Heat Transfer Coefficient Converter

What Is Heat Transfer Coefficient

Heat transfer coefficient measures convective heat transfer efficiency between a surface and fluid. You express this property in watts per square meter per kelvin (W/(m²·K)) in SI units. Higher coefficients indicate more effective heat transfer.

HVAC engineers use heat transfer coefficients to size heat exchangers and calculate building loads. Electronics designers select cooling solutions based on achievable coefficients. Process engineers optimize fluid flow to maximize heat transfer.

Newton Law of Cooling

Calculate convective heat transfer using Newton law:

Where Q equals heat transfer rate in watts, h equals heat transfer coefficient, A equals surface area, Ts equals surface temperature, and T∞ equals fluid temperature.

Rearrange to solve for heat transfer coefficient:

Example: A surface transfers 500 W over 2 m² with 25°C temperature difference:

Typical Heat Transfer Coefficients

Overall Heat Transfer Coefficient

Calculate overall coefficient for composite walls and heat exchangers:

Where U equals overall coefficient, hi equals inside convection coefficient, d equals layer thickness, k equals layer conductivity, and ho equals outside convection coefficient.

Example: A wall with inside film (hi = 10), insulation (d = 0.1 m, k = 0.04), and outside film (ho = 25):

Unit Conversion Factors

Frequently Asked Questions