We agree about CBECS. However,
this was not in the scope of our study.
Our observations of the HVAC system types are limited to the 90 case
studies. We do not try to extrapolate
to what is commonly used in the various building types. We also clearly
mention that from this sample of 90
buildings there were 68 different
HVAC system configurations and
most buildings had some type of
“hybrid” solution with multiple system types in the same building.
The data used was limited to what
was in the publications, and typically, the data is metered/actual data.
WE’LL ANSWER YOUR LETTER point-by-point. We explicitly state that we
only reviewed case studies from HPB
magazine and ASHRAE Technology
Awards in ASHRAE Journal, and
that the EUI values are not representative of typical buildings.
For each of the different comparisons, we included bar charts showing the number of case studies (i.e.,
the sample sizes) in each category.
However, we’re not suggesting a comparison with common buildings. Our
intent was to only review the “high
performance” case studies as published in HPB and ASHRAE Journal.
We also do not claim that these
are high performance buildings, but
rather that they are case studies from
the HPB magazine and the ASHRAE
Technology Awards. This is more of
a question for ASHRAE and how
they select buildings for the technol-
ogy awards or for publication in the
We agree that it is misleading to look
at EUI against any one factor in isolation due to other confounding factors.
This was one of the main objectives
of the paper: to show that when considering EUI, you must consider all of
these various factors you mention. See
the “Results and Discussion” section
where this is discussed.
The Authors Respond
“ We agree that EUI values
inherently fail to capture
the dynamic nature of
buildings. Our article
shows that it is difficult to
make conclusions about a
building even with a static
Letters continued on Page 37