How is the overall heat transfer coefficient calculated?

1/U = 1/h_i + R_fi + (t/k) + R_fo + 1/h_o, where h_i and h_o are inner and outer convection coefficients (W/m²K), R_fi and R_fo are fouling resistances (m²K/W), t is wall thickness (m), and k is thermal conductivity (W/mK). For finned surfaces, multiply by fin efficiency η_f and surface area ratio.

What are typical U values for common heat exchangers?

Shell-and-tube (water/water): 1000–3000 W/m²K; shell-and-tube (gas/water): 50–500 W/m²K; plate heat exchanger (liquid/liquid): 3000–8000 W/m²K; air-cooled heat exchanger: 20–60 W/m²K. Source: Perry's Chemical Engineers' Handbook, Table 11-10.

Overall Heat Transfer Coefficient (U) Calculator

Calculate the overall heat transfer coefficient U combining convection, conduction, and fouling resistances for heat exchanger design.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How to Use

Enter the values for the patient or scenario you are assessing. Calculate the overall heat transfer coefficient U combining convection, conduction, and fouling resistances for heat exchanger design. Use the heat transfer coefficient u result to inform your clinical assessment.

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Frequently Asked Questions

How is the overall heat transfer coefficient calculated?

What are typical U values for common heat exchangers?