R438A is a "drop-in" replacement for R22.It can reduce condensing pressures and prolong compressor life however,it is not on the same stamp as R410A whose properties are completely different.
Through out the world many researchers have been working since the last four decades to find suitable alternatives to CFCs. Though there are many alternative refrigerants available in the market , in reality, till date no refrigerant is exactly replacing CFCs,HCFCs which dominated the refrigeration industries for more than sixty years due to its excellent chemical ,thermo-physical and thermodynamic properties. Therefore before we use any new refrigerant especially for retrofitting the existing system it is recommended to get the full details of the refrigerant. For new system it is a good practice to consult the OEM.
You should investigate this web site as well as the web site of the manufacturer of the refrigerant product you purchase prior to using it. There will be additional recommendations as well as warnings as per the manufacturer of the refrigerant as well as the equipment manufacturer. No refrigerant is truly a "drop in". Many factors must be considered.
ISCEON® MO99 (R438A)
ISCEON® MO99 (R438A) is a new retrofit refrigerant for R22 replacement, designed specifically for DX water chillers where the expansion valve has been tightly sized to the chiller capacity. MO29 (R422D) remains the multipurpose refrigerant and gives a satisfactory performance in the majority of DX water chillers.
ISCEON® MO99™ has been designed to closely match the pressure, temperature, enthalpy, and mass flow properties of R-22. Therefore, in most cases, the operational set-points currently used for evaporator pressures, thermal expansion valves, condenser head pressure control, etc. will be adequate for MO99™. It is recommended that after replacing the R-22 with MO99™, the system be started up and operation allowed to stabilize using these R-22 set-points. If desired, after the system has stabilized, operating controls can be fine tuned to optimize system performance. Detailed instructions for measuring and setting suction pressure, superheat, and subcooling are contained in the Appendix.
Table 1 shows approximate system performance changes following a retrofit and are general guidelines for system behavior. These values are based on field experience, calorimeter testing and thermodynamic property data; and assume equal compressor efficiency.
Cooling capacity and energy efficiency depend greatly on system design, operating conditions and the actual condition of the equipment. ISCEON® MO99™ provides similar cooling capacity and energy efficiency to R-22 in most systems. Actual performance depends on system design and operating conditions.
Table 1
ISCEON® MO99™ Compressor Calorimeter Performance Compared to R-22 in Refrigeration and Air Conditioning Systems Performance with subcooling based on thermocycle calculations from calorimeter data and do not include heat transfer effects
Low
Temperature*
-25°F evaporator
105°F condenser
65°F return gas with 10°F subcooling
Medium
Temperature
20°F evaporator
120°F condenser
65°F return gas with 10°F subcooling
A/C & High
Temperature
45°F evaporator
115°F condenser
65°F return gas with 15°F subcooling
Discharge
Temperature, °F
-22
-45
-31
Discharge Pressure, psi
+3
+6
+5
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"Memorize the calculations, you look like a fool searching your notes while teaching class"
R438A
Re: R438A
