Thermal Conductivity of Air (k)
Reference table, calculator, and chart for thermal conductivity of air over a range of temperatures
Thermal Conductivity of Air Calculator
Enter a temperature in Celsius or Kelvin to estimate thermal conductivity of air:
Thermal Conductivity of Air Table
| Temperature (°C) | k (W/m·K) |
|---|---|
| -20 | 0.0219 |
| -10 | 0.0230 |
| 0 | 0.0241 |
| 10 | 0.0251 |
| 15 | 0.0256 |
| 20 | 0.0260 |
| 25 | 0.0263 |
| 30 | 0.0267 |
| 40 | 0.0275 |
| 50 | 0.0283 |
| 60 | 0.0290 |
| 70 | 0.0297 |
| 80 | 0.0304 |
| 90 | 0.0311 |
| 100 | 0.0317 |
Thermal Conductivity of Air Graph
About Thermal Conductivity of Air (k)
Thermal conductivity (k) measures a material's ability to conduct heat. For air, it determines how efficiently thermal energy is transferred through the gas and is a key property in thermodynamics, heat transfer, HVAC system design, and fluid mechanics calculations.
Standard Reference Value
At 15°C (288.15 K) and 1 atm pressure, the thermal conductivity of dry air is approximately 0.0256 W/m·K. This value is commonly used for engineering calculations, HVAC modeling, heat exchanger design, and energy efficiency analyses.
Factors Affecting Thermal Conductivity
Thermal conductivity of air increases slightly with temperature and can vary with humidity and pressure. Accurate values are critical for:
- Heat Transfer Engineering: Designing and analyzing convective and conductive heat flow in ducts, equipment, and industrial systems.
- Thermodynamics & CFD Simulations: Calculating energy transfer, temperature distribution, and thermal performance in simulations.
- HVAC System Design: Sizing heating and cooling equipment and optimizing ventilation efficiency.
- Industrial Process Optimization: Predicting heat losses, energy consumption, and thermal management in manufacturing processes.
- Environmental Applications: Modeling airflow, indoor thermal comfort, and energy efficiency in buildings and controlled environments.
Engineering Applications
Engineers combine thermal conductivity with other air properties such as density, specific heat, dynamic viscosity, and kinematic viscosity to accurately model heat transfer, airflow, and energy systems. Reliable k data ensures precise calculations for HVAC optimization, energy-efficient design, CFD modeling, and thermal system performance.
Understanding the thermal conductivity of air is essential for thermodynamic modeling, heat exchanger design, computational simulations, and energy efficiency analyses, supporting both industrial and environmental engineering applications.