Psychrometric Properties: STD ATM
-20.0 10 to -20.0 90
Psychrometric properties of moist air — humidity ratio, enthalpy, dew point, wet-bulb temperature, and specific volume as functions of dry-bulb temperature and relative humidity; also includes saturation thermodynamic and transport properties (viscosity, thermal conductivity, Prandtl number, density) from ASHRAE 2021 tabulated data
| pressure condition | lookup key | dew point C (C) | dry bulb C (C) | enthalpy kJ kg (kJ/kg) | humidity ratio kg kg (kg/kg) | relative humidity pct (%) | specific volume m3 kg (m3/kg) | standard | wet bulb C (C) |
|---|---|---|---|---|---|---|---|---|---|
| STD ATM | -20.0 10 | -45.69 | -20 | -19.964 | 0.000063 | 10 | 0.7172 | ASHRAE Fundamentals 2017 Ch.1 | -19.11 |
| STD ATM | -20.0 100 | -22.27 | -20 | -18.557 | 0.000635 | 100 | 0.7179 | ASHRAE Fundamentals 2017 Ch.1 | -20.27 |
| STD ATM | -20.0 20 | -39.18 | -20 | -19.808 | 0.000127 | 20 | 0.7173 | ASHRAE Fundamentals 2017 Ch.1 | -19.65 |
| STD ATM | -20.0 30 | -35.17 | -20 | -19.651 | 0.00019 | 30 | 0.7174 | ASHRAE Fundamentals 2017 Ch.1 | -19.46 |
| STD ATM | -20.0 40 | -32.22 | -20 | -19.495 | 0.000254 | 40 | 0.7174 | ASHRAE Fundamentals 2017 Ch.1 | -20.23 |
| STD ATM | -20.0 50 | -29.88 | -20 | -19.339 | 0.000317 | 50 | 0.7175 | ASHRAE Fundamentals 2017 Ch.1 | -20.7 |
| STD ATM | -20.0 60 | -27.93 | -20 | -19.182 | 0.000381 | 60 | 0.7176 | ASHRAE Fundamentals 2017 Ch.1 | -20.94 |
| STD ATM | -20.0 70 | -26.25 | -20 | -19.026 | 0.000444 | 70 | 0.7177 | ASHRAE Fundamentals 2017 Ch.1 | -20.99 |
| STD ATM | -20.0 80 | -24.78 | -20 | -18.87 | 0.000508 | 80 | 0.7177 | ASHRAE Fundamentals 2017 Ch.1 | -20.88 |
| STD ATM | -20.0 90 | -23.46 | -20 | -18.713 | 0.000571 | 90 | 0.7178 | ASHRAE Fundamentals 2017 Ch.1 | -20.63 |
What else is in Engineering Database
AI built for engineering. Searches the engineering database, performs calculations, gives source-backed engineering insights.
Get started for free ↗Reference Data375 engineering tablesMaterial properties, pipe and shape dimensions, code tables, and electrical ratings across mechanical, civil, chemical, electrical, materials, and manufacturing engineering.
Browse dataCalculatorsDeterministic engineering calculatorsSizing, checking, and conversion tools that run against the reference tables. Inputs are code-compliant, outputs are traceable to the source standard.
Browse calculators