We will examine the key points regarding the replacement of R410A refrigerant with R32 gas in a previously operational air conditioning system.
Effect of Replacing R410A Refrigerant with R32 Gas in Compressor:
1. Lubrication
Both R410A and R32 utilize POE oil for lubrication. However, due to their solubility, the POE oil used with R32 tends to have lower viscosity compared to the POE oil used with R410A. Thus, replacing R410A with R32 can, in certain cases, impact lubrication efficiency. The viscosity of the oil within the compressor might be slightly higher than what R32 requires.
2. Amperage
The compressor’s electrical current consumption, or amperage, will be affected by the switch from R410A to R32. Ideally, maintaining the nominal electrical consumption of the compressor, representing the equipment’s characteristics when operating with R410A, is desirable.
Studies have shown that to achieve this nominal consumption value, the system should be charged with only 90% of the specified R410A weight. A charge greater than 90% could lead to an elevated electrical consumption above nominal levels, resulting in abnormal compressor heating and reduced equipment lifespan.
This is because the transition to R32 leads to an increase in the refrigerant’s mass flow rate, resulting in higher discharge pressure. This higher discharge pressure causes an increase in electrical current, and thus, power input.
3. Cooling Capacity
The cooling capacity provided by the compressor will also be impacted by the change from R410A to R32. For instance, considering a 90% load in grams compared to the R410A load, there will be a roughly 10% reduction in cooling capacity. In the graph example, cooling capacity drops from 2.4 kilowatts to 2.2 kilowatts.
Similarly, a 95% load compared to the R410A load leads to a ~5% increase in cooling capacity, but with higher-than-nominal electrical current consumption.
At a 100% load compared to the R410A load, the cooling capacity remains the same as the original equipment, but with higher-than-nominal electrical current consumption.
For a 105% load compared to the R410A load, there’s around a 5% decrease in cooling capacity, with higher-than-nominal electrical current consumption.
4. Discharge Temperature
With this transition, the refrigerant’s temperature at the compressor’s outlet will notably increase, potentially affecting the compressor’s lifespan.
5. Safety
For safety reasons, it’s not recommended to switch from R410A to R32 without manufacturer authorization, even though R32 is slightly flammable.
