natural ventilation and case studies of two buildings

1. Natural
Ventilation

2. Overview
Natural ventilation utilizes natural forces to provide fresh air
and remove stale air from buildings. It leverages two main
driving forces:
Wind-driven ventilation: Utilizes wind speed and
pressure differences around a building to push air
through openings.
Buoyancy-driven ventilation (stack effect): Exploits
temperature differences to create a natural convection
current. Warm air, being less dense, rises, drawing cooler
air in through lower openings.
2

3. 3
Energy Efficiency: By harnessing natural forces, it significantly reduces reliance on
mechanically driven fans, lowering building energy consumption by 10-30%.
Cost-Effectiveness: Natural ventilation systems are cheaper to install and maintain
compared to complex mechanical systems.
Improved Indoor Air Quality: Fresh air introduction dilutes pollutants and reduces
odors, creating a healthier environment for occupants.
Thermal Comfort: Air movement generated by natural ventilation can create a
perceived temperature reduction of up to 5°F, improving occupant comfort without
excessive cooling.
Reduced Carbon Emissions: Lower energy use translates to a smaller carbon
footprint for the building.
Benefits of Natural Ventilation

4. 4
Design Strategies for Effective
Natural Ventilation
Stack Ventilation: Leverage the "chimney effect" by strategically placing windows or
vents at different heights. Warm air rises, exiting through higher vents, while cooler air
is drawn in through lower openings.
Landscaping Considerations: Trees and windbreaks can be strategically used to
channel wind or create shade, influencing natural ventilation patterns.

5. 5
Climate Considerations: Natural ventilation is most effective in dry climates and during
moderate weather conditions. In humid climates, it may struggle to remove moisture
effectively [Department of Energy].
Wind Analysis: Understanding prevailing wind patterns is crucial. Strategically placed
windows and openings can capture breezes and optimize airflow through the building
[WBDG].
Building Design: The layout and design of the building significantly impact natural
ventilation. Consider factors like:
Window Placement: Windows on opposite walls (cross ventilation) or strategically
placed high and low windows (stack ventilation) can create airflow paths [WBDG].
Open Floor Plans: Interior openings between rooms can facilitate air circulation within
the building.
Light Wells and Courtyards: These elements can channel wind and enhance stack
ventilation effects.

6. Types of Natural Ventilation Systems
6
Cross
Ventilation
Airflow is achieved
through openings on
opposite walls, utilizing
wind pressure for fresh
air circulation.
Single-sided
Ventilation
Wind pushes air through
windows on one side of the
building, while exhaust vents on
the opposite side remove stale
air.
Stack
Ventilation
Utilizes the buoyancy
effect, with warm air exiting
through high vents and
cooler air drawn in through
lower openings.

7. 4
Limitations of Natural Ventilation
Climate Dependence: Effectiveness can be limited in hot, humid climates or during
periods of stagnant air.
Outdoor Air Quality: Natural ventilation relies on outdoor air, so polluted
environments may not be suitable.
Noise Control: Openings for ventilation can introduce unwanted noise from outside.
Security Concerns: Open windows and vents might pose security risks.

8. NATHMAL
KI
HAVELI

9. Jaisalmer, being an arid desert region, is prone to
extremes in terms of temperature. The temperature
varies greatly from day to night in both summer and
winter. The maximum summer temperature is around
49 °C (120 °F) while the minimum is 25 °C (77 °F).
LOCATION : Nathmal Ji Ki Haveli is a beautiful and historic mansion
located in the heart of Jaisalmer City in Rajasthan
CLIMATE :

10. Nathmal ki Haveli is an ornate architecture in the city
Jaisalmer which is otherwise known as the land of the
Golden Fort. It was commissioned to serve as the
residence of then prime minister Diwan Mohata Nathmal.
The extraordinary exteriors dripping with carvings and
the highly skilled work of the Haveli (similar on either side
but not identical) with two elephants made of limestone
guarding the entrance is the sight that every visitor is
privileged to see.
Central courtyards: A central courtyard of this haveli
acts as a light well and can help draw hot air upwards. As
hot air rises, cooler air is drawn in through windows and
doors on the ground floor, creating a cool and
comfortable living space.
Strategically placed windows and doors: Windows and
doors are often positioned to capture prevailing winds.
Wind catchers (large vents on upper floors) can further
channel wind into the Haveli.
Mehrabs (elevated seats): Mehrabs located by windows
or water bodies could be positioned to take advantage of
cooling breezes.

11. The building is planned around two
courtyards, the one in the front is
much smaller than the rear one .
The front part of the building is three
storeys high and has the main living
quarter as to obstruct harsh west
sun.
The rear portion is two storey high
and contains the ancillary
accomodation.
The one in the facade is a lot lower
than the true one. The first element of
the building is three storeys tall & has
the central living cottage. The back
part is two storey tall &include the
additional adaptation.
Front facade contain a large number
of openings as wind direction is from
southwest to northeast.
PLAN

12. The material used for walls in this haveli is mostly light sandstone
where as limestone has been used for the upper storeies and facade
since it can be easily carved.
The stone joints are made without mortar and are held together using
iron cramps.
Due to thick walls and mud plaster, it reduces the thermal load on the
building.
BUILDING MATERIAL

13. The entire building is of unequal height with
wind pavilions and high parapet walls,
creating an uneven skyline and shading in the
process.
At the second level, they have several
projections like sunshades and balconies.
At the lowest levels, the flat parts of the
building facade are deeply carved creating a
finned surface.
Uneven building forms also influence
radiative heat loss from walls.
FORM OF THE BUILDING

14. The courtyards provide the necessary
light and ventilation for all the
surrounding rooms.
While the front receives some sunlight
during the summer, the rear courtyard
is completely exposed to sun.
The streets and the two narrow shafts
are completely protected from the sun.
The differential heating of the vertical
ducts ensures continuous airfow
through the house.
FORM OF THE BUILDING

15. Windows and balconies are generally
fitted with jallis or lattice
windows(shutter like windows) for
privacy as well to restrict dust but at
the same time let in wind.
Doors are built with stone frames and
fitted with timber doors.
WINDOWS
Chajja
Detail of window

16. The roof is made of closely spaced
timber beams and then is covered by a
layer of reed or grass matting and finally
laid by a layer of earth on top.
These are then finished with stone
flooring or mud plaster.
The layer of earth and grass matting
keeps the interiors cool.
ROOF
Construction of the roof
Detail of Roof

17. 4
THE ENERGY
RESEARCH
INSTITUTE,
BANGALORE

18. THE ENERGY RESEARCH INSTITUTE (TERI), BANGALORE
ESTABLISHED IN 1974
PROJECT IS DESIGNED TO HOUSE AN OFFICE BLOCK WITH
WORKSTATIONS AND A SMALL GUEST HOUSE ATTACHED TO IT.
CONCERNED WITH EFFECTIVE UTILISATION OF ENERGY,
SUSTAINABLE USES 0F NATURAL RESOURCES, LARGE SCALE
ADAPTATION OF RENEWABLE ENERGY TECHNOLOGY.
Architects : Sanjay Mohe and V Tushar
CLIMATE :Bangalore has a tropical savanna climate
(Köppen climate classification Aw) with distinct
wet and dry seasons. Due to its high elevation,
Bangalore usually enjoys a more moderate climate
throughout the year, although occasional heat
waves can make summer somewhat
uncomfortable.

19. Potential of setting an example
of treating waste water as is
done in Osho Ashram, Pune.
Wind flowing over Nallah
carrying foul air.
BUFFER
ZONE
NECESSARY
Existing building
to be removed
BUILDING HAS BEEN DIVIDED INTO INDIVIDUAL
AND COMMON AREAS
75 INTIMATE SMALL SPACES ARE PROVIDED FOR
INDIVIDUAL WORK.
COMMON AREAS REFER TO THE ATRIUMS,
COURTS, NODES AND CORRIDORS MEANT FOR
WIDER INTERACTION
ORIENTATION
BUILDING IS ORIENTED ALONG NS-EW DIRECTION
SW IS THE PRIMARY WIND AND LIGHT DIRECTION
FOR BANGALORE.
ALONG SW FACADE IS A FOUL SMELLING DRAIN.
HENCE ENTRANCE IS TOWARDS NE DIRECTION.
ALL WINDOW OPENINGS ARE IN THIS DIRECTION
SOUTH WALL IS DOUBLE WALL TO PROVIDE
INSULATION FROM SOUTHERN SUN.
BUILDING DETAILS

20. PLANS

21. VENTILATION IS ENHANCED BY THE USE OF SOLAR CHIMNEYS AND
VENTS.
ALLOWS BREEZE TO FLOW OVER BUILDING.
CREATES NEGATIVE PRESSURE.
STARTS PULLING FRESH AIR FLOW AT BODY LEVEL TO PROVIDE
THERMAL COMFORT.
HOT AIR RISES TOWARDS THE TOP ON SOUTHERN FAÇADE.
The primary winds blow
from the south to north
over the nallah, hence the
building needs to react to
this if, the foul unhygienic
air has to be prevented
from entering the building.
The blank wall carries a
system of cuddapah.
The colour black was
deliberately chosen
because of its heat-
absorptive power.

22. Abundant natural light inside due
to intelligently designed
fenestrations.
Openings have been designed
such that requirement of artificial
lighting is minimal throughout the
day when the building is under
maximum usage.
By creating atrium spaces with skylights, sections of the Centre are designed in such a way
that natural daylight enters into the heart of the building, considerably reducing the
dependence on artificial lighting. This is supplemented by a skylight roof and energy- efficient
artificial lighting

23. INDOOR ENVIRONMENTAL QUALITY ENHANCEMENT
south west wall
cladded with black
cudappa slabs
cavity which serves as
a bottle neck for
convection currents.
INDOOR ENVIRONMENTAL QUALITY IS VERY WELL
ACHIEVED WITH THE HELP OF NON VOC PAINTS AND
LOCAL FLOORING MATERIAL WITH LESS EMBODIED
ENERGY.
INDOOR AIR QUALITY IS VERY WELL MAINTAINED
WITH EFFECTIVE TECHNIQUE AND USE OF CAVITY
WALL IN SOUTH TO HEAT UP THE INTERIOR AIR.
OCCUPANT COMFORT IS ACHIEVED WITH
CONDUCTION & RADIATION AS EXTERNAL AGENT
BODY HEAT & AIR FLOW AS INTERNAL AGENT
PLANTS ARE BEING USED IN THE INTERIOR COMMON
CONNECTING SPACES FOR REFRESHMENT AND AIR
CIRCULATION.
PROPER MAINTENANCE IS TAKEN CARE IN THE
INTERIOR TO MAKE AN HYGNIC LIVING
NORTH LIGHTING IS PROVIDED FOR GLARE LESS
LIGHTING SYSTEM AND ITS MADE TO BE USED IN THE
WORKSPACE
SOLAR INDUCTION VENTS
HOT STILL DAYS
WIND INDUCED VENTS
SOLAR CHIMNEY
WINDY DAYS

24. MIXED USE OF VEGETATION HAS BEEN USED TO MAKE THE CAMPUS GREEN AND FRESH.
SOLAR CHIMNEY PLAYS A MAJOR ROLE IN MAINTAIN CONSTANT AIR FLOW IN THE INTERIOR
VENTILATION PLAYS A MAJOR ROLE IN CREATING COMFORT NESS IN THE INTERIOR

25. Thank you
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KASHISH AHUJA
TANUSHREE SHARMA
SAMRITI SHARMA
GUNJAN VERMA