KasperCalc: Thermodynamics Calculator — Steam Tables & Fluid Properties

Thermodynamics Property Calculator

Quick Fluid Selection

Water & Steam

Refrigerants

Air & Atmospheric

Browse All 414 Fluids

Unit System

SI Strict — K, Pa, J/kg SI Engineering — °C, kPa, kJ/kg US Customary — °F, psia, BTU/lbm US Process / HVAC — °F, psia, cP/cSt Textbook SI — K, kPa, kJ/kg Textbook US — °R, psia, BTU/lbm

Custom Units

Per-Property Unit Overrides — applied on top of any base preset

Temperature

Pressure

Density (ρ)

Sp. Energy (h, u)

Sp. Entropy / Heat (s, c_p)

Conductivity (λ)

Dyn. Viscosity (μ)

Kin. Viscosity (ν)

Prandtl (Pr)

Always dimensionless

Inputs

Selected Fluid

Water / Steam (H₂O)

Temperature

Pressure

Output Properties

Thermodynamic State

Temperature T K

Pressure P Pa

Density ρ kg/m³

Sp. Volume v m³/kg

Sp. Enthalpy h J/kg

Sp. Int. Energy u J/kg

Sp. Entropy s J/(kg·K)

Heat & Transport

Sp. Heat c_p J/(kg·K)

Sp. Heat c_v J/(kg·K)

Dyn. Viscosity μ Pa·s

Kin. Viscosity ν m²/s

Thermal Cond. λ W/(m·K)

Thermal Diff. α m²/s

Prandtl Number Pr —

Phase & Saturation

Phase —

Quality x 0–1

Sat. Temp T_sat K

Sat. Press P_sat Pa

Sat. Liq. h_f J/kg

Sat. Vap. h_g J/kg

Latent Heat h_fg J/kg

Sat. Liq. s_f J/(kg·K)

Sat. Vap. s_g J/(kg·K)

Generate Report

Status & Warnings

Ready — enter T and P above to calculate

Graphs

T-sweep at the entered pressure. Select a property to plot after calculating.

P-sweep at the entered temperature. Select a property to plot after calculating.

Saturation envelope and critical point for the selected fluid in T–P space.

Property vs Temperature

Property vs Pressure

Phase Diagram & Saturation Curve

Property Tables

T (K)	P_sat (Pa)	ρ_f (kg/m³)	ρ_g (kg/m³)	h_f (J/kg)	h_fg (J/kg)	h_g (J/kg)	s_f (J/kg·K)	s_g (J/kg·K)	μ_f (Pa·s)	λ_f (W/m·K)	Pr_f
Select a fluid and press Calculate to populate the saturation table

P_sat (Pa)	T_sat (K)	ρ_f (kg/m³)	ρ_g (kg/m³)	h_f (J/kg)	h_fg (J/kg)	h_g (J/kg)	s_f (J/kg·K)	s_g (J/kg·K)	c_p,f (J/kg·K)	μ_f (Pa·s)	Pr_f
Select a fluid and press Calculate to populate the saturation table

T (K)	P (Pa)	Phase	ρ (kg/m³)	h (J/kg)	s (J/kg·K)	c_p (J/kg·K)	u (J/kg)	μ (Pa·s)	λ (W/m·K)	Pr
Select a fluid and mode, then press Calculate to populate the property grid

Reference Guide — Thermodynamics

How KasperCalc Thermodynamics Works

KasperCalc computes thermodynamic properties using a precomputed, structured T/P grid derived from CoolProp 7.2.0 equations of state. Each fluid is solved across a dense mesh — log-spaced in pressure, linearly-spaced in temperature, with adaptive refinement near critical points, saturation curves, and phase boundaries.

Results are stored as compressed lookup tables and served directly in the browser — no server calls, no runtime equation solving, and no internet connection required after the initial page load. The calculator interpolates between precomputed grid points to return property values at arbitrary T and P.

For fluids with a two-phase region, the saturation curve is stored separately at 500 temperature points from T_triple to T_crit, with full liquid and vapor properties at each point. Bulk grid properties inside the two-phase dome are stored as NaN; phase behavior is resolved from the saturation table instead.

Accuracy Note: KasperCalc values are grid-interpolated approximations of CoolProp equations of state. Near phase boundaries and critical points, precision is reduced. Results are suitable for engineering estimates and education but should not be used for safety-critical design without independent verification.

Computed Properties (per T/P Node)

Density — ρ (kg/m³)
Isobaric specific heat — c_p (J/kg·K)
Isochoric specific heat — c_v (J/kg·K)
Specific enthalpy — h (J/kg)
Specific entropy — s (J/kg·K)
Specific internal energy — u (J/kg)
Dynamic viscosity — μ (Pa·s)
Thermal conductivity — λ (W/m·K)
Prandtl number — Pr (dimensionless)

Derived at Display Time

Kinematic viscosity — ν = μ/ρ (m²/s)
Thermal diffusivity — α = λ/(ρc_p) (m²/s)
Specific volume — v = 1/ρ (m³/kg)

Phase Flag Codes

Flag	Phase Region
0	Liquid (subcooled)
1	Gas / Supercritical vapor
2	Two-phase — bulk NaN; sat. liq/vap stored separately
3	Supercritical liquid
4	Supercritical gas
255	Failed / out-of-range (NaN)

Comparing Property Sources: NIST · CoolProp · KasperCalc

NIST WebBook

Experimental Authority

Authoritative thermophysical and thermochemical database backed by evaluated experimental data. The primary reference standard for validation and benchmark comparisons.

✓ Highest experimental accuracy
✓ Peer-reviewed, documented lineage
✓ Trusted reference standard
✗ Clunky UI
✗ Paid service advertisement
✗ Not designed for engineers

KasperCalc

Fast Browser Lookup

Lightweight, precomputed property database optimized for browser lookup, embedded tools, and offline use. Approximates CoolProp via a structured, pre-solved T/P grid.

✓ Instant browser-native lookup
✓ Works fully offline
✓ SI and US customary units
✓ Deterministic performance
✗ Grid-interpolated (approx.)
✗ Reduced precision near T_crit

CoolProp

High-Fidelity Physics Engine

Open-source thermophysical library solving equations of state (EOS) on demand. Supports 400+ fluids, refrigerants, incompressible mixtures, and full phase behavior via iterative numerical solvers.

✓ High-fidelity, all phases
✓ Critical & two-phase region
✓ 400+ fluids & mixtures
✗ Requires Python / C++
✗ Computational overhead
✗ Not browser-native

NIST WebBook

Experimental Authority

Authoritative thermophysical and thermochemical database backed by evaluated experimental data. The primary reference standard for validation and benchmark comparisons.

✓ Highest experimental accuracy
✓ Peer-reviewed, documented lineage
✓ Trusted reference standard
✗ Clunky UI
✗ Paid service advertisement
✗ Not designed for engineers

KasperCalc

Fast Browser Lookup

Lightweight, precomputed property database optimized for browser lookup, embedded tools, and offline use. Approximates CoolProp via a structured, pre-solved T/P grid.

✓ Instant browser-native lookup
✓ Works fully offline
✓ SI and US customary units
✓ Deterministic performance
✗ Grid-interpolated (approx.)
✗ Reduced precision near T_crit

CoolProp

High-Fidelity Physics Engine

Open-source thermophysical library solving equations of state (EOS) on demand. Supports 400+ fluids, refrigerants, incompressible mixtures, and full phase behavior via iterative numerical solvers.

✓ High-fidelity, all phases
✓ Critical & two-phase region
✓ 400+ fluids & mixtures
✗ Requires Python / C++
✗ Computational overhead
✗ Not browser-native

Grid & Data Strategy — Mesh, Resolution & Storage

Temperature Axis

500 linearly-spaced points from T_min to T_max, plus 50 adaptive points clustered within ±20% of T_crit. Total: up to ~530 unique T-points per fluid.

Pressure Axis

200 log-spaced points from P_triple (or 101,325 Pa) to P_max, plus 50 linear points within ±20% of P_crit, plus a guaranteed 101,325 Pa (1 atm) point. Total: up to ~240 unique P-points per fluid.

Pressure Bands

The pressure axis is divided into bands of 20 pressure points each to enable partial-file loading. Each band is stored as a separate .bin and .json file. A fluid with 240 pressure points has ~12 bands.

Saturation Curve

500 temperature points from T_triple to T_crit. Both saturated liquid (Q=0) and saturated vapor (Q=1) properties stored at each point: density, c_p, enthalpy, entropy, viscosity, and conductivity.

Incompressible Fluids (INCOMP)

INCOMP fluids (always single-phase liquid) use the same T/P grid structure but are evaluated via PropsSI with the full fluid string (e.g. INCOMP::MEG[0.3]). No saturation curve. c_v is stored as NaN. Phase flag is always 0 (liquid).

File Format

File	Contents	Format
`meta.json`	Fluid metadata, T/P axes info, band list, critical & triple points	JSON (UTF-8)
`meta.bin`	Same as meta.json (UTF-8 encoded)	Raw bytes
`grid_band_NNN_*.bin`	Grid property data: T, P, rho, cp, cv, h, s, u, visc, cond, Pr, phase flag	Float32 × 11 + uint8
`saturation.bin`	Saturation curve: T, P, liq/vap density, cp, h, s, visc, cond + phase flag	Float32 × 14 + uint8

Float32 Precision

All grid and saturation values are stored as 32-bit IEEE 754 floats (~7 significant decimal digits). This is sufficient for engineering calculations but introduces small rounding errors relative to CoolProp double-precision output.

NaN Encoding

Failed or undefined properties (two-phase bulk, out-of-range, INCOMP c_v) are stored as IEEE 754 NaN in binary files and as JSON null in text files.

Typical grid sizes: Water: ~104,000 grid points. R-134a: ~93,000 grid points. A simple incompressible fluid (e.g. MEG[0.3]): ~100,500 grid points.

Available Fluids: All 400+ CoolProp Fluids

Water & Steam

Water (H₂O) Water Heavy Water (D₂O) HeavyWater

Light Gases & Noble Gases

Air (pseudo-pure) Air Nitrogen (N₂) Nitrogen Oxygen (O₂) Oxygen Hydrogen (H₂) Hydrogen Parahydrogen ParaHydrogen Deuterium (D₂) Deuterium Helium (He) Helium Neon (Ne) Neon Argon (Ar) Argon Krypton (Kr) Krypton Xenon (Xe) Xenon Fluorine (F₂) Fluorine

Inorganic Compounds

Ammonia (NH₃) Ammonia Carbon Dioxide (CO₂) CarbonDioxide Carbon Monoxide (CO) CarbonMonoxide Carbonyl Sulfide (COS) CarbonylSulfide Hydrogen Chloride (HCl) HydrogenChloride Hydrogen Sulfide (H₂S) HydrogenSulfide Nitrous Oxide (N₂O) NitrousOxide Sulfur Dioxide (SO₂) SulfurDioxide Sulfur Hexafluoride (SF₆) SulfurHexafluoride

Alkanes (Paraffins) — C1 through C10

Methane (CH₄) Methane Ethane (C₂H₆) Ethane Propane (C₃H₈) n-Propane n-Butane n-Butane Isobutane IsoButane n-Pentane n-Pentane Isopentane Isopentane Neopentane Neopentane n-Hexane n-Hexane n-Heptane n-Heptane n-Octane n-Octane n-Nonane n-Nonane n-Decane n-Decane

Cyclic Hydrocarbons & Aromatics

Cyclopropane CycloPropane Cyclopentane Cyclopentane Cyclohexane CycloHexane Benzene (C₆H₆) Benzene Toluene (C₇H₈) Toluene Ethylbenzene EthylBenzene m-Xylene m-Xylene o-Xylene o-Xylene p-Xylene p-Xylene

Alkenes, Alkynes & Dienes

Ethylene (C₂H₄) Ethylene Propylene (C₃H₆) Propylene 1-Butene 1-Butene cis-2-Butene cis-2-Butene trans-2-Butene trans-2-Butene Isobutene IsoButene Propyne Propyne

Oxygenates, Alcohols & Ethers

Methanol (CH₃OH) Methanol Ethanol (C₂H₅OH) Ethanol Acetone (C₃H₆O) Acetone Dimethyl Ether DimethylEther Diethyl Ether DiethylEther Dimethyl Carbonate DimethylCarbonate

Siloxanes (Organic Silicon Compounds)

MM (hexamethyldisiloxane) MM MDM (octamethyltrisiloxane) MDM MD2M (decamethyltetrasiloxane) MD2M MD3M MD3M MD4M MD4M D4 (cyclo-octamethyltetrasiloxane) D4 D5 (cyclo-decamethylpentasiloxane) D5 D6 (cyclo-dodecamethylhexasiloxane) D6

Fatty Acid Methyl Esters (Biodiesel / FAME)

Methyl Linoleate (C18:2) MethylLinoleate Methyl Linolenate (C18:3) MethylLinolenate Methyl Oleate (C18:1) MethylOleate Methyl Palmitate (C16:0) MethylPalmitate Methyl Stearate (C18:0) MethylStearate

Refrigerants — CFC / HCFC (Legacy, Phase-Out)

R-11 (CCl₃F) R11 R-12 (CCl₂F₂) R12 R-13 (CClF₃) R13 R-21 (CHCl₂F) R21 R-22 (CHClF₂) R22 R-113 (C₂Cl₃F₃) R113 R-114 (C₂Cl₂F₄) R114 R-115 (C₂ClF₅) R115 R-123 R123 R-124 R124 R-141b R141b R-142b R142b

Refrigerants — HFC (Hydrofluorocarbons)

R-23 (CHF₃) R23 R-152a R152A R-161 R161 R-32 (CH₂F₂) R32 R-41 (CH₃F) R41 R-125 (CHF₂CF₃) R125 R-134a (CH₂FCF₃) R134a R-143a (CH₃CF₃) R143a R-227ea (CF₃CHFCF₃) R227EA R-236ea R236EA R-236fa R236FA R-245ca R245ca R-245fa R245fa R-365mfc R365MFC

Refrigerants — PFC (Perfluorocarbons) & Iodotrifluoromethane

R-14 (CF₄) R14 R-116 (C₂F₆) R116 R-218 (C₃F₈) R218 RC-318 (cyclo-C₄F₈) RC318 R-13I1 (CF₃I) R13I1

Refrigerants — HFO (Hydrofluoroolefins, Low-GWP)

R-1234yf (CF₃CF=CH₂) R1234yf R-1234ze(E) (trans) R1234ze(E) R-1234ze(Z) (cis) R1234ze(Z) R-1243zf R1243zf R-1233zd(E) R1233zd(E) R-1336mzz(E) R1336mzz(E)

Refrigerant Blends (Pseudo-Pure)

R-404A (R125/R134a/R143a) R404A R-407C (R32/R125/R134a) R407C R-410A (R32/R125) R410A R-507A (R125/R143a) R507A

Added with CoolProp 8.0.0

These twelve fluids are new in CoolProp 8.0.0. Their tables were made with the same pipeline and grid as the others; each file's metadata records the CoolProp version used.

Chlorine (Cl₂) Chlorine CAS 7782-50-5 Vinyl Chloride (C₂H₃Cl) VinylChloride CAS 75-01-4 R-1130(E), trans-1,2-Dichloroethene R1130(E) CAS 156-60-5 Propylene Glycol (C₃H₈O₂) PropyleneGlycol CAS 57-55-6 Tetrahydrofuran (THF, C₄H₈O) Tetrahydrofuran CAS 109-99-9 R-1123 (HFO, CF₂=CHF) R1123 CAS 359-11-5 R-1132(E) (HFO, trans-CHF=CHF) R1132(E) CAS 1630-78-0 R-1336mzz(Z) (HFO) R1336mzz(Z) CAS 692-49-9 R-1224yd(Z) (HCFO, CF₃CF=CHCl) R1224YDZ CAS 111512-60-8 n-Perfluorobutane (C₄F₁₀) n-Perfluorobutane CAS 355-25-9 n-Perfluoropentane (C₅F₁₂) n-Perfluoropentane CAS 678-26-2 n-Perfluorohexane (C₆F₁₄) n-Perfluorohexane CAS 355-42-0

INCOMP — Pure Incompressible Fluids (72 fluids)

Single-phase liquid models from CoolProp's INCOMP backend: heat-transfer oils (Therminol, Dowtherm, Syltherm, Paratherm, Dynalene), ready-mixed secondary coolants, molten salts and food components. No saturation curve. c_v = NaN. Phase is always 0 (liquid). Names and temperature limits are from the CoolProp documentation; outside those limits the tables are not valid.

Aspen Temper -10, Potassium acetate/formate AS10 -10 to 30 °C Aspen Temper -20, Potassium acetate/formate AS20 -20 to 30 °C Aspen Temper -30, Potassium acetate/formate AS30 -30 to 30 °C Aspen Temper -40, Potassium acetate/formate AS40 -40 to 30 °C Aspen Temper -55, Potassium acetate/formate AS55 -55 to 30 °C Acetone, liquid phase at 10 bar Acetone -75 to 143.33 °C Air, gaseous phase at 1 atm (101325 Pa) Air -75 to 250 °C Diethylbenzene mixture - Dowtherm J DEB -80 to 100 °C Dynalene SF DSF 0 to 315 °C Dowtherm J DowJ -80 to 345 °C Dowtherm J, Diethylbenzene mixture DowJ2 -73 to 315 °C Dowtherm Q DowQ -35 to 360 °C Dowtherm Q, Diphenylethane/alkylated aromatics DowQ2 -35 to 330 °C Ethanol, liquid phase at 10 bar Ethanol -75 to 150.69 °C Food ash model (2006 ASHRAE Handbook, Choi and Okos 1986) FoodAsh -40 to 150 °C Food carbohydrate model (2006 ASHRAE Handbook, Choi and Okos 1986) FoodCarbohydrate -40 to 150 °C Food fat model (2006 ASHRAE Handbook, Choi and Okos 1986) FoodFat -40 to 150 °C Food fiber model (2006 ASHRAE Handbook, Choi and Okos 1986) FoodFiber -40 to 150 °C Food ice model (2006 ASHRAE Handbook, Choi and Okos 1986) FoodIce -40 to 150 °C Food protein model (2006 ASHRAE Handbook, Choi and Okos 1986) FoodProtein -40 to 150 °C Food water model (2006 ASHRAE Handbook, Choi and Okos 1986) FoodWater -40 to 150 °C Dynalene HC10 HC10 -10 to 218 °C Dynalene HC20 HC20 -20 to 210 °C Dynalene HC30 HC30 -30 to 210 °C Dynalene HC40 HC40 -40 to 200 °C Dynalene HC50 HC50 -50 to 210 °C Hydrocarbon blend - Dynalene MV HCB -80 to 100 °C Hydrocarbon mixture - Gilotherm D12 HCM -80 to 100 °C Hydrofluoroether - HFE-7100 3M Novec HFE -80 to 100 °C HFE-7100, Hydrofluoroether HFE2 -80.33 to 64.27 °C HyCool 20, Potassium formate HY20 -20 to 50 °C HyCool 30, Potassium formate HY30 -30 to 50 °C HyCool 40, Potassium formate HY40 -40 to 20 °C HyCool 45, Potassium formate HY45 -45 to 20 °C HyCool 50, Potassium formate HY50 -50 to 20 °C Hexane, liquid phase at 10 bar Hexane -75 to 165.03 °C Liquid sodium LiqNa 126.85 to 2226.85 °C NBS, Water NBS 1 to 100 °C Nitrate salt, 0.6 NaNO3 and 0.4 KNO3 NaK 300 to 600 °C Pirobloc HTF-BASIC PBB 50 to 300 °C Paracryol, Aliphatic Hydrocarbon PCL -40 to 180 °C Paratherm CR PCR -100 to 220 °C Paratherm GLT PGLT -15 to 315 °C Paratherm HE PHE 0 to 330 °C Paratherm HR PHR -15 to 370 °C Paratherm LR PLR -85 to 230 °C Paratherm MR PMR -40 to 315 °C Polydimethylsiloxane 1 - Baysilone KT3 PMS1 -80 to 100 °C Polydimethylsiloxane 2 - Syltherm XLT PMS2 -80 to 100 °C Paratherm NF PNF -10 to 315 °C Paratherm NF, Hydrotreated mineral oil PNF2 -10 to 320 °C Syltherm 800 S800 -40 to 398 °C Synthetic alkyl benzene - Marlotherm X SAB -80 to 100 °C Therminol 66 T66 0 to 380 °C Therminol 72 T72 -10 to 380 °C Citrus oil terpene - d-Limonene TCO -80 to 100 °C Therminol D12 TD12 -85 to 230 °C Therminol VP-1 TVP1 12 to 397 °C Thermogen VP 1869 TVP1869 -80 to 20 °C Texatherm 22 TX22 0 to 350 °C Tyfoxit 1.10, Potassium Acetate TY10 -10 to 40 °C Tyfoxit 1.15, Potassium Acetate TY15 -20 to 40 °C Tyfoxit 1.20, Potassium Acetate TY20 -40 to 40 °C Tyfoxit 1.24, Potassium Acetate TY24 -55 to 40 °C Water, fit of EOS from 1 bar to 100 bar Water 0 to 200 °C Syltherm XLT XLT -100 to 260 °C Syltherm XLT, Polydimethylsiloxane XLT2 -100 to 260 °C Zitrec S10, Potassium formate/Sodium propionate ZS10 -8 to 90 °C Zitrec S25, Potassium formate/Sodium propionate ZS25 -23 to 90 °C Zitrec S40, Potassium formate/Sodium propionate ZS40 -38 to 90 °C Zitrec S45, Potassium formate/Sodium propionate ZS45 -43 to 90 °C Zitrec S55, Potassium formate/Sodium propionate ZS55 -55 to 90 °C

INCOMP — Solutions with Concentration

Accessed as INCOMP::BaseFluid[fraction], e.g. INCOMP::MEG[0.3] for 30% ethylene glycol by mass. Codes starting with M (and FRE, LiBr, Ice…) use mass fraction; the A, G, P, V and Z codes use volume fraction. Concentrations outside the range return NaN (phase 255).

Freezium, Potassium Formate FRE -40.15 to 39.85 °C, 19–50% by mass Ice slurry with Ethanol IceEA -33.15 to -8.15 °C, 5–35% by mass Ice slurry with NaCl IceNA -18.15 to -3.15 °C, 5–35% by mass Ice slurry with Propylene Glycol IcePG -43.15 to -8.15 °C, 5–35% by mass Lithium bromide - water LiBr -0.15 to 226.85 °C, 0–75% by mass Ammonia (NH3) - water MAM -100 to 30 °C, 0–30% by mass Melinder, Ammonia - water MAM2 -49 to 20 °C, 8–24% by mass Calcium Chloride (CaCl2) - water MCA -100 to 40 °C, 0–30% by mass Melinder, Calcium Chloride - water MCA2 -44 to 30 °C, 9–29% by mass Ethyl Alcohol (Ethanol) - water MEA -100 to 40 °C, 0–60% by mass Melinder, Ethanol - water MEA2 -44 to 20 °C, 11–60% by mass Ethylene Glycol - water MEG -100 to 100 °C, 0–60% by mass Melinder, Ethylene Glycol - water MEG2 -44 to 40 °C, 0–56% by mass Glycerol - water MGL -100 to 40 °C, 0–60% by mass Melinder, Glycerol - water MGL2 -40 to 40 °C, 20–63% by mass MIT Seawater (salinity) MITSW 0 to 120 °C, 0–12% by mass Potassium Acetate (CH3CO2K) - water MKA -100 to 40 °C, 0–45% by mass Melinder, Potassium Acetate - water MKA2 -44 to 30 °C, 11–41% by mass Potassium Carbonate (K2CO3) - water MKC -100 to 40 °C, 0–40% by mass Melinder, Potassium Carbonate - water MKC2 -35 to 30 °C, 0–39% by mass Potassium Formate (CHKO2) - water MKF -100 to 40 °C, 0–48% by mass Lithium Chloride (LiCl) - water MLI -100 to 40 °C, 0–24% by mass Methyl Alcohol (Methanol) - water MMA -100 to 40 °C, 0–60% by mass Melinder, Methanol - water MMA2 -50 to 20 °C, 8–47% by mass Magnesium Chloride (MgCl2) - water MMG -100 to 40 °C, 0–30% by mass Melinder, Magnesium Chloride - water MMG2 -30 to 30 °C, 0–21% by mass Sodium Chloride (NaCl) - water MNA -100 to 40 °C, 0–23% by mass Melinder, Sodium Chloride - water MNA2 -20 to 30 °C, 0–23% by mass Propylene Glycol - water MPG -100 to 100 °C, 0–60% by mass Melinder, Propylene Glycol - water MPG2 -45 to 40 °C, 15–57% by mass ASHRAE, Ethylene Glycol AEG -35 to 100 °C, 10–60% by volume Antifrogen KF, Potassium Formate AKF -40 to 50 °C, 40–100% by volume Antifrogen L, Propylene Glycol AL -40 to 80 °C, 10–60% by volume Antifrogen N, Ethylene Glycol AN -40 to 80 °C, 10–60% by volume ASHRAE, Propylene Glycol APG -35 to 100 °C, 10–60% by volume Glykosol N, Ethylene Glycol GKN -53 to 100 °C, 10–60% by volume Pekasol 2000, Potassium acetate/formate PK2 -62 to 100 °C, 30–100% by volume Pekasol L, Propylene Glycol PKL -49 to 100 °C, 10–60% by volume Zitrec AC, Corrosion Inhibitor ZAC 0 to 100 °C, 6–50% by volume Zitrec FC, Propylene Glycol ZFC -40 to 100 °C, 30–60% by volume Zitrec LC, Propylene Glycol ZLC -50 to 100 °C, 30–70% by volume Zitrec M, Ethylene Glycol ZM -50 to 120 °C, 0–100% by volume Zitrec MC, Ethylene Glycol ZMC -50 to 110 °C, 30–70% by volume VDI, Calcium Chloride VCA -55 to 20 °C, 15–30% by volume VDI, Potassium Carbonate VKC -35 to 20 °C, 13–39% by volume VDI, Methanol VMA -80 to 0 °C, 10–90% by volume VDI, Magnesium Chloride VMG -33 to 20 °C, 7–21% by volume VDI, Sodium Chloride VNA -21 to 20 °C, 7–23% by volume

Key Thermodynamic Formulas & Relationships

Derived Properties (Computed at Display Time)

Specific Volume v = 1 / ρ [m³/kg]

Kinematic Viscosity ν = μ / ρ [m²/s]

Thermal Diffusivity α = λ / (ρ · c_p) [m²/s]

Prandtl Number Pr = μ · c_p / λ [dimensionless] Pr = ν / α (alternate form)

Saturation & Quality

Quality (Dryness Fraction) x = (h − h_f) / h_fg [0–1] where h_fg = h_g − h_f (latent heat)

Two-Phase Mixture Properties h = h_f + x · h_fg s = s_f + x · s_fg v = v_f + x · v_fg

Clausius-Clapeyron Equation dP/dT = h_fg / (T · v_fg) Relates slope of saturation curve to latent heat

Ideal Gas Relations

Ideal Gas Law P v = R T or P = ρ R T R = R𝕄 / M (specific gas constant)

Mayer Relation c_p − c_v = R [J/(kg·K)]

Heat Capacity Ratio γ = c_p / c_v [dimensionless] Air: γ ≈ 1.4 Steam: γ ≈ 1.3

First & Second Law of Thermodynamics

First Law (Closed System) dh = du + d(Pv) = δq + v dP

First Law (Open/Flow System) q − w = Δh + ΔKE + ΔPE For pumps & turbines: w = h_in − h_out

Second Law / Entropy Relations T ds = du + P dv (1st Gibbs equation) T ds = dh − v dP (2nd Gibbs equation) ds ≥ δq / T (Clausius inequality)

Isentropic Processes (Ideal, Reversible Adiabatic)

Isentropic Relations (Ideal Gas) T₂/T₁ = (P₂/P₁)^(γ−1)/γ T₂/T₁ = (v₁/v₂)^γ−1

Isentropic Efficiency (Turbine) η_T = (h₁−h₂) / (h₁−h_2s)

Isentropic Efficiency (Compressor) η_C = (h_2s−h₁) / (h₂−h₁)

Heat Transfer Dimensionless Numbers

Reynolds Number Re = ρ V D / μ = V D / ν

Nusselt Number Nu = h_conv D / λ

Stanton Number St = Nu / (Re · Pr) = h_conv / (ρ V c_p)

Note: Subscripts f and g denote saturated liquid and saturated vapor respectively. Subscript fg denotes the difference (g − f). Subscript s denotes isentropic (reversible adiabatic) conditions.

CARD 06

Unit System Presets

The calculator offers six unit presets. Each preset applies a consistent set of conversions to every displayed output: temperature, pressure, energy, transport properties, and so on. The raw data is always stored in base SI (CoolProp native); unit conversion happens at display time, so you can switch presets without re-running a calculation.

Side-by-Side Unit Comparison

Property	SI Strict	SI Engineering	US Customary	US Process-HVAC	Textbook SI	Textbook US
Temperature	K	°C	°F	°F	°C	°F
Pressure	Pa	kPa	psia	psia	kPa	psia
Density	kg/m³	kg/m³	lbm/ft³	lbm/ft³	kg/m³	lbm/ft³
Spec. Volume	m³/kg	m³/kg	ft³/lbm	ft³/lbm	m³/kg	ft³/lbm
cp / cv	J/(kg·K)	kJ/(kg·K)	BTU/(lbm·°R)	BTU/(lbm·°F)	kJ/(kg·K)	BTU/(lbm·°R)
Enthalpy (h)	J/kg	kJ/kg	BTU/lbm	BTU/lbm	kJ/kg	BTU/lbm
Entropy (s)	J/(kg·K)	kJ/(kg·K)	BTU/(lbm·°R)	BTU/(lbm·°R)	kJ/(kg·K)	BTU/(lbm·°R)
Int. Energy (u)	J/kg	kJ/kg	BTU/lbm	BTU/lbm	kJ/kg	BTU/lbm
Dyn. Viscosity	Pa·s	mPa·s	lbm/(ft·s)	cP	Pa·s	cP
Conductivity	W/(m·K)	W/(m·K)	BTU/(hr·ft·°F)	BTU/(hr·ft·°F)	W/(m·K)	BTU/(hr·ft·°F)
Prandtl	dimensionless

Preset Descriptions

SI Strict

All outputs exactly as returned by CoolProp (no conversion applied). Temperature in Kelvin, pressure in Pascals, energies in J/kg. Best for verifying raw data, feeding other software, or writing equations where absolute temperature is required. Entropy and enthalpy offsets are CoolProp reference-state values; treat absolute numbers as deltas only.

SI Engineering

Practical metric units standard in European and international engineering practice. Temperature shifts to °C for intuitive feel; pressures scale to kPa; energies scale to kJ/kg. Viscosity displayed in mPa·s (= cP numerically), which is more legible for liquids than Pa·s. Matches the output style of most modern SI-based engineering textbooks and process simulators.

US Customary

Traditional US engineering units used in mechanical, aerospace, and general US practice. Pressure in psia (absolute), density in lbm/ft³, energies in BTU/lbm. Viscosity in lbm/(ft·s) for use with the BTU/ft/hr system. Consistent with ASHRAE fundamentals handbooks and many US mechanical engineering references.

US Process-HVAC

Tuned for process engineering and HVAC applications in the United States. Matches US Customary in most respects, but viscosity is displayed in centipoise (cP). This is the universal industrial standard found in Perry's, GPSA, and most process datasheets and specific heat labels °F in the denominator (numerically identical to °R for Δ values). Common in oil & gas, refrigeration, and building systems work.

Textbook SI

Matches the conventions of leading thermodynamics textbooks in SI edition: Çengel & Boles, Moran & Shapiro, Smith, Van Ness & Abbott. Temperature in °C, pressure in kPa, energies in kJ/kg, entropy in kJ/(kg·K). Viscosity kept in Pa·s (= kg/(m·s)) as shown in most textbook tables. Ideal for checking homework or worked examples against a reference book.

Textbook US

Matches US-edition thermodynamics textbooks: Çengel & Boles (US), Faires & Simmang, and steam tables common in US universities. Temperature in °F, absolute temperature in °R where needed, pressure in psia, energies in BTU/lbm. Viscosity in cP for readability. Entropy uses °R in the denominator to match steam table formatting. Use this when cross-referencing textbook appendix tables.

Absolute vs. Relative Temperature: BTU/lbm·°R and BTU/lbm·°F are numerically identical for differences (Δ1 °F = Δ1 °R), but absolute temperature for ideal-gas or isentropic calculations always requires Rankine (°R) or Kelvin (K). The calculator uses the correct absolute scale internally regardless of the display preset.

Tip: cP (centipoise) = mPa·s exactly. 1 cP = 0.001 Pa·s. Water at 20 °C ≈ 1.002 cP. This equivalence makes it easy to switch between US Process and SI Engineering viscosity values with no arithmetic.

Thermodynamic Property Calculator — Steam Tables, Refrigerant Properties, Gas and Fluid Thermophysical Data