Technology Review PDF

Technology – Oct 9 In class notes Week 2 – Sun + Atmosphere - Tilt and rotation How the earth rotates and how the energy of the sun is received Which parts gets the highest or most energy on land Albedo - how reflective a surface is...

Technology – Oct 9 In class notes Week 2 – Sun + Atmosphere - Tilt and rotation How the earth rotates and how the energy of the sun is received Which parts gets the highest or most energy on land Albedo - how reflective a surface is Different environments absorb and reflect more or less energy Temp of earth is determined by the balance between energy from the sun and its loss back into space. - Atmosphere Is mostly comprised of: water vapour, carbon dioxide, methane and nitrous-oxide When the suns energy reaches the earth 1/3 is reflected back to space ½ is absorbed by the earths surface and warms it The green house effect. Increased warming of the earths surface due to the heat energy from the sun being absorbed in the atmosphere and re emitted back to the surface Energy Terms: - Joule; The amount of work done when a force of one newton displaces a mass through a distance of one metre in the direction of that force - Watt; equal to one joule/second Comfort zone The narrow range of temperature and humidity that create ideal environmental conditions for an average human body - Comfort zone ranges: Temp: 20 C to 26 C Relative humidity: 20 to 75% Week 3 – Water and precipitation Precipitation Terms: - Humidity: is the amount of water vapour in the air - Relative Humidity: (RH) which is expressed as a percentage, is the amount of water vapour the air contains compared to the max possible at the temp and pressure - Rainbow Shadow: a dry area on the leeward side of the mountain system Convection: the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder denser material to sink under the influence of gravity which consequently results in transfer of heat. (hot air goes up, cold air goes down) Water cycle terms: - Evaporation: is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. The surrounding gas must not be saturated with the evaporating substance - Condensation: is the change of the physical state of matter from the gas phase into liquid phase, and is the reverse of vaporization - Transpiration: is the process of the water movement through a plant and its evaporation from aerial parts such as leaves stems and flowers - Sublimation: is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase - Melting: is a physical process that results in the phase transition of a substance from solid to a liquid Week 4 – Wind Environment Terms: - Weather, the state of the atmosphere, including temperature, atmospheric pressure, wind, humidity, precipitation and cloud cover. - Climate: is generally defined as “the average weather” - Dry bulb temperature: the temperature of air as measured by a thermometer - Microclimate: variation in climate over a small scale - Relative humidity: the amount of water vapour present in the air expressed as a percentage of the amount needed for saturation at the same temp Wind Flow: Building shell: Positive pressure is a pressure that is greater than the environment that surrounds that system Negative Pressure, pressure lower than that of the surrounding Wind Flow: Interior space – Natural ventilation: supplying air to, and removing air from an indoor space without using mechanical systems Forces producing natural ventilation: 1. Air movements produced by pressure differences 2. Air changes cause by difference of temperature Optimum Shape: An attempt to balance the environmental impacts on a building across seasonal changes “that which loses the minimum amount of outgoing btu in the winter and accepts the least amount of incoming btu in summer” Building in response to climate conditions “low temperature tends to press buildings into a compact form and heavy radiation impacts tend to elongate the shapes, mostly in the east-west direction.” Built from climatic trends: Cool zone: winter temps are more impactful than the suns heat, building form is compressed to minimize surface area Temperature zone: the temperature range permits more flexible plan, allowing for max frontages, cross pattern Hot arid zone: thermal stress favours compressed squared shape built structures or garden can create desirable microclimates  Hot- Humid zones: the east and west ends receive heavy sun. This preference slender, elongated structures, shade allows for freer forms. Wind breaks: A barrier that diverts the air currents upward creating an area of relative calm created near the ground on the leeward side This diversion of air has a few impacts: o Diverts the force of air o Change in air temp o Change in air humidity o Evaporation effects o Snow drift formation Wind break form Larges impacts: o Shape o Height Wind Shadow: Sheltered, windless areas created by windbreaks Windward: upwind from the point of reference Leeward downwind from the diversion Week 5 – Materials and thermal comfort Roof Trend: “the roof is determining the element in the general form and appearance of the regional house types” o Flat roofs appear in the hot zones o Vaulted roofs are found in dry areas o Inclined roofs are found in the temperature climates with consistently dry summers o Higher roofs are used in wet temp and cooler territories Building Envelope: The walls, roofs and floor of a building which separate its exterior environment The building goal: ▪ Minimum heat loss – winter ▪ Minimum heat gain – summer Envelope terms: - conduction: is the transfer of heat energy, if the material is very conductive, then it transfers heat very quickly and easily - Insulation: the reduction of heat transfer (the transfer of thermal energy between objects of differing temp) - Thermal bridge: area or component of an object which has higher thermal conductivity than the sun surrounding material Insulation terms: - U-value: is a measure of how well a material conducts heat overtime (lower the better) - R- value: is a measure of how well a two dimensional barrier resists the conductive flow of heat (the higher the better) Passive Conditioning: Uses the building features to take advantage of natural systems to achieve indoor conditions that meet the needs of human comfort. Passive methods minimize the energy required to achieve indoor comfort. Relies on insulation, natural ventilation, site designs and other design strategies that don’t use energy inputs Active conditioning: Uses mechanical systems to circulate air that has been modified to meet the needs of human comfort. Bioclimatic Approach: A systematic approach of analyzing local and geional climate trends to find the balanced approach to build design Emphasize passive conditioning in design Climate – biology – technology- architecture