ASHRAE Journal - March 2020 - 67

COLUMN IEQ APPLICATIONS

between two lecture classroom and ofﬁce buildings
TABLE 1 Summary of building attributes.
dedicated to the Terry College of Business. A second
BUILDING TYPE
BUILDING
FLOOR
BEDS
FLOORS
YEAR BUILT
PAIRS AREA (FT 2)
comparison was made between two residential dorResidential Rutherford
80,300
260
4
2013
mitory style buildings that are primarily occupied by
ﬁrst-year students. Data gathered on all four buildReed
36,000
299
3
1953; Major
Renovation in 1998
ings included energy and water use over a two-year
Lecture
Correll
74,300
N/A
4
2015
period, maintenance work orders, and results of an
Classroom,
Ofﬁces
online survey on the indoor environmental quality
(IEQ) perceptions by the occupants. The remainSanford
38,000
N/A
3
1997
der of this column focuses on the IEQ aspects of the
study with a brief commentary on the other results as
difﬁculty with the perceived effect on performance
well for comparative purposes.
question as worded is the reference point used by each
Building IEQ was evaluated using voluntary online
subject when considering their change in performance.
surveys sent out to all students attending classes in these As is the nature of any study like this, the survey was also
two learning centers and to the students who reside
dependent on many factors outside of building perforwithin the residential halls. Each survey asked the
mance, such as the occupant's level of clothing and outrespondents to evaluate aspects of the building's IEQ on
door ambient conditions. However, the relative results
a seven-point scale ranging from extremely dissatisﬁed
of the two different types of buildings can still be used to
to extremely satisﬁed. One additional question asked
evaluate the overall perception of the occupants.
how they felt the IEQ of the building either increased or
Survey Results and Analysis
decreased their work or performance within the buildWe begin the comparison with the classroom/lecture
ing. The answer choices for these performance-related
hall buildings, with the comparative results from all
questions ranged from +20% to -20%, with -20% being
survey responses summarized in Figure 1. For the newer
interpreted as "completely dissatisﬁed" and a positive
building (Correll Hall), the overall average response was
20% as "completely satisﬁed." We realize this is a somewhat subjective interpretation of a percentage impact on a +7.1% satisfaction with IEQ and its impact on performance, while for the older building (Sanford Hall) the
performance (positive or negative), but IEQ perception
average came out at -1.2% dissatisfaction and impact.
is a subjective topic.
It is recognized that these are based on the somewhat
The evaluation of IEQ included questions involving
arbitrary scale presented to the respondents, but are still
satisfaction regarding daylighting, humidity control,
useful for a comparative purpose. An analysis of these
thermal comfort, air quality perception, acoustics, and
results using a statistical comparison of means (t-test)
the overall level of satisfaction with the building's IEQ.
Other questions within the survey included basic demo- of the overall averages indicated there is a signiﬁcant
difference between the two buildings at the 0.3% siggraphic identiﬁcation such as gender, race and age.
niﬁcance level; thus, we conclude that there is a posiOccupants of all buildings were asked the same questive impact on the occupants' perception of percentage
tions. The overall satisfaction question speciﬁcally
asked: "Indoor environmental quality (IEQ) refers to the of performance within the newer building. The overall
quality of a building's environment in relation to health scope and level of effort available only allowed for comparison of two building type pairs; thus generalizing
and well-being of those who occupy the space. IEQ is
conclusions from these results to all buildings is not
determined by many factors, such as temperature,
really possible. But, the comparisons presented here do
lighting (artiﬁcial and natural), air quality, and humidprovide insight into potential trends.
ity. Please estimate how your performance in regard to
The sample size was smaller for the lecture halls comwork, study, research, etc., is increased or decreased by
pared to the residential building, likely related to the
the IEQ of this building."
greater amount of time students spend in the residenThis question was used as a baseline for the overall
tial halls versus the lecture halls. This creates a larger
satisfaction of each building, but note that it is speciﬁc
personal investment in the building, which encourages
to the subjective judgement of each individual. One
MARCH 2020

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ASHRAE Journal - March 2020

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