AircoFridge Optimizer uses surfactant agents to reduce foaming, and to minimize residual oil film thickness. It is desirable to reduce foaming in compressors because the gas trapped in foam bubbles is a poor lubricant. Minimizing oil foam in the compressor is important to insure proper lubrication.
Foaming also causes problems in evaporator coils. After the liquid refrigerant and refrigeration oil mixture pass through the expansion valve, the refrigerant absorbs heat and vaporizes. Because the refrigerant and the oil are miscible and well mixed, when the refrigerant vaporizes, it does so in small pockets or bubbles. Consequently, a significant amount of foaming occurs as the refrigerant vaporizes while passing through the evaporator. This foaming action can be seen by taking a refrigeration oil sample that is laden with refrigerant.
Reducing foam in the evaporator coil is important because foam slows the heat transfer process. Comparing oil foam to a Styrofoam coffee cup is a good analogy. In one case, the foam is trapped in a liquid, and in another case, it is a trapped gas in a solid. As you know, it takes surprisingly little Styrofoam to keep the heat of scalding coffee from your hands. Because the oil foam acts as an insulator, the amount of heat transfer (cooling) in the evaporator is restricted. Therefore, reducing oil foaming in the evaporator coil increases the coil’s heat transfer efficiency, which, in turn, increases the refrigeration or air conditioner unit’s cooling capacity. AircoFridge Optimizer’s anti-foam additive reduces foaming and increases the cooling capacity. Controlled laboratory test found that the temperatures of the airflow exiting the evaporator coil dropped 2˚F after AircoFridge Optimizer was added. This increase cooling efficiency results in energy savings because the compressor operates fewer hours, for the same amount of cooling. The overall maintenance cost is also reduced because the unit is subjected to less wear and tear.
The surfactant agent that reduces oil foam also reduces refrigeration oil film thickness that accumulates inside condenser and evaporator coils. Because this oil film acts as an insulator in both coils, heat transfer is impaired. While a reduction in oil film build-up has been verified, it is difficult to precisely quantify the reduction since direct measurement is impractical. It has been AircoFridge Optimizer’s experience that when larger units are treated with the supplement, the amount of oil removed to prevent over filling can exceed the amount added, indicated the film thickness on all internal surfaces decreased. This conclusion is consistent with the observed improvement in heat transfer when AFO is used.