4.3.1 Avoiding excessive heat gain
A fundamental consideration in designing a window or skylight for natural daylight in Hong Kong is to avoid excessive
heat gain that might result from the opening. Sunlight comes with heat. When a lot of sunlight enters the building it
can bring in sufficient heat to cause the ‘greenhouse effect’. Indoor temperatures will rise significantly causing the air
conditioning system to work harder to achieve the required comfort level. To limit the heat gain when bringing in sunlight,
the following need to be considered:
A. Size of window or skylight
When determining the size of the opening, it is essential to distinguish between the need to see outside and the
requirement to allow daylight to enter. Windows for viewing need to be of a certain size to be useful, but the same does
not apply to skylights. The larger the opening, the more light and heat that enters. With proper internal reflective devices,
correct finishing materials and colours, a small skylight can actually provide an impressive daylighting effect.
Figure 79 Design balancing size of skylight with daylight and heat gain
Figure 80 Effect of skylights in ifc mall, Central
(Source: Photographer, William Furniss)
Figure 81 Effect of skylights in ifc mall, Central
(Source: Photographer, William Furniss)
4
Green design for shopping malls and shop spaces
4.3
Natural lighting in shopping malls and shop spaces
108 Hong Kong Green Shop Guide
