Question

The inside and outside heat transfer coefficient for a heat exchangers are $2500W/m^{2}K$ and $4000W/m^{2}K$ respectively. What is the overall heat transfer coefficient?

• A. $2.438kW/m^{2}K$
• B. $1.538kW/m^{2}K$
• C. $3.230kW/m^{2}K$
• D. $0.142kW/m^{2}K$

Answer 1

The correct option is B $1.538kW/m^{2}K$

$\frac{1}{U}=\frac{1}{U_i}+\frac{1}{U_0}=\frac{1}{2500}+\frac{1}{4000}$

$U=1538.46W/m^{2}K$

$=1.538kW/m^{2}K$