We are going to develop a comparison between TWO refrigerant gases: the R507A and its substitute, the R448A.
Let’s start by saying that both the R507A and the R448A are internally composed of a mixture of several gases. Therefore, although the R507A has minimal glide, it is better for both gases to be charged in liquid phase.
The R-507A is an azeotropic blend, consisting of the gases R-125 and R-143a, each comprising 50%.
The R507A is known for its chemical stability, good thermodynamic properties, and low toxicity. Its main application is in low and medium-temperature installations.
On the other hand, the refrigerant gas R448A is composed of a mixture of gases: R32 at 26%, R1234ze at 7%, R134a at 21%, R125 at 26%, and R1234yf at 20%.
The glide of R507A is very low, and lower than that of R448A. Recall that glide is the temperature change of the gas while changing phase.
Neither R404A nor R448A harm the ozone layer.
The R448A has a global warming potential (GWP) of 1387, whereas R507A has a GWP of 3985. Precisely this high GWP value is what condemns the use of R507A due to ecological restrictions.
R448A is considered a replacement refrigerant for R507A in low and medium-temperature applications in the evaporator.
The transition from R507A to R448A does not require any modification in the compressor, as the discharge temperature with R448A is very similar to that of R507A.
R448A is a perfect substitute because it works just as well as R507A with POE type oil.
R448A is compatible with the components and seals of an existing R507A installation.
Both R507A and R448A are gases with a safety classification of A1, group L1, meaning they have low toxicity and are non-flammable.
We are going to talk about the type of oil used in an air conditioning unit with a capacity of 12000 BTU per hour, which operates with R410A refrigerant gas.
Firstly, we must mention that most 12000 BTU per hour air conditioning units use rotary compressors. These compressors are more cost-effective to manufacture, compact, and offer high performance, low noise levels, and acceptable durability.
Now, it’s time to answer the question: What type of oil does the rotary compressor in a 12000 BTU per hour air conditioning unit use?
Logically, the characteristics of the lubricant will depend on the compressor manufacturer. However, in many cases, we are not aware of the machine’s technical specifications, and as specialized technicians, we must perform an oil change in the compressor.
So, the question arises again: What oil should we use when we are not aware of the compressor’s technical specifications and need to perform maintenance by changing the old lubricant?
In such cases, we can generalize and say that the replacement oil should have similar technical characteristics to the original oil and belong to a reputable brand that guarantees the success of our work.
Considering the above, the lubricant that we propose as a perfect alternative for these situations is the POE 68 oil, which in most cases is an excellent option to replace the old oil.
The POE 68 oil has a viscosity close to 68 centistokes at 40°C, which ensures optimal performance at the working temperatures of the refrigerant in the equipment.
It is essential to remember that oil return can be challenging in split-type air conditioning systems because the oil must travel from the evaporator in the indoor unit inside the room back to the compressor in the outdoor unit outside the room.
During this process, problems may arise that affect the proper return of the lubricating oil, such as improper inclination or positioning of the return pipes. However, the type of lubricant is crucial for the correct functioning of the equipment.
When the oil does not return adequately to the compressor, there can be insufficient lubrication, leading to premature compressor wear and a decrease in its lifespan. Additionally, excess oil in the evaporator can affect the system’s performance and reduce its efficiency.
Not only is POE 68 oil a perfect alternative for rotary compressors due to its quality and viscosity, but it is also important for this oil to have a viscosity stability index close to or higher than 100.
Let’s remember that the viscosity stability index is a numerical measure that describes how the viscosity of a lubricating oil varies with changes in temperature.
When a lubricating oil has a viscosity index of 100, it is considered to have very stable viscosity over a wide range of temperatures. As the viscosity index decreases below 100, it indicates that the oil’s viscosity tends to change more significantly with temperature variations.
In this case, according to the table, this POE 68 oil has a viscosity index of 120.
So we can conclude that the POE 68 oil not only has the perfect viscosity but must also have the capacity to stabilize this viscosity value.
We will conduct a comparison between two refrigerant gases: R22 and its replacement, R417A.
Before delving into the details, it’s essential to highlight that R417A is a replacement gas for R22, specifically designed for medium and high-temperature applications such as refrigeration and air conditioning. It is also suitable for heat pump systems that previously used R22.
Regarding their composition, R22 is internally composed of a single component without any gas mixture, allowing it to be charged in either liquid or gaseous phase.
On the other hand, R417A, also known as Isceon 59, is a gas mixture consisting of 50% R-134a, 46.6% R-125, and 3.4% R600 Butane. Due to this composition, R417A must be charged in its liquid phase.
The main drawback of R22 is its detrimental impact on the ozone layer, leading to severe environmental restrictions on its usage. In contrast, R417A (Isceon 59) does not harm the ozone layer. However, its high Global Warming Potential (GWP) of 2346 makes it subject to environmental restrictions in certain regions, limiting its market usage in the short term.
Both R22 and R417A are compatible with mineral oils and alkylbenzenes, meaning that when switching from R22 to R417A, there’s no need to change the compressor oil.
An additional advantage of this change is that no equipment components need to be replaced.
While there might be a slight decrease in the cooling capacity of the system when using R417A, this difference is imperceptible. Moreover, this new cooling capacity results in lower electricity consumption compared to R22.
Both R22 and R417A are safe to use, as they are non-toxic and non-flammable.
We are going to develop a comparison between TWO refrigerant gases. We’re talking about R404A and its substitute, gas R448A.
Let’s start by saying that both R404A and R448A are internally composed of a mixture of several gases, which is why both should always be charged in liquid phase.
For example, R404A contains approximately 4% R134A, 44% R125, and 52% R-143A.
Meanwhile, refrigerant gas R448A is composed of a mixture of gases as follows: R32 (26%), R1234ze (7%), R134a (21%), R125 (26%), and R1234yf (20%).
The glide of R404A is very low and lower than that of R448A. Remember, glide is the temperature change of the gas during phase transition.
Neither R404A nor R448A damage the ozone layer.
R448A has a global warming potential (GWP) of 1387, while R404A has a GWP of 3920. It is precisely this high GWP value that condemns the use of R404A due to environmental restrictions.
R448A is considered a replacement refrigerant for R404A in low and medium-temperature applications in the evaporator.
The change from R404A to R448A does not require any modification in the compressor because the discharge temperature of the R448A is very similar to that of R404A.
R448A is a perfect substitute because it works just like R404A with POE-type oil.
R448A is compatible with the components and seals of an existing R404A installation.
Both R404A and R448A are gases with a safety classification of A1, group L1, meaning they have low toxicity and are not flammable.
In this post, we are going to conduct an interesting comparison between the refrigerant gases R134a and R600a. So get ready to discover the differences between them!.
Let’s start by saying that R600a and R134a are pure gases that can be recharged in both liquid and gaseous phases since they are not composed of gas mixtures.
R600a is a hydrocarbon used as a refrigerant, mainly in domestic refrigerators.
On the other hand, R134a is used in equipment of any power, such as domestic and commercial refrigerators, chillers for building air conditioning, chillers for machine cooling, and automotive air conditioning systems.
The main advantage of R600a is its low environmental impact and excellent thermodynamic properties, which contribute to its increasing use.
R600a does not harm the ozone layer and has a Global Warming Potential (GWP) of 3.
On the other hand, R134a also does not harm the ozone layer but has a GWP of 1430, which, over the years, is starting to face challenges with stricter environmental regulations.
R600a (isobutane) has a safety classification of A3 – non-toxic but flammable. R134a is non-toxic and non-flammable.
Although R600a (isobutane) is flammable, its use in refrigeration systems with lower cooling capacity reduces the risk due to the significantly low amount of R600a refrigerant used.
Isobutane R600a, like other hydrocarbon refrigerants, generally has good miscibility with any type of lubricant, although in many cases, it is recommended to use oils with higher viscosity.
R134a is compatible with POE oil in conventional refrigeration and PAG oil in automotive air conditioning.
R600a has proven to reduce the energy consumption of refrigeration systems compared to R134a.
R600a and R134a are not direct substitutes for each other in equipment that has already been used, unless authorized by the manufacturer. However, if R600a is replaced by R134a, the capillary must be changed because the displacement of the compressor with R600a is higher than with R134a.
Welcome to this post where we’ll embark on an intriguing comparison between the refrigerants R134a and R290. Brace yourselves to uncover the fascinating differences between these two!
Let’s start by emphasizing that both R290 and R134a are pure gases, capable of being recharged in either liquid or gaseous phase since they are not composed of gas mixtures.
Propane, or R290, serves as a hydrocarbon refrigerant primarily used in domestic refrigerators, small commercial cooling devices, as well as in low-power air conditioning units and heat pumps. Meanwhile, R134a finds use in equipment of any power range, including domestic and commercial refrigerators, air conditioning chillers for buildings, machine cooling chillers, and automotive air conditioning systems.
The primary advantage of R290 lies in its low environmental impact and excellent thermodynamic properties, making it increasingly favored in various applications. R290 is ozone-friendly and boasts an impressively low Global Warming Potential (GWP) of only 3.
On the other hand, R134a also doesn’t harm the ozone layer but has a relatively higher GWP of 1430. As the years pass, this poses challenges due to more stringent environmental restrictions.
R290 propane carries a safety classification of A3, being non-toxic but extremely flammable. In contrast, R134a is non-toxic and non-flammable.
Although R290 propane is flammable, the risk is reduced since it is primarily used in cooling circuits with lower cooling capacities, resulting in notably lower quantities of the refrigerant being present.
Moreover, R290, like other hydrocarbon-type refrigerants, exhibits excellent miscibility with any type of lubricant, although it is recommended to use lubricants with higher viscosity levels. R134a, on the other hand, is compatible with POE oil in conventional refrigeration and PAG oil in automotive air conditioning systems.
R290 has demonstrated a remarkable reduction in energy consumption in refrigeration systems when compared to R134a.
Furthermore, it’s crucial to note that R290 and R134a are not interchangeable gases in systems that have already been in operation, unless explicitly authorized by the manufacturer. Using R290 in systems not designed for this gas can lead to instability and adversely affect the compressor’s lifespan.
DO NOT SUBSTITUTE ONE GAS FOR ANOTHER.
For instance, for a refrigeration unit operating at -10°C, an absolute pressure of 29.4 psi is obtained from the table. The atmospheric pressure should be subtracted from the table value, for example:
The pressure-temperature charts for R290 (propane) in gauge pressure do NOT REQUIRE CALCULATIONS, as they provide direct values, using an atmospheric pressure reference of 14.7 psi.
We will develop a comparison between TWO refrigerant gases with serious ecological issues. We’re talking about R404A and R22.
R22 destroys the ozone layer and has a global warming potential (gwp) of 1760, while r404a does not deplete the ozone layer but has a gwp of 3922
R22 is a pure refrigerant, meaning it is composed of a single gas. On the other hand, R404A is internally formed by a mixture of several gases.
R22 is used in various fields, including air conditioning, refrigeration, and freezing, while R404A is mainly used for freezing and with less efficiency in refrigeration. It is not used in air conditioning.
Both R22 and R404A are non-toxic and non-flammable.<break time=”2s”/>
In the case of R22, it is possible to recharge it in both liquid and gaseous phases without any problem due to its nature as a pure refrigerant. However, R404A, being a gas mixture, must always be recharged in the liquid phase. This is an important consideration to take into account when performing maintenance on refrigeration systems.
Furthermore, it’s interesting to know the internal composition of R404A. This refrigerant contains approximately 4% of R134a, 44% R125 gas, and 52% R32
Another significant difference between the two gases is their compatibility with different types of oil. R22 is compatible with mineral oil and alkylbenzene but not with POE oil.
On the other hand, the refrigerant gas R404A is only compatible with POE oil.
Although R404A and R22 have a similar cooling performance, there are still many differences between them in real-world use.
The saturation pressures of R404A and R22 are different at the same temperature, making them not interchangeable.
If you replace R22 with R404A, problems may arise with the operation of the expansion valve, pressure control, lubrication, accumulators, separators, and refrigerant gas flow.
Additionally, since the density of R404A gas is approximately 50% higher than that of R22, using R404A requires a larger pipe diameter for the same displacement.
Let’s examine the differences in the measurements of the capillary tube for both refrigerant gases under the same operating condition.
For the same compressor, the current required for R404A is higher than that for R22.
Welcome to this exciting POST where we will compare two refrigerant gases: R32 and R410A Which one will be the best? Let’s find out together!
Let’s start by saying that R410A is a blend of two gases, while R32 is a pure gas composed of a single component.
R410A is primarily composed of R32 and R125 in a 50% proportion for each component. On the other hand, R32, being a pure gas, can be charged in both liquid and gas phases. R410A, being composed of two gases, must be recharged only in the liquid phase.
Both refrigerant gases, R32 and R410A, work with POE (Polyolester) oil. However, due to the presence of R125 within R410A, the latter exhibits better miscibility with POE oil compared to R32.
This means that R410A mixes more easily, which facilitates the return of POE oil to the compressor in the refrigeration system. As a result, in many compressors with R32, POE oil works with lower viscosity compared to when it works with R410A.
R32 has a higher temperature at the compressor outlet compared to R410A. Therefore, when working with R32, it is essential to use POE oils with a high viscosity index, meaning that the viscosity remains more stable with temperature changes.
Now, let’s talk about performance. R32 has greater cooling and heating capacity compared to R410A. This means that a smaller amount of gas is needed to achieve the same level of cooling and heating.
It is also important to consider the environmental impact. The Global Warming Potential (GWP) of R410A is 2085, while the GWP of R32 is 675. This indicates that R32 has a lower environmental footprint in terms of greenhouse gas emissions.
Now, let’s discuss safety. Although R32 is flammable, its flammability level is low compared to hydrocarbon refrigerants like propane. Therefore, R32 is classified as a mildly flammable refrigerant while maintaining high safety standards.
In summary, R32 stands out as a more efficient refrigerant gas for both cooling and heating compared to R410A. Its lower GWP and controlled flammability make it an attractive option for air conditioning systems.
Since the miscibility of R32 with POE oil is lower compared to R410A, it is highly recommended to strictly follow the equipment manufacturer’s installation recommendations to ensure proper oil return to the compressor.
What Happens If You Replace R410A Air Conditioner Gas with R32 Refrigerant?
Both R410A and R32 use POE oil, but due to solubility, R32 tends to have lower viscosity.
The viscosity index of oil used with R32 is usually higher than that needed for R410A.
When making this change, the refrigerant temperature at the compressor outlet will increase, which could affect the compressor’s lifespan.
If switching to R32 to achieve a similar cooling capacity increase, the refrigerant charge should be around 95% of what was used with R410A.
Adding the same amount of R32 as used with R410A will maintain cooling capacity but with higher electricity consumption.
If more R32 than the original R410A amount is added, cooling capacity will decrease.
By charging 90% of the original R410A amount with R32, similar electricity consumption will be maintained, but with lower cooling capacity.
Beyond 90%, the compressor’s electricity consumption will increase compared to what it used to be with R410A.
Switching to R32 will result in an increase in refrigerant mass flow rate, leading to higher discharge pressure. This higher discharge pressure causes an increase in electric current and thus input power.
The figure illustrates the relationship between Coefficient of Performance (COP) and the charge of four different quantities of R32. You’ll notice that the COPs of these charges are lower than those of the standard system, indicating that a direct replacement of R410A with R32 might not necessarily increase the COP.
Moreover, it’s important to note that by increasing electricity consumption when switching to R32, the compressor temperature might also further increase.
It is not recommended for safety reasons to change R410A to R32 without manufacturer authorization, even though it is proven that R32 is slightly flammable.
We are going to develop a comparison between the refrigerant gases R134a and one of its substitutes in the new automotive air conditioning systems, which is R1234yf.
R1234yf is a substance remarkably similar in cooling performance to its predecessor, R134a, while having a Global Warming Potential (GWP) of 1 compared to the GWP of R134a, which is 1430.
Both R134a and R1234yf are pure refrigerants, meaning they are composed of a single gas. Therefore, both R134a and R1234yf can be recharged in both liquid and gas phases without any issues.
R1234yf requires specific PAG, PVE, and POE oils designed for this gas. It’s important to ensure that the oil used is compatible with R1234yf.
R1234yf is highly corrosive, so only clean and properly specified lubricants can protect the system.
R134a uses POE oil in conventional refrigeration and PAG oil in automotive air conditioning.
R1234yf has low toxicity, is slightly flammable, and shows excellent compatibility with most materials. It is classified as A2L, group L2 in terms of safety. Similarly, R134a is non-toxic, non-flammable, and classified as A1, L1.
In addition to the automotive sector, both R134a and R1234yf are used in chillers for air conditioning in buildings and machine cooling.
Vehicles using R1234yf have different service fittings compared to vehicles using R134a to prevent cross-contamination with different refrigerants. For example, adapters are required to connect pressure measurement gauges.
R1234yf is more expensive than R134a.
It is not recommended to change from R1234yf to R134a for legal reasons.
Although the system may operate and cool when switching from R1234yf to R134a, its performance and capacity will be affected, and some inconveniences may arise, which we will discuss next.
R1234yf systems that control freeze protection by pressure may lose cooling performance if charged with R134a. This is due to the lower adjustment requirement of R134a.
Mixing R134a with R1234yf will alter the refrigerant pressure and may result in evaporator freezing in pressure-controlled systems, reducing the airflow.
The expansion valve setting for R1234yf refrigerant is different compared to R134a. Changing from R1234yf to R134a may result in a system with incorrect refrigerant flow and heat exchanger mal-distribution, leading to a loss of cooling performance or durability issues.
Changing from R1234yf to R134a can result in an increase in suction line pressure drop, reducing the efficiency of the equipment. This can be particularly damaging in the case of dual evaporator systems.
