Climatic Design PDF

ARCH 400 | CLIMATIC DESIGN ARCH. JIFFER JOHN L. TAALA, UAP, PSPE, MSSD Vernacular Architecture – North America Vernacular Architecture – North America Vernacular Architecture – South America Vernacular Architecture – Africa Vernacular Architecture – Middle East Vernacular Architecture – S...

ARCH 400 | CLIMATIC DESIGN ARCH. JIFFER JOHN L. TAALA, UAP, PSPE, MSSD Vernacular Architecture – North America Vernacular Architecture – North America Vernacular Architecture – South America Vernacular Architecture – Africa Vernacular Architecture – Middle East Vernacular Architecture – South East Asia Vernacular Architecture – South East Asia Guess the location of the buildings Guess the location of the buildings Guess the location of the buildings Guess the location of the buildings Guess the location of the buildings What is climatic design? The climatic design of a building is a method which helps to reduce the building energy demand for heating and cooling and also it aims to use natural energy resources in order to provide more comfort in buildings. (Yousefi, 2017) Importance of Climatic Design Climate has a major effect on building performance and energy consumption. The process of identifying, understanding, and controlling climatic influences at the building site is perhaps the most critical part of building design. The key objectives of climatic design include: 1. To reduce the energy cost of a building 2. To use "natural energy" instead of mechanical system and power 3. To provide a comfortable and healthy environment for people What are the goals of designing with the climate? 1. suit the climate it is built in 2. keep the occupants thermally comfortable (that is, they do not feel too hot or too cold) 3. use minimal heating or cooling. https://www.yourhome.gov.au/passive-design/design-climate Factors Affecting Climatic Design The local micro-climate and site factors will affect the actual environmental conditions of the building. The important site-related factors should be considered when making the climate analysis: Topography - elevation, slopes, hills and valleys, ground surface conditions. Vegetation - height, mass, silhouette, texture, location, growth patterns. Built forms - nearby buildings, surface conditions. Factors Affecting Climatic Design Major thermal design factors to be studied include: solar heat gain conduction heat flow and ventilation heat flow Factors Affecting Climatic Design The design variables in architectural expression that are important will include: Shape - surface-to-volume ratio; orientation; building height. Building fabric - materials and construction; thermal insulation; surface qualities; shading and sun control. Fenestration - the size, position and orientation of windows; window glass materials; external and internal shading devices. Ventilation - air-tightness; outdoor fresh air; cross ventilation and natural ventilation. Elements of Climatic Design The design of buildings that respond to the environment involves the use of principles of solar design as also a detailed understanding of the complex interrelationship between architectural design, building materials, human behaviour and climatic factors. This kind of design, not restricted just to the use of solar energy but including the utilisation of all forms of natural energy to provide required comfort conditions within the built-up space may be defined as climatic design. Before elaborating on the ways and means to achieve human comfort in the built-space, it would be useful to define what exactly constitutes comfort. https://mhathwar.tripod.com/thesis/climaticarch/climatic_architecture.html Thermal comfort criteria Comfort levels are influenced by three main factors: Mean radiant temperature (MRT): Temperature is one of the main parameters on which comfort of the inhabitants depends. The standards adopted for the establishment of comfortable temperature are however very demanding on the HVAC system of the building. In summer the acceptable temperature is considered to be 24-25 degrees C while in winter it is 22-23 degrees C. maintaining a temperature of 24 degrees C within the structure when the outside temperature is 35-37 degrees C puts a huge strain on the HVAC system leading to huge energy costs. Therefore, it would be wise to revise our criteria for thermal comfort and accept a standard for thermal neutrality instead, i.e. the person feels neither too hot nor too cold, nor feels any local discomfort due to asymmetric radiation, drafts, cold floors and furniture, non-uniform clothing, etc. At same time there has to be a willingness to adapt to the local weather conditions so as not to make unrealistic demands from the air- conditioning system. We should realize that the days of wasteful spending are now over and a measure of austerity has to be there in our energy spending. Humidity : humidity is also a major factor affecting comfort levels within a space. The moisture content present in the air is called ‘humidity’. The level of humidity greatly influences evaporative cooling. Greater the moisture content in the air lesser is the effect of evaporative cooling. Therefore efforts to reduce humidity levels within a space result in better conditions. In the design of HVAC systems humidity level of 40-50% is considered acceptable, but one should also remember that this standard is not a law and human adaptability can be stretched to farther limits. Air Movement : Air movement or ventilation can be used to considerably cool the interiors of a building. Air movement over the skin results in Evaporative cooling- as the air moves over the skin, the perspiration on the skin surface evaporates leading to cooling of the surrounding area. Air movement also affects conductive-convective heat transfer between skin and air. The velocity of the air is also important as stagnant air creates a suffocating effect as the air turns stale due to respiration, foul odours, smoke, etc. Therefore removal of this air and its replacement with fresh air is very important which directly depends on adequate cross ventilation of the spaces, which results in proper air movement and velocity. A combination of these three factors is responsible for the maintenance of proper living conditions within the space. It is therefore, possible to maximise the cooling effect of these factors by making use of proper design elements and the principles of solar architecture to reduce our dependency on external energy to maintain a comfortable living environment. Principles and Strategies of Climatic Design The objectives in the design of a structure that responds to the environment should be to maximize solar gain in winter and minimize heat gain in summer. Heat gain can take place in one of the following ways of natural thermal transmission-conduction, convection, and radiation in addition to evaporation, which plays a major role in the cooling of the indoor environment. There is thus an inherent contradiction in the tasks that the building envelope has to perform in summer and winter. Principles and Strategies of Climatic Design Sources of heat gain The proper use of shading devices can prevent direct solar radiation from reaching all or part of the roof, walls or windows of a building. Natural vegetation, neighbouring buildings or the surrounding landscape can provide shading - for example on the north-facing slope of a hill or valley. Shading devices on the building (fixed or movable, the latter being manually or automatically controlled) can prevent radiation from reaching critical parts such as windows, doors and even roofs. Indirect solar gain from the sky or reflected from the surrounding buildings or the ground and air heated by irradiated surfaces such as roads and pavements can also contribute significantly to cooling load. A significant amount of heat is also produced by appliances, electric lighting and occupants, which during the overheating season can lead to uncomfortably high temperatures. The use of Natural Daylight to replace artificial light where appropriate and the use of high efficiency artificial lighting can reduce cooling costs drastically, especially in commercial buildings. Heat producing appliances should be placed such that the heat can be quickly removed from the building to reduce cooling load. Control of heat gain Solar control involves the prevention of unwanted solar heat gain taking into consideration the following factors in design: Microclimate and site design Building envelope Control of internal gains. Tropical Design This is concerned with countries where discomfort due to heat and humidity are the dominant problems. Tropical Design is applicable to Tropical and Sub-tropical climates and Equatorial Climates covering the Southeast Asian Countries. (Hong, 1999) What is bioclimatic architecture? Bioclimatic architecture is a way of designing buildings based on the local climate, with the aim of ensuring thermal comfort using environmental resources. They must also blend into their natural surroundings. The main aims of bioclimatic architecture are to create healthy, comfortable homes for the inhabitants of these buildings, while respecting the environment. To do this, it is essential to avoid using polluting materials, ensure the wellbeing of local biodiversity and make efficient use of energy, building materials, water and other resources. https://www.iberdrola.com/innovation/bioclimatic-architecture-passivhaus What is a climate- responsive architecture? The climate-responsive architecture aims to design the optimized building according to specific characteristics of that particular site, to minimize extreme energy use and have a reduced impact on the natural environment. What is green architecture? A philosophy of architecture that advocates sustainable energy sources, the conservation of energy, the reuse and safety of building materials, and the siting of a building with consideration of its impact on the environment. https://www.britannica.com/art/green-architecture Green architecture is a sustainable method of green building design: it is design and construction with the environment in mind. Green architects generally work with the key concepts of creating an energy- efficient, environmentally friendly house. https://united-architects.org/members/green-architecture/ What is a green building? A ‘green’ building is a building that, in its design, construction or operation, reduces or eliminates negative impacts, and can create positive impacts, on our climate and natural environment. Green buildings preserve precious natural resources and improve our quality of life. https://www.worldgbc.org/what-green-building