1. EXPERIMENTS IN
ENERGY OLYMPICS
WEST OF ENGLAND CARBON CHALLENGE
2012-11-07, 1600
Sukumar Natarajan
with contributions from Julian Padget, Ian Walker
and Teresa Chiang, Nadya Dara, Gokhan Mevlevioglu

2. Energy Use /
Climate Efficiency / Building
Change Security Design
Energy and the Design of Environments (EDEn)
ENergy Literacy
COPSE /
through an
Prometheus
IntelligenT home
(both using
ENergy advisor
UKCP09 data)
(ENLITEN)

3. CONTEXT
• Domestic:
• Users have control over decisions
• Relatively easy to connect cause and effect
• Non domestic:
• Users generally have less control
• More tricky to connect cause and effect

4. Question 1: Does (the type of)
feedback affect energy consumption?
Savings from various studies range from 0% to 22%
Larger and longer term trials show less than 5% savings from control
Three types of displays were proposed in the literature
Experiment 1: laboratory test
Experiment 2: live (student residence)

5. convey information. Th
tion simultaneously in a direct and intuitive manner [24]. Anderson
inclusion of human face
and White [25] found through working with focus groups that the know
Human faces are
design of a speedometer dial was particularly preferred even when reduced to
for its qual-
ities of eye-catching movement, intuitive scale and direction of and biol
to their social
be processed differently
change, and ease of making comparisons. It will be interesting to and mor
detected faster
see if similar preferences are seen in this study.
Question 1: Does (the type of)
Fig. 1. Numerical display [29]. The intention of this w
Ambient displays (Fig. 3) provide an overall indication of a situa-
capturing property mak
tion, sometimes make use of peripheral vision, and do displays. Specifically, th
not require
like faces.
users’ detailed attention [8,22]. No text or numbers are shown;
feedback affect energy consumption?
instead, pictures, colours, sounds or flashing lights are used to
2.2.2. Colour
convey information. The present work attempts to introduce theA large number of
inclusion of human faces in the design of user interface prototypes.
and screen design hav
ARTICLE IN PRESS Human faces are known to have the capacity to attract attention, attentio
G Model and directional
ENB-3818; No. of Pages 10 colour, size, orientation
even when reduced to cartoon form [26,27]. Presumably thankssearch or
when people
T. Chiang et al. / Energy and Buildings xxx (2012) xxx–xxx 3 to their social and biological significance, human faces seem to have th
been found to
be processed differently by the human brain: changes stimuli due to its highlig
in faces are
Analogue displays (e.g. Fig. 2) illustrate the scale of consump-
tion usually without numbers, using graphs, charts, dials, column
detected faster and more accurately than in other objects [e.g. 28].target stim
rate potential
also help to shorten se
gauges and bars. ComparedFig. 1. Numerical display [29]. often
to numerical displays, these are The intention of this work is to find out if the face’s attention
[after 5]. As colour is
Fig. 2. Analogue display [30].
considered easier to read and interpret, especially when making capturing property makes it a useful cue in the design of energy colour c
processing of
comparisons, e.g. between current and target values [24]. Ana- amounts of cognitive c
displays. Specifically, the study looked at two-dimensional cartoon-
☺
logue displays can be effective in checking readings, evaluating the present work also
future states and conveying quantitative and qualitative informa- like faces. (i.e. non black-on-white
tion simultaneously in a direct and intuitive manner [24]. Anderson display designs (details
and White [25] found through working with focus groups that the 3.2).
design of a speedometer dial was particularly preferred for its qual- 2.2.2. Colour
ities of eye-catching movement, intuitive scale and direction of A large number of studies [e.g. 32–34] on web pageUsers’ preferences design
2.3.
change, and ease of making comparisons. It will be interesting to
and screen design have shown that comprehension, distraction
see if similar preferences are seen in this study.
Ambient displays (Fig. 3) provide an overall indication of a situa- and directional attention are heavily influenced by the Previous research ha
location,
tion, sometimes make use of peripheral vision, and do not require colour, size, orientation, shape and luminance of targetstion people preferred to
[e.g. 35,36]
could help to serve pre
users’ detailed attention [8,22]. No text or numbers are shown; when people search or read displays. Colour, in particular,designed two t
the USA has
instead, pictures, colours, sounds or flashing lights are used to
convey information. The present work attempts to introduce the been found to have the capacity to attract attention to targetbar graph
consumption:
distribution graphic des
stimuli due to its highlighting and association effects, and to sepa-
inclusion of human faces in the design of user interface prototypes.
bourhood mapped on a
Human faces are known to have the capacity to attract attention, rate potential target stimuli from non-target stimuli [37]. It might
consumption [40]. This
even when reduced to cartoon form [26,27]. Presumably thanks
also help to shorten search time more than shapes or numbers concepthe same design
to their social and biological significance, human faces seem to
be processed differently by the human brain: display [30].
Fig. 2. Analogue changes in faces are [after 5]. As colour is a basic [31].
Fig. 3. Ambient design element of visual perception, and difficult t
“childish” the
detected faster and more accurately than in other objects [e.g. 28]. processing of colour coded information does not require large
easy to comprehend due to the consistent exposure in a number
digital
Fig. 1. Numerical display [29].
analogue
The intention of this work is to find out if the face’s attention
capturing property makes it a useful cue in the design of energy
displays. Specifically, the study looked at two-dimensional cartoon-
ambient
of activities both at home (kitchen timer, [after clock, TV, For these reasons,
amounts of cognitive capacities alarm 38,39]. etc.)
7
The present work studie
the present work also investigates the effectiveness of coloured studies ha
and work (security systems, vending machines, etc.). The present design, as previous
work intends to examine presenting energy informationagainst black-on-whitein better pe
(i.e. non black-on-white7 ) display designs with pure polarity) resulted
like faces.
numbers. (negative polarity) [56,57].
display designs (details of the experiment are described in Section
detailed 2.2.2. Colour illustrate 3.2). provide an
Please cite this article in press as: T. Chiang, et al., A laboratory test of the efficacy of energy d
quantitative scale of
A large number of studies [e.g. 32–34] on web page design
and screen design have shown that comprehension, distraction “indication”
(2012), http://dx.doi.org/10.1016/j.enbuild.2012.07.026
information consumption
and directional attention are heavily influenced by the location,
colour, size, orientation, shape and luminance of targets [e.g. 35,36]
2.3.
of the situation
Users’ preferences
when people search or read displays. Colour, in particular, has
been found to have the capacity to attract attention to target Previous research has shown mixed findings on what informa-
stimuli due to its highlighting and association effects, and to sepa- tion people preferred to receive and which type of graphical design
rate potential target stimuli from non-target stimuli [37]. It might could help to serve presenting information better. Researchers in
also help to shorten search time more than shapes or numbers
[after 5]. As colour is a basic element of visual perception, the
the USA designed two types of graphical displays to show energy
we wanted to control these quite carefully, so COTS were not an option
Fig. 2. Analogue display [30].
processing of colour coded information does not require large consumption: bar graphs and distribution graphs. Fig. 4 is one of the
amounts of cognitive capacities [after 38,39]. For these reasons, distribution graphic designs that displayed little houses in a neigh-
the present work also investigates the effectiveness of coloured
bourhood mapped on an x–y axis graph according to their energy
(i.e. non black-on-white7 ) display designs against black-on-white
display designs (details of the experiment are described in Section consumption [40]. This design was ranked most preferred, while
3.2). the same design concept presented in Norway [41] was judged as
Fig. 3. Ambient design [31]. “childish” and difficult to interpret.
2.3. Users’ preferences
easy to comprehend due to the consistent exposure in a number
Previous research has shown mixed findings on what informa-
of activities both at home (kitchen timer, alarm clock, TV, etc.)
tion people preferred to receive and which type of graphical design 7
The present work studied black-on-white design instead of white-on-black
could help to serve presenting information better. Researchersetc.). The present
and work (security systems, vending machines, in design, as previous studies have shown that dark text on light background (positive

6. Experiment 1: The key question is
How good are we at detecting change in
information: speed and accuracy

7. Let’s do a quick test

9. Fig. 9. Mean accuracy rates.
Fig. 9. Mean accuracy rates.
mage (bottom).
dium, high, which were
UK household’s annual
ottom).
splay design had a black-
ersion (Fig. 7). The overall
high, which were
as white. Red and green
ousehold’s annual
eir associative meanings, Fig. 10. Mean response times.
ranges,had a black- and
esign respectively,

10. mages used the same
he design changed ran- The interviews were semi-structured, such that discussion
d Test images differed stemmed from the core questions. In many instances, more than
e display components.
ickly and accurately as
anging display compo-
o ensure that the time
se was minimised, the
e “@” key (next to the
“Today so far” and “Yester-
rage electricity consumption
average daily consumption
he full range and divided by
0–6 kWh, the medium range
1 kWh and higher. It is worth
G Model
ENB-3818; No. of Pages 10 ARTICLE IN PRESS
ximations appropriate to the
bt be different, these are not 8 T. Chiang et al. / Energy and Buildings xxx (2012) xxx–xxx
nts were focused on changes
Table 3 Fig. 11. Display design preferences. backgrounds as possi
Summary of response time and accuracy.
pants had undertaken
Response time Correct Preference that the participants
ng, et al., A laboratory test of the efficacy of energy display interface design, Energy Buildings or higher, and theref
Design typea Ang > Amb = Nmr Nmr = Amb > Ang Nmr > Amb = Ang
d.2012.07.026 Colourb
B/W = Clr B/W = Clr Amb > Ang = Nmr ulation at large. Furth
Amb B/W > Amb Clr rule out a correlation
a
Amb: ambient, Ang: analogue, Nmr: numerical. performance.
b
B/W: black-on-white, Clr: colour. (b) Lab based experiment:
> means significantly greater than, = means marginally different. “laboratory condition
capture perception in
by removing the dist
found that if users find the product features similar to their previ-
in their domestic env
ous experience, they are more likely to perform tasks better [51,52].
study provided a usefu

11. Experiment 2: The key question is
How good are we at reducing energy when
presented the same information in different ways?

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Student residences with good wifi access, 4 x kitchens per floor
P C
P B
EachC“kitchen group” was sub-metered by lights and small power
P
P A
Recyc
li
Kitchens comparable to each other with 7 students per group
ng
P G
6 kitchens were selected, 2 each on floors 7, 8 and 9
2 non-participating groups were used as control
Baseline period for comparison was the average over a period of days
a
immediately before the start of the experiment
Outdoor
Tennis Courts

13. Cumulative consumption Total Cumulative
from 00:01 to time of consumption from
update (say 09:00) 00:01 to 00:00
colour
blind safe
Average daily Average daily
consumption consumption last
this week week

17. Group
A B C D E F
1-2
Weeks 3-4
5-6
“Winner takes it all” £20 per member
of the group that reduced the most over 6 weeks

19. Confidence intervals for the experiment
groups did not include zero change, so these
results are significant at the 0.05 level.
Plainspeak: there is a 95% probability that
these results did not occur due to pure
chance
Participants preferred this the most, yet Confidence intervals for the control groups
ambient seems to perform better! did include zero change.
Plainspeak: the change for these groups from
baseline are not reliably different from zero

21. Question 2: Is competitive ranking enough,
on its own, to deliver savings?
In the previous experiment, groups were competing against absolute savings
However, this tends to favour groups starting from a low baseline
We wanted to test if comparing against one’s own savings would be different
Further, this time every person stood to gain financially as rewards were
calculated using an arbitrary fixed rate (35p) per kWh saved cumulatively
compared to the baseline period.

22. Experiment 3: The key question is
How good are we at reducing energy when
comparing our performance against the
performance of others?

24. Mean change in consumption (kWh) compared to baseline

25. Questions 3 & 4: Will any of these ideas work in
an office environment? Do rewards matter?
Applied the idea of self-relative ranking from previous experiment to BH offices
Information was separated by lighting and small power
Instead of monetary units, performance was measured in “meters run”
Provide additional context to ranking information
Test if rewards are essential and if (any) savings persist over time.
Information on how to save was given before the start of the competition
Environmental attitudes were measured before and after the competition
Due to technical problems experiment ran for 5 weeks instead of 6

26. Therefore, the percentage of energy for heating would probably increase. For example,
Figure 3.2.3 illustrates the difference in percentage of energy subsectors in June and
April, where it is clear that heating is the first largest consumer in April whereas in June
Proportion of total energy consumption in both buildings by end-use
small power consumes over a half of all energy.
60.00%
50.00%
40.00%
30.00% June
April
20.00%
10.00%
0.00%
Small Lighting Canteen Lift Server Printers Heating
power room room
Figure 3.2.3. Comparison of total Buildings energy consumption by sectors in June and April.
40/141

27. Equivalent of “net earnings”
in the previous study The effectiveness of behavioural interventions
to reduce office energy consumption
Figure 3.4.1. Scheme of display screens.
Provide context on “how far
Lighting away” other groups are
Computer
Weekday Weekend Nominal Weekday Weekend Nominal
Floor Floor
average average Average average average Average

28. Mean percentage savings and ranges
0%
% reduction from baseline
10%
20%
30%
Lighting Computers Total

29. % savings from baseline
after one week
-40%
-27%
-13%
0%
13%
27%
14/07/2012
22/07/2012
29/07/2012
05/08/2012
12/08/2012
The first data point is the average saving
19/08/2012
End of
period
26/08/2012
Computer Use
02/09/2012
competition
09/09/2012
16/09/2012
23/09/2012
30/09/2012
Lighting
07/10/2012
Tablets
14/10/2012
Removed
21/10/2012
28/10/2012
Average savings over all groups split by end-use

30. general level of the awareness has not changed much.
Q1. I am an environmentally aware person interventions
The effectiveness of behavioural
to reduce office energy consumption
50.00%
However, questions about humans’ rights and abilities to prevent the destruction of the
45.00%
40.00%
Earth (3, 5, 7) in both buildings were more optimistic than in the previous questionnaires
35.00%
and the percentage of ‘agree’ answers was by 8-­12% higher.
30.00%
25.00%
4.3.2. Behavioural change. before competition
20.00%
15.00% after competition
Interestingly, the answers about behavioural actions performed by occupants have
10.00%
significantly improved in both buildings by an average 15.6% (Figure 4.3.2, Appendix P,
5.00%
0.00%
Table P2). The most significant was improvement in turning off lights overnight by 50.25%
1 2 3 4 5 6 7
on the Ground floor of the Building 1 and switching off monitors on the Second floor of the
(Strongly (Strongly
Building disagree)grew from 25% to 71% and the use of ‘sleep’ mode that increased form
2 that agree)
33% to 71%.
Figure 4.3.1. Comparison of responses before and after the competition on Question 1.
120.00%
In Building 1 on the Ground and First floors the amount of positive responses was lower
by 100.00% whereas on the winning floor (the Second) the amount of positive answers
3-­5%,
Building 2
reached 100%, higher by 18.75% than before the competition (Appendix P, Table P2).
80.00% before
Building 2
In Building 2 the change is slightly more significant (Appendix P, Table P2). On the First
after
60.00%
and the Third floors awareness was higher by about 25%, whereas on the Second floor it
Building 1
before
was lower by 14%.
40.00%
Building 1
after
The questions that represent environmental attitude (2, 4, 6, 8) in general received slightly
20.00%
less positive response from both buildings (Appendix P, Table P2). However, for the
0.00%
Second Floor of Building 1 (winner) some questions were answered more positively, such
9. adjust 10. swtich off 11. turn off 12. use 13. switch off
as Question 4 lights36%) and Question 6 (by 21%) whereas other questions (2, 8) were
(by comp lights 'sleep' mode monitor
about the same level.
Figure 4.3.2. The comparison of positive responses about ecological behaviour.

31. ANSWERS
• Simplyputting something in place seems to have an effect
• We need to be wary, however, of the Hawthorne effect
• What people say and what they do don’t always match
• Some designs may be better than others
WHAT WE DON’T KNOW
• How do hybrid designs perform?
• Are these savings sustained? How can we make them habitual?
• What is an appropriate baseline measure?
• Are rewards essential? Need they be monetary?