Energy Efficiency Refurbishments: Principles, Details, Case Studies

144 Pages·2013·13.794 MB·English

by  Clemens Richarz, Christina Schulz

Energy efficiency refurbishments

Edition ∂ Green Books
Energy efficiency
refurbishments
Principles
Details
Examples
Clemens Richarz
Christina Schulz
Imprint
Authors: This work is subject to copyright. All rights are reserved,
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Christina Schulz, Dipl.-Ing. Architect specifically the rights of translation, reprinting, recitation,
re-use of illustrations and tables, broadcasting, reproduc-
Co-authors: tion on microfilms or in other ways, and storage in data
Prof. Dr. Volker Quaschning, Berlin banks.
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Prof. Dr. Joachim Stoll, Munich provisions of the German Copyright Law in its current ver-
Dipl.-Ing. (FH) Medin Verem, Gröbenzell sion. A copyright fee must always be paid. Violations are
Prof. Dipl.-Ing. Friedemann Zeitler, Penzberg liable for prosecution under the German Copyright Law.
Project management: DTP & layout:
Jakob Schoof, Dipl.-Ing. Roswitha Siegler
Editorial work: Reproduction:
Christina Schulz, Dipl.-Ing. Architect Martin Härtl OHG, Munich
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Illustrations: 1st edition 2013
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Contents
Introduction 6 Building services measures 86
Principles 8 Heating 88
Domestic hot water 97
Energy demand 8 Cooling 100
Thermal comfort 14 Ventilation 106
Interior climate 17 Artificial light 114
Exterior climate 20 Photovoltaics 118
Design parameters 24
Appropriateness 27
Economy 30 Project analyses 122
Energy accounting 34
Residential building 122
Non-residential building 130
Construction-related measures 38
Heat sinks 38 Appendix 138
Heat sources 68
Ventilation 76
Daylight 80
Introduction
Approximately 80 % of the world‘s lion tonnes is available in existing build-
resources is being consumed by 20 % of ings, which requires an investment of
the world’s population. When considering approximately DM 350 – 400 billion
the growth forecasts for the newly indus- (€180 –200 billion).”
trialised countries, it is apparent why the It is gradually becoming clear that reduc-
reduction of energy consumption has tion in the volume of CO emissions
2
become the focus of our attention. The caused by the conditioning of buildings
problem concerning the finite nature of can only be achieved by performing the
energy reserves with the consequent relevant upgrades to the vast majority of
uncontrollable upward spiral of prices existing buildings.
and the fight to get a share of the dwin-
dling resources represents only one side Sustainable development of building stock
of the coin. The other side is the risk to The importance of refurbishment that is
our environment caused by the build-up sustainable as distinct from solely energy
of carbon dioxide (CO) in the Earth’s efficient is best illustrated by taking a look
2
atmosphere which is released through the at residential buildings. Owing to their
combustion of fossil fuels. In highly indus- poor layouts, many apartments can only
trialised countries, the building sector, in be let at huge discounts, regardless of
particular, accounts for about 50 % of the whether their heating energy consump-
total CO emissions through the construc- tion already meets more recent standards
2
tion and operation of buildings. In Ger- or not. So long as serious deficiencies,
many, for example, 20 % of the emissions such as lack of contact with the outside
stem from the production and transporta- world due to the inadequate size or even
tion of building materials and 30 % from absence of balconies and windows, out-
conditioning the buildings (heating, venti- dated sanitary facilities and, generally,
lation, cooling and lighting). insufficient floor space are not eliminated,
A conservative approach to the use of these apartments will remain unattractive
resources, one which is based on long and difficult to let. Experience has shown
life cycles and therefore positive in terms that this in turn leads to undesirable seg-
of sustainability, will increasingly influ- regation processes in the demographic
ence all aspects of construction. In this structure of an apartment block, the hous-
context, making existing building stock ing complex or even the whole district
energy efficient through refurbishment is with a related potential for social conflict.
of utmost importance. The long-term via- Energy efficiency upgrades to such
bility of these buildings requires that apartments, ignoring the need to improve
upgrades incorporate energy efficiency the overall living standards, do not fulfil
and energy saving features. the aims of a sustainable, long-term and
holistic approach.
Reduction of CO emissions through refurbishment Besides improving the energy standards,
2
The preface to the German Thermal Insu- sustainable refurbishment should involve
lation Ordinance 1995 (Wärmeschutzver- changing the layouts to such an extent
ordnung), even at the time of its introduc- that they meet the needs of current and
tion, stated the following: “The real CO future tenants. Such work includes, for
2
reductions must be achieved in the exist- example, bathroom modifications to
ing building stock. The cross-ministry accommodate the needs of the elderly or
working group for CO reduction assumes alterations to the interior layouts with the
2
that a potential saving of about 100 mil- aim of achieving greater flexibility of use
6
(increase or decrease of room sizes, vari- types of buildings each with their own
ous user groups, etc.). Naturally, the particular characteristics. Furthermore,
same problems apply to non-residential the plant technology is considered as an
buildings. In general, the conversion or integral component of the overall energy
further development of existing buildings efficiency refurbishment concept. The
should not be restricted to energy approach to finding solutions is in
aspects, but should also address func- accordance with the methods used in
tional and architectural issues. The the EnEV and the associated standards,
involvement of architects is therefore since these, irrespective of their legal
indispensable when it comes to sustaina- relevance, allow for a comprehensive
ble refurbishments. understanding of all the relevant factors
affecting the energy balance.
Content of this book The nature and extent of refurbishment
Since inadequate energy efficiency measures to existing buildings are fre-
standards are frequently the trigger for quently influenced by external circum-
more extensive refurbishment work, it is stances and regulations which impact on
essential that architects possess basic the project management. These include,
knowledge in energy-related matters. for example, fire protection issues (suita-
Without know-how in this field, it will bility of components upon renewal), build-
become increasingly difficult to secure ing legislation (altered distance to neigh-
appropriate commissions. Hence a dan- bouring buildings as a result of exten-
ger exists that architects might be sions and insulation measures), tax law
excluded from the entire refurbishment (repayment options for maintenance and
process. construction costs, preservation orders
If architects however display the neces- for monuments), building costs (subsidy
sary skills, their competencies will be in programmes, rent increases) and, above
demand from the inception of projects. all, tenancy law (tenants’ obligation to
During the course of the planning work, accept changes, apportionment of
they will then be able illustrate the poten- expenses). All issues mentioned above
tial of a building as a whole and help must be solved in detail and individually
ensure that energy performance meas- for the property concerned during the
ures are incorporated into a viable, sus- course of the planning work and in collab-
tainable concept. oration with the appropriate experts. The
This book is designed to encourage the outcome will highlight whether and to
inclusion of energy-related aspects in what extent the issues concerning project
the planning process for refurbishment management will affect the refurbishment
work. In order to establish a direct refer- process itself. As is the case for all build-
ence to statutory provisions, all energy ing projects, it is these boundary condi-
efficiency issues are considered accord- tions which define the feasibility of a
ing to the objectives of the German scheme and they should therefore be
Energy Saving Ordinance, the Energie- clarified in advance.
einsparverordnung 2009 (EnEV). The
energy efficiency upgrade of a building We hope that this book will help readers to
is therefore investigated for both winter gain an insight into this topic and stimu-
and summer conditions. The refurbish- late them to consider sustainability-
ments presented are not limited to resi- related issues when refurbishing existing
dential buildings and include various building stock.
7
Principles
• Energy demand
• Thermal comfort
• Interior climate
• Exterior climate
• Design parameters
• Appropriateness
• Economy
• Energy accounting
Energy demand – have been made at the climate confer- their levels until reaching the lower level
ences held by the United Nations. of the industrialised countries.
The increasing demand for energy – not This target is also linked to a controlled
least because of the heating, cooling and Global aims world population growth. A world popu-
ventilating of buildings – and the continu- There are different predictions concern- lation of seven billion people is also
ous growth of world population are lead- ing the development of resource con- regarded as a possible limit in this
ing to an unprecedented demand for the sumption up to the year 2050. These dif- case. Under these circumstances, the
primary resources oil, gas and coal. At ferent approaches can generally be pre- CO emissions would be approximately
2
the same time, geologists expect oil pro- sented as three scenarios with different 18 billion tonnes in 2050.
duction to reach a high over the next objectives. In each case, the annual car-
years and then to start declining (fig. 1.1 bon dioxide emissions are used as a A smooth and structured transformation
and 1.6, p. 11). point of reference (fig. 1.3): into an era which allows human life with-
It can therefore be assumed that it will • Scenario 1 is based on the assumption out the use of finite resources to generate
no longer be possible to meet the that there will be continuous growth energy is only realistic if the limit
demand for the resources oil and gas mainly due to the efforts being made by described in scenario 3 is met (worldwide
over the course of the next fifty years. the emerging countries to catch up, reduction to 18 billion tonnes of CO per
2
This will have economic, and naturally which is leading to an incredible year by 2050).
also political, consequences. One of the increase in resource consumption.
consequences of resource depletion Even though resource consumption in Situation in Germany
will be a sharp increase of carbon diox- the industrialised countries will almost In terms of decreasing CO emissions,
2
ide (CO) emissions. This in turn is remain stable, the other countries will the attempts of governmental institutions
2
leading to a progressive change of the raise their energy consumption, reach- in Germany are related to the targets
Earth’s atmosphere with rising global ing the same level as that of the indus- referred to in scenario 3. They are to be
warming and severe harm to the climate. trialised countries owing to better living met exclusively by improving energy effi-
Industrialisation and world population standards. The CO emissions in sce- ciency, increasing the use of renewable
2
growth have already led to the CO nario 1 are at approximately 90 billion energies and extending the running times
2
content of the air being higher today than tonnes in 2050. of nuclear power plants. Questions con-
the level in any of the preindustrial peri- • Scenario 2 is based on the assumption cerning the living standards and the life
ods (fig. 1.2). that the industrialised nations will halve style of the society, i.e. questions con-
In the meantime, all predictions concern- their CO emissions by 2050 in accord- cerning the reasons for the high demand
2
ing CO emissions expect the primary ance with agreements made and the of energy, are not considered. It therefore
2
energy demand and the related level of other countries will only reduce or appears extremely unlikely that these tar-
CO emissions to almost triple from the increase their level until it meets that of gets will actually be met.
2
year 2000 to 2050, if the current develop- the industrialised countries. This sce- Since Germany is responsible for only 2 %
ment persists. nario is based on a limited world popu- of the global CO emissions, the country’s
2
Since the various nations show consider- lation growth – regardless of how this attempts will have only marginal influence
able differences in their energy demand might be achieved – stopping at around on the global carbon footprint. The pur-
and CO emissions per capita, one of the seven billion people worldwide. pose of the measures undertaken in Ger-
2
main questions of concern is how the The CO emissions in scenario 2 are at many and other smaller industrialised
2
resources that appear to be growing approximately 35 billion tonnes in 2050, countries is aimed far more at developing
increasingly scarce should be distributed so at approximately today’s level. holistic models for life styles that are able
(fig. 1.5, p. 11). The question concerning • In principle, scenario 3 corresponds to manage with a maximum of two tonnes
energy consumption is therefore also a with the aims of scenario 2, however, the of CO emissions per capita and year.
2
political issue, which can, at the end of overall reduction targets are higher. The A significant aspect of this strategy is the
the day, only be answered by politicians industrialised countries will lower their development of know-how concerning the
in a global context. Attempts to find CO emissions by 80 % and the other improvements to buildings that are bene-
2
answers – unfortunately so far to no avail countries will only increase or reduce ficial in terms of energy consumption.
8
Energy demand
Renewable energy supply 2009 2050
The overall aim of all efforts must be to
secure the generation of power without 0.5%
8.4%
the use of finite resources. The problem
0.51%
concerning security of supply, which gen-
8.52%
erally occurs in the case of renewable
power production due to the time lag 20.9%
between supply and demand, must be 14.67%
given top priority. A combination of sev-
eral measures, which are currently being 58.1%
developed and improved, appears to be 60.46% 5.01%
most promising. This solution includes: 4.9%
10.84%
• intelligent power grids
7.2%
• a network of various power generators
(sun during the day, wind at night)
• a network of various storage facilities
(e.g. compressed air storage, storage
of heat generated by solar radiation World population totals 6810 million World population totals 9276 million
during the day and use of the heat at
night to produce steam, hydrogen pro- Oceania 36 mil. Oceania 47 mil.
Latin America/Caribbean 580 mil. Latin America/Caribbean 778 mil.
duction through electrolysis and the
Africa 999 mil. Africa 1941 mil.
production of methane involving a reac- North America 341 mil. North America 457 mil.
tion with CO) Europe 738 mil. Europe 668 mil.
2 Asia 4117 mil. Asia 5385 mil.
A global emission deal including a fine for 1.1
those who exceed a certain CO limit,
2 v]350
which would then be used to finance spe- m
p
cific renewable energies, would offer an n [p
additional incentive to accelerate the atio
transformation to renewable energies on ntr
e
a global scale. A levy of approximately nc300
o
€20 for each tonne of CO2 exceeding the O c2
determined limit is currently under discus- C
sion.
Ice age cycles
If a target of two tonnes per capita were
250
agreed on up until 2050, Germany, from
2010 onwards, would have to invest
approximately €360 billion levied by fines
in renewable energies during this period.
In relation to the target year 2050, this
200
would account for an average of €9 billion
per year. This amount would increase the
-400000 -300000 -200000 -100000 2010 AD
Federal Budget 2011 (€307 billion) by
approximately 3 %. 1.2
A study performed by the authors Mark
Jacobson (Stanford University) and Mark O]290 90
DeLucchi (University of California) dem- ons [bil. t C 8700 S c e n ario 1 (9 bil. people)
1.1 Predictions of the development of the world ssi
population up until 2050 mi 60
e
1.2 t n Hhaiest utaoriarri.cl Tpahlr odec erevesecsluoerpsri mnagree nf ltfu roecfqt uCuaeOtino2t nlcyso ancpcapeulnsieterdad t tibooy nr e inla - Annual 50
tivise the problems of climate change. There is 31.5
clear evidence of the rise caused by mankind 40 (7 bil. people) Scenario 2 35
over the last 200 years.
(7 bil. people)
Fwreoimlrl eiancicnarsse tuasn specr hetoad ni6cg0te 0tdh pa. ptT mthhe ei f s CfiguOrnt2ih fciecora ndntecevene to lionf p tthmhisee anastir - 30 22.7 24.7 Scenario 3
sessment becomes clear when one considers 20 18
that the so-called Pettenkofer limit for interior (7 bil. people)
space is limited to 1000 ppm. Rooms should be 10
ventilated once the concentration rises above
this value, as otherwise comfortable conditions
can no longer be maintained.
1.3 Development of global CO emissions up until 1990 2000 2010 2020 2030 2040 2050
2
2050 in accordance with the different scenarios
1.3
9
Principles
Available renewable Worldwide energy Energy sources Power that has to be onstrates how energy could be supplied
energy in accessible demand in 2030 installed for a full supply
places with renewable energy at short notice by 2030 using already
available technology and exclusively
wind, water and solar power (fig. 1.4) [1].
Water 2 TW Water power 490 000 Whereas large-scale solar power plants
1.1 TW Tidal turbines 1 MW
(proportion of 9%) <1% installed generate electricity close to the equator,
Wind 40–85 TW wind farms are used in the northern hemi-
5350
sphere. In order to cover the full power
Tidal turbines 1 MW
<2% installed demand, the solar and wind plants are
supplemented by water power plants.
approx. 900 High performance power grids are able to
Water power plants 1300
balance peak demand periods and
MW 70% installed
energy gaps by distributing the power
generated by renewable sources on a
large scale during alternating periods and
in a demand-oriented way. In practise,
Wind power 5.8 TW 3 800 000 however, the development of the neces-
(proportion of 51%) Wind turbines 5 MW
sary globally coordinated transmission
1% installed
when covered networks frequently has not been very
by power from successful due to national interests or
720 000
renewable
Wave energy converters 0.75 MW due to resistance stemming from locally
sources, 11.5 TW
Sun 580 TW are required <1% installed organised citizens’ movements.
including: Jacobson and DeLucchi have estimated
costs of 100 trillion dollars for the transfor-
mation of the global energy system.
Solar power 4.6 TW 1 700 000 000 Based on similar assumptions, a number
(proportion of 40%) Photovoltaic power plants of studies have forecasted a doubling of
on roofs 3 KW
electricity prices in Germany in compari-
<1% installed
son to today’s level if the power is to be
supplied exclusively by renewable energy
49 000 sources.
Solar thermal power plants
300 MW
<1% installed In summary, the following can be said:
The future form of energy will be that gen-
erated from renewable sources, possibly
40 000
also energy stored in its transformed form
Photovoltaic power plants
300 MW as methane gas.
<1% installed This type of energy will lead to increased
costs. For economic reasons alone, it is
therefore necessary to reduce energy
consumption before a high demand is
covered by renewable but expensive
megawatt (MW) = 1000 kW energy. In the case of buildings, this
gigawatt (GW) = 1000 MW means that a reduced energy demand
terawatt (TW) = 1000 GW
achieved through structural measures still
1.4 has the highest priority when it comes to
assessing the energy efficiency of build-
ings – even in an era of renewable power
generation.
1.4 Scenario for a totally renewable energy supply in 1.6 Historical development of oil extraction for con-
Energy terms
2030. In order to provide a continuous supply, ventional and unconventional oil as well as con-
the facilities that are to be installed generate densate (NGL) including a forecast for the pos- According to the accounting methods
more power than is actually required. sible development up until 2050. The forecast is determined by the German energy saving
1.5 Country-specific levels of CO emissions in mil- based on the development of extraction over the
2 directives (EnEV, GEMIS [2]), the energy
lion tonnes. The table shows that all measures past 25 years, which was determined by global
undertaken to reduce CO emissions have been free trade with uniform prices. It is therefore fair- demand of buildings can be described
2
in vain. ly optimistic. from four different perspectives. The rele-
The industrialised countries have been able to The real price development generally depends
almost retain or even slightly reduce their level on whether a uniform world market will prevail or vant terms are explained in the following
of CO2 emissions since 1992, however, due to whether individual countries (e.g. China) will se- paragraphs (fig. 1.7).
the technological catch-up and the population cure access to specified production rates based
growth in other countries, the overall demand for on bilateral agreements.
primary energy and therefore also the emission 1.7 Relation between useful energy, final energy, Useful energy demand
of carbon dioxide continues to rise. Without primary energy and CO2 emissions according to In order to use a building in the climate
serious, globally effective and binding agree- EnEV and GEMIS
ments, there is no end to this spiral movement. conditions prevailing in Germany, energy
10