The exterior walls of a house have a total area of 220 m2 and are at 11.9°C and the surrounding air is at 6.7° C. Find the rate of convective cooling of the walls, assuming a convection coefficient of 3.4 W/(m2 · C°).
To find the rate of convective cooling of the walls, we need to calculate the heat transfer rate from the walls to the surrounding air.
The heat transfer rate can be calculated using the following formula:
Q = U × A × ΔT
Where:
Q is the heat transfer rate (in watts)
U is the convection coefficient (in W/(m2 · C°))
A is the surface area (in square meters)
ΔT is the temperature difference between the surface and the surrounding air (in °C)
In this case, the convection coefficient is given as 3.4 W/(m2 · C°), the surface area is 220 m2, and the temperature difference is (11.9°C - 6.7°C) = 5.2°C.
Therefore, we can substitute these values into the formula:
Q = 3.4 × 220 × 5.2
Calculating this equation will give us the rate of convective cooling of the walls.
Q = 3862.4 W
Hence, the rate of convective cooling of the walls is 3862.4 watts.