ASHRAE Journal - January 2021 - 32

TECHNICAL FEATURE

convenient and often safer; thus,
geometrical congruence is key.

FIGURE 4 Example of poor mapping between the interface and controlled system (left). Much like HVAC systems,
stoves have a thermal lag between user input and feedback, making it difficult to efficiently explore and build
a mental map. Moreover, memory recall is required between uses of this stove since the labels are worn off.
Fortunately, another user developed a " folk label " 6 (right).

Interface Aesthetic and Placement
To some design professionals and
owners, interfaces may be seen as
ruining the aesthetic of a building
or as a weakness of the building. It
may be tempting to conceal interfaces, but this reduces occupants'
real and perceived control. Users
should be able to immediately find
interfaces in an intuitive and accessible location (e.g., light switches
beside doorways that can be reached
without having to navigate dark
rooms). Thus, there is great value in
developing attractive interfaces that
architects choose to feature rather
than conceal. Attractive interfaces
have the added benefit of being
more enticing for occupants to use
and explore.
Interface placement is paramount.
Figure 5 shows a case where the light
switch for a hotel room bathroom
is beside the door, but its location
is much worse than it first appears.
The switch for the bathroom light is
on the wall outside the bathroom,
behind the bathroom door. What's
worse, the hallway is too narrow for
an occupant to be able walk around
the open door, so the occupant must
leave the bathroom and close the
door to reach around to the light
switch-not an ideal situation for
desperate situations.

Automatic vs. Manual Control
There is contentious debate about
whether to provide occupants with
control over interfaces and the corresponding indoor environment.
Our experience is that building
designers and owners have an inherent mistrust of occupants and their
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actions. For example, a locked clear
box over an interface to prevent
occupant interactions is a frequent
sight. More subtly and perhaps more
tauntingly, sometimes thermostats
are set to digitally restrict setpoints
from deviating more than several
degrees or to serve as a placebo (with
no impact on the setpoint). Similar
restrictions are often seen with
operable windows that are locked
or that display signs requesting no
interference from occupants or
warning them of alarms.
The problem with restricting
access to and use of building interfaces is that it neglects adaptive
comfort theory, which places great
importance on the psychological
benefits of perceived control. These
psychological benefits extend to benefits of behavioral and physiological
adaptation. For example, we know
that providing operable windows
can relax the comfortable temperature range for occupants (see ANSI/
ASHRAE Standard 55-2017, Thermal
Environmental Conditions for Human
Occupancy). Yet in modern building

JAN UARY 2021

FIGURE 5 A bathroom light switch on the wrong side
of the door.

design practice, such affordances
seem to be largely taken from occupants. We accept that it is not always
appropriate for occupants to have
control (e.g., in shared transient
spaces where occupants do not take
ownership over a space); however,
we maintain that the pendulum
towards full automation without
occupant input must swing back.
Moreover, occupants are creative
interventionists who almost always
place comfort above energy savings-especially if they're not paying. The authors have seen many
examples of creative and tenacious
people reclaiming control over their
environment. From placing frozen

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ASHRAE Journal - January 2021

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