Page 130 - Hong Kong Green School Guide

3. Green School Guide - 3.5 Indoor Environmental Quality
Hong Kong Green School Guide 128
3.5.4 Interior Lighting Quality
Benefits
• Improve visual comfort;
• Reduce unnecessary lighting and
energy; and
• Promote measurement of interior
lighting quality.
Applies to NS & ES
Issues to Consider
a. Opportunities
• Schools can promote, monitor and implement measures to improve interior
lighting quality.
b. Constraints
• Evaluation of lighting quality.
c. Solutions
• Major parameters to evaluate lighting quality are:
- - Illuminance, also referred to as lighting level, measured in lux;
- - Illuminance variation, uniformity of light level across the room;
- - Glare index, caused by excessive light entering the eye due to improper
lighting positioning and/or incorrect luminaire; and
- - Colour rendering index (CRI), the ability of a light source to render colours
of surfaces accurately, CRI >80 is recommended.
• Lighting quality can be evaluated by:
- - Illuminance (lighting level) and illuminance variation measured by lux
meter;
- - Glare index can be determined from lighting technical specification or by
lighting simulation; and
- - Colour rendering index (CRI) can be determined in lighting technical
specification.