Net ZEB Case Studies - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 360

7.2.2.4 Assessment of the Design Process
Upon interviewing several design team members, several notable
conclusions were drawn. They stated that the main (two-day) design
charrette was very effective, that the collaboration between the large group
of experts exceeded expectations, and that the work that was completed
in advance was essential to a productive group design session. However,
improved communication between the designers and builder teams
regarding some of the more innovative aspects of the house, such as the
ductwork linking the BIPV/T roof to the sites of demand would have been
desirable. Also, the use of design tools was somewhat fragmented, since at
least four separate models were used. It would have been preferable to use
a single tool, so that proper thermal couplings between house components
could be assessed (O'Brien, Athienitis, and Kesik, 2009). However, such a
toolforearlydesignstageiscurrentlyunavailable.Thisisdifficultwhennew
technologies, such as the BIPV/T roof linked to a ventilated slab, are being
modeled.
7.2.3 Measured Performance
ÉcoTerra's zone temperatures and energy consumption were monitored by
over 150 sensors from construction to early 2012. The data were collected
at regular intervals and stored in an on-site database. The database could
be queried remotely for ongoing analyses that were being performed on
the house for several years following occupancy. The major categories of
electricity use that are measured are PV generation, the heat pump, DHW,
and total electricity use. The data were disaggregated using knowledge of
power draw and by using pattern recognition on the total power draw,
as explained by Doiron, O'Brien, and Athienitis (2011). The heat pump
electricity consumption for both heating and cooling are combined. For
the purpose of the analysis that follows, it is assumed that only heating
or cooling occur in any given month and that therefore, there is a modest
amount of cooling in July and heating is used for the months other than
June through August.
Key results are shown in Figures 7.12 and 7.13 . Some notable lessons from
the data for the period from December 2009 to November 2010 are
explained next.