In this article, we will perform a comparison between two types of compressors: one that operates with R290 refrigerant and another that uses R404A.
Let’s start by highlighting that equipment incorporating the R290 compressor is used in refrigeration, freezing, and air conditioning applications, generally with lower cooling capacities. This allows for a smaller amount of R290 to be concentrated, thereby compensating for its flammability.
Due to these flammability characteristics, the use of R290 is particularly recommended in new equipment designed specifically for this type of gas.
On the other hand, the compressor that works with R404A, being non-flammable, can be used in a variety of cooling capacities, but in refrigeration and freezing applications, and not in air conditioning.
In terms of refrigerant molecules, R404A, in vapor state, is heavier than R290. This means that with a slight volume of gas passing through the compressor, several grams of R404A will be transported.
Although R404A is less efficient in terms of cooling compared to R290, the larger amount of grams passing through the R404A compressor ensures proper cooling of the product.
In contrast, R290 is less dense, resulting in a lower flow of grams through the compressor. However, each gram of R290 has a higher cooling capacity, compensating for its lower density.
A compressor using R290 handles fewer grams of gas compared to the R404A compressor, but each gram of R290 has a greater cooling capacity than a gram of R404A.
Regarding oil compatibility, R290 is compatible with mineral oil, alkylbenzene, and polyolester oil (POE), while the R404A compressor only uses POE oil.
The compressor system using R290 gas is more efficient in terms of consumption compared to R404A for the same cooling capacity. The amount of R404A refrigerant needed in grams to achieve the same cooling effect as R290 is higher.
As for the temperature at the compressor outlet, it is slightly lower in the R404A compressor compared to the R290 compressor. This is beneficial for the durability of the R404A compressor; however, as we observe in the graph, the discharge temperature of R290 is also low.
The R290 compressor can be charged in both liquid and vapor phases without issues, while the R404A compressor must be charged in the liquid phase.