built environment facing climate change€¦ · 3 built environment facing climate change a...

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BUILT ENVIRONMENT FACING CLIMATE CHANGE

A framework for the technical evaluation of

residential buildings’ energy retrofit

Authors: Annamaria Belleri, Chiara Dipasquale, Jennifer Adami

Affiliation: Eurac Research

Session no.: 4J/28.05.2019

Diamond sponsors


A framework for the technical evaluation of

residential buildings’ energy retrofit



Session no.: 4J/28.05.2019

Diamond sponsors

2


A framework for the technical evaluation of residential

buildings’ energy retrofit

Annamaria Belleri, Chiara Dipasquale, Jennifer Adami

1.2%

Building

renovation

rate in EU

75%

of EU

buildings are

not energy

efficient

Buildings are

responsible

for the 40%

of energy

consumption

Source: EU Building Stock Observatory

3





Organizational barriers: lack of awareness on renovation benefits, multi-

property buildings, mistrust of stakeholders

Technical barriers: overwhelming possibilities offered by the market, lack of

documented energy savings

Financial barriers: lack of access to finance, priority given to quick rates

of return, uncertainty related to investment payback period

Barriers to energy retrofit

How to evaluate residential buildings’ energy retrofit?

4









175

350

220

155150 150

70

50

0

50

100

150

200

250

300

350

400

1920-1954 1954-1989 1989-2004 2004-2014

Numero edifici realizzati Fabbisogno energetico(kWH/m2 anno)

Nr of buildings Heating need

Image courtesy of IPES

social housing

tot 13’500 housing

Social housing building stock in South Tyrol

5





ID TypologyHeating Degrees

Construction period Apartment nr

1 Small multifamily house 2894 1976-91 8

2 Big multifamily house 2894 1976-91 24




1

2

3

4

5

Reference buildings

6





PC

Gas boiler

Heat pump

District heating

Radiant floor

Photovoltaic system

KlimaKit retrofit packages

Retrofit package Drivers Intervention type

KlimaKit BASE Deterioration of envelope physical properties

Envelope retrofit

KlimaKit FULL Deterioration of envelope physical properties;Obsolete indoor space distribution;Need of new functionalities.

Envelope retrofitHeat pump installation and new radiant system distribution

KlimaKit FLEXI Deterioration of envelope physical properties;District heating network availability

Envelope retrofitDistrict heating connection

KlimaKit nZEB Deterioration of envelope physical properties;Obsolete indoor space distribution;Need of new functionalities;Zero operation costs

Envelope retrofitHeat pump installation and new radiant system distributionPV installation

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Uwall [W/m²K]

Uroof [W/m²K]

Ufloor [W/m²K]

Uwindow [W/m²K]

Air tightness [n50]

Mech. Vent. with HR

≤ 0.33 ≤ 0.29 ≤ 0.32≤ 2.20

(double glazing)

3 (CasaClima C)

-

≤ 0.22 ≤ 0.19 ≤ 0.23≤ 1.30

(double glazing)

1.5(CasaClima A

e B)-

≤ 0.15 ≤ 0.15 ≤ 0.20≤ 1.00

(triple glazing)

0.6(CasaClima

Gold)

0.6 vol/hHR 70%

Level 1: comply with minimum requirements of

national and local regulation for buildings undergoing

retrofit intervention;

Level 2: comply with minimum requirements of

national and local regulation to access for incentives;

Level 3: have performance that allow to reach the

target of nearly zero energy. In this case mechanical

ventilation is installed to keep acceptable IAQ levels.

Technical requirements for envelope retrofit

8





T5.5

T5.6

System efficiency

Pre-retrofit generation system (gas boiler) 0.8

Condensation gas boiler 0.9

District heating 0.95

Heating and Domestic Hot Water (DHW) system model

PV

DHW storage

Space heating set temperature 20 ±0.5 °C

Supply DHW temperature 45 °C

Supply temperature to radiators 45 °C

Supply temperature to radiant panels 35 °C

Generation system

Distribution devices

Buffer

Cost [€/kWh]

CO2 equivalent

emissions

[kg/kWh_final]

gas 0.08 0.249

electricity 0.2 0.647

district heat 0.07 0.15

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• 3D model

• Available surfaces for PV installation

• Solar radiation (climate conditions, shadings)

• Electricity demand (hourly)

• Tecno-economical inputs (cost variance, PV

degradation)

€

PV modules position

and capacity

Optimization of PV system capacity to minimize NPV

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PV capacity (kWp) 4 3.4 2.6El. loads coverage (%) 30 31 31

PV capacity (kWp) 35 21.3 18El. loads coverage (%) 27 28 29

PV capacity (kWp) 13.3 7.8 6.6El. loads coverage (%) 28 30 31

Optimized

photovoltaic system

KlimaKit nZEB

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0

10

20

30

40

50

60

70

80

BA

SE

-L1

BA

SE

-L2

BA

SE

-L3

FU

LL

-L1

FU

LL

-L2

FU

LL

-L3

nZ

EB

-L1

nZ

EB

-L2

nZ

EB

-L3

FLE

XI-

L1

FL

EX

I-L

2

FLE

XI-

L3

BA

SE

-L1

BA

SE

-L2

BA

SE

-L3

FU

LL

-L1

FU

LL

-L2

FU

LL

-L3

nZ

EB

-L1

nZ

EB

-L2

nZ

EB

-L3

FLE

XI-

L1

FL

EX

I-L

2

FLE

XI-

L3

BA

SE

-L1

BA

SE

-L2

BA

SE

-L3

FU

LL

-L1

FU

LL

-L2

FU

LL

-L3

nZ

EB

-L1

nZ

EB

-L2

nZ

EB

-L3

FLE

XI-

L1

FLE

XI-

L2

FLE

XI-

L3

BA

SE

-L1

BA

SE

-L2

BA

SE

-L3

FU

LL

-L1

FU

LL

-L2

FU

LL

-L3

nZ

EB

-L1

nZ

EB

-L2

nZ

EB

-L3

FLE

XI-

L1

FLE

XI-

L2

FLE

XI-

L3

BA

SE

-L1

BA

SE

-L2

BA

SE

-L3

FLE

XI-

L1

FLE

XI-

L2

FLE

XI-

L3

Po

st-

retr

ofit C

O2

em

issio

n [kgC

O2

/m2

-y]

Predicted Post-retrofit CO2 emission

12





BASE-L1

BASE-L2BASE-L3

FULL-L1

FULL-L2

FULL-L3NZEB-L1

NZEB-L2

NZEB-L3

FLEXI-L1

FLEXI-L2FLEXI-L3

PRE-RETROFIT

0

200

400

600

800

1000

1200

1400

0 20 40 60 80 100 120

Op

erat

ive

cost

s [€

/ap

artm

ent-

y]

CO2 equivalent emissions [kgCO2eq/m²-a]

13





BASE-L1

BASE-L2BASE-L3

FULL-L1

FULL-L2

FULL-L3NZEB-L1

NZEB-L2

NZEB-L3

FLEXI-L1

FLEXI-L2

FLEXI-L3

0

100

200

300

400

500

600

700

0 10 20 30 40 50 60

Op

erat

ive

cost

s [€

/ap

artm

ent-

y]


14





BASE-L1

BASE-L2BASE-L3

FULL-L1

FULL-L2

FULL-L3NZEB-L1

NZEB-L2

NZEB-L3

FLEXI-L1

FLEXI-L2

FLEXI-L3

0

100

200

300

400

500

600

700

0 10 20 30 40 50 60

Op

erat

ive

cost

s [€

/ap

artm

ent-

y]


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Conclusions and future research

• Building energy simulation allows to consider interactive effects between energy conservation and

energy efficiency measures covering building envelope, ventilation, heating and DHW systems.

• Despite their difference in terms of architecture and actual energy performance, similar overall

performance are obtained for all the considered reference buildings in the retrofit scenario

analysed (same climate)

• Best performance in terms of costs and CO2 emissions during building operation are achieved thanks

to the use of heat pump combined with photovoltaic system, despite the higher cost of electricity

(in Italy) with respect to gas or district heating.

• Thanks to optimization of PV capacity to minimize Net Present Value of the PV plant, PV generated

electricity can cover circa 30% of electrical loads of the heat pump over the whole year.

• Reference building information and simulation results for retrofit kits are collected in a

database. The database will be the backbone for the KlimaKit analysis tool, an early assessment

tool to inform decision makers on potential energy savings and PBT of an energy intervention.


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The research leading to these results has received funding from the European Regional

Development Fund (EFRE-FESR/2014-2020) under the project KlimaKit CUP number

B56J16001740001.

http://www.klimakit.it/

Project partner

Associated partner

http://www.klimakit.it/

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End of the presentation



Session no.: 4J/28.05.2019

Diamond sponsors

built environment facing climate change€¦ · 3 built environment facing climate change a...

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