Is R134a and HFC-134a the same?
It can be seen from the above that R134a and HFC134a are two different substances, but their physical properties are basically the same, and they can be substituted by each other. Both R134a and HFC134a are ODP values of zero.
What is the specific heat of R134a?
148.4 kJ/kg
For HFC-134a, H (ref) = 148.4 kJ/kg and S (ref) = 0.7967 kJ/kg·K.
How do you read a pressure enthalpy graph?
On the P-H diagram, pressure is indicated on the y-axis and enthalpy is indicated on the x-axis. Typically enthalpy is in units of Btu/lb and pressure is in units of pounds per square inch (psi). The upside down U figure shown on the diagram designates the points at which the refrigerant changes phase.
Can HFC-134a and R134a be mixed?
You’re wondering if you can mix different refrigerants for your air conditioning system. The short-long-only answer is no, never.
What is the critical pressure of R134A?
R-134a Properties – Imperial Units
| Temperature (oF) | Pressure (psia) | Specific Volume Vapor (cu.ft./lb.) |
|---|---|---|
| 100 | 138.28 | 0.340 |
| 125 | 198.27 | 0.232 |
| 150 | 276.12 | 0.159 |
| 175 | 375.69 | 0.107 |
What pressure does R134A run at?
For the normal running pressure in an R134A system, the coil should run at 22 pounds per square inch at the lowest temperature, 45−20 = 25 degrees Fahrenheit. Similarly, at the highest temperature, 60−20 = 40 degrees Fahrenheit, the coil should run at 57 psi.
What refrigerant can be mixed with R-134a?
There are three refrigerants that can be used to replace R-134a: R-1234yf, R-152a, and R-744. More on these replacements later.
What is the running pressure of 134a?
What is the suction pressure of R134A?
The normal running pressure of R134A is between 22 and 57 psi.
What are the properties of R134a?
Properties of R-134a
| No | Properties | R-134a |
|---|---|---|
| 2 | Auto-Ignition Temperature | 1418°F or 770°C |
| 3 | Ozone Depletion Level | 0 |
| 4 | Solubility In Water | 0.11% by weight at 77°F or 25°C |
| 5 | Critical Temperature | 252°F or 122°C |
What is the enthalpy of HFC-134a?
S (ref) are the saturated liquid enthalpy and entropy at –40 °C. For HFC-134a, H (ref) = 148.4 kJ/kg and S (ref) = 0.7967 kJ/kg·K.
What are the units of HFC-134a refrigerant?
Thermodynamic Properties of HFC-134a Refrigerant (1,1,1,2-tetrafluoroethane) SI Units New tables of the thermodynamic properties of HFC-134a have been developed and are presented here.
What does the Freon 134a constant pressure table mean?
Freon™ 134a Superheated Vapor—Constant Pressure Tables (continued) V = Volume in ft3/lb H = Enthalpy in Btu/lb S = Entropy in [Btu/lb·°R] v s = Velocity of Sound in ft/sec C p = Heat Capacity at Constant Pressure in Btu/(lb)(°F) C p /C v = Heat Capacity Ratio (Dimensionless)
Where are the constants for HFC-134a calculated?
The data fit and calcu- lation of constants for HFC-134a were performed for Du Pont at the National Institute of Standards and Tech- nology (NIST) under the supervision of Dr. Mark O. McLinden. The constants were calculated in SI units.