Talk:Refrigerant

What is this?

If a refrigerant is described as "Carb. Anhydr.", what is the chemical involved? Mjroots (talk) 07:48, 1 September 2011 (UTC)

Carbon dioxide Synonyms: Carbonic anhydride aka R-744; CO2 without water content 84.197.184.6 (talk) 21:27, 6 November 2011 (UTC)

Carbonic acid minus water. Gah4 (talk) 23:06, 29 November 2025 (UTC)

Natural refrigerants

There are a number of natural refrigerants that are growing in popularity and cause little or no harm to the climate – including CO2, ammonia, propane and water.

Helpful here might be the German-language Wikipedia, which lists them all:

https://de.wikipedia.org/wiki/K%C3%A4ltemittel#Nat%C3%BCrliche_K%C3%A4ltemittel

There is also: https://en.wikipedia.org/wiki/Natural_refrigerant

-- Fph GmbH (talk) 15:52, 9 April 2023 (UTC)

The article contains significant content on natural refrigerants as of September 2025. Fiske (talk) 15:18, 1 September 2025 (UTC)

I don't see any mention of cyclopentane, though? That in particular is becoming increasingly common as a refrigerant in household appliances. Snappyapple632 (talk) 20:49, 7 November 2025 (UTC)

Cyclopentane is primarily used as a blowing agent for foam insulation. A common application is as a blowing agent for polyurethane foam insulation in refrigerators and freezers. The GreenFreeze system uses cyclopentane this way. You'll sometimes see equipment labeled with R-600a (isobutane, the refrigerant) and cyclopentane (in the insulation). Fiske (talk) 03:17, 8 November 2025 (UTC)

Self-referential reference

The source [1] of this statement "Refrigerants can carry 10 times more energy per kg than water, and 50 times more than air" is a webpage that quotes this statement and attributes it to this Wikipedia entry. ([1]:"refrigerant (CHEBI:78433)". www.ebi.ac.uk. Retrieved 2025-02-22.) 2603:7000:9501:3A00:DCC7:818:A78F:545 (talk) 20:43, 28 May 2025 (UTC)

Deleted that statement, which is ambiguous in addition to being self-referential (water has a higher latent heat of vaporization than any refrigerant...). Fiske (talk) 11:29, 29 May 2025 (UTC)

Water has a high latent heat for temperature ranges where it has a liquid-vapor phase transition. That is, from 273K to 647K. Refrigerants are often needed outside that range. Gah4 (talk) 10:59, 27 November 2025 (UTC)

You are quite correct. Two major reasons that water is not often used as a refrigerant are its high triple-point temperature, 0.01 degC (since ice is not tolerable in a flow loop), and its sub-atmospheric vapor pressure for temperatures below 100 degC ... an evaporator at, say, 10 degC would have to operate at a vacuum pressure of 0.012 atm and with a very low vapor density.

The statement discussed is ambiguous because it does not distinguish between latent heat and sensible heat and does not mention a temperature range. In some temperature ranges, that statement is simply wrong. Fiske (talk) 02:39, 30 November 2025 (UTC)

R numbers

Should the article mention the refrigerant R numbers for those mentioned? R-290 for propane, carbon dioxide R-744, isobutane R600a, ammonia R-717? Gah4 (talk) 23:14, 29 November 2025 (UTC)

R-numbers are tabulated in the section Charactertistics of some common refrigerants, including the four natural refrigerants you mention. A very comprehensive listing is in the article List of Refrigerants. Most of the R-numbers are also mentioned in passing throughout in this article. The numbers of the four you mention are also in the section Comparative performance of refrigerants.

Natural refrigerants are often called by name (e.g., "ammonia" rather than "R-717"), whereas complex molecules and mixtures are usually described by R-number, e.g., R-410A. Fiske (talk) 02:29, 30 November 2025 (UTC)