Convection
Newton’s Law:
Q = hc (Tair — Tw)
O
Where q = heat flux due to convection ( W/m )
Hc = convective heat transfer coefficient (W/m K) Tair = bulk fluid (air) temperature (°C)
Tw = surface temperature (°C)
Newton’s Law can be written as
T — T „ 1
|
With R = — h |
|
Air w |
 |
|||||||
|
|||||||
|
|||||||
2 * 2 The hc is related to flow state. hc = 3 ~ 6 W/m K for natural convection and 6 ~ 35 W/m K for air
Flow in and around buildings.
Posted in Fundamentals of Heating. Ventilating, and Air-Conditioning