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Improving the energy efficiency of users, not just their products. Edward Elias Behaviour Driven Design
Improving the energy
efficiency of users, not
just their products.
Edward Elias
Beh
avio
ur D
riven
Des
ign
Issue
Factor
Climate Change
Amount of Energy Used
The
key
issu
es
“Domestic energy consumption has increased by 32% since 1970 and by 19%
since 1990” - Department of Trade and Industry, 2002
On current trends, world demand for energy is set to increase by 53% between
2004 and 2030.
“Using energy more efficiently is a cost effective way of cutting carbon dioxide
emissions.”- UK Government, 2007
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Issue
Factor
Sources
Climate Change
Amount of Energy Used
Manufacture Use DisposalDistribution
Sou
rces
of e
nerg
y us
e
Life Cycle Assessment study into fridges showed that 90% of total energy use of
a refrigerator during its manufacture, lifetime and disposal came from the use
phase during its life. - Rüdenauer & Gensch, 2005
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Issue
Factor
Sources
Influences
Climate Change
Amount of Energy Used
Manufacture Use Disposal
Engineering Technology
User Behaviour
Distribution
Product Behaviour
Influ
enci
ng e
nerg
y us
e
Even the most efficiently designed product will waste energy if it is used badly.
Wood et al. present findings from studies which show the impact user behaviour
can have on domestic energy use ranges from 26– 36%
- Wood & Newborough, 2002
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Issue
Factor
Sources
Influences
Climate Change
Amount of Energy Used
Manufacture Use Disposal
Engineering Technology
User Behaviour
Distribution
User-CentredDesign
EnergyEducation
EnergyFeedback
Product Behaviour
Influ
enci
ng u
ser
beha
viou
r
Initially [after an information campaign] there was a 30% reduction in usage, but
in a subsequent week the savings had quickly fallen to 9%.- Hayes & Cone, 1977
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Issue
Factor
Sources
Influences
Change Mechanism
Climate Change
Amount of Energy Used
Manufacture Use Disposal
Engineering Technology
User Behaviour
Engineering Design
Distribution
User-CentredDesign
EnergyEducation
EnergyFeedback
Product Behaviour
The
who
le p
ictu
re
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Rel
atio
nshi
p m
atrix
Current Products and User Behaviour
User Education and Energy Feedback
Old New
Existing
User Behaviour
Products 1 2
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Rel
atio
nshi
p m
atrix
Current Products and User Behaviour
User Education and Energy Feedback
Design for Current User Behaviour
Design for New User Behaviour
Old New
Existing
Next Generation
User Behaviour
Products
Behaviour Driven Design
1 2
3 4
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Rel
atio
nshi
p m
atrix
User Behaviour
Product Function
Old
Old
New
New
Information and Feedback
“Fridge with alarm on door”
“Information on why to keep the door closed”
“Self-closing door”
Product Behaviour Focus
User Behaviour Focus
“Vending machine fridge”
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Our
met
hodo
logy1. How much energy is actually being lost due to
inefficient use?
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Our
met
hodo
logy1. How much energy is actually being lost due to
inefficient use?
Theoretical minimum
The minimum amount of energy required to perform a desired function,
below which it is impossible to go due to the laws of physics.
Intrinsic losses
Energy losses associated with the engineering technology and materials
of a product.
User-related loses
Energy losses related to actions of the user.
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Our
met
hodo
logy1. How much energy is actually being lost due to
inefficient use?
Theoretical minimum
The minimum amount of energy required to perform a desired function,
below which it is impossible to go due to the laws of physics.
Intrinsic losses
Energy losses associated with the engineering technology and materials
of a product.
User-related loses
Energy losses related to actions of the user.
2. What is causing the user-related losses?
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Our
met
hodo
logy1. How much energy is actually being lost due to
inefficient use?
Theoretical minimum
The minimum amount of energy required to perform a desired function,
below which it is impossible to go due to the laws of physics.
Intrinsic losses
Energy losses associated with the engineering technology and materials
of a product.
User-related loses
Energy losses related to actions of the user.
2. What is causing the user-related losses?
3. How can we design for them?
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The
oret
ical
min
imum
Energy Use
Time
Theoretical minimum
Product AIntrinsic losses
For example:
To boil 1 litre of water requires 0.093 kWh (Due to the laws of Thermodynamics)
A sample kettle took 2.5 minutes to boil and used 0.117 kWh.
The difference (0.024 kWh) is the intrinsic losses of the product.
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Use
r-re
late
d lo
ssesEnergy Use
Theoretical Minimum
Intrinsic Losses
User-related Losses
User-related Losses
0.023 kWh
0.059 kWh
0.093 kWh
Scenario A
1.5 litres of boiled water
Scenario B
20% overfilled
Base Case
1 litre of boiled water
0.176 kWh(633,600 Joules)
0.140 kWh(505,440 Joules)
0.117 kWh(421, 200 Joules)
0.024 kWh
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Use
r vi
deo
stud
ies
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Vid
eo a
ctio
n lo
gTime Action
08:21:14 Microwave finishes cooking
08:21:17 Person A opens microwave and inspects food
08:21:22 Person A removes food from microwave
08:21:24 Person B opens freezer and looks inside
08:21:26 Person B closes freezer
08:21:26 Person B opens fridge
08:21:35 Person B removes orange juice and closes fridge
08:21:37 Person B drinks orange juice
08:21:45 Person B opens fridge
08:21:46 Person A wets a cloth in the sink
08:21:47 Person B places orange juice in fridge
08:21:50 Person A begins to wipe the inside of the…
08:22:06 Person B removes some…
08:22:14
08:22:39...
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Beh
avio
ur s
cena
riosAction Motive No.
1 Open Door 1 Look / Search / Sort inside 1
2 Take out an item 2
3 Load an item 3
4 Load a hot item 4
5 Load a frozen item 5
6 Load shopping 6
7 Play with / Boredom 7
2 Leave Open 1 Loading 8
2 Searching / Sorting 9
3 Cleaning 10
4 During quick task with item 11
5 Forgetful 12
6 Distracted / Doing something non related 13
7 Not closed properly 14
8 Use as a light 15
3 Overfill 16
4 Too high a setting 17
5 Throw away unused food 1 Forgot about it / bought too much 18
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Beh
avio
ur a
sses
smen
tsBehaviourScenario
Time Taken(seconds)
FrequencyObserved
AverageTime
Percentage Time
1.1 (look inside) 229 16 14.3 17
1.2 (take out) 464 66 7.0 35
1.3 (put in) 289 65 4.4 22
1.6 (load shopping) 20 1 20.0 1
2.1 (loading) 7 1 7.0 > 1
2.2 (searching) 72 5 14.4 5
2.4 (quick task) 169 7 24.1 13
2.6 (distracted) 81 1 81.0 6
2.7 (not closed) 7 1 7.0 > 1
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Des
ign
asse
ssm
ents
Behaviour Scenario
1 2 3 4 5 6 7
1.1 (look inside) -1 -2 2 2 -1 2 2
1.2 (take out) -1 1 2 2 2 2 -1
1.2 (put in) -1 1 2 2 2 2 -1
1.6 (load shopping) -1 -1 2 2 -1 2 -1
2.1 (load) -1 -2 1 -1 -1 2 -2
2.2 (searching) -1 2 2 2 1 2 2
2.4 (quick task) -1 -2 -2 2 1 2 2
2.6 (distracted) -1 2 2 2 1 2 2
2.7 (not closed -1 2 2 2 1 2 2
A scale from +2 to -2 allowed for some simple weighting to be applied,
revealing the best design solutions.
Design Concept No.
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Gen
eric
des
ign
prin
cipl
esBehaviour Scenarios Generic Principles Possible Solution Elements
1, 2, 7, 8, 10, 17, 19 Improve visibility Glass / transparent door
Video camera feed from inside
Computer log of contents
12, 13, 14, 15 Self adjusting Self closing door
Self regulating temperature
Self regulating on / off function
2, 3, 4, 5, 6, 8, 11, 12, 13, 14, 15 Segmentation Different sealed sections
Separate doors and openings for different areas
Separation of items requiring different temperatures
Modular design
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Mor
phol
ogic
al d
esig
n
The morphological design approach allows designers to pick and chose the
right solution elements for their product.
Again a simple weighting system has been used, green is an absolute
solution, yellow is a partial solution.
Behavioural Scenario
Generic Principle
Design Solutions Elements
A 1 A B C D
5 X Y Z
2 F G H I
B 5 X Y Z
…. … … … …
N N N … N
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Con
clus
ionsEnergy use during use phase is a key area to focus on for
improved life cycle energy reduction
User-related losses are an important consideration
A design led solution is an essential approach
Behaviour analysis to highlight the worst behaviours and areas
for improvement.
Careful analysis of the behaviour results can guide the redesign efforts.
Behaviour Driven Design can “Lock-in” good behaviour
at the design stage.
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