personal attack.
 * I first read through this 3O request last week but decided not to take it on. with hopes that some with expertise might be available. However, when no one else helped and the request was reposted, I decided to give it a go. do have a science background (geology), worked in that field, took two semesters of college physics, and have been responsible for museum HVAC systems, so I can read scientific and engineering articles with some degree of understanding. Before writing my response, I looked at six different sources, including U.S. Department of Energy guidelines for heat pumps. I did not find any current source that had the same data set as the table in question. That is what led me to believe that this content in out of date. That being said, you may well be able to find a 2023 DOE info or fact sheet that includes this exact table and would, therefore, be able to simply update the source. Or, you might find slightly different data and decide that an update would be useful.
 * For the record, I did not cut and paste anything from the discussion above. In fact, I did not even re-read your discussion after conducting research and beginning to draft my response My response cited MOS, providing guidance that I believe was lacking in your discussion. I also provided an exmaple of another way to present this type of data that would be more user-friendly. I used the phrase "more than ten years old" because, in fact, when I checked, every single source for this table was published more than ten years ago. I guess I should have been more precise, coming up with an average; let's just say all sources were published eleven to thirteen years ago, and many have been removed from the Internet.
 * My suggestion was to remove the table or publish an updated version. Updating means refreshing data and providing current sources. Notice I did not suggest retaining the table as is as a third option. That was intentional as I do not support that option for the reasons stated. @Chidgk1, with regards to finding an expert, none of the conflict resolution processes of Wikipedia provide or guarantee an expert in the subject matter. What you typically get is an experienced editor with a basic understanding of Wikipedia's guidelines and mission, as well as a reasoned response. If you believe this topic requires an expert, please take it to WikiProject Engineering or WikiProject Electrical Engineering. However, I ask both of you to consider that if an expert is needed to interpret and moderate a decision on this topic, then the table may be conveying information that is too technical and too dense for Wikipedia. Asking who the audience is for this information is a really good start. Best of luck. Rublamb (talk) 20:12, 4 October 2023 (UTC)
 * Chidgk1’s question at WP:Third opinion was “Should this Table be removed from the article?” This was an excellent wording to use because it cut through the various threads and asked a question that could be answered with either a Yes or No.
 * Rublamb’s opinion was “I recommend either updating the table or removing it.” If the Table is updated, that means retaining it in the article. Considering Chidgk1’s question in its strictest wording, Rublamb’s opinion was “I recommend either [no] or yes.” However, Rublamb’s opinion was actually aimed at the various threads visible in the numerous edits by Chidgk1 and me.
 * On several occasions I have tried to make the point that this Table is a comparative table to demonstrate the manner in which COP varies with output temperature. I haven’t yet seen any acknowledgement that either Chidgk1 or Rublamb understand the significance of this observation. The first 6 lines of this Table are not presenting details of, say a Westinghouse unit versus a Mitsubishi unit, to demonstrate that one is superior to the other; it is presenting a single number to represent a generic class of heat pump, solely to demonstrate the variation in COP with output temperature. This is a bit like saying that automobiles with 6-cylinder gasoline engines travel at 72 mph whereas those with 8-cylinder engines travel at 81 mph. Clearly the former class of automobiles generally have less power than the latter and travel slower under identical conditions - updating these speeds to represent the current automobiles on the market is not going to reverse this trend.
 * Chidgk1 and Rublamb have both written that they have explained their reason for advocating removal of the Table but I reject that view. I haven’t yet seen a plausible and legitimate reason for removing the Table. If the Table is removed it removes some useful and valuable information that is currently accessible by readers, leaving readers with only the equation to see how COP varies with output temperature; the equation is only useful for this purpose to those with an adequate understanding of linear algebra. In the absence of the Table, variation of COP with output temperature can be calculated, beginning by examining the following equation (which can be derived using the article):
 * $${\mathrm{COP}} = \frac{Q}{W}$$
 * This Task can be simplified by assuming the heat pump is an ideal device operating on the reverse Carnot cycle so that the equation is:
 * $$ {\rm COP}_{\rm heating}=\frac{T_{\rm H}}{T_{\rm H}-T_{\rm C}} $$
 * where TH is the output temperature.
 * To examine the way COP varies with output temperature I think the majority of readers will find it easier to use the Table than the Carnot equation.
 * I have apologised to Rublamb for my intemperate language last night.


 * <i style="color: green;">Dolphin</i> ( t ) 10:55, 5 October 2023 (UTC)
 * I think your suggestion to consider the readers is useful. Perhaps we can step back from this narrow question for a while and ponder the readers in the talk section below. Chidgk1 (talk) 16:33, 5 October 2023 (UTC)