For a few years now, the world of heat pumps and air conditioning has been revolutionized by this new gas called R32, replacing R410A. Let's see the differences between these two refrigerant gases and what makes R32 a good candidate to replace R410A.
Here are the main differences between the two gases R32 and R410A:
|*PRG 675||GWP 2087.5|
|Pure gas||Mixture 50% R32 + 50% R125|
|slightly flammable (A2L)||not classified as flammable (A1)|
|the cheapest||more expensive|
|slightly more efficient||less efficient|
*Global warming potential (characterizes the potency of greenhouse gases)
We'll see that both have their advantages and disadvantages, but that the European F-Gas regulation has opted to limit GWP for the future, just as it did at the time to abandon HCFCs and R22.
1. R410A has a GWP 3 times greater than R32
The GWP of R32 between 550 and 675 is 3 times lower than that of R410 of 2087.5.
GWP stands for Global Warming Potential. By convention, it is expressed in "CO2 equivalent", and the GWP of CO2 is 1.
As a reminder, there are 3 types of refrigerant gases:
Initially, 65 countries signed the Montreal Protocol in 1987, revised in 1990, which signaled the abandonment of CFCs that were extremely harmful to the ozone layer. For example, R11 and R12 are CFCs with GWPs of 4600 and 10900 ?♂️. Initially planned for 2000, this ban on CFCs was brought forward to 31.12.1995.
These gases are then replaced by HCFCs, such as R22. Overall, they are less harmful to the environment, with lower average GWPs. The advantage of HCFCs over CFCs is that their ODP (Ozone Depletion Potential) is negligible. R22 is used in many industrial refrigeration and air-conditioning appliances.
Since January 1, 2010, HCFCs have been banned from use. Machines must be serviced using recycled gas only. And since January 1, 2015, it has been forbidden to use or introduce any HCFC, even recycled ones, onto the market. No more HCFCs.
This was followed by the advent of HFC fluorinated gases, which have no chlorinated molecules, a lower GWP (except R410A, which has a higher GWP than R22), and above all zero ODP. These gases are R134A, R410A and R407C. R410A is still used in many of today's most modern machines, but is tending to be replaced by the latest F-Gas darling, R32.
The new European regulation of F-Gas, namely n°517/2014 valid since 01.01.2015 has set the ambitious target of reducing greenhouse gases by 80 to 95% by 2050, compared with 1990 figures. The ultimate goal is to limit the global temperature rise to a maximum of 2°C.
Specifically in relation to heat pumps and air conditioners, the ban laid down by this regulation n°517/2014 concerns bi-block air conditioning systems that contain less than 3kg of gas with a GWP greater than 750, all by January 1, 2025.
Reversible air conditioners for individual homes are directly targeted, as they generally contain less than 3kg of refrigerant. The various heat pumps on the market will also have to adapt to this ban, as some contain less than 3kg of R410A, whose GWP is well over 750.
By way of example, here's the refrigerant charge for a few well-known heat pump references:
|Heat pump model||Fluid type||Fluid load (kg)|
|Daikin Altherma 3 H HT||R32||4.2|
|AQUAREA HIGH PERFORMANCE|
ALL IN ONE" DUO
|R410A||1.2 à 2.55|
|NIBE F2120-8 to 20||R410A||2.4 à 3|
|Alfea Extensa Duo 5 to 10||R410A||1.1 à 1.8|
|Alfea Extensa Duo 5 to 10||R32||0.97 à 1.63|
2. R410A is a mixture while R32 is pure
In fact, R32 is already present in R410A, which is a mixture of R32 at 50% and R125 at 50%. R32 thus has the same toxicity class as R410A: i.e. it is classified as low toxicity.
3. R32 is slightly flammable, not R410A
A disadvantage of R32 compared to R410A is its flammability and toxicity class according to the standard NIOSH. In fact, R32 is classified as A2L, which means it is low in toxicity but slightly flammable.
This isn't great news, given that we're planning to install these in individual homes or ERP buildings.
However, following a modification of article CH 35 of the decree of June 25, 1980 by the decree of May 10, 2019, it is possible for cat. 1 to cat. 4 ERP to use flammable fluids provided a number of measures aimed at controlling the risk are implemented.
4. R32 is cheaper than R410A
R32 is available on the market at prices about 20% lower than R410A.
from a dozen kg, bottled R32 costs 20€ / kg, while R410A costs more like 25€ / kg
Here's an example from an online shop: refrigerantboys.com
5. For the same power, R32 is more efficient
According to a study by the Center for Environmental Energy Engineering at the University of Maryland in the USA, published in 2013Using R32 in a thermodynamic cycle gives 10% more power and 9% more COP than the same cycle using R410A.
R32 is therefore an excellent candidate to replace R410A in air conditioning and heat pump applications
R290: the other natural refrigerant replacing R410A
We talk a lot about R32, which, it's true, is already present in many new-generation heat pumps for several brands, including Daikin and Atlantic, but other brands such as Swedish NIBE and German Vaillant, as well as Wolf and Dimplex, have opted for an even cleaner gas. It's a gas we know well, since it's R290, also known as propane.
Widely used in cylinders to power stoves, for example, this liquefied petroleum gas is highly resistant to cold, but above all is far less harmful to the ozone layer than HFCs, since its GWP or GWP is 3 and its ODP is 0. NIBE, Vaillant, Wolf and Dimplex, all Europeans, are therefore making a choice in favor of the environment, but there is a but.
In fact, this gas, which is very interesting from an ecological point of view (and economically, since at the time of writing it's worth less than €2 per kg), is unfortunately even more flammable than R32, since it's classified as A3, i.e. highly flammable, according to the NIOSH standard quoted above, and therefore requires even greater precautions.
Stiebel Eltron, the leading German heat pump specialist, has decided to use R454C for its HPAs from 01.01.2021. This gas has a GWP of 148, and excellent thermodynamic properties, enabling it, like R290, to operate at high temperatures up to 75°C.
R32, as a new generation HFC, has many advantages that justify its use to replace R410A. Its major disadvantage lies in its flammability, obliging equipment manufacturers to implement reinforced protective measures to avoid any fire and any disaster that could result from it. Japanese and French manufacturers have opted for R32.
However, the European side prefers R290 or propane because it is more environmentally friendly, but also more flammable. Its thermodynamic properties are very good and are close to those of the very widespread gas that was R22 in its time: what pleases the manufacturers.
Research is advancing all the time, and new gases are already being studied that could prove better than R32 or R290, but this has yet to be confirmed. These include DR-55 and DR-5A, which are HFO HFC blends. These two gases are said to offer similar performance to the base gas R410A, and to have a much lower environmental impact. In fact, the possible smooth candidates being studied to replace HFC R410A are shown in the image below, but for the moment the two most serious seem to be DR55 and DR5A. Well, DR55 isn't so new, since it was revealed by Chemours in 2015 at the Yokohama Summit. But this study has seriously evaluated the possibility of replacing R410A as a rival to R32.
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About the author
Juliena mechanical engineering graduate and specialist in climate engineering since 2009, has become a writer specializing in renewable energies, with expertise in heat pumps and photovoltaic solar panels for individual housing.