Experience at the University of East Anglia

‘ ’节能城市 论坛Chongqing - 23rd September 2005

2005 年 9 月 23 日

Low Energy Buildings and Low Carbon Strategies

Keith Tovey ( 杜伟贤 ) M.A., PhD, CEng, MICEHSBC Director of Low Carbon Innovation: and Charlotte Turner: School of Environmental SciencesCRed

• Construction of Low Energy Buildings

• Careful Monitoring of performance and adaptation where relevant

• Fuel efficient and alternative methods to provide energy

• Promoting awareness among occupants

• Tackling issues for reducing energy in existing buildings which are Grade 2 listed and of historic interest.

Low Energy and Low Carbon Strategies at UEA

• Low Energy Student Residencese.g. Constable Terrace

• Low Energy Educational Buildings using “TermoDeck” construction

• Elizabeth Fry Building

• ZICER Building

Low Energy Building Projects at UEA

In all cases Capital Cost was an issue

The Termodeck buildings cost just 5% more yet consume only one quarter of energy

Constable Terrace - 1993

Low Energy Building Projects at UEA

Student Residence: Constable Terrace – 1993

Over 50% of ventilation heat is recovered

U-Values (Wm-2K-1) 

Walls Windows Roof Floor

Actual 0.22 2 0.15 0.18

1990 standard

0.45 5* 0.25 0.45

1994 0.45 3 0.25 0.45

2002 0.35 2.2 0.16 0.25

2005 0.35 2.2 0.16 0.25

Constable Terrace - 1993

The building has a low energy consumption.

It shows a significant saving on carbon dioxide emissions.

The Elizabeth Fry Building

Heater

Diffuser

Supply duct to

hollow core slabs

Two channel regenerative heat exchanger Floor Slabs

Incoming

Air

Exhaust Air

Filter

Exhaust Airfrom rooms

Principle of TermoDeck Operation

• Air is circulated through whole fabric of building • Uses regenerative Heat Exchangers ~ 85% efficient

Quadruple Glazing

Thick Insulation

Air circulates through whole fabric of building

Principle of Operation

Mean Surface Temperature close to Air Temperature

• Heated using a single domestic heating boiler (24 kW)

• No heating needed at temperatures as cool as 6 - 7oC

• 87% of ventilation heat recovered

• In summer building is pre-cooled overnight

Key Facts

Performance of Elizabeth Fry Building

thermal comfort +28%User Satisfaction

noise +26%

lighting +25%

air quality +36%

A Low Energy Building is also a better place to work in

Actual Low Energy

Normal

kg CO2/ m2 / yr

5.8 34 41

Carbon Dioxide Emissions for Space and Water Heating

Performance of Elizabeth Fry BuildingCareful Monitoring and Analysis can reduce energy consumption

• “Termodeck” construction

Zuckerman Institute for Connective Environmental Research

The ZICER Building

• 34 kW Photo Voltaic Array

ZICER Construction

Ducts in floor slab

Performance of ZICER Building

• Initially performance was poor• Performance improved with new Management Strategy

20052004 EFry

ZICER

Temperature of air and fabric in building varies little even on a day in summer (June 21st – 22nd 2005)

Performance of ZICER Building

• Construction of Low Energy Buildings

• Careful Monitoring of performance and adaptation where relevant

• Fuel efficient and alternative methods to provide energy

• Promoting awareness among occupants

• Tackling issues for reducing energy in existing buildings which are Grade 2 listed and of historic interest.

Low Energy and Low Carbon Strategies at UEA

EngineGenerator

36% Electricity

GAS

61% Flue Losses

3% Radiation Losses 36%

efficient

Generation of Electricity with a Gas Engine

EngineGenerator

36% Electricity45% Heat

GAS

Engine heat Exchanger

Exhaust Heat

Exchanger

11% Flue Losses

3% Radiation Losses 81%

efficient

Combined Heat and Power at UEA

Localised generation can make use of waste heat.

Reduces conversion losses significantly

1997/98 electricity gas oil Total

MWh 19895 35148 33

Emission factor kg/kWh 0.46 0.186 0.277

Carbon dioxide Tonnes 9152 6538 9 15699

Electricity Heat

1999/

2000

Total site

CHP generation

export import boilers CHP oil total

MWh 20437 15630 977 5783 14510 28263 923Emission

factorkg/kWh -0.46 0.46 0.186 0.186 0.277

Carbon dioxide

Tonnes -449 2660 2699 5257 256 10422

Performance of CHP unitsBefore installation

After installation

This represents a 33% saving in carbon dioxide

Load Factor of CHP Plant at UEA

Demand for Heat is low in summer: plant cannot be used effectively

More electricity could be generated in summer

Condenser

Evaporator

Throttle Valve

Heat rejected

Heat extracted for cooling

High TemperatureHigh Pressure

Low TemperatureLow Pressure

Heat from external source

Absorber

Desorber

Heat Exchanger

W ~ 0

Normal Air-conditioning

• Adsorption Heat pump uses Waste Heat from CHP• Will provide most of chilling requirements in summer• Will reduce electricity demand in summer• Will increase electricity generated locally

Compressor

Adsorption Air-Conditioning

Legislation can help and hinder effective use of energy

The method by which electricity is traded in the UK ( The BETTA System) has adversely affected viability of CHP in the UK.

The European Union Emission Trading System has anomalies which hinder effective developments such as Adsorption Chilling.

Building Regulations can hinder the building of most energy efficient buildings

Performance of Photo Voltaic Array

Sometimes electricity is exported

Inverters are only 91% efficient

Most use is for computers

DC power packs are inefficient typically less than 60% efficient

Need an integrated approach

Peak output is 34 kW

• Construction of Low Energy Buildings

• Careful Monitoring of performance and adaptation where relevant

• Fuel efficient and alternative methods to provide energy

• Promoting awareness among occupants

• Tackling issues for reducing energy in existing buildings which are Grade 2 listed and of historic interest.

Low Energy and Low Carbon Strategies at UEA

Raising Awareness

Each person in UK causes the emission of 9 tonnes of CO2 each year.

What do 9 tonnes of CO2 look like?

5 hot air balloons

China: 2.5 tonnes or 1.4 balloons

Comparison of emissions of different countries

Raising Awareness

Raising Awareness

• Computers do NOT switch off when using the soft “SHUT DOWN”. Typically they will waste 60 kg CO2 a year.

• A Toyota Corolla (1400cc): 1 party balloon every 60m.

• 10 gms of carbon dioxide has an equivalent volume of 1 party balloon.

• Standby on electrical appliances 80 kWh a year - 4000 balloons.

• A Mobile Phone charger: > 20 kWh per year ~ 1000 balloons each year.

Target Day

Results of the “Big Switch-Off”

With a concerted effort savings of 25% or more are possibleHow can these be translated into long term savings?

An integrated approach to Energy Efficiency is needed.

• Technical – initial good design

• Effective management – up to 50% can be saved.

• Awareness on the part of the user. Up to 25% can be saved.

Ventilation heating requirements are becoming a dominant issue in low energy buildings

To achieve full potential of low energy buildings effective record keeping, analysis, and management is essential.

Conclusions - 1

Effective design of low energy buildings will cost little more than conventional buildings.

Combined Heat and Power can be effective in reducing carbon emissions when GAS is available.

Tri-generation should always be considered when there are significant summer or year long chilling requirements.

Incorporation of renewable energy systems into buildings is attractive. However an integrated approach to generation and use in needed.

Conclusions - 2

Promoting effective awareness can reduce energy consumption in low energy buildings dramatically. Ways to prevent “back-sliding” must be researched

Some Regional, National, and International legislation is not conducive to promoting the most energy efficient strategies in communities.

Experience at the University of East Anglia

‘ ’节能城市 论坛Chongqing - 23rd September 2005

2005 年 9 月 23 日

Low Energy Buildings and Low Carbon Strategies

Keith Tovey ( 杜伟贤 ) M.A., PhD, CEng, MICEHSBC Director of Low Carbon Innovation: and Charlotte Turner: School of Environmental SciencesCRed