R-134a Properties Calculator

• •Use the R-134a Properties Calculator to check your hand calculations on homework or exam problems — comparing its result with your own working helps identify arithmetic errors before they propagate.
• •Use it during the early design phase to rapidly iterate on parameters and narrow down feasible configurations before committing time to detailed finite element simulations or full design packages.
• •Use it when reviewing a colleague's calculation or checking a vendor's data sheet for plausibility — a quick sanity check can prevent costly downstream errors.
• •Use it to generate reference data for a technical report or presentation without manual computation, ensuring consistent, reproducible numbers throughout the document.
• •Use it in the field when a quick estimate is needed and a full engineering software package is not available.

The R-134a Properties Calculator is a precision engineering calculation tool designed for students, engineers, and technical professionals. Comprehensive R-134a refrigerant property lookup: enter any two properties to get T, P, v, h, s, u, quality and phase; it reports pairs it cannot resolve All calculations are performed using established engineering formulas from the relevant scientific literature and standards. Follow the units printed beside each field. Where a unit selector is provided, the selected unit is converted internally. Results are computed in your browser without sending data to a server, which keeps your inputs private. This calculator is intended as a supplementary tool for learning and design exploration; always verify results against authoritative references for safety-critical applications.

R-134a (1,1,1,2-Tetrafluoroethane, CH₂FCF₃) is a hydrofluorocarbon (HFC) refrigerant that replaced R-12 (CFC) in automotive air conditioning and medium-temperature refrigeration applications following the Montreal Protocol's CFC phaseout. R-134a has zero ozone depletion potential (unlike CFCs) but has a global warming potential (GWP) of 1430, making it a target for replacement under the Kigali Amendment to the Montreal Protocol. Its thermodynamic properties are well-characterized in ASHRAE and NIST databases, with the most accurate formulation being the Tillner-Roth and Baehr (1994) equation of state, adopted by NIST REFPROP. Key properties at standard conditions: normal boiling point −26.1°C (just below the freezing point of water, making it unsuitable for low-temperature refrigeration), critical temperature 101.06°C, critical pressure 4.059 MPa, molecular weight 102.03 g/mol. The vapor pressure curve sets the relationship between evaporator temperature and pressure: at 0°C, P_sat ≈ 293 kPa; at 40°C, P_sat ≈ 1017 kPa. For a vapor-compression refrigeration cycle, these pressures define the low and high pressure sides of the system. The latent heat of vaporization is 198.6 kJ/kg at 0°C, relatively high for an HFC and giving good cooling capacity per unit mass flow. Specific heat of saturated liquid is about 1.34 kJ/(kg·K) and of saturated vapor 0.90 kJ/(kg·K) at 0°C. The saturation dome is wide, allowing substantial superheat and subcooling without crossing saturation. The calculator evaluates the Tillner-Roth and Baehr equation of state directly for any two known properties within its stated range, covering compressed liquid, saturated mixtures, superheated vapor and supercritical states, with a selectable ASHRAE, IIR or NBP enthalpy reference; for a few pairs it reports that the state is ambiguous or cannot be resolved, for example close to the critical point.

• •Automotive air conditioning: R-134a is the standard refrigerant for mobile AC in most vehicles built after 1994, replacing the ozone-depleting R-12. System designers use the property tables to size components and predict cycle performance.
• •Domestic refrigerators and freezers: medium-temperature refrigeration (0°C evaporator) uses R-134a for refrigerator applications. Freezers typically use R-404A or other low-temperature refrigerants.
• •Commercial chillers and heat pumps: water-cooled chillers in commercial HVAC historically used R-134a. Current-generation units often use R-1234yf or other low-GWP alternatives due to climate regulations.
• •Cascade refrigeration systems: R-134a is the high-temperature stage in cascade systems for ultra-low temperature applications, paired with R-23 or CO₂ for the low temperature stage.
• •Training and education: R-134a is the most common refrigerant used in university HVAC/refrigeration courses, with extensive published property tables and cycle analysis examples.