Meeb Chap 3 - Site And Resources

Front 1

Microclimate:
What influences a microclimate?

Back 1

Site items:
1. Soil type
2. Ground
3. Topography
4. Vegetation
5. Water presence
6. View
7. Human activity

Climate items:
1. Sun
2. Air temperature
3. Humidity
4. Precipitation
5. Air motion
6. Air quality

Front 2

Microclimate:
What is heat island effect?

Back 2

Refers to urban air and surface temperatures that are higher than those of nearby rural areas...usually by 2 to 10 degrees higher.

The rise in ambient temperature that occurs over large paved areas. Strategic placement of trees can reduce this effect and reduce energy consumption for cooling by 15-30%.

Front 3

Microclimate:
Name several factors related to Urban Heat Island Effect.

Back 3

1. Rain and wind don't provide same advantange of evaporative cooling and summer breezes in the city as they do in rural areas.

2. Direct solar radiation is reflected in the city, thus increasing solar gain in urban areas.

3. Contaminated air blocks sunlight from reaching the city, but helps prevent heat from escaping in winter.

Front 4

Microclimate:
Urban Heat Island Effect factors in winter include:

Back 4

Factories, vehicles, hardscapes and geometry reduce the amount of energy needed to heat buildings. Thus reducing typical heating practices (use of fossil fuels, furnaces, and power plants) which contribute to airborne particles and fog.

Front 5

Microclimate:
Urban Heat Island Effect factors in summer inclued:

Back 5

City's internal heat worsens. A/C units' mechanical heat is added to building heat, A/C units power requirements place additional demands on power plants. This can be avoided by using PV cells.

Higher summer sun angles make solar access less problematic.

Front 6

Microclimate:
Horizontal layers site analysis

Back 6

Diagram pp. 72
1. Sky layer: provides isolation by height, activity on this level places heavy requirements on lower levels

2. Near-surface layer: provides overview of surface activities

3. Surface layer: the most varied and public level.

4. Subsurface layer: Isolated by enclosure; location of building services - MEP and parking.

Front 7

Microclimate:
Direct Sun and Daylight-
Explain Solar Envelope and when its implemented

Back 7

Solar envelope is employed when direct sunlight is desirable at the ground floor. The buildable area is defined by local ordinances. Usually requires the northern façade to have a low slope that corresponds with sun altitude at 2pm on Dec. 21st. (Fig 3.7, 3.8, 3.9, pp. 75)

Front 8

Microclimate:
Noise Control-
What materials mask sound?

Back 8

Plants and water fountains.

Front 9

Microclimate:
Noise Control-
What is the best way to generate Sound Shadows on the surface of a site?

Back 9

By installing hard surface barriers-walls. They don’t help reduce sound at upper windows and are usually installed between highways and housing developments. (fig. 3.19, pp. 94).
1. Effective height (H): height between the line of sight and top of sound barrier

2. Diffraction angle (B): Angle generated between receiver and top of sound barrier.

Front 10

Microclimate:
What is the Greenhouse Effect?

Back 10

Climate change phenomenon that is created from gases that absorb long-wave radiation (heat) from the earth's surface are accumulating in the atmosphere.

Causes an increase in ultraviolet radiation at earth's surface. Results in severe damage to ecosystems.

Front 11

Microclimate:
How do clouds contribute to the Greenhouse Effect?

Back 11

They reflect about 25% of incoming solar radiation, but return 2/3 heat back to earth.

Front 12

Microclimate:
Air Pollution-
How does the atmosphere impact the Greenhouse Effect?

Back 12

It keep earth 60 degrees warmer than it would be without heat trapping.

Front 13

Microclimate:
Air Pollution-
Increasing Green House gases would cause what problem?

Back 13

It would reflect more incoming solar radiation, but would reflect even more outgoing radiation, resulting in global warming.

Front 14

Microclimate:
Air Pollution-
What else contributes to air pollution?

Back 14

Buildings and transporation systems.

Front 15

Microclimate:
What is Ventilation?

Back 15

The introduction of fresh air to interiors to replinish the oxygen.

Helps carry away carbon dioxide and odors.

Front 16

Microclimate:
What is Cooling?

Back 16

It replaces heated indoor air with cooler outdoor air.

It's limited to times when the outdoor air temp is lower than the indoor air temp and outdoor humidity is at or below that desired indoors.

Requires more quantities of air than ventilation.

It influences building citing, window size and placement

Front 17

Microclimate:
Name and identify wind patterns.

Back 17

Fig. 3.26, pp. 101
1. Bar effect
2. Venturi effect
3. Gap effect
4. Corner effect
5. Wake effect

Increased winds occure at 45 degrees to the building face.

For the Bar effect, the downward spinning wind behind the building can reach 1.4 times average wind speed.