Welcome to MCAD Central

Join our MCAD Central community forums, the largest resource for MCAD (Mechanical Computer-Aided Design) professionals, including files, forums, jobs, articles, calendar, and more.

Register Log in

Convection Coefficient?

Luis Aguirre

New member
Hello Hammerpe,

The values for the convection coefficient also known as the film coefficient are Btu/(hr*ft^2*F) or W/(m^2*K). Adding fins will definetely help to disipate more heat. If you still having problems later on post them I will see If I can fix them.



New member

It sounds a little as if you have a units problem. You need to use consistent units throughout. Depending on your chosen units system, you need to make sure all parameters are in appropriate units; eg:

SI Metric:

Heat: Watts (or Joules/second)

Heat Flux: Watts/square metre

Temperature: Degrees Kelvin

Thermal Conductivity: Watts / metre / degree Kelvin

Specific Heat: Joules / kg / degree Kelvin

Convection: Watts / square meter / degree Kelvin

Inch / Pound / Second:

Heat: BTU

Heat Flux: BTU / second /square inch

Temperature: Degrees Fahrenheit

Thermal Conductivity: BTU / second / inch / degree Fahrenheit

Specific Heat: BTU / pound / degree Fahrenheit

Convection: BTU / second / square inch / degree Fahrenheit

Foot / Pound / Second:

Heat: foot . pound force

Heat Flux: foot . pound force / second /square foot

Temperature: Degrees Fahrenheit

Thermal Conductivity: foot . pound force / second / foot / degree Fahrenheit

Specific Heat: foot . pound force / slug / degree Fahrenheit

Convection: foot . pound force / second / square foot / degree Fahrenheit

Note that you may need to adjust the


New member
Hi all

I know this was all started a long time ago but I have recently been doing the same sort of thing. I've been looking for a realistic convection coefficient for forced convection in air and have come across the info above.

Do you have a reference for the above values so I can quote them in my report or details or link to where I can find them?