Sizing of Heater

[ukd]

Hi,
Can anybody explain me how to size a space heater in a package unit.

I have the following info.

Cabinet Size (LXWXH):4.5 X1 X 2.6 m
Hydraulic Diameter : 1.63636 m
Air density at 10deg C : 1.3375 kg/m3
Air Velocity : 55 m/s
Dynamic Viscosity : 1.68E-05 kg.m/s
Reynolds Number : 7.17E+06
Specific Heat of air : 1.01E+03 J/Kg.K
Thermal Conducivity of air : 2.34E-02 W/m.K
Thickness of plate all side : 0.003 m
Insulation Thickness : 0.025 mm
Thermal conductivity of Insulation : 0.038 W/m.K
Temperature Inside Cabinet : 30 Deg C
Temperature Outside Cabinet : -9Deg C

From the above date,How can I calculate

a) Gross Heat Loss
b) Nusselt Number
c) Heater Size in Watts

Please correct me if there is any unrelavant info / if info is wrong.Please help me to find the size of heater.

 

[ukd]

Addition to the above data,

Please consider

Outside plate is of SS-316 with thermail conductivity of 16.27 W/m.K

 

[willard3]

In order to solve the problem, you'll need some temperatures.

Sounds like a homework problem........