QUESTION $2[20$ MARKS$]$

a$)$ Solar heat gain is short wave radiation from the sun that heats a building, either directly through an opening such as a window, or indirectly through the fabric of the building. Describe the influences of thermal behaviour of building on indoor climate that caused by the solar heat gain.

$[10$ marks$]$

b$)$ Ventilation system is the process by which air is introduced and contaminated air is removed from an occupied space. There are two types of ventilation system namely mechanical and natural ventilation.

Explain why mechanical ventilation is preferred over natural ventilation in a commercial building.

$[10$ marks$]$