TROPICAL DESIGN
Tropical Design
- Strategic arrangement of elements in building and structures to respond to specific weather, sun, and climate
Global climatic factors
- Earth rotation
- Axis inclination
- Winds
Axis Inclination
- Responsible for earth’s seasonal change
- Hipparchus of Nicea is historically credited as man who first proposed earth’s axis gradually shifts
Obliquity – term used for tilt
- Earth’s axis is tilted 23.44 degrees from plane of its oebit around the sun
The 4 seasons can be determined by solstices and equinoxes
Solstices
- The point of maximum axial tilt toward or away from the sun
- Winter solstice: Dec 21st
- Summer solstice: June 21st
Equinox
- When the directuon of tilt and the sun are perpendicular
- Spring Equinox: March 20th
- Autumnal Equinox: September 22nd
Wind
- Movement of air relative to surface of the earth
WIND PATTERNS
Polar Eaterlies
- Found in north and south poles
- 60-90 degrees latitude
Prevailing Easterlies
- Northern and southern hemisphere
- Blow from west to east
- 30-60 degrees latitude
Tropical Easterlies
- Equator
- East to west flor wind pattern
- 0-30 degrees
Intertropical convergence zone (ITCZ)
- Also known as equatorial zone or intertropical fromt
- Forms when most south and northeast trade winds converge in a low pressure zone near the equator.
CLIMATE ZONES AND DATA ANALYSIS
Climate
- Conditions of the atmosphere at a particilar location for a long period of time
Weather
- Can change from day to day, month to month, or to a year
TYPES OF CLIMATE ZONES:
1. Tropical
- 0-23.5 degrees (equator)
- Hot with wet and dry sewsoms
- Tropical rainforests
- Border the ITCZ
2. Subtropical
- above 23.5 degrees (between tropics)
- flora and fauna
- Hot, mild summers & mild winters
- Large mass of water
3. Subarctic
- 40-60 degrees
- short summers and long snowy winters
- Still has flora and fauna
- deciduous trees
- Taiga (worlds largest land biome)
4. Dry
- sahara and saudi
- Less than 10 inches of rain per year with hot days
- evaporation exceeds precipitation
- nocturnal animals
- waxy plants
5. Polar
- 60-90 degrees (nortth and south pole)
- freezing temp all year
- covered in permafrost
CLIMATE DATA ANALYSIS
· Temperature – measurement of warmth and coldness of an object or specified location with reference to some standard value
· Thermal comfort – atleast 80% of its occupants must be thermally comfortable
· Solar Radiation
- A solar radiation sensor measures solar energy from the sun
- Radiant energy emitted bu the sun from nuclear fusion reaction that creates electromagnetic energy
· Relative Humidity
- Ratio of the partial pressure of water vapor to the equilibrium vapor pressure of water at a given temperature
- Maximum and minimum relative humidity determine the dryness of the atmosphere
· Rainfall
- Amount of rain that falls in a place during a particular period. Usually measured by the deptg in inches or millimeters
- Influences the relative humidity and is useful for designing rainwater harvesting systems
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· Wind
- It is the flow of gases on a large scale. On the surface of the earth, wind consists of the bulk movement of air
- Monthly rainfall influences the relative humidity and is usef ul for designing rainwater harvesting systems
· Wind Rose
- Shows the wind directions in a particular location. Useful to create a natural ventilation
· Sun Path
- Also called the day arc which reders to the daily and seasonal arc like path that the sun appears to flow across the sky
- Crucial for designing proper sun shading devices
CLIMATE DATA ANALYSIS IN DAVAO CITY, PHILIPPINES AND
Temperatures over the year in Davao City, Philippines.
- On average, temperatures are always high.
- Warmest month is April at 33° Celsius (91° Fahrenheit).
- Coolest month is July with 31° Celsius (88° Fahrenheit).
- Average annual maximum temperature is: 32° Celsius (90° Fahrenheit)
- Average annual minimum temperature is: 22° Celsius (72° Fahrenheit)
Average direct normal irradiation in Davao
- DNI is the amount of solar radiation received per unit area by a surface that is always held perpendicular (or normal) to the rays that come in a straight line from the sun
Mean monthly humidity over the year
- January is the most humid
- April is the least humid
- Average annual humidity is 81%
Average number of days each month with rain, snow, and hail
- June is the rainiest month
- March is the driest
Mean monthly precipitation over the year, including rain, snow, and hail
- May is the wettest
- March is the driest
Mean monthly wind speed
- February has the fastest monthly wind sped
- Average annual percentage of wind is 2m per second
Wind rose
- Wind blows for Davao city are mostly coming from the south direction, 41.50%
MICROCLIMATIC DESIGN CONSIDERERATIONS
· TYPE I – Two pronounced seasons; dry from November to April, and wet during the rest of the year.
· TYPE II - No dry season with pronounced rainfall from November to January.
· TYPE III - Seasons are not very pronounced, relatively dry from November to April, and wet during the rest of the year.
· TYPE IV - Rainfall is more or less evenly distributed throughout the year.
MACROCLIMATE - large stereotypical climatic regions
Tundra - a cold dry region that is permanently frozen
Desert - low rain and fluctuating temperatures
rainforest - warm and humid with lots of
rainfall
MICROCLIMATE
- relatively small areas that differ from their surrounding regions.
- affected by winds, vegetation, soil,
latitude, season, humidity, pressure, evaporation,
and even shade-giving objects.
- These small climates within the larger climate can provide specialized habitats for organisms that would otherwise perish in that location.
TOPOGRAPHY
- It is the relief of an area.
- If an area is close to a body of water, it tends to make milder climates.
- Mountainous areas tend to have more extreme weather because it acts as a barrier to air
movements and moisture.
VEGETATION
- refers to the ground cover provided by plants, and is, by far, the most abundant biotic element of the biosphere.
- Places with plants and vegetation have different thermal
properties. The main differences are;
- Plants have a lower heat capacity and thermal conductivity than building materials and hard surfaces.
- Solar radiation is mostly absorbed in the leaves and the
reflected radiation is very small.
- Rainwater is absorbed in the soil. Water later evaporated
from the soil and mainly from the leaves.
- The evaporation rate is much higher in green areas than in
unplanted hard-covered areas.
- Plants reduce the wind speed and its fluctuations near
the ground.
WINDBREAKS
- Barriers of Trees, shrubs and/or grass which help lessen and redirect wind velocity
Typhoon resilient trees
Katmon
- Deep roots that can withstand strong winds
- Tolerant of waterlogging
Kamagong
- One of the country’s hardest wood
- Deep roots for effective wind breaker
Pili
- Deep and extensive root system
- Buttresses give extra support against typhoons, protects soil from heavy saturation
Bitaog
- Commonly found in coastal areas serves as defense against strong winds along with mangroves
Narra
- Extensive rooting system and strong wood properties
GROUND SURFACE
- Ground surface whether natural or man-made, its characteristics of reflectance, permeability, and soil temperature influence the microclimate. Depending on
the ground surface, incident radiation can be absorbed, reflected, or stored and re-radiated later. In other words, radiative heat gain could be decreased or increased during the daytime. The emissivity of a surface depends on its texture. During the nighttime, rough surfaces would re-radiate the heat absorbed during the day faster than smooth surfaces. Based on the climatic context this could beused to our advantage.
BUILT ENVIRONMENT
- Human made surroundings
URBAN HEAT ISLAND EFFECT
- Related to higher summer temperatures in urban areas than in their rural surroundings
SDP AND SITE ANALYSIS
Site planning – planning a piece of land to meet development program that is efficient. Includes zoning, access, circulation, privacy, security, land draiage, utilities, etc
Site development planning – art and science of arranging structures
Process:
Research > analysis > synthesis
SITE ANALYSIS
- Assessing a location’s physica;, mental, and social qualities to design an architectural solution
ELEMENTS OF SITE ANALYSIS
1. Location
Geographical Location
• Site Boundary
• Site Security
• Existing Buildings
2. Neighboring buildings
•Distance, Heights
• Uses
• Vernacular
• Line of Sight
• Rights to Light
• Legal Restrictions
3. Site and zoning
• Zoning classifications
• Setbacks, Easements
• Height restrictions
• Allowable Maximum Building Footprint (AMBF)
• Uses, and parking requirements
4. Accessibility
• Public routes
• Public Transport Links
• Private routes
• Vehicle access
• Pedestrian access
• Existing circulation
routes within
5. Topography
• Site Contour, Terrain & Slope
• Gradients
• Key features/restrictions
• Soil Conditions and Composition
6. Views and Vistas
• Private views out
• Public views in
7. Sun path
• Sun paths
• Solar gains
• Shading
8. Wind patterns
• Prevailing direction of
wind
• Seasonal winds
(Amihan, Habagat)
• Natural Ventilation
• Passive Cooling
9. Vegetation
• Protected zones
• Protected species
• Available vegetation
(endemic)
• Ownership
• Impacts
10. Utilities and hazards
• Electricity lines & substations, Water Lines, Sewage & Drainage, Telephone lines, Internet Service Provider
• Dilapidated Buildings
• Unfinished building works
DAYLIGHTING
- is the controlled admission of natural light, direct sunlight, and diffused skylight into a building to
reduce electric lighting and save energy.
DAYLIGHTING SYSTEMS
- comprised not just by daylight apertures but is coupled with a daylight responsive lighting control system
· Climate responsive window-to-wall area ratio
· High performance glazing
· Daylighting optimized fenestration design
· Skylights (passive or active)
· Tabular daylight devices
· Daylight redirection devices
· Solar shading devices
· Daylight responsive electric lighting controls
· Daylight optimized interior design
SUN PATH CHART
Month – months which sun are at an angle
Origin - location of site
Time – Exact location of the sun
Sun – location of the sun with respect to time
SUN PATH DIGITAL TOOK
Azimuth – solar angular position from the north clockwise
Altitude – elevation angle from the ground
Zenith – angle measured from the vertical to the elevation angle
PASSIVE DESIGN
- Design that works with the environment to exclude unwanted heat or cold and take advantage of sun and breezes. Minimizing the need for mechanical heating or cooling
- Geronimo Manahan – “The passively cooled urban house”
Passive Cooling
- The use of passive cooling principles in the tropics results in a building that is energy efficient and results in substantial savings I running cost of both cooling and lighting
- Typically, initial cost will be higher
- However, often offset by minimal operating costs
Active cooling
- Equipment that consumes energy
- Initial cost will below
- Soon recouped by the cost for equipment, maintenance and energy consumption
Ventilation
- Circulation of air or replacing stale air with fresh air
Stack ventilation
- Uses the principles of convection to induce air flow