This has been prepared after the case study of various passive design techniques suitable for hot climate of Nepal. It includes national and international case studies. It also deals with the methods of passive cooling and ventilation in the buildings followed by theoretical findings and research in the case studies. It is the initial attempt to study passive design techniques suitable for sub-tropical climate. The modern society will use these methods in a sustainable way.

1. Passive Design Techniques
for
Subtropical Climate
of
Nepal
Shristi Kuikel (68048)
B.Arch V/I
Seminar & Directed Studies

2. • Research Objectives
• Problem Statement& Sub- Problems
• Passive design
• Methods
• Climatology
• Principles of Passive Design
• Methods of Passive Design Techniques
CONTENTS

3. Problem Statement & Sub Problems
Use of passive design techniques to make a building energy efficient in
sub-tropical climate of Nepal
 What kind of temperature is found in sub-tropical climate?
 What is passive solar design?
 What are the basic principles of passive solar design techniques?
 What are the methods of passive design techniques used in sub-tropical
climates?
 What are the efficiency and economics of passive solar design techniques?
 To understand passive design techniques for sub-tropical climate of Nepal
 To find out the best methods of passive design techniques for sub-tropical climate
of Nepal
Research Objectives

4. Passive Design
 Control comfort without the consumption of fuels
 Sustainable building - reducing - fossil fuels and –
 Reducing electricity > heating and cooling buildings
 Relies on sun’s energy for the heating and cooling of living spaces

5. METHODS
METHODS
OTHER
SYSTEMS
BUILDING
ORIENTATIO
N
PLANNING
& DESIGN
ROOFS,
WALLS &
OPENINGS
EXTERNAL
SPACES

6. CLIMATOLOGY
 Day - 27 ˚C – 40˚C, >31- 34 ˚C
 Night fall upto 22 ˚C.
 Dry air, low humidity and minimal
rainfall discourage plant life
 Dry and dusty ground reflects the
strong sunlight producing an
uncomfortable ground glare
.
Source:
http://en.climatedata.org/location/47721/
Climate graph for sub tropical climate

7. 1. BUILDING ORIENTATION
 Sun rises –East, Sun sets- West
 Building – solar gain- South facing
(max. sun’s advantage)
 Building axis- East West- longest
dimension- South
 Resulting shape rectangular
 Reduce heating and cooling costs
by 85%
 Building shape & layout provide
maximum solar radiation
 Big openings in the South &
small openings on the North
AAMAGHAR

8. INFERENCE
 All bedrooms get afternoon sun & mornings
sun at kitchen
 Maximum utilisation of natural sunlight
 Natural/ cross ventilation in dormitory and
all other common rooms

9. 2. PLANNING & DESIGNING
 Open/ free planning
 Narrow streets, small squares
shaded by tall vegetation
 Courtyards- cool air pools,
shade> protection from hot and
dusty wind
 Water bodies, plants> modifies
micro climate

10. LUMBINI MUSEUM
 Large welcoming courtyard
(water pool)
 Centrally placed water bodies
INFERENCE
 Balances external temperature
 High degree -human comfort - outdoor

11.  Located on the midst of
pond
 Room temperature
maintained 25˚C
NATIONAL ASSEMBLY BUILDING, DHAKA
 .Circular geometry -the lowest S/V ratio
 Conduction gains from the building envelope & solar gains
from windows are least, in comparison to other building
geometries
 Most energy efficient in warm & humid climate.

12. INFERENCE
 Balances external temperature
 High degree -human comfort - outdoor

13. 3. ROOFS, WALLS AND OPENINGS
 Day- desirable openings- small- high on
walls
 Night- large enough- ventilation – heat
emitted by walls & roof
 Achieve both – large openings with
shutters
 Windows on the south allows natural light
to bathe the house throughout the day>
minimizes the use of artificial light
 Insulate them in the winter after the sun
goes down, as well as shade them in the
summer

14. PLACEMENT OF OPENINGS
 Location of openings- deflection – indoor air ciculation
 Asymmetrical- unequal pressure – influences air flow
 Adjustable Louvres – influence & control air flow
 Every room with windows on two walls- desirable

15. THE FINCH HOUSE, COLORADO
 Two curved roofs extend into overhangs for
windows
 Overhangs blocks the summer sun & enters
winter Sun
 Max openings on South, min. on North,
West and East
 Windows on the south allows natural light
to bathe the house throughout the day>
minimizes the use of artificial light
 Insulate them in the winter after the sun
goes down, as well as shade them in the
summer

16. 3. EXTERNAL SPACES
 Day to day activities – outdoor
 Pavements, dry ground- heat
quickly ( glare & reflected heat
radiation)
 Night- reradiate heat stored,
 Enclosure provision- shade- keep
out dust and winds
 Trees, plants water – shade- visual
& psychological effect

17. 3. OTHER SYSTEM
Earth Air Tunneling System
 Temperature 4m below Earth’s
surface- constant throughout –year
 Useful in providing bldgs with a/c
 Air –pumped
 Long pipes-buried-one connected
to house- another –outside
 Hot exterior air- drawn out
 Cool air- introduced into the house

18.  Takes in air -70m long tunnel (hume pipe) 0.5m
dia. 4m deep down –Earth’s surface
 4 m depth from the soil surface, temp is 19 ˚C
average throughout year
 Conference room and a class room of the building
are air conditioned with EAT
 Cools down the room in summer , heat in winter
CENTRE FOR ENERGY STUDIES, PULCHOWK
INFERENCE
 High degree -human
comfort - INDOOR

19. What are the efficiency and economics of passive solar design
techniques?
EFFICIENCY
LOW LIFE
CYCLE COST
BETTER
ENVIRONM
ENT
COST
EFFECTIVE
DESIGN
BETTER
HEALTH &
PRODUCTI
VITY

20.  Main strategies - subtropical climate of Nepal are solar passive heating in
winter, reduce direct solar gains though building orientation and shading,
enhancement - air movement and rain protection
 Not all houses are orientated north and south as recommended for the
reduction of direct solar gains through the facade
 Case studied buildings have adequate shading, semi- opened, outdoor spaces
for any kind of activities and are protected from heavy rains by a wide roof
overhang
CONCLUSION

21. YOU CAN FIND MORE INFO AT:
 COURSE MANUAL OF BUILDING SCIENCE AND TECHNOLOGY,
DEPARTMENT OF ARCHITECTURE, BAE, 2013
 O.H. KOENIGSBERGER, MANUAL OF TROPICAL HOUSING AND
BUILDING: CLIMATIC DESIGN
 http://solarthermalmagazine.com/2014/09/02/passive-solar-design-
techniques-simplified-a-6-part-video-lesson/
 http://www.denverpost.com/ci_21285701/solar-home-passive-
design-is-easier-more-effective
 https://www.youtube.com/watch?v=eP6Y5-
rDIY4&feature=youtu.be&list=PL5137A0EC28EA7343, April 17,2010

22. THANK YOU