THE AECB ENERGY PERFORMANCE STANDARDS

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THE AECB ENERGY PERFORMANCE STANDARDS

• Presented by
• David Olivier

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What I shall talk about

• The AECB energy performance standards
• Some common misunderstandings
• What the standards could achieve
• Case studies
• Emerging issues

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The AECB Energy Performance Standards
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• Background - Voluntary Energy Standards in Other
  Countries
• Germany - Passive House Standard www.passiv.de
• Began 1990 with four pilot houses in Darmstadt
• Pioneered very high insulation and airtightness
  standards, first used in Sweden and Canada
• Used highly energy-efficient lighting,
  ventilation, electrical appliances and equipment
  
• 80 overall reduction in energy use and CO2
  emissions vs. the German dwelling stock.
• Switzerland - MINERGIE standard www.minergie.ch
• USA - Energy Star, plus lots of programs at
  state, city or county level
• Canada - R-2000 Program, C-2000 Program, etc
• Norway - Low Energy Standards for houses and
  other buildings
• and others.

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A Summary of the AECB Standards
PLATINUM (not being actively promoted yet)
99-100 reduction in CO2 emissions vs. an average
UK building
GOLD Step 3
95 reduction in CO2 emissions from the average
PASSIVHAUS Step 2
80 reduction in CO2 emissions
SILVER Step 1
70 reduction in CO2 emissions
BRONZE (not being actively promoted)
45 reduction in CO2 emissions
The predicted energy use and CO2 emissions are
based on accurate reflections of reality in
calculations, building on successful overseas
programs
These standards are spelt out further on the AECB
website www.aecb.net.
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Summary - AECB Silver Standard 30 of Current
CO2 Emissions Opaque U-values lt0.15 W/m2K
roof, lt0.25 walls, lt0.20 ground floor, Glazing
U-values lt1.5 W/m2K, doors lt1.0 W/m2K Air
permeability lt1.5 or 3.0 m3/m2hr _at_ 50 Pa MEV
or MVHR Specific heat loss also limited to
1.05 W/K per m2 floor area Peak space heating
load usually lt30 W per m2 floor area Vent.
system specific fanpower lt1.5 W per l./s
Vent. system heat recovery gt70 as seasonal
average, excl. fan heat gains
Energy-efficient lighting systems, electrical
appliances office equipment Stresses
built-in energy efficiency, not bolted-on
technology.
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Summary - Passivhaus Standard 20 of Current CO2
Emissions Opaque real U-values lt0.15 W/m2K,
usually lt0.10 W/m2K Glazing U-values lt0.8
W/m2K Air permeability lt0.6 ac/h lt0.75
m3/m2hr _at_ 50 Pa Specific heat loss also
limited to 0.65 W/K per m2 floor area Peak
space heating load usually lt10 W per m2 floor
area Space heating useful energy lt15
kWh/m2yr Vent. system specific fanpower
lt1.44 W per l./s Vent. system heat recovery
gt75 as seasonal average, excl. fan heat gains
but incl. benefit of earth tube if used
Energy-efficient lighting systems, electrical
appliances office equipment Enough
electricity generation from dedicated/on-site
renewables e.g., PV, micro-hydro, to offset CO2
emissions from elec. used for lights
appliances. Or CHP. Pushes energy efficiency
far beyond existing UK awareness, custom or
practice.
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Summary - AECB Gold Standard 5 of Current CO2
Emissions Opaque real U-values lt0.15 W/m2K,
usually lt0.10 W/m2K Glazing U-values lt0.8
W/m2K Air permeability lt0.75 m3/m2hr _at_ 50 Pa
Peak space heating load usually lt10 W per m2
floor area Space heating useful energy lt15
kWh/m2yr Thermally almost as Passivhaus
Standard but pushes efficient use of electricity
further, reflecting current knowledge
technology Vent. system specific fanpower
lt0.8 W per l./s Vent. system heat recovery
gt85 as seasonal average, excl. fan heat gains
but incl. benefit of earth tube if used The
most energy-efficient lighting systems,
electrical appliances office equipment on the
EU market Enough electricity generation from
dedicated/on-site renewables e.g PV,
micro-hydro, to offset the CO2 emissions from
elec. used for lights appliances. Or CHP
Pushes energy efficiency technology far beyond UK
awareness, custom or practice.
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Summary Performance Version of Standards
Domestic and Non-Domestic Buildings
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The Standards in ContextSilver - Takes us to
c.30 of current CO2 emissions. Straightforward,
off-the-shelf energy efficiency technologies
which are available in the UK. No renewables
needed. A stepping stone to ... Passivhaus -
Down from 30 to c.20 of current emissions.
International best practice energy efficiency
technologies can be obtained in the UK if
designers know where to go. Sometimes no
renewables needed. With modifications leads to
Gold - Down from 20 to c.5 of current
emissions. International best practice energy
efficiency technology, albeit sometimes
obtainable with difficulty, plus modest
investment in renewables. Sidesteps requirements
which at present lead to controversy e.g. solid
biomass, green electricity. Overall - Very
important to get UK emissions down to 5-10 of
current levels. The earth has sufficient carbon
sinks to cope with very low emissions for a
longer time, but cannot absorb current emissions.
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The standards do not regulate embodied energy.
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Even after meeting best international practice on
energy efficiency, embodied energy is a small
proportion of a house or offices total energy
use.
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The standards do not regulate materials use.
PVC pipes, wiring and windows
Paint/varnish
Plastic foam insulation
Adhesives
Chipboard
Sustainable forestry
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Some Common UK Misunderstandings
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Over-optimistic procedures/methods have been used
to calculate the energy consumption of new
housing.
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This leads to erroneous claims that Part L1
(housing) of the UK Building Regulations has
reached a limit.
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Similar claims are heard with respect to Part L2
(non-domestic) of the UK Building Regulations.
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We build in ways which fail to keep the heat in.
Masonry wall with 90 mm cavity the 40 mm
partial-fill polyisocyanurate foam slabs float
in the cavity.
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Gap between insulation slabs, allowing air
movement.
Gap between inner leaf and insulation, allowing
continuous air circulation
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Is the insulation board supposed to be firmly
attached to the inner leaf or to the outer
leaf?!
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If it were, it would be thermally bridged by this
mortar snot
No insulation is present
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Another example of gaps between and behind the
thermal insulation.
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New UK dwellings are leakier than those built in
Canada, Sweden or Germany 60 years ago.
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Renewables Issues to Consider Not a
straightforward kWh for kWh replacement for
fossil fuels. Low-cost firm supplies are very
limited. Not top priority while a large,
cheap energy efficiency potential remains
unexploited. A few building-integrated
renewables e.g., passive solar housing design,
daylighting design of offices or schools, are a
very high priority and should always be
incorporated at design stage. There are no
government incentives for such renewables.
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Renewables Priorities? In a new dwelling, as
much heat, c.1,500 kWh/yr, is lost through the
tank insulation and from the distribution pipes
as a small solar hot water system provides. The
temperature difference between hot water tank and
dwelling interior is four times greater than the
mean temperature difference between the dwelling
interior and the outside air. Should Building
or Planning Regulations, or voluntary higher
energy standards, encourage us initially to spend
resources on improved tank insulation, improved
pipe insulation and/or on solar collectors?!
There are no government or planning incentives
for ultra-high tank and pipe insulation, only for
solar.
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What The Standards Could Achieve
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Benefits of Adopting Effective Energy Performance
Standards for New Housing
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Case Studies
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Headquarters of the Rocky Mountain Institute in
Old Snowmass, Colorado, USA (built in 1983,
photovoltaics added in 1992).
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An Infill Mid-Terrace House, almost AECB Silver
Standard, London SW13 (designed 1985).
Reyburn House Measured Energy Use from
1990-2005 Gas 90 kWh/m2yr. Electricity 22
kWh/m2yr. Total 112 kWh/m2yr.
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• Viewed from South in Summer
• In the 2003 2006 heatwaves, it was the only
  inhabitable house in
• London SW13 - apart from one which had air
  conditioning.
• Features
• High thermal capacity
• All glazing faces due
• N or S
• Some shading by a
• deciduous tree to the SW
• In heatwaves, windows
• are opened by night the
• MVHR system keeps the
• coolth in the house by day.

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A Detached House to the AECB Silver Standard in
Charlbury, Oxon (built 1992-93).
Lower Watts House Measured Energy Use from
1993-2005 Gas 50 kWh/m2yr. Electricity 12
kWh/m2yr. Total 62 kWh/m2yr.
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A Detached House in Saskatoon, Saskatchewan,
Canada (built 1992).
North
wall South wall
Dumont House Measured Energy Use from 1993-2005
Electricity 40 kWh/m2yr. Measured Heat Loss 5 kW
at -40oC outside for a 400 m2 house each floor
is 130 m2. Insulation 15 tonnes of cellulose
fibre. Air Leakage 0.5 ac/h _at_ 50 Pa
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The Elizabeth Fry Building.
UEA, Norwich (1994).
3,500 m
2
of
floorspace
on four floors. Heated by two 24 kW(t) domestic
wall
-
hung condensing boilers. No cooling provided or
needed, only
automated summer night ventilation using hollow
-
core concrete floors.
High score in PROBE user survey. Large lecture
theatres in basem
ent,
seminar rooms and offices on other floors. Gas
usage 25
-
30 kWh/m
2
yr
since 1997.
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A Detached House to the Passivhaus Standard in
Hohen Neudorf, Brandenburg, Germany (2004).
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The first School to the Passivhaus Standard in
Waldshut, Germany (designed 2000 onwards,
finished 2003).
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A Detached Cottage to the AECB Gold Standard
Rural site in north-west Herefordshire (photos
taken 2006).
The project will produce all its energy from
solar, mainly passive gains, an experimental
solar water heating system and roof-integrated
photovoltaics.
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Emerging Issues For Low- or Zero-CO2 Buildings
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• Small-Scale Solid Biomass Heating
• Biomass is a scarce and valuable resource with
  many demands upon it. The EU sustainable resource
  is 8-9 of EU energy usage
• Space demands - automatic systems may need a
  separate boiler house or a larger plant room
• Efficiency - a heat load of 50-300 kWh/month
  e.g., an energy-efficient detached house, is not
  conducive to high conversion efficiency
  especially when burning solid fuels
• Capital cost - higher than boilers fuelled by
  liquid or gaseous fossil fuels (or
  cleaner-burning liquid or gaseous biofuels e.g.,
  several countries are feeding biomethane into
  their gas grid)
• Exhaust emissions - at best level with a
  poor-quality oil boiler, at worst 100-300 times
  higher. They include particulates and PAHs
• Older wood combustion technologies emit enough
  unburned CH4, N2O and soot particles that they
  are worse for climate change than an oil boiler!
  See e.g., http//www.eia.doe.gov/oiaf/1605/gg02rp
  t/methane.html http//www.vtwoodsmoke.org/pdf/Joha
  nsson03.pdf http//pubs.giss.nasa.gov/docs/2007/20
  07_Hansen_etal_2.pdf
• Solid biomass works well in very large CHP plant
  - as in Denmark.

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CO2 emissions are higher than realised
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Location of the UKs Geothermal Aquifers In
these areas, hot water may be available at about
2 km below ground. Geothermal hot water at 75oC
has heated central Southampton for 25 years. Bath
has hot water at the surface.
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• David Olivier, BSc MEI MASHRAE
• Principal
• ENERGY ADVISORY ASSOCIATES
• 1 Moores Cottages, Bircher, Leominster,
• Herefordshire, England, HR6 0AX
• Tel. [phone]. Fax [phone].
• E-mail dolivier_at_energyadvisoryassociates.co.uk
• Web www.energyadvisoryassociates.co.uk

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