Environmental Principles Week 3 Slideshow 1

Climate & Microclimate

Definition of Climate

• Climate = Average weather over time, primarily a function of the sun.

• Greek origin: Klima → "Slope of the Earth" (angle to the sun).

• Divided into Tropic, Temperate, and Arctic zones based on sun angles.

How Climate Works

• Sun-driven atmospheric system → Earth’s surface absorbs heat → Air rises, creating low-pressure zones → Winds are generated due to pressure differences.

• Uneven heating (land vs. water) affects wind patterns and temperature extremes.

• Seasonal & rotational effects modify air currents.

• Mountains impact climate:

  • Windward side = wetter (air rises, cools, condenses into precipitation).

  • Leeward side = drier ("rain shadow" effect).

• Large bodies of water moderate temperature, reducing extremes.

Microclimate

Definition: Climate conditions of a small localized area (e.g., around a building).

• Factors affecting microclimate:

  1. Topography – South-facing slopes receive more sunlight & warmth.

  2. Solar Radiation – Amount of sunlight exposure.

  3. Wind – Air movement influenced by surroundings.

  4. Vegetation – Provides shade, alters humidity, and reduces wind effects.

  5. Water Bodies – Regulate temperature, increase humidity, and create breezes.

Effects of Microclimate

• North vs. South Slope: South slopes warmer due to higher solar exposure.

• Landforms: Low areas trap cold air → Frost pockets form.

• Soil Type:

  • Light-colored sand reflects heat, reducing air temperature.

  • Rocks store heat in the day, releasing it at night (e.g., cliff dwellings).

• Vegetation Role:

  • Trees reduce temperatures through shading & transpiration.

  • In cold climates, plants block wind chill.

• Manmade Structures:

  • Urban Heat Island Effect – Dark surfaces (asphalt) absorb heat, raising temperatures.

  • Buildings create wind tunnels & shade → Can reduce or increase heat exposure.

Climate Adaptation Strategies in Architecture

Cold Climate (Winter Dominant)

• Key Rules:

  1. Insulate well (beyond code requirements).

  2. Minimize air infiltration (tight construction).

  3. Use passive solar heating:

     • Maximize south-facing windows.

     • Incorporate thermal mass inside the building.

  4. Create sheltered microclimates to reduce cold impact.

Hot & Dry Climate

• Key Rules:

  1. Avoid direct solar gain (shade the building).

  2. Minimize daytime ventilation (to keep heat out).

  3. Promote night-time flushing (cool air circulation).

  4. Use evaporative cooling techniques.

  5. Use heavy thermal mass (stores cool nighttime air).

Hot & Humid Climate

• Key Rules:

  1. Avoid direct solar gain (large overhanging roofs).

  2. Maximize ventilation (constant air movement).

  3. Use lightweight materials (prevent heat retention & condensation).

  4. No basements (moisture issues).

  5. Encourage stack ventilation (hot air rises, pulling cool air in).

  6. Incorporate courtyards & open-air spaces.

Temperate Climate (Balanced Seasons)

• Key Rules:

  1. Balance strategies between hot & cold climates.

  2. Adaptability is key – Use flexible building envelopes.

  3. Utilize solar angles – Sun provides winter heating, but summer shading.

Climate Anomalies

• Example: Lugano, Switzerland vs. Quebec (Same Latitude, Different Climate)

  • Lugano: Warm due to lake reflections, winter sun exposure, and Alps blocking cold winds.

  • Quebec: Harsh winters due to lack of moderating features.