Sustainable Buildings for ChinaSustainable Buildings for China

Professors Leon GlicksmanProfessors Leon Glicksman11, Yi Jiang, Yi Jiang22, and , and Qingyan (Yan) ChenQingyan (Yan) Chen11

11Massachusetts Institute of Technology, USAMassachusetts Institute of Technology, USA22Tsinghua University, Beijing, ChinaTsinghua University, Beijing, China

January 7, 1999January 7, 1999

BackgroundBackground

Increased purchasing power due to Increased purchasing power due to economy growtheconomy growth

Demand for improved living standards Demand for improved living standards Winter heatingWinter heating Summer coolingSummer cooling Larger floor area per personLarger floor area per person

Largest producer of air conditionersLargest producer of air conditioners

BackgroundBackground

Winter Heating:Winter Heating: 130 million tons standard coal for urban heating130 million tons standard coal for urban heating 248-260 million tons standard coal for rural 248-260 million tons standard coal for rural

heatingheating 30% of Chinese total energy consumption30% of Chinese total energy consumption Heating region is expanded to Shanghai and Heating region is expanded to Shanghai and

Wuhan (below Yangtze River)Wuhan (below Yangtze River)

BackgroundBackground

Summer Cooling:Summer Cooling: 35% of residential buildings in Beijing35% of residential buildings in Beijing 65% of residential buildings in Shanghai65% of residential buildings in Shanghai 50% of residential buildings in Guangzhou50% of residential buildings in Guangzhou 20%-25% annual increase in sales20%-25% annual increase in sales

ProblemsProblems

High demand for electricity in summerHigh demand for electricity in summerHeat and noise pollution in micro-climateHeat and noise pollution in micro-climateEffect on the environmentEffect on the environment

Future growth (American level?)Future growth (American level?)

U.S. BuildingsU.S. Buildings

1/3 of total energy1/3 of total energy1/2 of electricity1/2 of electricity90% of time spent indoors90% of time spent indoorsMajor health problems: indoor climateMajor health problems: indoor climate

Basic Deficiencies Basic Deficiencies

Very poor windows, single glazed, poorly fittedVery poor windows, single glazed, poorly fitted Little or no insulationLittle or no insulation Absence of summer shadingAbsence of summer shading Poor maintenancePoor maintenance Rapid deteriorationRapid deterioration

Current Chinese Housing PolicyCurrent Chinese Housing Policy

Will turn to market system in 1999Will turn to market system in 1999 Will encourage the housing industry to Will encourage the housing industry to

absorb public savings absorb public savings Will maintain economic growthWill maintain economic growth

Consequences:Consequences: High speed growth in housing industryHigh speed growth in housing industry Demand for high quality housingDemand for high quality housing

Current Proposed Strategies for Energy

Conservation in Chinese Housing Current Proposed Strategies for Energy

Conservation in Chinese Housing Insulation of building fabricsInsulation of building fabrics Improvement of windows to reduce Improvement of windows to reduce

infiltrationinfiltration Improvement of district heating systems Improvement of district heating systems Metering system for heatingMetering system for heating Improvement of lighting systemsImprovement of lighting systems

Problems Remaining in Chinese Housing

Problems Remaining in Chinese Housing

Little consideration for summer coolingLittle consideration for summer cooling Little consideration of natural ventilationLittle consideration of natural ventilation Little consideration of building formsLittle consideration of building forms Little consideration of indoor air qualityLittle consideration of indoor air quality No alternative for room air-conditionersNo alternative for room air-conditioners

An Example of Current Design:A 30 cm (12 inch) concrete wall

Identify and Develop Solutions

for Urban Buildings in China Identify and Develop Solutions

for Urban Buildings in China Energy efficientEnergy efficient Simple and genericSimple and generic Appropriate for local areaAppropriate for local area Cost effectiveCost effective Acceptable by local peopleAcceptable by local people Use of local material and laborUse of local material and labor

Environmental Impacts of 1m2 Brick Wallover 40 years, for Beijing Climate

coal fired district heating

embodied in wall structure and insulation

% o

f ze

ro i

ns

ula

tio

n c

as

e

37cm 37cm 37cm5cm 10cm

MJEnergy

CO2eq.Global

Warming

SO2eq.AcidRain

0102030405060708090

100

MJEnergy

CO2eq.Global

Warming

SO2eq.AcidRain

no insulation

Energy

GlobalWarming

MJEnergy

CO2eq.Global

Warming

SO2eq.AcidRain

0102030405060708090

100

MJEnergy

CO2eq.Global

Warming

SO2eq.AcidRain

5cm of insulation

MJEnergy

CO2eq.Global

Warming

SO2eq.AcidRain

0102030405060708090

100

MJEnergy

CO2eq.Global

Warming

SO2eq.AcidRain

10cm of insulation

Acid Rain

Energy

Energy

GlobalWarming

GlobalWarming

Acid Rain

Acid Rain

[kg CO2 equiv.]

[MJ]

[kg SO2 equiv.]

10355

28823

7068

2812

1017695 3979

18093

6123

Building Insulation and Heat Pump (1m2 of Block Wall, for Beijing Climate)

no insu

latio

n

10cm

insu

latio

n

0 36 37

106 20 11

0

50

100

150

0

50

100

150

Generation Capacity

Savings 69 56 62

Investment Costs for Power Generation

US$

20

13 7

US$

Global Warming from Heatingkg CO2 equiv. over 40 years

01,0002,0003,0004,0005,000

no insu

latio

n

5cm

insu

latio

n

10cm

insu

latio

n

Heating Costs, heat-pump COP 3, electricity from coal, total of 40 years, discount-rate 7%

Initial Investment in Insulation

Net Savings 25

5cm

insu

latio

n

Provide healthy and comfortable living space with little or no energy consumption in summer

Provide healthy and comfortable living space with little or no energy consumption in summer

Key Point:

The Team The Team

Technology Development, Design, Evaluation, and TrainingTechnology Development, Design, Evaluation, and Training MIT, USAMIT, USA Tsinghua University, ChinaTsinghua University, China Tongji University, ChinaTongji University, China

Construction (Demonstration projects)Construction (Demonstration projects) Beijing: Vanke Property Development Co.Beijing: Vanke Property Development Co.

万科房地产发展公司 万科房地产发展公司 5-floor luxury housing5-floor luxury housing 12-floor affordable housing12-floor affordable housing 30-32 floor middle-class housing30-32 floor middle-class housing

Shanghai (To be identified)Shanghai (To be identified)

Technologies to Improve Building Design

Technologies to Improve Building Design

VentilationVentilation Natural ventilationNatural ventilation Night cooling and thermal storage wallsNight cooling and thermal storage walls Advanced mechanical ventilation systemsAdvanced mechanical ventilation systems

Shading devices and passive solarShading devices and passive solar Heat pumpsHeat pumps Desiccants dehumidificationDesiccants dehumidification

Possible Solutions Possible Solutions Natural ventilation to replace air conditioningNatural ventilation to replace air conditioning Thermal mass and night coolingThermal mass and night cooling Ground coupled heating and cooling systemsGround coupled heating and cooling systems Centralized energy systemsCentralized energy systems Improved windowsImproved windows Application of vernacular technologiesApplication of vernacular technologies Overall building designOverall building design Incentives for adoption of energy efficient designsIncentives for adoption of energy efficient designs

Improvement of WindowsImprovement of Windows

Double glazingDouble glazing New types of frame New types of frame Better insulationBetter insulation Lower infiltration with acceptable indoor Lower infiltration with acceptable indoor

air qualityair quality

Improvement of District HeatingImprovement of District Heating

High efficiency by CHPHigh efficiency by CHP Large scale network with multi-heat sourcesLarge scale network with multi-heat sources High reliability by loop network combined with High reliability by loop network combined with

computer added fault detection systemcomputer added fault detection system Special control policy to make buildings being Special control policy to make buildings being

heated equally heated equally Energy reduced from 50 W/mEnergy reduced from 50 W/m22K to 30 W/mK to 30 W/m22KK

Metering System for HeatingMetering System for Heating

Largest potential saving in heating Largest potential saving in heating 25% - 40% savings in test buildings25% - 40% savings in test buildings Difficulties:Difficulties:

Strongly related to the housing reform Strongly related to the housing reform Indoor system has to be changedIndoor system has to be changed High cost for installationHigh cost for installation

Energy SavingsEnergy Savings

30% 30% of energy saving by improving the of energy saving by improving the fabricfabric

Additional 20% of energy saving by better Additional 20% of energy saving by better control of the district heating systemcontrol of the district heating system

Additional 20% of energy saving by use of Additional 20% of energy saving by use of metering systems for heatingmetering systems for heating

A Study in Beijing:Results from 83 apartments

A Study in Beijing:Results from 83 apartments

Measurements of the room air Measurements of the room air temperatures over a two-month periodtemperatures over a two-month period Shading by deviceShading by device Shading by vegetationShading by vegetation VentilationVentilation Building layoutBuilding layout

Low and Middle Rise HousingLow and Middle Rise Housing

High Rise HousingHigh Rise Housing

Thermal EnvironmentThermal Environment

kitchen Bedroo

m

Bedroom

Bedroom

WCLiving room

Balcony

NorthEntrance

DoorWindow

RHLog

Shading ComparisonShading ComparisonShading ComparisonShading Comparison

Shading ComparisonShading ComparisonShading ComparisonShading Comparison

No shadingShaded

26. 0

26. 5

27. 0

27. 5

28. 0

28. 5

29. 0

29. 5

30. 0

30. 5

31. 0

31. 5

Ti me

Tem

pera

ture

(deg

ree

C)

Wi th Sunshi neWi thout Sunchi ne

Vegetation ComparisonVegetation ComparisonVegetation ComparisonVegetation Comparison

Vegetation ComparisonVegetation ComparisonVegetation ComparisonVegetation Comparison

Little vegetationLots of vegetation

24. 0

24. 5

25. 0

25. 5

26. 0

26. 5

27. 0

27. 5

28. 0

28. 5

29. 0

29. 5

30. 0

30. 5

31. 0

T i me

Tem

pera

ture

(deg

ree

C)

Low Vi rescence

Hi gh Vi rescence

Use of Vegetation Use of Vegetation

Reduction on solar radiation Reduction on solar radiation Direct radiation on the building surfacesDirect radiation on the building surfaces Reflection from the groundReflection from the ground

Improvement in building micro climateImprovement in building micro climate Reduction of outdoor air temperatureReduction of outdoor air temperature Change of air movementChange of air movement Improvement on air qualityImprovement on air quality Decrease of noiseDecrease of noise

Comparison between Mechanical and Natural Ventilation

Comparison between Mechanical and Natural Ventilation

Living room

Balcony

Bed room

Bed room

WC Kitchen

Entrance

Other’s roomOther’s room

NorthNorth

Comparison between Mechanical and Natural Ventilation

Comparison between Mechanical and Natural Ventilation

NaturalMechanical

26. 0

26. 5

27. 0

27. 5

28. 0

28. 5

29. 0

29. 5

30. 0

30. 5

31. 0

31. 5

32. 0

Ti me

Tem

pera

ture

(deg

ree

C)

Nature Venti l at i onMechani cal Venti l at i on

Different Natural Ventilation DesignsDifferent Natural

Ventilation Designs

Bad designGood design

25. 0

25. 5

26. 0

26. 5

27. 0

27. 5

28. 0

28. 5

29. 0

29. 5

30. 0

30. 5

31. 0

31. 5

32. 0

32. 5

33. 0

Ti me

Tem

pera

ture

(deg

ree

C)

Bad Vent i l at i on

Good Vent i l at i on

Comparison of Different Apartment Layouts

Comparison of Different Apartment Layouts

Different apartments in the same flat can Different apartments in the same flat can result in 300% difference in cooling loadresult in 300% difference in cooling load

Careful arrangement of the kitchen, Careful arrangement of the kitchen, bathroom and corridor can greatly bathroom and corridor can greatly reduce cooling demandreduce cooling demand

Use of Air Conditioners:A survey over 300 apartments

Use of Air Conditioners:A survey over 300 apartments

Results from the SurveyResults from the Survey

Age < 19 20-40 40-60 > 60Sex M F M F M F M FLike AC (%) 42.86 52.00 48.57 35.59 37.50 31.25 22.22 29.63Neutral (%) 42.86 32.00 42.86 52.54 37.50 37.04 37.04 33.33Dislike AC (%) 14.29 16.00 8.57 11.86 25.00 25.93 40.74 37.04

Why like AC:1. Cool 40%2. Modern Technology 34%3. Climate control 23%4. Others 3%

Why dislike AC:1. Separated with the nature 47%2. Draft and noise 26%3. Energy and first costs 23%4. Others 4%

Preliminary Understandings:The survey results

Preliminary Understandings:The survey results

Comfort does not mean a low air Comfort does not mean a low air temperature in summertemperature in summer

Air-conditioning may not be necessary in Air-conditioning may not be necessary in Beijing with acceptable comfortBeijing with acceptable comfort

The use of air-conditioning can be The use of air-conditioning can be reduced greatly in southern Chinareduced greatly in southern China

Be comfortableBe comfortable Be healthyBe healthy Be energy efficientBe energy efficient Be economicBe economic Be flexible and integral to the cultureBe flexible and integral to the culture

Sustainable Housing for ChinaSustainable Housing for China

Current Building

Building Energy Distribution (Winter)

Heating Losses in Beijing Winter

Walls32%

Roof7%

Infiltration Load34%

Window Conduction

27%

Heating Energy Consumption Comparation Beijing Winter

0

10

20

30

40

50

60

70

80(KWH/m^2)

Brick Wall 37cm Brick U=1.51W/m 2̂K

Sigle Glazing WindowU=6.31W/m 2̂K

5cm Performed MineralBoard,U=0.54W/m 2̂K

Insulation Wall+Double Glazing Window U=2.79W/m 2̂K

Insulation Wall

Sigle Glazing WindowU=6.31W/m 2̂K

Window and Wall Insulation (Winter)

Cooling Load of Building in Beijing Summer

Wall9% Roof

4%

Latent Load of Infiltration.

22%

Window Conduction.

1%

Sensible Load of Infiltration

1%

Latent Load of Occupant

13%

Sensible Load of Internal Heat

23%

Window Solar Radiation.

27%

Building Energy Distribution (Summer)

Cooling Energy Consumption Comparation Beijing Summer

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00(KWH/m^2)

Brick Wall 37cm Brick U=1.51W/m 2̂K

Sigle Glazing WindowU=6.31W/m 2̂K

5cm Performed MineralBoard,U=0.54W/m 2̂K

Insulation Wall+Double Glazing Window U=2.79W/m 2̂K

Insulation Wall

Sigle Glazing WindowU=6.31W/m 2̂K

Window and Wall Insulation (Summer)

Natural Ventilation:Building design

Natural Ventilation:Building design

Natural Ventilation DesignNatural Ventilation Design

Natural Ventilation

Natural ventilation: Airflow at MIT campus

Natural ventilation: Airflow at MIT campus

Comfort Hours with Natural Ventilation

Comfort Hours Beijing

744 672 744

637

418

135

27 71

451

699720 744

6062

0 0 0

83

244

245

66

186

214

45

0 0

1083

0 0 0 0

51

142

148

213

30

0 0 0

584

0 0 0 031

197

503

273

240 0 0

1028

ho

urs

pe

r m

on

th (

ye

ar)

Hot and/or Humid

Comfort 2m/s

Comfort

Below comfort

Comfort Zones for Developed Countries (B. Givoni)

Comfort Hours with Natural Ventilation

Comfort Hours Beijing

744 672 744

599

333

835 23

331

625

720 744

5623

0 0 0

121

345

375

152

331

319

107

0 0

1750

0 0 0 0

33

131

257

235

210 0 0

677

0 0 0 015

110

308

111

10 0 0 0

554

ho

urs

pe

r m

on

th (

ye

ar)

Hot and/or Humid

Comfort 2m/s

Comfort

Below comfort

Comfort Zones for Developing Countries (B. Givoni)

Night Time

Walls Release HeatMaximum Ventilation

Day Time

Walls Absorb Heat GainsMinimum Ventilation

Natural Ventilation:Night cooling

Natural Ventilation:Night cooling

1 6

1 8

2 0

2 2

2 4

2 6

2 8

3 0

3 2

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4

E x t e r n a l T e m p e r a t u r e ( ° C )

I n t e r n a l T e m p e r a t u r e ( ° C )

W a l l T e m p e r a t u r e ( ° C )

h o u r

Shading Devices (Summer)

Cooling Load Due to South Windows Shanghai Summer

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

Full Shading for SouthWindows

No Shading for SouthWindows

Different Design

(KWH/m^2)

September

Augest

July

June

Dense Rock

k W/mK 3.46 kg/m3 3204Cp J/kg 836 m2/s 1.3E-06

average heat extraction /year: 50MJ/m2

Ground Temperature Changes with Heat Pump

0.0

50.0

100.0

150.0

200.0

250.0

300.0

0 2 4 6 8 10 12

Temperature [C]

Dep

th [m

]

10

50

100

year

Room

Small Chiller

Cooling coil

Hea

t ex

chan

ger

Desiccant adsorption

sun

Desiccant regeneration

Outdoor

Cooling tower

air

Operation of Desiccant SystemDesiccant dehumidification + Cooling Tower

Outdoor air

Desiccant System

Desiccant Cooling

Operation of Desiccant System in Beijing with ASHRAE Comfort Zone

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Months

Ra

tio

of

ea

ch

op

era

tio

n

Solar Heating Desiccant + Cooling Tower Additional Cooling

Desiccant Cooling

Operation of Desiccant System in Shanghai

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Months

Ra

tio

of

ea

ch

op

era

tio

n

Solar Heating Desiccant + Cooling Tower Additional Cooling

SupportSupport

MITMIT

Kann-Rasmussen Foundation ($200,000/year)

Tsinghua UniversityTsinghua University

National Natural Science Foundation National Natural Science Foundation (RMB 1,000,000)(RMB 1,000,000)

ObjectiveObjective

Identify energy efficient and sustainable designs Identify energy efficient and sustainable designs and technologiesand technologies

Use economic and appropriate solutions for Use economic and appropriate solutions for ChinaChina

Build demonstration buildingsBuild demonstration buildings Publicize results to public, designers, officials, Publicize results to public, designers, officials,

and industryand industry Prepare design guidelinesPrepare design guidelines Train designers and plannersTrain designers and planners

Milestones Milestones

Background data, energy use of residential Background data, energy use of residential buildingsbuildings

First order evaluation of promising systems for First order evaluation of promising systems for energy efficiencyenergy efficiency

In-depth study of several most promisingIn-depth study of several most promising Prototype design studies, model, evaluationsPrototype design studies, model, evaluations Full-scale demonstrationsFull-scale demonstrations Development of design guidelinesDevelopment of design guidelines