rapid planning€¦ · rapid planning – green building research assistants in kigali leonard...

Jakob Schweiger, Joshua Ishimwe

LOW-ENERGY AND COMFORTABLE

BUILDINGS IN RWANDA

JOSHUA ISHIMWE, JAKOB SCHWEIGER

RAPID PLANNING

RAPID PLANNING - LOCATIONS

Project goal: Finding planning solutions for rapidly growing cities

RAPID PLANNING – GREEN BUILDING

RESEARCH ASSISTANTS IN KIGALI

Leonard Byiringiro

Ba. Of Eng. Buildig and construction engineering

Joshua Ishingwe

Ba. Of Eng. Buildig and construction engineering

Remy Ruberambuga

Ba. of Eng. Building and construction engineering

Michel Schmitt

Ba. of Eng. Green Buildings

Jakob Schweiger

Ma. of Sci. Energyefficient and sustainable buildings

OVERVIEW

• Definition of climate

• Climate Engineering

• Climate in Kigali

• Indoor climate comfort

• Residential building 2-storey

• School house

• Office building

• Outlook

Goal: Create curiosity about climat engineering in Kigali

DEFINITION OF CLIMATE

Humidity

Climate - Weather

long term - short term

Temperature Athmospheric pressure

Wind

Percipitation

Athmospheric particle count

CLASSIFICATION OF CLIMATE BY SIZE

Source: Printerest.com

CATHEGORISATION OF THE MACROCLIMATE

Cool

Temperate

Desert

Subtropics

Tropics

Source: Hausladen, Liedl, de Saldanha: Building to Suit the Climate. A Handbook. Basel, 2012

CLIMATE ENGINEERING - COOL

Polar climate: Igloo

Source: Sol Power .The Evolution of Solar Architecture by Sophia Behling, Stefan Behling, Norman Foster

CLIMATE ENGINEERING - TEMPERATE

Mountain climate: Farmhouse in Switzerland


CLIMATE ENGINEERING - TEMPERATE

Mediterean climate:

Thermal mass and shading in Italy


CLIMATE ENGINEERING - DESERT

Desert climate:

Thermal mass and wind catcher

in Pakistan

Source: Rudofsky, Bernard: architecture without architects. Doubleday & Company. New York. 1987.

CLIMATE ENGINEERING - SUBTROPIC

Subtropical climate:

Chinese „Roundhouse“ with roof

overhang for shading and light

construction


CLIMATE ENGINEERING - TROPIC

Tropical climate:

King‘s hut in Rwanda

• Shelter from rain and

insulation against sun

• No windows to prevent solar

radiation and overheating Source: Printerest.com

CLIMATE ENGINEERING

But!

The building usage and their architecture changed

“Vernacular architecture does not go through fashion cycles.

It is nearly immutable, indeed, unimprovable, since it serves its purpose to

perfection.“

Offices Schools More storey

buildings

Shopping

centers Hospitals Hotels

MORE SUSTAINABLITY WITH CLIMATE

ENGINEERING

people

planet profit

Energy-efficiency

Less air pollution Comfortable housings

Energy-efficiency

Resource efficiency

CLIMATE ENGINEERING TODAY

Climate engineering software based on:

- Mathemathical models

- Physical correlations (eg. Thermo-dynamics)

- Research results on comfort of humans (ASHREA 55,...)

Source: IDA ICE

MESOCLIMATE IN KIGALI

15

17

19

21

23

25

Ou

tsid

e t

em

pera

ture

in

°C

Temperature Temperature night Temperature day

Source: Meteonorm 2017


50

55

60

65

70

75

80

85

90

95

100

rel. H

um

idit

y i

n %

rel. Humidity rel. Humidity night rel. Humidity daySource: Meteonorm 2017


150

170

190

210

230

250

270

Rad

iati

on

in

W/m

²

diffus radiation day direct radiation daySource: Meteonorm 2017


10

12

14

16

18

20

22

24

26

28

30

0

100

200

300

400

500

600

700

800

900

1000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Tem

pera

ture

in

°C

Rad

iati

on

in

W/m

²

Typical day in rainy season

direct radiation diffuse radiation TemperatureSource: Meteonorm 2017


10

12

14

16

18

20

22

24

26

28

30

0

100

200

300

400

500

600

700

800

900

1000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Tem

pera

ture

in

°C

Rad

iati

on

in

W/m

²

Typical day in dry season

direct radiation diffuse radiation TemperatureSource: Meteonorm 2017


0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0.016

0.018

0.020

0 5 10 15 20 25 30 35 40

Ab

so

lute

hu

mid

ity [

kg

H2O

/ kg

air

]

Dry bulb temperature [°C] Source: Meteonorm 2017

INDOOR COMFORT

New requirements to architecture and...

PPD in % (Predicted percentage of dissatisfied) Source: Hausladen, Saldanha, Liedl, Sager: ClimaDesign. München, 2004. p.33.

2-STOREY RESIDENTIAL – BASIC MODEL

Rooms:

Ground floor

• Storage

• Toilet

• Living and cooking

First floor

• Child 1

• Child 2

• Parents

• Bathroom

• Floor

Building part Material U-value

Ground floor slab Concrete 2.4 W / m²K

Exterior wall CSEB 2.3 W / m²K

Interior wall CSEB 2.3 W / m²K

Floor Concrete 2.4 W / m²K

Windows Single glazing 5.9 W / m²K

Roof Corrugated metal 5.9 W / m²K

Usage:

• Residential 4-5 pers.

• Cooking inside – lunch + dinner

• Electrical light

• Ventilation with window

openings and ventilation bricks

2-STOREY RESIDENTIAL – BASIC MODEL

0

500

1000

1500

2000

2500

3000

10

20

30

40

Un

met

ho

urs

in

h

Op

era

tive

tem

pera

ture

in

°C

Min op temp, DegC

Max op temp, DegC

Unmet hours (cooling)

Unmet hours (heating)

8% 7% 7%

17% 17% 17% 20%

17%

0%5%10%15%20%25%30%

0

20

40

60

80

100

Ø P

PD

in

%

Rel. h

um

idit

y i

n %

Min rel hum, %

Max rel hum, %

Ø PPD in %/Pers

Temperature, Humidity, PPD, heating and cooling demand

0

500

1000

1500

2000

2500

3000

10

20

30

40

Un

met

ho

urs

in

h

Op

era

tive

tem

pera

ture

in

°C

Min op temp, DegC

Max op temp, DegC

Unmet hours (cooling)

Unmet hours (heating)

7% 7% 7% 9% 8%

11% 9% 8% 0%5%10%15%20%25%30%

0

20

40

60

80

100

Ø P

PD

in

%

Rel. h

um

idit

y i

n %

Min rel hum, %

Max rel hum, %

Ø PPD in %/Pers

2-STOREY RESIDENTIAL – ROOF INSUALTION

Temperature, Humidity, PPD, heating and cooling demand

+ 6 cm Strawtec panel under the corrugated metal sheet

1-STOREY PRIMARY SCHOOL

Rooms:

Ground floor

• Class room 1

• Class room 2

• Class room 3







Roof Corrugated metal 5.9 W / m²K

Usage:

• School 1 teacher 35-40

• Start at 7am

• End at 5pm

• 1 hour lunchbreak

• No electrical light

• Ventilation through ventilation

bricks and windows

1-STOREY PRIMARY SCHOOL – BASIC

MODEL

15

17

19

21

23

25

27

29

31

33

35

0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14 16 18 20 22 24O

pera

tive t

em

pera

ture

in

°C

PP

D in

%

Hour in h

PPD, PredictedPercentage ofDissatisfied

Operativetemperature


1-STOREY PRIMARY SCHOOL – ROOF

INSULATION

15

17

19

21

23

25

27

29

31

33

35

0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14 16 18 20 22 24O

pera

tive t

em

pera

ture

in

°C

PP

D in

%

Hour in h




+ 6 cm straw board under the corrugated metal sheet

1-STOREY PRIMARY SCHOOL – ROOF

INSULATION DOUBLE

15

17

19

21

23

25

27

29

31

33

35

0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14 16 18 20 22 24O

pera

tive t

em

pera

ture

in

°C

PP

D in

%

Hour in h





1-STOREY PRIMARY SCHOOL – ROOF INSULATION

DOUBLE – REMOVED VENT. BRICKS

15

17

19

21

23

25

27

29

31

33

35

0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14 16 18 20 22 24O

pera

tive t

em

pera

ture

in

°C

PP

D in

%

Hour in h





+ removing of the ventilation bricks

3-STOREY OFFICE BUILDING - BASIC

Rooms:

• Offices 6-8 people

• Floor

• Staircase







Roof Corrugated metal

+Straw panel

1.2 W / m²K

Usage:

• Offices 6-8 occupants

• Start at 7am

• End at 5pm

• Ideal cooling, heating and

ventilation


• 1 computer per occupant

Floors:

• Ground: 90% window/wall

• 1st: 40% window/wall

• 2nd: 20% window/wall

Building

• East-West orientation

• Office - building

• Location in Kigali

3-STOREY OFFICE BUILDING - BASIC

0

20

40

60

80

100

120

140

Purchased energy

Heating

Equipment,tenant

HVAC aux

Cooling

Energy-demand:

• 126 kWh/m²*a in total

• With 0.22 $/kWh

27.7 $/m²*a energy demand

For the whole building:

33,600$/a

+ fixed costs

+ maintainance & service

CLIMATE ENGINEERING IN TROPICAL ZONES

Window wall ratio 40%

Solar control glacing g=0.4

Light blades turnable

Overhang with photovoltaik

Solarcontrol glacing g=0.2

Low absorbtion

Source: Hausladen, Liedl, de Saldanha: Building to Suit the Climate. A Handbook. Basel, 2012

3-STOREY OFFICE BUILDING - OPTIMATED

Usage:

• Offices 6-8 occupants

• Start at 7am

• End at 5pm

• Ideal cooling, heating and

ventilation


• 1 computer per occupant

Rooms:

• Offices 6-8 people

• Floor

• Staircase

Floors:

• Ground: 90% window/wall

• 1st: 40% window/wall

• 2nd: 20% window/wall







Roof Corrugated metal

+Straw panel

1.2 W / m²K

3-STOREY OFFICE BUILDING - OPTIMATED

Energy-demand:

• 129 kWh/m²*a in total

• With 0.22 $/kWh

28.4 $/m²*a energy demand

For the whole building:

34,500$/a

+ fixed costs

+ maintainance & service

0

20

40

60

80

100

120

140

Purchased energy

Heating

Equipment,tenant

HVAC aux

Cooling

CURRENT STAGE OF CLIMATE ENGINEERING

IN RWANDA

Climate data in Kigali:

• Min. one weather station per district in Rwnada METEO Rwanda

• No mesoclimate date for hill-side, wet-land etc.

• Global warming can change climate for the next years

Comfort of Rwandese inhabitants

• ASHREA claims, that their researches of thermal comfort are international applicable

• Research in Madagascar show that 28°C indoor temperature are comfortable

Climate Engineering

• Many international software products for thermal comfort

• Lack of knowledge for software use in Rwanda

• Some international publications about climate engineering in tropical zones may not be applicable to Rwandan housings due to high location and therefore special climate

OUTLOOK – HEAT ISLAND EFFECT

Source: Photo Foster + P.

OUTLOOK – CLIMAT ENGINEERING IN THE

CITY

Source: LAVA

OUTLOOK – CLIMATE ENGINEERING IN THE

CITY

Source: LAVA

CONTACTS

Green building team in Kigali

Jakob Schweiger [email protected] Remy Ruberambuga [email protected] Michel Schmitt [email protected] Leonard Byiringiro [email protected] Joshua Ishimwe [email protected] Rapid Planning – Kigali coordinator

Sylvie Kayitesi [email protected] Rapid Planning – Kigali focal point coordinator

Bernd Franke [email protected]

TO READ

Energy and Resource Efficiency Building Code for Tropical Countries: Guidelines (Final Draft) • Link: http://eebea.org/?q=doc-2.3.4 • Special guidelines for buildings in tropical highlands

The Rapid Planning project • Link: http://rapid-planning.net/ • Research in the sectors food, waste, waste water, fresh water and energy • Comming: Scenarios in the differnet sectors and synergies

Software for climate engineering • IDA ICE by equa https://www.equa.se/de/ from Sweden • Trnsys by Thermal Energy System Specialists http://www.trnsys.com/ from

the US

http://eebea.org/?q=doc-2.3.4




http://rapid-planning.net/




https://www.equa.se/de/

https://www.equa.se/de/

http://www.trnsys.com/

http://www.trnsys.com/

CONTACTS

Murakoze!

Danke!

Merci!

Thank you!

RAPID PLANNING

Murakoze! Thank you!

Merci!

Danke!

rapid planning€¦ · rapid planning – green building research assistants in kigali leonard...

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