APPLIED ENVIRONMENTAL STUDIES CLASS TWO - Macroclimate and Microclimate Part 1: Climate Overview John Seitz, RA, LEED AP Assistant Adjunct Professor Professor Paul C. King, RA, AIA, ARA Assistant Professor First considerations and The central purpose of planning is to create for any person or group of people an environment suited to their needs. Our first steps are. 1. To select a site ensuring that the selected region and site can support client needs and the program. This requires knowledge of the overall climate, Macroclimate, the regional climate Mesoclimate and local site environment, Microclimate. Macroclimate Mesoclimate Microclimate 1. Once a site has been chosen we must respond to the climate in our choices of site and building strategies. We may both Shape the building and site to respond to the climate. Shape the building and site to modify the climate. 1
Climate Defined: and The prevailing weather conditions of a region averaged over a series of years. Weather conditions that influence climate include temperature humidity precipitation wind access to sun Weather conditions in turn are influenced by topography latitude elevation adjacency to large bodies of water or land features (oceans, lakes, deserts, mountains) Average Temperature (NOAA data) US temperatures Average Annual Precipitation (NOAA data) Average Wind at 80 meters (NREL data) Average available solar power (NREL data) 2
Climate and How well do we know our climates? How often does the sun shine (on an annual basis) in Pittsburg? New York City? Los Angeles? Phoenix? 45% 58% 71% 85% and Alaska includes both Zones 7 and 8. Zone 1 also includes Hawaii, Guam, Puerto Rico and the US Virgin Islands. Current continental US Climate Zones as defined by the International Energy Conservation Code (IECC) and the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE). 3
and The 7 simplified US continental climate zones. The sub-arctic climate zone, not shown on the map, appears only in Alaska. As defined by USDOE Build America 2010 Simplified US Climate Zones and Hot humid Hot dry Mixed dry Mixed humid Cold Very Cold Marine Sub Arctic Miami, FL and Savannah, GA San Diego, CA and Phoenix, AZ Amarillo, TX New York, NY and Atlanta, GA Chicago, IL, Albany, NY Fargo, ND San Francisco, CA Nome, Alaska 4
Climate - Role of water and Water moderates the climate by reducing the temperature extremes (water heats up and cools down more slowly than land) Day- warm air rises off the land pulling breezes onshore Night- warm air rises off the water pulling breezes offshore This is due to waters high specific heat. Specific heat is the amount of heat, measured in calories, required to raise the temperature of one gram of a substance by one Celsius degree. Water has the highest specific heat of 1. 5
Climate - Role of land forms and Wind drives air up a slope, the air cools and drops moisture. Windward slope (the side exposed to the wind or to prevailing winds ) tends to be cool, humid and vegetated. (California, Seattle Washington, Oregon) Leeward slope (the side away from the wind) is warm and dry. (New Mexico, Arizona, Nevada, Colorado) Climate - Role of elevation and At greater elevations the air is thinner and the temperature is colder (because the air is capable of holding less heat) The temp drops 5 degrees Fahrenheit for every 1,000 feet, assuming the air is dry, or 3 degrees F if the air is saturated. This is called the adiabatic lapse rate 6
The Sun and Climate and The sun is the source of all terrestrial energy and it sets in motion the thermal currents of the oceans and the winds. We cannot alter the suns global affect. The Sun Since the sun is the source of all terrestrial energy differences in climate are created by influences that effect this energy after it reaches the earth. Factors that create climactic differences do so by modifying the heating effects of the sun. Macroclimate On the largest scale Macroclimate is the climate over a large area or region. It may be influenced by the location (latitude) or large changes in geography including mountain ranges and oceans. Mesoclimate The climate of a smaller area like a city that differs from the surrounding climate and may be influenced by local factors both natural and man made. Microclimate The smallest area of local climate that can be as small as the differences in weather on different sides of a small building or on the inside of a garden wall. More energy reaches the surface of this planet every day from the sun than we currently consume in ten years. The Sun and Climate and The seasons are caused by the tilt of the earth. the earth rotates around the sun changing the amount of radiation exposure in the different hemispheres. The Winter and Summer Solstices as well as the equinox are all dependent upon the tilt of the earth s axis. The Earth s tilt creates the seasons. The Winter Solstice On December 21 st the sun is at its lowest point in the sky and we receive the fewest hours of daylight The Equinox On September 21 st and March 21 st the sun is halfway between its highest and lowest points and we receive equal amounts of daylight and nighttime hours. The Summer Solstice On June 21 st the sun is at its highest point in the sky and we receive the greatest hours of daylight. Image Source: The Passive Solar Energy Book by Edward Mazria 7
The Sun and Climate and In June at noon: At 40 degrees North Latitude (NYC) the sun is almost at an angle of 75 degrees. In December at noon: At 40 degrees North Latitude (NYC) the sun is at an angle close to 28 degrees. Image Source: The Passive Solar Energy Book by Edward Mazria The Sun and Climate - Latitude and Polar Zones: Begin at 66.5 degrees north and south latitude and extend to the poles. Temperate Zones: Are located between 66.5 degrees (the Arctic and Antarctic Circles) and 23.5 degrees (the Tropic of Cancer in the North and the Tropic of Capricorn in the South). Tropical Zone: Is located between 23.5 degrees the Tropic of Cancer and the Tropic of Capricorn and the equator. Deserts: Typically occur along the tropic of Cancer or the Tropic of Capricorn 8
The Sun and Climate Solar Radiation and Not all Solar Radiation will reach the ground It may be reflected, absorbed or diffused by the atmosphere Reflected 31% is reflected by the upper atmosphere Absorbed 19% is absorbed by dust, ozone and water in the upper atmosphere. Diffused 4% is diffused into the clouds in the lower atmosphere. Direct 47% of solar radiation hits the earths surface. Image Source: The Passive Solar Energy Book by Edward Mazria The Sun and Climate Solar Reflectance and Thermal Emittance and The Solar Reflectance Index (0 100) measures both reflected solar energy and radiated heat. It is defined so that a standard black roof membrane (reflectance 0.05, emittance 0.90) is 0 and a standard white roof membrane (reflectance 0.80, emittance 0.90) is 100. 9
The Sun and Climate Designing for the Sun and When we design with the sun in mind we consider the angle of the sun at different times of the year and at different times of the day. Seasonal changes in sun angles allow us to shape buildings to maximize opportunities for all year daylight capture and cold season passive heating, while shading to protect against the hot summer sun. Morning and Evening Sun: Will warm the East and West exposures. High Summer Sun: Will warm the roof. In colder climates we look to take advantage of this while in hotter climates we look to minimize the impact. Designing an Overhang: A south facing overhand will block the high summer sun reducing heat gain while the low winter sun is allowed to enter warming the interior. Image Source: The Passive Solar Energy Book by Edward Mazria Building orientation and solar energy intensity Building latitude, orientation and season have a significant effect upon solar energy intensity. Each outer concentric circle represents a 2 degrees F increase in temp. Each inner arrow represents 250 Btu/sqft/day. It is possible to design your building to capture or reject that heat based on thermal comfort needs. 10
The Sun and Climate Designing for the Sun and In the Northern Hemisphere a buildings orientation is typically shown on a site plan by indicating its position relative to north. In the Northern Hemisphere: The greatest amount of solar radiation is on the southern exposure and the least amount is on the north. North Exposure: An appropriate design response is to minimize glass to reduce heat loss. South Exposure: The majority of the glass exposure should take advantage of the sunlight. A horizontal overhang can help limit heat gain in warmer climates and during summer months. East and West Exposures: Are both treated in a similar fashion with moderate glass and vertical shading louvers. Image Source: The Passive Solar Energy Book by Edward Mazria and The Sun and Climate - Latitude in US New York City (40 degrees NL) 11
The Sun and Climate - Charting the Sun and Standing in a single location we project the path of the sun onto a graph marking its location for every hour from sunrise to sunset. The chart will show. The sun s altitude or angle above the horizon The sun s azimuth or angle relative to true North for Each month of the year Each hour of the day Image Source: The Passive Solar Energy Book by Edward Mazria The Sun and Climate - Charting the Sun and This chart includes: Month of the year The chart highlights in red the path of the sun for April 21 st and August 21 st The Altitude of the Sun At 12 noon the sun reaches an angle of 60 degrees above the horizon Azimuth or Bearing of the Sun When the sun rises its position on the horizon is 105 degrees east of south. It sets 105 degrees west of south. Time of the day The sun rises just before 5:30 am and it sets just after 6:30 pm. 12
and The Sun and Climate - Charting the Sun SUN CHART READING THE CHART PATH/DATE TIME ALTITUDE BEARING Reading the Sun Chart Revit Step by Step Still View Revit Step by Step Solar Study Animation TRACKING THE PATH 5 AM 7 AM 9 AM 12 NOON 3 PM 5 PM 7 PM REVIT TUTORIAL STILL VIEW SOLAR STUDY EXERCISES NEW MONTH NEW LOCATION Q & A 13
The Sun and Climate Designing for the Sun Homework SUN CHART READING THE CHART PATH/DATE TIME ALTITUDE BEARING TRACKING THE PATH 5 AM 7 AM 9 AM 12 NOON 3 PM 5 PM 7 PM REVIT TUTORIAL STILL VIEW SOLAR STUDY EXERCISES NEW MONTH NEW LOCATION Q & A The Sun and Climate Designing for the Sun Homework SUN CHART READING THE CHART PATH/DATE TIME ALTITUDE BEARING Reading the Sun Chart Find the Angle and Calculate or draw. TRACKING THE PATH 5 AM 7 AM 9 AM 12 NOON 3 PM 5 PM 7 PM REVIT TUTORIAL STILL VIEW SOLAR STUDY EXERCISES NEW MONTH NEW LOCATION Q & A Remember your trigonometry Sine of Angle = o/h Cosine of Angle = a/h Tangent of Angle = o/a 14
APPLIED ENVIRONMENTAL STUDIES CLASS TWO - Macroclimate and Microclimate See Solar Study Activities Using Revit See Part 2: Climate Change John Seitz, RA, LEED AP Assistant Adjunct Professor Professor Paul C. King, RA, AIA, ARA Assistant Professor 15