FBE 03 Building Construction Science Lecture 6 Building

FBE 03: Building Construction & Science Lecture 6 Building Orientation Principles

Introduction • designers need to consider for solar geometry and climatology • wind, rain, temperature and humidity all affect the design of buildings • sun typically has the greatest impact on the esthetics of a project • climatic forces typically offers as much opportunity to harness its power, or creates as many issues to deal with

• Issues provided by sun: ü thermal; the sun is the primary source of all natural heating ü light, and the sun provides the most desirable lighting conditions in most cases • artificial lighting and heating systems can replace or offset solar light and heat, the effects of the sun are always too powerful to ignore when designing a project

• Latitude and Longitude which are abstract measurement lines inscribed around the earth • Latitude is the angular distance north or south of the earth’s equator • Longitude is the angular distance on the earth’s surface, measured east or west from the prime meridian at Greenwich, England

Relationship of the sun to the earth at the solstice’s and equinox

Relationship of the sun to the earth during a revolution in orbit

The Earth’s rotation • arc of the sun changes throughout the year due to the fact that the earth’s rotational axis is at an angle to the orbit of the earth around the sun • angle determines the amount of solar radiation any point on the earth will receive during a day • change in angle determines the amount of solar radiation any point on the earth will receive during a day ü the first is the number of hours the sun will strike a point on the surface. • The lower the sun angle the less time it will be visible from a point on the earth, the higher the angle the more time it will be visible

Sun control strategies • Solar gains ü angles of the sun are the primary determining factor in solar heat gain for buildings ü basic rule of thumb is that in cold climates you want to maximize winter solar gains ü hot climates you try to minimize solar gains year round

Sun control strategies • Hot–humid climates ü large roofs with overhangs to avoid sun and shed rain ü Heavy heat gains on east side and higher gains on west side • Hot–arid climates • Massive walls used to absorb heat during the day • Minimal surface exposure to sun Buildings oriented

Sun control strategies • Temperate climates ü Open to winter sun on south ü Shaded open areas with east and west shade overhangs in summer ü Deciduous trees nearby shade in summer and allow winter sun

Sun control strategies

Daylighting • 50% of the energy use of many modern buildings comes from artificial illumination • efficiency of the systems used to maintain building comfort, including lighting • daylighting has often been avoided due to concerns over solar radiation gains, or a desire to keep lighting more consistent

daylighting systems • Exterior Environment • Interface Medium • Interior Environment

daylighting systems • Exterior Environment ü sky, sun, land adjacent structures change the intensity of the light. ü The brightness of the sun changes due to vegetation and clouds, while the direction shifts throughout the year.

daylighting systems • Interface Medium ü The glazing and building fenestration, or aperture through which the daylight enters the space. ü Openings act as filters for different conditions, often times different openings should be used for heat gain vs. daylight

daylighting systems • Interior Environment ü The shape and reflectance of the space will distribute light in different ways. ü Deeper, lower spaces get less sunlight, and lighter colored floors tend to reflect light deeper into a space.

Types of exterior openings for solar radiation and light