1. Adaptation and Control
Assalamualaikum wrt wbt
Adaptation and Control
Climate Themes:
Hot Humid and Hot Arid Climate

2. Presentation Summary In this presentation, we will discuss:
Hot humid region
Characteristics
Indigenous solutions
Current solution
Hot Arid region
In this presentation, we will discuss:
Climate issues
The Importance of the geographic region
Climate Zones of North America
Climate Zones of Canada
The 4 primary bioclimatic types
Comfort Zone
Microclimate 2

3. General Climate Control Strategies
Passive control of heat flows:
When cold discomfort (underheated) conditions prevail:
minimise heat loss
utilise heat gain from the sun and internal sources
When hot discomfort (overheated) conditions prevail:
prevent heat gain
maximuse heat dissipation

4. Characteristics Indigenous solutions Current solution
Hot Region: Hot Humid
Characteristics
Indigenous solutions
Current solution

5. hot-humid climate
characterized by high humidity and warm summer temperatures.
High precipitation
the nights are usually warm with very little diurnal variation (often less than 5 deg C).
As the humidity is high, evaporation from the skin is restricted. Evaporative cooling will be neither effective nor desirable as it would increase the humidity.
Little variations of temperature between night and day due to the high humidity and cloud cover which prevents re-radiation to the night sky.
Sunshine is available all year long with very low air speed.

6. hot-humid climate
The designer should ensure that the indoor temperature does not become higher than the outdoor.
Adequate ventilation may ensure this by removing any excess heat input, but this is not enough.
the main function of the buildings is to simply moderate the daytime heating effects of the external air (Givoni).
it is important to design buildings whose structure and interior are best able to keep warm air out.
The ventilation keeps air moving through the environment and, therefore, keeps the inhabitants cooler.

7. Design Strategy in Warm-humid Climates
The whole building should be lightweight to allow rapid cooling down at night.
East and west walls should have minimum or no windows in order to exclude the low angle east and west sun. They should be reflective and/or well insulated. North and south walls should be as open as possible, to allow for cross ventilation.
This requires that the plan arrangement should avoid double-banked rooms. The spacing of buildings should be carefully considered to avoid obstruction of the wind. The openings require protection from the sun and driving rain but also from mosquitoes and other insects which abound in these climates.
At times orientation for wind and for sun give conflicting requirements, solar orientation should take precedence, as there are ways of deflecting wind, but no ways of altering the sun’s movement. With oblique wind incidence a projecting wing wall at the downwind end of the building would create a positive pressure zone. On the leeward side a similar wing wall at the upwind end would help to create a negative pressure zone. The combined effect of these may ensure a better cross ventilation than that given by wind with normal incidence.

8. Undue increase of ceiling temperature may be prevented by:
using a reflective roof surface
having a separate ceiling
ensuring adequate ventilation of the attic space
using reflective surfaces both for the underside of the roof and for the top of the ceiling
using some resistive insulation for or on the ceiling

10. Choose window type for good airflow eg, louvres rather than awning/hopper windows;
Elevate house to catch the breezes (in areas prone to tropical cyclones, there is a trade-off - construction cost increases);

11. Because the climate is warm all year, building heat gain should be minimised by:
orienting the long axis of the house east-west
The long north- and south-facing walls can easily be shaded by the eaves;
keeping windows on east and west walls to a minimum;
shading the walls and windows - use shutters, verandahs, canopies and/or eaves and fixed overhangs;
using pale colours for walls and roof, to reflect the heat of the sun;
reflective foil insulation is good, because it reflects incoming sunshine, but bulk insulation is not desirable, because it prevents the house cooling down at night;
ventilation of the roof space, to reduce heat build-up there: the increased heat loss in the cooler season is not important;
metal roofs which cool rapidly at night. Daytime heat gain can be minimised by using sheeting with a reflective coating on its underside.
Because of the warm climate:
outdoor living areas( verandahs or under an elevated house ) will be particularly useful. Shelter from the rain is needed in summer; shade is also desirable.

12. Bio-climatic Design: HOT-HUMID
Where warm to hot stable conditions predominate with high humidity throughout the year. Cooling degrees days greatly exceed heating degree days.
RULES:
SOLAR AVOIDANCE : large roofs with overhangs that shade walls and to allow windows open at all times
PROMOTE VENTILATION
USE LIGHTWEIGHT MATERIALS that do not hold heat and that will not promote condensation and dampness (mold/mildew)
eliminate basements and concrete
use STACK EFFECT to ventilate through high spaces
use of COURTYARDS and semi-enclosed outside spaces
use WATER FEATURES for cooling
Bio-climatic Design: HOT-HUMID
A hot humid climate exists where warm to hot stable conditions predominate with high humidity throughout the year. Cooling degrees days greatly exceed heating degree days.
The general RULES that govern Hot Humid design are:
SOLAR AVOIDANCE: Design buildings with large roofs with overhangs that shade the walls and allow windows to be open at all times. These climates can also be very rainy and it is important for natural ventilation to allow the windows to be open during rainy times. Large roof overhangs can protect the openings and interior spaced from rain penetration.
PROMOTE VENTILATION: In this type of climate is does not usually cool down at night so we do not need to prevent this air from entering the room. Often the only comfort possible is through the sensation on our skin of air movement. You can supplement the natural movement of air by fans. Ceiling and window or oscillating fans are good. Remember though that the fan is not cooling the space at all. It is merely giving the occupant the sensation of cooling. Ceiling fans can help to mix the air and prevent stratification.
USE LIGHTWEIGHT MATERIALS that do not hold heat and that will not promote condensation and dampness (mold/mildew). Concrete and other such materials are not suitable here.
eliminate basements and concrete. Basements in these types of climates have a huge tendency to hold dampness and promote the growth of mold. Use an alternate method of space creation for mechanical systems and storage. You won’t want to use the moldy goods anyway! These types of climates tend not to have frost depth issues, so constructing a basement is not a natural byproduct of deep foundation walls.
use STACK EFFECT to ventilate through high spaces. Hot air rises. You can allow the natural rise of hot air plus high level operable windows to encourage the exhaust of the overheated interior air, thereby drawing in cooler outside air to replace it.
use of COURTYARDS and semi-enclosed outside spaces. These are often cooler than the interior environments.
use WATER FEATURES for cooling. Even though the air is humid, water features can make the occupant feel cooler, even by the sound of the running water or fountain.
House in Seaside, Florida 12

15. Characteristics Indigenous solutions Current solution
Hot Region: Hot Arid
Characteristics
Indigenous solutions
Current solution

16. Bio-climatic Design: HOT-ARID
Where very high summer temperatures with great fluctuation predominate with dry conditions throughout the year. Cooling degrees days greatly exceed heating degree days.
RULES:
Solar avoidance : keep DIRECT SOLAR GAIN out of the building
avoid daytime ventilation
promote nighttime flushing with cool evening air
achieve daylighting by reflectance and use of LIGHT non-heat absorbing colours
create a cooler MICROCLIMATE by using light / lightweight materials
respect the DIURNAL CYCLE
use heavy mass for walls and DO NOT INSULATE
Bio-climatic Design: HOT-ARID
Hot arid conditions are deemed to exist where very high summer temperatures with great fluctuation predominate with dry conditions throughout the year. Cooling degrees days greatly exceed heating degree days.
The general RULES that govern Hot Arid design are:
Solar avoidance : keep DIRECT SOLAR GAIN out of the building. During the daylight hours completely avoid letting direct sun enter the building. This will mean keeping the window openings very small, or shading the openings, or providing ventilating shutters to allow air but not sun to enter the building. If the sun enters the building it will heat up the thermal mass of the building. This is the number one issue to avoid.
avoid daytime ventilation. The daytime air in hot climates is HOT. You do not want to encourage it to enter the building. You only ventilate these buildings at night.
promote nighttime flushing with cool evening air. The evening air in a desert climate is substantially cooler than in the daytime. If you promote ventilation in the cool evening hours you will draw heat out of the thermal mass of the building and cool it down for sleeping.
achieve daylighting by reflectance and use of LIGHT non-heat absorbing colours. If you use light colours the building will not attract or hold as much solar heat as dark colours absorb heat. Light colours will also help light to bounce around and achieve a good level of brightness without the use of direct beam radiation from the sun.
create a cooler MICROCLIMATE by using light / lightweight materials. Lightweight materials such as fabrics, rattan and wood do not hold heat. So use these materials for furnishings to keep the environment next to the body airy and cool.
respect the DIURNAL CYCLE
use heavy mass for walls and DO NOT INSULATE 16

17. Hot arid buildings use the mass of the building to moderate heat flow through the envelope.
Inhabitants can also sleep in the outside area i.e. the roof if it gets too hot at night.

18. Extremely hot summers and moderately cold winters
The cold season last from November till March
The summers are extremely hot and dry with great temperature difference between day and night

19. Modern buildings in the hot arid climate also use small windows and create airy interior by introducing courtyards inside the buildings

20. In many arid, desert regions, buildings are designed with flat roofs, small openings, and heavy weight materials.
These materials include dried mud in rural areas and reinforced concrete in urban areas (Givoni).
The thick exterior roof and walls help to absorb temperature fluctuations and, therefore, keep internal temperatures from rising above the outside surface temperature.
An important function of the roof is its color. A white or light colored roof will stay approximately the same temperature as the outdoor air during the day, and six to ten deg C cooler than the outside air at night
This is an important feature because the cooler nighttime air will be channeled down by the sloop of the roof and into the rooms in the building.
One function of the small openings is to prevent dust, a huge problem in Africa, West Asia, and West Australia, from entering buildings. Windows are arranged so that equal areas are open on
the windward and leeward sides of the building. The reason for this is very simple, the
air stream can be directed into rooms that need constant ventilation such as the bedroom
(Givoni). When one window is positioned higher than another, thermal force will direct
the airflow from the high window to the lower window creating good ventilation.

21. Courtyards, patios, and verandas are other common features of buildings in hot
climates. With high walls, these outside areas provide shade and a relaxing environment
to their inhabitants for social gatherings, evening entertainment, food preparation, and
domestic work such as laundry (Oktay). Concrete is the most common material used in
the walls because it has low cost and high thermal capacity which in turn reduces internal
temperatures (Givoni 316). This keeps the patios cooler and more enjoyable. Another
way to provide shade in a more aesthetically pleasing way is through greenery. For
example, trees, shrubs, and bushes provide natural shade from the sun while giving the
courtyard area a pleasing look. Why are these outside areas so important? They are
important because essential functions happen outside like cooking and entertaining. The
outside environment in hot regions is just as important as the inside because it is a
daytime relief from the intense climate. The following chart was created to show the
optimal comfort temperature for an outside area in a hot region. As one can see,
depending on the orientation of the building, there is a different corresponding optimal
temperature (Bensalem). Generally between the afternoon hours of the day (1:00pm to
4:00pm), the most comfortable temperature is around degrees C.

23. Traditional hot climate design:
In hot dry (arid) climates windows are kept to a minimum to prevent the sun from entering the building. Bright stucco finishes are used to reflect light and keep the environment bright.
Traditional hot climate design:
In hot dry (arid) climates windows are kept to a minimum to prevent the sun from entering the building. Bright stucco finishes are used to reflect light and keep the environment bright. 23

24. Courtyard buildings:
Courtyards are used in hot arid climates and work well because sun can warm these spaces in cooler months. Courtyards do NOT work well in cold climates because of low winter sun angles.
Courtyard buildings:
Courtyard types were also developed for use in hot arid climates. They work well in southerly climates because the sun can warm these spaces in cooler months and the architecture, covered exterior corridors and vegetation create a cool “microclimate” in the hot months. Courtyards do NOT work well in cold climates because of low winter sun angles. They will be miserably cold and damp, and their geometry will prevent solar penetration to the interiors of buildings, that might be used to warm them up naturally. This is particularly the case if one looks at the cross sectional dimension of a courtyard. The taller and narrower the opening, the less sun penetration is possible. 24

25. Courtyards as cooling element
The courtyards are introduced to cool the house environment.

28. Pueblo Indian houses, Chaco Canyon, New Mexico

29. The buildings does not use insulation and have limited number of openings to keep the sunlight out.

30. If construction materials are not available, shade is optimized through construction of tent

31. Assignment 1 (Class assignment)-discussion and drawings
The assignment will fulfill the following objectives of the course:
To understand the climatic factors and zones of the world and how to make full use of this knowledge and attributes for architectural design.
To understand the ideas of passive design in the built environment as the main consideration when designing. Hence the design must not be relegated as an afterthought.
Students are required to:
analyze the content of the papers distributed
generate sketches of the design strategies appropriate to the climate conditions

32. wasalam