Question

Airflow through a long 0.2m square air conditioning duct maintained the outer duct surface temperature at 10degree.if the horizontal duct is uninsulated and exposed to air at 35degree in the crawl space beneath at home.

What is the heat gain per unit length of the duct.

Answer 1

125°C/m

Step-by-step explanation:

The difference in temperature will be:

35 - 10 = 25

The outer duct surface is heated 25°C by the air from 10°C to 35°C;

This heat gain is simply divided by 0.2m to get heat gain per unit length:

25/0.2 = 125

125°C/m

If you're American, this will be °F I believe, so the answer will be:

125°F/m