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Solar Thermal System in Buildings

- Solar thermal technology -

Mitsuhiro Udagawa ProfessorDepartment of ArchitectureKogakuin UniversityTokyo, Japan

udagawa@cc.kogakuin.ac.jp

Asian Workshop on Energy and Environmental Technologies, February 13, 2008Bureau of Environment, Tokyo Metropolitan Government

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Solar Thermal Technology in Buildings

SystemsHot Water HeatingSpace HeatingCooling

ComponentsSolar CollectorSolar Hot Water Heater

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Development of Solar cooling(1974)

Total Floor Area 127m2

Collector area: 102m2 Heat storage tank: 5m3

Absorption chiller: 7kW, 75 – 90 degrees C(Yazaki, Solar House One)

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Solar Collector- Flat plate collector -

図３．太陽集熱器の構造

集熱板

透過体

受熱箱断熱材

透明断熱材

熱媒入口

固定金具

熱媒出口

Super Blue Panel (Yazaki Corp.)

Transparent insulation (plastic film)

Glass cover

Insulation

Absorber plate

Casefluid inlet

fluid outlet

Mounting hook

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Solar Collector- Evacuated Tubular Collector -

Evacuated Tubular Collectors on the top of the Tokyo International Forum

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Solar Water Heater

Cumulative installation: 5,000,0000 units

Collector area: 3m2

Installation:250,000-300,000Yen

Collector 4-6m2

Tank 200-300L

City water

Hot water

Auxiliary Boiler

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Solar Hot Water Heating system

•Solar collector and Heat Storage tank

•Pump with heat collection control system

Heat storage tank

Collector 6-8m2

City water

Hot water

Auxiliary BoilerTank 300-370L

Pump

Differencialthermostat

Freeze free liquid

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Solar space heating system 1985

Collector 12m2 Solar floor heating

USH(Udagawa1985)

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T

CT

T

TW

T3

T2

TH

C

CB

City waterSolar storage tank

300 liters

200 V8.4 kW

Thermometer

Valve switch

Pump controller

Solar collector1.19 m2 x 6 units : total 11.5 m2

Titled angle : 60 degrees

Surge tank (72 liters)

Pump50W x 2 L (17 m2) D (9 m2) S (9 m2)

Thermometer

DHW supply

Solar floor heating300 mm thick concrete slab

Switch valve

ElectricDHWheater460 liters

: Calory meterC

Room air conditioner

USHSolar floor and DHW heating for single family house

Solar contribution(1985 – 2004)

DHW: 50%Space heating: 50%

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• Active + Passive Heating• Solar collector+floor heating and Tromb wall

Solar House (Chiryu, Aichi Pref.)

(Photo and drawing by Okamoto, Chiryu Heater)

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OM Solar SystemIntegrated solar house with air collector

Solar collector (Glass cover)

Solar collector (w/o Glass cover)

Handling Box

Concrete slab hot air

outdoor air

DHW tank

hot airfloor heating

(OM solar)

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Solar PV and Thermal SystemsSolar PV House appeared (1990s)

PV system with well insulated house and Solar DHW heating

(Housing area near Akita City, Misawa Home Co.)

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Hybrid Solar House

4 collectors + 24 PV modules (Yazaki Co.)

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Solar Hot Water Heating System with PV pump

(Yazaki Corp.)

Collector 4m2

PV module

Water tank 200L

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Solar systems for apartment housesNoborito solar house, 1978

– Feasibility study by Japan Housing Corporation -

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Solar apartment houses

Chiryu City Kanazawa City

- Examples of solar DHW system for multi-family house in 1980s

- Individual system using balcony mounted solar collector

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17Solar apartment house(Chino City, Nagano Pref.)

(Chiryu heater)

Solar space and hot water heating for a lowrise apartment house(Chiryu City)

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Large Solar Building- Senior Center in Shiobara -

Health care center for elderly peopleSolar heating and cooling system (Yazaki, 2003)

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- Senior Center in Shiobara -

Solar heating and cooling systemtotal floor area 610m2

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室内（FC）へ床暖房へ

Heat storage tan

温水焚吸収式冷温水機70.3kw

(20RT）

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温水プール60t

Tank 7.2tonSwimming pool60ton

FC unitsFloor heating

Absorption chiller70.3kW

Cooling tower

HEX

Tank for hot spring water, 30ton

Collector 258m2

Aborption chiller

(Yazaki)

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Fujieda SunppuHospitalSolar DHW heating system, 2000

(Yazaki)

Hot water tank 1.65m3 x 2units

Boiler 140kW x 2units

Hot water supply

Collector 96m2

Tank 5m3

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OM Solar Systems- integrated solar house design -

Office building of OM Solar “Egg of Earth”, Hamamatsu, 2004

(OM Solar)

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Solar Desiccant Dehumidification and Cooling System(Harunocho Regional Center, Hamamatsu)

Figure 2 Solar desiccant cooling operation in summer

Aseismatic pit

Primary desiccant

Secondary desiccant

MD

FanAHU A

AHU B

Damper

Cooling coil

Regeneration process

Dehumidification cooling process

Free access floor

(OM solar)

Floor pit

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Expected Solar Energy Use in Japan

19.10(3%)

10.54(1.8%)

New energy total(Gross energy）

1.340.28Wind power

1.180.21Solar PV

0.9(4.39)

0.59Solar thermal

FY2010FY2003

(Primary Energy, 106 kL Oil/year)

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Expected Collector Area

for 4 years, 2007-2010

stock

x 106 m2Collector Area

0.25

1.3

12.8

7.7

Installed in 2005*

Expected installation until 2010(every year)

Expected until 2010

Existing Area in 2004

*Solar DHW system and Solar Water heater

**Collector Area 1m2 = 0.07kL Equivalent Oil

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Feature of Solar Thermal System

Solar thermal systemHeat load: Hot water heating, space heating and coolingSolar system: Tightly connected with Heat LoadHeat load influenced by weather condition and behavior of the occupants

PV systemElectricity, for all purposeGrid connected system: sell and buy the electric power

Solar thermal system vs. PV system

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Example of Energy Requirement in Buildings in Japan

- Hot water heating and Space heating, Major heat requirements

- Solar heating to reduce hot water heating energy

- Building thermal insulation and solar energy to reduce space heating energy

Energy Use in Residential House

46GJ/family for year

2%

28%

35%

35%

Cooling

Space heating

DHW

Lights+Applinaces

Residential House46 GJ/family for a year

Space Heating

Hot water Heating

Lights and Appliances

Cooling

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Solar Thermal System for Today, Tomorrow

IntegrationIntegration with Heat loads and Building service systemsIntegration with Building thermal system and Architectural design

StandardizationStandardization of Systems and ComponentsStandardization of Design and Evaluation Methods

Cost effectivenessReduce Installation costImprovement of Pay back period

Including Finance, Subsidy