Daylighting in Building Design

Daylighting

• Daylighting refers to the use of natural light in building design.
• Careful arrangement of windows, skylights, and reflective surfaces is key.
• This technique improves productivity, connection to the outdoors, health, and energy savings.

Daylight vs. Sunlight

• Sunlight is direct light from the sun, often unsuitable for interiors due to glare and heat gain.
• Daylight, or diffuse natural light from the sky, is the desirable light for interiors.
• Daylight provides even light distribution, avoiding direct sunlight's intensity.

Daylight in Buildings

• Daylight is a crucial aspect of passive building design, influencing visual and thermal comfort.
• Understanding how daylight enters a building and its effective use is essential for successful daylighting.

Factors Affecting Daylighting

• The quantity and quality of daylight in buildings constantly change due to natural variations in sun and sky conditions.
• These variations include random factors like cloud formations, daily progression from day to night, and seasonal changes in daylight length and prevailing weather.

Benefits of Daylighting

• Choosing better sustainable strategies to benefit from daylighting.
• Utilizing solar renewable energy sources, i.e., PV panels.
• Choosing passive design strategies such as passive heating/cooling.
• Reducing the overheating inside the building due to heat gains.
• Solar analysis is crucial for effective solar energy harnessing.

Solar Analysis

• Solar analysis determines the evaluation and analysis of solar energy potentials and characteristics at a specified location or area.
• It involves evaluating factors like solar irradiance, sun path, shading, and other environmental and geographical conditions.
• These conditions can affect the performance of solar energy systems like solar photovoltaic (PV) panels and solar thermal systems.

Daylight in Architecture

• Daylight plays a key role in architectural design.

Importance of Solar System Design

• Optimize solar system design by determining the optimal orientation, tilt, and solar technology for a specific location.
• Evaluate solar potential to make informed decisions regarding solar energy utilization.
• Enhance energy performance by using solar energy systems and reducing overheating hence lower cooling loads.
• Promote environmental sustainability by promoting the effective use of renewable solar energy, reducing reliance on fossil fuels, and mitigating greenhouse gas emissions.
• Improve human well-being and psychological health.

Importance of Passive Design

• Saves energy costs by using free sources like the sun's heat and light.
• Allows sun's energy to penetrate buildings through windows and outer walls.
• Reduces a building's environmental impact significantly.

Solar Heat Gain

• Solar heat gain is categorized into transparent elements (windows/curtain walls) and opaque elements (wall/roof).

Two Types of Solar Analysis in Revit

• Solar Study: Visualizes the sun's path and shadows on the building or site at a given time.
• Solar Analysis: Demonstrates and quantifies the distribution and intensity of solar radiation on building surfaces, considering shading by adjacent objects like vegetation and buildings.

Sun Path Analysis

• Explains the analysis of the sun's position (altitude and azimuth) for the study of sun paths.
• Covers important periods of the year that include solstices and equinoxes.
• Provides strategies to use the sun in passive heating and cooling strategies.

Different Times through the Day (Morning Interval)

• Morning sunlight, particularly in colder climates, can passively heat spaces, lowering heating demands.
• Low-angle morning sunlight can cause glare, which can be mitigated using shading or blinds.

Different Times through the Day (Noon)

• Analyzing the sun's impact during the summer can help design shading devices, facade materials, and insulation to reduce cooling demands.
• Capturing the sun's heat during the noon period can reduce heating loads in cold climates.

Different Times through the Day (Occupancy Hours)

• Daylighting during occupancy hours can reduce artificial lighting needs, saving energy and improving occupant well-being.
• Avoiding glare, which can cause visual discomfort, is crucial during daylighting.

Sun Path Visualization

• Use Revit's Sun and Shadows features, to visualize the impact of the sun's positions on the building or site at a particular time.

Daylighting Simulation

• Daylighting simulations can show how daylight changes over time.

Factors Affecting Daylighting in Buildings

• Building apertures' size, orientation, and nature.
• Shape and surroundings of the building.
• Optical properties of the surfaces within and surrounding the building.
• Aperture locations and sizes.

Light Distribution and Glare

• For visual comfort, light must be well distributed, avoiding discomfort from glare.
• Evenly distributed light is essential for good daylighting.

Glare

• High brightness next to low brightness levels cause discomfort.
• Controlling glare is especially important for daylighting due to the intensity of direct sunlight.

Redirecting Light

• Redirecting sunlight to desired locations using elements like light shelves and baffles improves even light distribution.
• Light shelves are devices that shade windows, reducing glare and improving light penetration.

Light Shelves

• Light shelves are effective in distributing light (reducing glare) while not reducing the total amount of light, and can be transparent and diffusive.

Illuminance

• Illuminance is the measure of light on a surface area.
• Measured in lux (one lumen per square meter).

Comfortable Illumination Levels

• Proper lighting levels are dependent on the building occupants' tasks.
• This can be seen in tables of recommended illumination levels for various activities, matching local building codes and standards.

Dynamic Daylighting Metrics

• Evaluating daylight over time, using actual climate data, and considering actual occupied hours for appropriate metrics are essential.
• Spatial Daylight Autonomy (SDA) and Annual Sunlight Exposure (ASE) are two examples.

Spatial Daylight Autonomy (SDA)

• SDA calculates the percentage of a space that receives a certain level of light for a particular time period (e.g., 50% of the occupied hours at 300 lux).
• This metric describes annual daylight sufficiency in a space.

Annual Sunlight Exposure (ASE)

• ASE measures the percentage of a space exceeding a given illuminance level (e.g., 1000 lux) for a specific number of hours (e.g., 250 hours annually).
• This metric measures the potential for visual discomfort in a space caused by excessively bright sunlight.

Explore the principles and practices of daylighting in architecture. This quiz covers the differences between daylight and sunlight, the importance of natural light in building design, and factors influencing daylight quality. Enhance your understanding of passive design and its benefits.