Summary IBPM

Britt Kusters | Eindhoven University of Technology
12-04-18

Summary IBPM: Lighting, Heat & Moisture, Sound
Summary IBPM | Lighting
1 Building & Light
Light can be described in three quality related terms:
 Form: light provides information about shape, colour and texture
 Feeling
 Function: functional aspect of light: to enable people to perform their
visual task

Building envelope:
- Influences to daylight quantity and quality of a space
- Influences outdoor view

What is light?
1. Wave phenomenon
2. Continuing stream of photons
 Visually perceived electromagnetic radiation
Human light sensitivity curve V = 380-780nm

Main light sources
 Sun (daylight): direct & indirect (reflections)  daylight is dynamic, good
colour rendering quality (continuous spectrum), enters room through
openings in external divisions, quality/quantity depends aspects of daylight
openings
 Lamps (electric light sources)  static character, no continuous spectrum,
relatively small bright surface, can be determined in advance

Light incident on a material can interact in three possible ways:
 Reflection
 Absorption
 Transmission

2 Daylight design
Three basic functions for interacting with daylight:
1. Letting it enter the room
2. Redirecting it into the room
3. Blocking it from the building (opening also allow solar radiation enter the
building)

3 Daylight
Daylight: visible part of solar radiation from sun received by earth’s surface
Sun: point light source (distance earthsun is high)

We distinguish between:
- Direct component (direct sunlight)
- Difuse component (part of light emitted by sun that reaches earth by
scattering and reflections through atmosphere)

Sky conditions:
- Overcast sky: 100% cloudiness, no direct sunlight
- Cloudy sky: >70% cloudiness

,Britt Kusters | Eindhoven University of Technology
12-04-18

- Partly cloudy sky: 30-70% cloudiness
- Clear sky: <30% cloudiness


Standard CIE-skies:
- Uniform
- Overcast
- Intermediate: foggy version of clear sky
- Clear

Daylight factor: horizontal illuminance in a point in a space as percentage of
external horizontal illuminace in unobstructed feld under a given illuminance
distribution of the sky
Three methods:
1. Daylight simulator: DF= Ehor./Ehorr.f*100%




2.




3. Simulation software: Radiance, DIALux, Relux

Luminance of sunlight varies with

, Britt Kusters | Eindhoven University of Technology
12-04-18

- Thickness of air mass which it has to pass through
- Geographical latitude
- Elevation angle of sun
- Atmospheric conditions


Designing with varying sky domes:
1. Climate with mostly cloudy sky conditions:
- Large daylight openings
- Light interior
- Depth of space max. 2 times window height
- Reside in day-lit area near façade
- Daylight from two sides

2. Sunny conditions
- Orientation and position of sun are essential
- Warm periods: solar shading necessary
- Window openings in north façade (northern hemisphere)
- Solar entrance on south façade (northern hemisphere)

4 Daylight quality
Elements that influence view quality:
 Distance to observed buildings
 Observations of weather
 Observations of movement
 Observations of natural elements
 Privacy


Daylight entrance




Glare
 Direct:
- Too high luminances
- Too high contrasts
 Indirect: reflections