Cold and Cloudy climatic region

The ppt consists of types of climatic regions in india, 5 typesof climatic zones in india, their description , cold and cloudy zone, shimla, himachal pradesh, types of design features according to climatic zones, active and passive cooling and heating techniques in cold and cloudy region.

1. ELECTIVES - II ENVIRONMENTAL DESIGN PRESENTATION ON COLD & CLOUDY ZONE Guided by- Ar. Deepali Hejib BY Rajni Sharma. Priyal Ajmera. Divyanshu Verma. Thakur Prachi. Yash Agrawal.

2. INTRODUCTION Based on the type of climate map of India can be divided into 5 major divisions. Hot & Dry, Warm & Humid, Composite, Temperate & Cold & Cloudy. Regions that lie in the cold climate zone are situated at high altitudes. The temperatures range between 20–30 ºC in summers, while in winters, it can range from -3 ºC to 8 ºC, or less. The cold region can be further divided into 2 categories Cold & Sunny - The cold and sunny type of climate is experienced in Leh ( Ladakh ). The region is mountainous, has little vegetation, and is considered to as a cold desert. Cold N Cloudy - Generally, the northern part of India experiences this type of climate. Most cold and cloudy regions are situated at high altitudes. Shimla, Shillong , Srinagar and Mahabaleshwar are examples of places belonging to this climatic zone. These are generally highland regions having abundant vegetation in summer.

3. State such as J&K, Himachal Pradesh, Uttarakhand, Arunachal Pradesh, Sikkim & northern parts of UP have cold and cloudy climate. These are generally highland regions having abundant vegetation in summer. Heat Gain is low in winter with a high percentage of diffuse radiation. Hence, winters are extremely cold. In summer, the maximum ambient temperatures is in the range of 20 – 30 o C during the day and 17 – 27 o C at night, making summers quite pleasant. COLD WARM & HUMID HOT & DRY COMPOSITE TEMPERAE INTRODUCTION

4. The relative humidity is generally high and ranges from 70 – 80%. Annual total precipitation is about 1000 mm and is disturbed evenly throughout the year. This region experiences cold winds in the winter season. Hence, protection from winds is essential in this type of climate. The sky is overcast for most part of the year except during the brief summer. In winter, the values range between 4 and 8 o C during the day and -3 to 4 o C at night, making it quite chilly. Thus trapping the sun’s heat whenever possible is a major design concern. At the same time, the buildings in such regions need to be properly insulated so that the internal heat is retained with minimum loss to the environment. Exposure to cold winds should also be minimized. CHARACTERISTICS.

5. The main objectives of building design in these zones are - Resisting heat loss & To resist heat loss, the following measures may be taken into consideration: Decrease the exposed surface area of the building. Using materials that heat up fast but release heat slowly. Providing buffer spaces between the living area and the outside. Decreasing the rate of ventilation inside the building. Heat gain can be promoted by - Avoiding excessive shading. Utilising the heat from appliances. Trapping the heat of the sun. CHARACTERISTICS.

6. SITE Landform - In cold climates, heat gain is desirable. Hence, buildings should be located on the south slope of a hill or mountain for better access to solar radiation . Open spaces and built form - Buildings in cold climates should be clustered together to minimise exposure to cold winds .Open spaces must be such that they allow maximum south sun. They should be treated with a hard and reflective surface so that they reflect solar radiation onto each other. Street width and orientation - The street orientation should be east-west to allow for maximum south sun to enter the building. The street should be wide enough to ensure that the buildings on one side do not shade those on the other side. RECOMMENDATION . The general recommendations for regions with a cold and cloudy, or cold and sunny climate are as follows –

7. ORIENTATION AND PLANFORM In the cold zones, the buildings must be compact with small S/V ratios . This is because the lesser the surface area, the lower is the heat loss from the building.  Windows should preferably face south to encourage direct gain. The north side of the building should be well-insulated. Living areas can be located on the southern side while utility areas such as stores can be on the northern side.  Air-lock lobbies at the entrance and exit points of the building reduce heat loss.  The heat generated by appliances in rooms such as kitchens may be recycled to heat the other parts of the building. RECOMMENDATION .

8. BUILDING ENVELOPE Roof - False ceilings are a regular roof feature of houses in cold climates. One can also use internal insulation such as polyurethane foam (PUF), thermocol , wood wool, etc. A sloping roof enables quick drainage of rain water and snow. Walls - Walls should be of low U-value to resist heat loss. The south-facing walls could be of high thermal capacity to store day time heat for later use rest of the walls should also be insulated. Hollow and lightweight concrete blocks are also suitable . On the windward or north side, a cavity wall can be adopted. Fenestration - It is advisable to have the maximum window area on the southern side of the building to facilitate direct heat gain. They should be sealed and double glazed. Double glazing helps to avoid heat losses during winter nights Colour and texture - The external surfaces of the walls should be dark in colour for high absorptivity to facilitate heat gains. RECOMMENDATION .

9. TROMBE WALL A Trombe wall is a system for indirect solar heat gain and, although not extremely common, is a good example of thermal mass, solar gain, and glazing properties used together to achieve human comfort goals passively  It consists of a dark coloured 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. A successful Trombe wall optimizes heat gain and minimizes heat loss during cold times, and avoids excess heat gain in hot times. TECHNIQES .

10. CASE STUDY 1 KOTI BANAL ARCHITECTURE UTTARAKHAND AND HIMACHAL PRADESH

11. Introduction In the Rajgarhi area of Uttarkhashi district of Uttarakhand, India a large number of intact buildings of a distinct earthquake resistant type known as Koti Banal can be found. This construction type has been in practice for more than 200 yrs & it is reported that Koti Banal architecture withstood & performed well during many past damaging earthquakes in the region (e.g. 1991 Uttarkashi quake of magnitude 6.6 on the Richter scale). The building are considered as the basics of modern earthquake- resistant design. KOTI BANAL ARCHITECTURE

12. DESIGN FEATURES:- Sitting & Orientation: - Situated on a firm ridge or plane ground having rock outcrop without any buildings in the immediate vicinity. Thermal strategy: - High thermal mass of the building envelope retains heat. - Small window opening prevent heat loss and are south-facing. - Low floor height (2.2 – 2.5 m) reduces the internal volume of air to be heated. - The attic space acts a thermal buffer. Small window opening

13. DESIGN FEATURES:- Earthquake resistance: -Regular plan and elevation shapes, integration of wooden beam over the total height of the building , small opening size and arrangement of shear walls. - Walls are strengthened against out-of-plane failure by shear key in the form of a wooden member which runs vertically through the storey and is structurally connected to the timber framing of the building.

14. DESIGN FEATURES:- Earthquake resistance: - For lateral load resistance (horizontal), pair of wooden logs connected to each other by wooden shear pins/tenons from a wooden frame which is braced by well dressed flat stone masonry. - The dry stones masonry between the logs enables a certain level of flexibility and allows lateral deflections of the building without damage effects.

15. KOTI BANAL ARCHITECTURE

16. BUILDING FEATURES :- 1. Typology Multi-stoned detached structure of height varying between 7 -12 m above the plinth. They have rectangular plan configurations with the length and width varying from 4-8m . 2. Structure The building rest upon a raised dry stone masonry platform over the foundation made in rubble masonry in the lower part. The walls consists of a configuration with orthogonally arranged wooden logs interconnected at the junction by wooden pins/tenons. For the two bottom most layers single wooden logs while for upper layers double wooden logs are used. The infill between the logs is furnished with well-dressed flat stones which are dry packed or by using A paste of pulses as mortar. This wooden structure is not used for the upper part of the wall where the dressed stones have a load-bearing function. The structure is further reinforced by wooden beams which are perpendicular to the wooden logs at the middle of the walls connecting two parallel outer walls.

17. 4. Wall system 50-60 cm thick timber- reinforced stone masonry. The thickness of the walls is determined by the thickness of the two parallel arranged wooden logs. 3. Roof system Typically, the roofing span is half of the building width . The roof constructed consists of a wooden frame which is expected to act as a flexible diaphragm and is clad with slate tiles. 5. Floor Wooden beams door and planks resting on wooden joists supported by beams or walls. BUILDING FEATURES :-

18. 6. Door / windows A single small door access on the ground floor and relatively small south facing windows floors above with wooden frames and shutters. 7. Semi-outdoor spaces The upper two floor is have balconies running around the whole building cantilevering from the wooden logs of the flooring system with a wooden railing. BUILDING FEATURES :-

19. CASE STUDY 2 ENERGY EFFICIENT BUILDING

20. HIMURJA OFFICE BUILDING,SHIMLA The Himurja building is a multi-storeyed office that is located on a sharply sloping site and employs a number of passive solar strategies well suited for the Cold and Cloudy climate of Shimla. It is also a good example of how to integrate renewable energy systems into the design of a building. Climate of Shimla Solar Radiation: Low in winter with high percentage of diffuse radiation Temperature : Summer Midday- 20-30 deg. C ; Summer night-17-21 deg. C; Winter Midday-4-8 deg. C; Winter night: -3 to -4 de. C Relative humidity : Varies between 70% to 80% Precipitation: Moderate, distributed evenly throughout year. Annual total around 1000 mm Winds: Generally intense, especially during rainfall. Mainly dependent on topography. Sky Condition: Overcast for most part of the year. Vegetation: Highland regions with abundant vegetation in summer

21. Building Feature Description Typology 4 storeyed building of built up area 635 sq. m terraced with an existing building. The ground and first floor are coupled with the earth. Structure RCC Structure Roof System Well insulated sloping roof clad with metal sheets and ideally oriented solar panel Wall System Stone masonry in exposed walls, while insulated RCC diaphragm walls coupled with the earth. All external walls have good insulation of 5 cm thick glass wool. Door/Windows South facing openings of double glazed panels and hard plastic windows in some faces. Buffer Spaces South facing solarium Section demonstrating various passive solar features integrated inn the building HIMURJA OFFICE BUILDING,FEATURES

22. HIMURJA OFFICE BUILDING,SHIMLA Floor Plan of Himurja Office Building A south west view o the office building showing specially designed sunspaces for maximizing solar gains in winter Sunspaces can be used to collect the suns heat, store it centrally and distribute it to other rooms. The wind is pre-heated in the sunspace before entering the building. A sunspace, unlike direct gain and tromba wall system, adds a room to the building. Winter Section : Two openings are provided on the wall dividing the sunspace and room. The air in the sunspace rises when heated by radiation, and is drawn inside the room and cool air in the room which is at a lower level is let back in sunspace. This forms a cycle of passive heating air flow. Summer section: Low inlets and high outlets can be used in a "stack effect" which can be in the form of wind catchers. Since warn air will rise. A wind catcher placed with an opening exposed to the prevailing wind direction forces the air inside and warm air inside the room is drawn out due to negative pressure formed inside the room. Sunspace can be ventilated to the outside to avoid heating. Schematic Section for Winters Schematic Section for Summers

23. ROCKBED Rock beds are a means of enlarging the thermal mass of the building and thereby increasing the ability to store energy. Air is drawn from the sunspace and through bed of rocks. Heat is given off to the rocks and air is recirculated to a location in the hot space to collect more heat. AT night when heat is needed, air from the occupied space is drawn through the rock bed, where it picks up heat and distributed back to the occupied space. The rock bed can be located under a concrete slab that will be heated by bed. Schematic Section of Rockbed

24. DAYLIGHT, SOLARIUM, SOLAR CHIMNEY, AIR HEATING PANELS Sitting and Orientation: The building is set into the slope of the site and the orientation provides maximum exposure to the south side Daylight design: Distribution of daylight in spaces is achieved through careful integration of window and light shelves Light reflected off the light shelves is distributed into the deep plan of the building .by designing a ceiling profile that provides effective reflectivity. Artificial lighting is seldom required in the south oriented spaces, which are well-lit during working hours Insulation: Good insulation of 5cm thick glass wool in RCC diaphragm walls prevents heat loss. Infiltration losses are minimized through weather-proofed hard plastic windows. Double glazing helps control heat loss from glazing without creating any internal condensation.

25. Design Features Thermal Strategy: Coupling the ground and first floor with the earth prevents heat loss to a great extent. With the openings on the south and west facades, the building maximizes solar gain. The plan of the building and its three dimensional form allow maximum penetration of sun maximizing both solar heat gain and daylight. The judiciously designed thermal mass absorbs and provide heat in the spaces throughout the day. Air heating panels designed as an integral part of the southern well panels provide effective heat gain. Distribution of heat gain in the entire building is achieved through a connective loop Ventilation: To optimize ventilation during summer, the contraceptive loop is coupled with solar chimneys designed as an integral part of the roof. Buffer spaces: A solarium or sunspace is built as an integral part of the southern wall maximizing heat gain. Renewable energy systems: The photovoltaic system of 1.5kWp meets the energy demand for lighting whenever required. Roof-mounted solar water system (1000 litre per day) has been used in the building. The water is circulated through radiators for space heating especially in the northern spaces A view of curved ceiling with glass blocks to distribute daylight and roof-mounted solar water heating system

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