Architecture Tropical Design Module 4 PDF

05/12/2024 Architecture Tropical Design MODULE 4 Ar. Angel Clyde G. Manuel, uap 1 Theories and principles of tropical design 2 1  05/12/2024 Basics of pass...

05/12/2024 Architecture Tropical Design MODULE 4 Ar. Angel Clyde G. Manuel, uap 1 Theories and principles of tropical design 2 1  05/12/2024 Basics of passive design 3 4 2  05/12/2024 GOALS FOR VARIOUS CLIMATES ▪ Cold climates ▪ Maximum thermal retention ▪ Maximum heat gain ▪ Maximum wind resistance 5 GOALS FOR VARIOUS CLIMATES ▪ Temperate climates ▪ Moderate thermal retention ▪ Moderate heat gain ▪ Slight wind exposure (humidity control) 6 3  05/12/2024 GOALS FOR VARIOUS CLIMATES ▪ Hot-humid climates ▪ Maximum wind exposure ▪ Maximum internal airflow ▪ Minimum heat gain 7 GOALS FOR VARIOUS CLIMATES ▪ Hot-dry climates ▪ Minimum heat gain ▪ Moderate wind resistance ▪ Moderate internal airflow 8 4  05/12/2024 GERONIMO MANAHAN “The passively cooled urban house”, a prototype house designed by Geronimo Manahan in collaboration with the Ministry of Energy. 9 10 5  05/12/2024 PASSIVE DESIGN Design that works with the environment to exclude unwanted heat or cold and take advantage of sun and breezes (inducing comfort conditions in the building interiors), therefore avoiding or minimizing the need for mechanical heating or cooling. 11 PASSIVE COOLING The use of passive cooling principles in the tropics results in a building that is comfortable, energy efficient and results in substantial savings in running costs of both cooling and lighting. 12 6  05/12/2024 PROS/CONS OF PASSIVE COOLING ▪ Typically, initial costs for passive cooling systems will be higher because these systems are typically integral to the building envelope ▪ However, this is often offset by the minimal operating costs required, as well as the minimized impact on the environment. 13 ACTIVE COOLING A building design approach that addresses the problem of inducing comfort by means of equipment that consume energy. 14 7  05/12/2024 PROS/CONS OF ACTIVE COOLING ▪ In active systems, the initial cost of the building envelope will be low. ▪ But this will soon be recouped by the costs for equipment, maintenance, and energy consumption. 15 Principles of passive design 16 8  05/12/2024 PRINCIPLES OF PASSIVE DESIGN  Avoid heat gain  Encourage natural ventilation  Make use of natural light  Create cool outdoor areas 17 AVOID HEAT GAIN 1. Orient the building to reduce exposure to midday sun, particularly summer sun. 2. Use materials with low thermal mass as a rule. 3. Shade walls and windows, particularly any walls with high thermal mass. 4. Use glazing on windows that cannot be effectively shaded. 5. Use insulation, light colors, and heat- reflective surfaces. 18 9  05/12/2024 19 Low thermal mass High thermal mass o Wood o Brick o Insulation Materials o Concrete o Lightweight Concrete o Stone o Plastics o Thermal Mass Floor System o Gypsum Board o Adobe o Rammed Earth 20 10  05/12/2024 ENCOURAGE Orient the building and windows towards prevailing winds. NATURAL Include operable windows and ceiling vents that enable the VENTILATION building to naturally ventilate. 21 MAKE USE OF NATURAL LIGHT Install shaded windows. Install shaded skylights, light tubes, and other natural lighting devices. 22 11  05/12/2024 CREATE COOL OUTDOOR AREAS Use verandas and deep balconies to shade and cool incoming air. Use landscaping to provide shade without blocking cooling breezes and use planting to reduce ground temperature and minimize reflected heat. 23 Passive design considerations 24 12  05/12/2024 MAIN CONSIDERATIONS 1. Orientation 2. Ventilation 3. Landscaping 4. Thermal Mass 5. Insulation 6. Windows 7. Natural lighting 25 1. ORIENTATION Orientation concerns the position of the building on the site as well as the arrangement of the rooms within it. 26 13  05/12/2024 ORIENTATION ▪ There are two main goals to consider when considering the building orientation: ▪ Orientation for minimal solar heat gain. ▪ Orientation for maximum air flow. 27 Sun charts illustrating the variation in the sun’s movement in relation to latitude. 28 14  05/12/2024 29 SUN PATH DIAGRAMS  Azimuth Lines - Azimuth angles run around the edge of the diagram.  Altitude Lines - Altitude angles are represented as concentric circular dotted lines that run from the center of the diagram out.  Date Lines - Date lines start on the eastern side of the graph and run to the western side and represent the path of the sun on one day of the year.  Hour Lines/Analemma - Hour lines are shown as figure-eight-type lines that intersect the date lines and represent the position of the sun at a specific hour of the day. 30 15  05/12/2024 31 32 16  05/12/2024 33 34 17  05/12/2024 SUN PATH DIAGRAMS  Azimuth Lines - Azimuth angles run around the edge of the diagram.  Altitude Lines - Altitude angles are represented as concentric circular dotted lines that run from the center of the diagram out.  Date Lines - Date lines start on the eastern side of the graph and run to the western side and represent the path of the sun on one particular day of the year.  Hour Lines/Analemma - Hour lines are shown as figure-eight-type lines that intersect the date lines and represent the position of the sun at a specific hour of the day. 35 SUN PATH DIAGRAMS How to read sun path diagrams: 36 18  05/12/2024 SUN PATH DIAGRAMS How to read sun path diagrams: At 9:00AM, 37 SUNPATH DIAGRAMS How to read sun path diagrams: At 9:00AM, On April 1, 38 19  05/12/2024 SUNPATH DIAGRAMS How to read sun path diagrams: At 9:00AM, On April 1, the azimuth is 62 degrees, and 39 SUNPATH DIAGRAMS How to read sun path diagrams: At 9:00AM, On April 1, the azimuth is 62 degrees, and the altitude is 30 degrees. 40 20  05/12/2024 41 ORIENTATION FOR MIN. HEAT GAIN ▪ Generally, the best approach is to design so that all walls are shaded from the sun all year round. ▪ It may be desirable to admit some northern sun especially during the cool months (October- March). This can be done by planning the width of eaves and awnings. 42 21  05/12/2024 ORIENTATION FOR MAX. AIR FLOW ▪ In the Philippines, the prevailing winds are north- easterly from October-March and south-westerly from April-September. The building design must take advantage of this. ▪ The lack of breeze during the hottest days can pose challenges for achieving effective natural ventilation. Designing to encourage convection flow is very effective at these times. 43 PASSIVE SOLAR DESIGN WORKS IN 3 WAYS 44 22  05/12/2024 The rule of convection Warm air rises, cool air sinks. 45 2. VENTILATION Ventilation, circulation of air or to replace stale air with fresh air. 46 23  05/12/2024 STACK VENTILATION Uses the principle of convection to induce air flow. 47 PASSIVE VENTILATION ▪ Designing a building in a way that maximizes natural ventilation will greatly reduce the need for air-conditioning ▪ Air movement over the body, even if the air not much cooler, creates a feeling of cool due to the evaporation of moisture from the skin 48 24  05/12/2024 49 PASSIVE VENTILATION METHODS Maximizing breezes ▪ Orient the building to make the most of prevailing winds in the locality ▪ Align vents, windows and doors (reasonably straight line) to allow air to flow through the building ▪ Minimize internal obstacles or blockages such as internal walls to allow for unimpeded ventilation ▪ Raise the building off the ground to catch breezes 50 25  05/12/2024 PASSIVE VENTILATION METHODS ▪ Removing hot air ▪ Design for convection air flow to remove hot air from the building ▪ Convection air flow is created by hot air rising and exiting at the highest point, which naturally draws in cool air from the outside ▪ This can be achieved by placing low window openings across a space from high window openings ▪ This will be even more effective if the incoming air is being drawn from a shaded area where plants/trees grow 51 52 26  05/12/2024 PASSIVE VENTILATION METHODS ▪ Designing for “mixed-mode” use ▪ A building can be design to be mixed-mode. This means that it will rely on natural ventilation in cooler months, and use energy-efficient air conditioning in hotter months ▪ Low thermal mass materials are particularly suitable for mixed-mode buildings, provided that the building is well insulated 53 PASSIVE VENTILATION METHODS Roof ventilation Ventilating the ceiling cavity is an effective way of replacing accumulated hot air with cool air from outside using convection It also reduces heat radiated from the ceiling cavity towards the inner parts of the building Example: Ridge vents can let hot air out while cool air enters through the eave vents 54 27  05/12/2024 55 3. LANDSCAPING Reducing the extent of paving and other hard surfaces with vegetation. 56 28  05/12/2024 LANDSCAPING ▪ The hard surfaces of pavement around buildings absorb and re-radiate heat, creating a hotter microclimate ▪ Thus, it is smart to minimize the extent of paving and replace them with vegetation 57 URBAN HEAT ISLAND A city or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities. 58 29  05/12/2024 59 LANDSCAPING ▪ Planting areas around the building creates a cooler environment due to a plant’s ability to transpire or lose moisture, which cools the air ▪ External temperatures can be reduced by over 5°C by using ground cover or lawn instead of paving ▪ Denser vegetation provides a greater cooling effect ▪ Air that is drawn from planted areas is much cooler than air drawn from paved areas 60 30  05/12/2024 61 62 31  05/12/2024 4. THERMAL MASS Thermal mass is the ability of building materials to absorb, store, and release heat. 63 64 32  05/12/2024 TROMBE WALL A trombe wall is a system for indirect solar heat gain. It consists of a dark colored wall of high thermal mass facing the sun, with glazing spaced in front to leave a small air space. The glazing traps solar radiation like a small greenhouse. 65 THERMAL MASS ▪ In tropical climates, the use of materials with low thermal mass is preferable particularly on walls that are directly exposed to the sun. ▪ This is because lightweight construction such as timber respond quickly to cooling breezes, allowing the building to cool down faster 66 33  05/12/2024 5. INSULATION Insulation controls the rate at which a building loses or gains heat, keeping warmer air in during winter and excluding external heat in summer. 67 INSULATION ▪ Insulation is one of the most effective ways to reduce heat input to a building and can be installed in the roof, ceiling and walls of the building. 68 34  05/12/2024 TYPES OF INSULATION ▪ There are generally two types of insulation: bulk insulation and reflective insulation. ▪ In the tropics, reflective insulation installed under roof sheeting is highly effective as it does not trap heat inside the building. However bulk insulation is more effective at preventing loss of cool air from the building and so improves the efficiency of air- conditioning. 69 Bulk insulation Bulk insulation acts as thermal mass and resists the transfer of heat. Bulk insulation includes materials such as mineral wool, cellulose fiber, polyester and polystyrene. 70 35  05/12/2024 ROCK WOOL A type of insulation that is made from actual rocks and minerals. This type of insulation is commonly used in building construction, industrial plants, and in automotive applications due to its excellent ability to block sound and heat. 71 GLASS WOOL An insulating material made from fibers of glass arranged using a binder into a texture similar to wool. The process traps many small pockets of air between the glass, and these small air pockets result in the thermal insulation properties. 72 36  05/12/2024 Reflective insulation Reflective insulation mainly resists heat flow due to its high reflectivity and low ability to re-radiate heat and is more effective when installed with an air layer next to the shiny surface. 73 REFLECTI VE INSULATI ON Reflective insulation is usually shiny aluminum foil laminated onto paper or plastic. 74 37  05/12/2024 R-VALUE ▪ Insulation materials are given an R-value, which rates the material’s resistance to heat flow and therefore indicates its effectiveness. ▪ The higher the R-value, the greater the insulating effect. 75 R-VALUE ▪ R-values are additive. For instance, if you have a material with an R-value of 12 attached to another material with an R-value of 3, then both materials combined have an R-value of 15. 76 38  05/12/2024 U-VALUE ▪ The U-value is the heat transfer coefficient, which simply means that is a measure of an assembly's capacity to transfer thermal energy across its thickness. ▪ The U-value of an assembly is the reciprocal of the total R-value of the assembly. 77 78 39  05/12/2024 R-VALUE RECOMMENDATIONS ▪ In the tropics, it is generally recommended to have a minimum of R 2.5 insulation in naturally ventilated house ceilings, and a minimum of R 3.5 insulation in ceilings and walls of air-conditioned houses. 79 R-VALUES OF MATERIALS Material Thickness R-value Air space 1/2" up to 4" 1.00 Common brick 4" 0.80 Concrete masonry unit (CMU) 4" 0.80 Hardwood 3/4" 0.68 Tile 0.05 Single pane window 1/4" 0.91 Double pane window with 1/4" air space 1.69 Double pane window with 1/2" air space 2.04 80 40  05/12/2024 6. WINDOWS Windows are an important way to encourage and direct air flow into a building. 81 WINDOWS ▪ Louvers and casement style windows allow building users to control how much natural air enters the building. 82 41  05/12/2024 WINDOWS ▪ Well-placed louvers or windows, at floor level and at the highest point of the room, create convection air flow which draws air into the building and creates breezes to cool occupants. 83 WINDOWS ▪ In a tropical climate, windows should ideally be shaded from direct sunlight all year round and should open to allow air flow. ▪ Where effective shading cannot be achieved, insulating windows against heat transfer can reduce cooling costs. 84 42  05/12/2024 TINTED GLASS ▪ Tinted glass has a tint applied to the glass during manufacture, to reduce the amount of heat transmitted through it. 85 REFLECTIVE COATINGS ▪ Reflective coatings are thin films of metal or metal oxide that are applied to standard glass. ▪ They stop greater amounts of heat gain than some toned glass, however, they have the potential to create glare problems for neighboring properties and can significantly reduce the quantity of light admitted through the glass. 86 43  05/12/2024 SOLAR SHADING Shading devices shield windows and other glazed areas from direct sunlight in order to reduce glare and excessive solar heat gain in warm weather. 87  Horizontal overhangs are most effective when they have southern orientations.  Horizontal louvers parallel to a wall permit air circulation near the wall and reduce conductive heat gain.  Louvers may be operated manually or controlled automatically with time or photoelectric controls to adapt to the solar angle. 88 44  05/12/2024  Slanted louvers provide more protection than those parallel to a wall.  Angle varies according to the range of solar angles.  Louvers hung from a solid overhang protect against low sun angles.  Louvers may interfere with view. 89  Vertical louvers are most effective for eastern or western exposures.  Louvers may be operated manually or controlled automatically with time or photoelectric controls to adapt to solar angle.  Separation from wall reduces conductive heat gain. 90 45  05/12/2024  Eggcrates combine the shading characteristics of horizontal and vertical louvers and have a high shading ratio.  Eggcrates, sometimes referred to as brise-soleil, are very efficient in hot climates. 91 92 46  05/12/2024  Solar blinds and screens can provide up to a 50% reduction in solar radiation, depending on their reflectivity.  Heat-absorbing glass can absorb up to 40% of the radiation reaching its surface. 93 94 47  05/12/2024 7. NATURAL LIGHTING Maximizing the amount of natural light that enters the building can lead to significant energy savings by reducing the need for artificial lighting. 95 MAXIMIZING NATURAL LIGHT ▪ Skylights ▪ Atria ▪ Light shelves ▪ Clerestory windows ▪ Light tubes 96 48  05/12/2024 SKYLIGHTS Skylights can provide good quality light to workspaces that are away from windows. But they need to be shaded and glazed to prevent heat transfer. Some skylights are also vented to allow hot air to escape. 97 ATRIA An atrium is a large open space, often several stories high and having a glazed roof and/or large windows. The benefit of an atrium is that hot air can be vented at the top rather than accumulating near the building users. 98 49  05/12/2024 LIGHT SHELVES A light shelf is an architectural element that allows daylight to penetrate deeper into a building. A light shelf is a horizontal light- reflecting overhang which is placed above eye-level and has a high- reflectance upper surface. 99 CLERESTORY WINDOWS These are high, vertically placed windows that are ideally north facing. Clerestory windows can be a good source of diffuse light and can also be useful in allowing hot air to leave the building. 100 50  05/12/2024 101 LIGHT TUBES Solar tubes, light tubes or light pipes are used for transporting or distributing natural or artificial light. 102 51  05/12/2024 Air movement 103 AIR MOVEMENT ▪ Air movement is vital in passively-cooled environments in hot-humid localities ▪ This is particularly critical for most urban areas and lowlands in the Philippines 104 52  05/12/2024 AIR MOVEMENT ▪ Moving air that hits the human body promotes evaporation of sweat and induces a cooling sensation. ▪ Thus, air flow into the interiors should be directed to the occupancy zones especially those far from windows 105 AIR MOVEMENT ▪ Although there is a need to induce air movement during the hot- humid periods of the year, there are also periods of the year when the building should be able to resist typhoon winds 106 53  05/12/2024 Principles of air flow 107 WIND The movement of air through a building is generated by differences in air pressure as well as temperature. The resulting patterns of air flow are affected more by building geometry and orientation than by air speed. 108 54  05/12/2024 PRINCIPLE #1 Air flows from a high pressure area to a low pressure area. 109 PRINCIPLE #2 Air possesses inertia. Once set in motion, it tends to continue to flow in its initial direction until some intervening force is met. 110 55  05/12/2024 PRINCIPLE #3 Air flows through the path of least resistance. 111 Inducing Air Movement 112 56  05/12/2024 Thermal Comfort Thermal comfort is the condition of mind that expresses satisfaction with the thermal environment. Maintaining this standard of thermal comfort for occupants of buildings or other enclosures is one of the important goals of HVAC design engineers. 113 114 57  05/12/2024  High inlets direct air flow upward, resulting in a loss of cooling effect.  Low inlets direct air flow at occupants.  Outlets should be as large or larger than inlets for maximum air flow.  The position of an outlet has little effect on the air flow but should allow rising warm air to escape. 115 Overhangs over openings direct flow upward which may be undesirable for cooling. Louvers can beneficially redirect and diffuse air flow. 116 58  05/12/2024 Roof overhangs increase incoming flow of air. Slots in overhangs equalize external pressure. 117 Sea and Land Breeze 118 59  05/12/2024 SEA AND LAND BREEZE ▪ SEA BREEZE – wind from the sea (high pressure) directed towards the land (low pressure); due to daytime heating. ▪ LAND BREEZE – wind from land (high pressure) directed towards the sea (low pressure); due to night-time cooling. 119 120 60  05/12/2024 Tropical Architecture 121 TROPICAL ARCHITECTURE Tropical architecture can be regarded as a type of green building applicable specifically for tropical climates, using design to optimally reduce buildings’ energy consumption, particularly the cooling load. 122 61  05/12/2024 MAIN OBJECTIVES (HOT HUMID) ▪ Maximize filtered air movement/speed up winds ▪ Minimize humidity and avoid mold growth ▪ Provide maximum shade, especially in late morning and all afternoon ▪ Create a cool and dark microclimate ▪ Low building density for better air movement ▪ Vegetation is desirable as a radiation absorbent surface and for its evaporative and shade properties. However, it has to be arranged in a way that does not impede air circulation 123 TROPICAL ARCHITECTURE ▪ Samoans long ago did not install walls to allow free-flow breezes. 124 62  05/12/2024 125 TROPICAL ARCHITECTURE ▪ Malayan homes’ plentiful windows aim to maximize cross-ventilation. 126 63  05/12/2024 127 BAHAY KUBO ▪ Living platform elevated on stilts, adaptation to damp ground conditions ▪ High-pitched roof, rain-water can be quickly drained, creates large air space (insulation), heat is radiated at an angle rather than directly on living space below ▪ Large windows, cross ventilation ▪ Operable windows, awning type, protection from rain at the same time provides shade ▪ Wide roof overhangs ▪ Walls and roof are constructed of thatch, low U-value ▪ Bamboo flooring, slats allows air to breeze upward ▪ Surrounding gardens 128 64  05/12/2024 129 BAHAY NA BATO ▪ Living platform is elevated, heavy stone walled ground floor ▪ High-pitched roof, rain-water can be quickly drained, creates large air space (insulation), heat is radiated at an angle rather than directly on living space below. ▪ Wide eaves, alero, underside was fitted with latticed vents ▪ Large windows, capiz panels allow daylight to penetrate interiors ▪ Ventanillas, operable windows on barandillas ▪ Volada, cantilevered gallery along the perimeter of the second floor, double layered façade ▪ Calado, latticed openings above interior walls ▪ Operable louvers or jalousies, dynamic exterior louvers ▪ Wooden walls, low U-value 130 65  05/12/2024 131 PRINCIPLES ▪ The consideration of the weather, hydrography and ecosystems of the environment in which buildings are built for maximum performance with the least impact. ▪ The efficacy and moderation in the use of construction materials, giving priority to low energy content compared to high energy. 132 66  05/12/2024 PRINCIPLES ▪ The reduction of energy consumption for heating, cooling, lighting and equipment, covering the remainder of the claim with renewable energy sources. ▪ The minimization of the building overall energy balance, covering the design, construction, use and end of its life. ▪ The fulfillment of requirements of comfort, safety, lighting and occupancy of buildings. 133 Improving Natural Ventilation and Daylighting 134 67  05/12/2024 ▪ Building should be sited in high altitudes for maximum cool airflow and locations with evaporative possibilities are advantageous. ▪ Settlements have to be properly oriented regarding prevailing winds ▪ Settlements in flat areas (less natural features: hill sides, slopes) should include vegetation because the air is cooled while crossing green shaded areas 135 ▪ Sun orientation: preference for north orientations of the main facades of the building ▪ Wind orientation: main walls and windows should face the prevailing wind direction 136 68  05/12/2024 ▪ Orient active living areas to the northeast to collect early morning sun. ▪ Glass areas should face north with properly designed overhangs. ▪ Plant trees in south. ▪ East and west windows should be avoided to minimize radiation with low sun angles. 137 ▪ Outlets at higher levels serve to vent hot air ▪ Semi-open spaces such as balconies and porches can be used advantageously for daytime activities as well as give protection from rainfall. 138 69  05/12/2024 ▪ The form of the roof should be planned to promote air flow. Vents at the rooftop induce ventilation and draw hot air out. A double roof with ventilated space in between can be used to promote air flow. The space between can also act as a heat buffer. ▪ Air should enter the building through shaded outdoor areas, avoiding passing through heated surfaces. 139 ▪ Openings of a comparatively smaller size can be placed on the windward side, while the corresponding openings on the leeward side should be bigger for facilitating natural ventilation. 140 70  05/12/2024 141  Opening shape matters and can influence airflow effectiveness. Long horizontal strip windows can ventilate a space more evenly.  Tall windows with openings at top and bottom can use convection as well as outside breezes to pull hot air out the top of the room while supplying cool air at the bottom. 142 71  05/12/2024 END 143 What should be the minimum depth of the sun shade for this window on October 16 at 10AM? 144 72  05/12/2024 Sun Path Diagram, Manila. 145 0.25m What should be the minimum depth of the sun shade for this window on May 16 at 1PM? 1.90m 0.30m 146 73