Net ZEB Case Studies - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 469

Thesecondevaluationconcernsthethermalcomfortinthebuildingwiththe
comparison of the model and the measurements for the annual temperature
profile of an office. The use of ceiling fans scheduled during design is also
discussed.
7.5.11.1 Energy Use
The methodology used by the design office (Garde et al. , 2011) to forecast
the energy consumption of the building in the design phase is rather basic
and simple to establish. It consists of listing all the equipment, appliances,
and systems installed in the building, using an assumed-use scenario
(number of hours of use per day and number of days per year) and
multiplying by a factor that accounts for the fact that all equipment is not
used at the same time and not at the maximum capacity (i.e., diversity
factor). In this method, there are several uncertainties associated with the
equipment installed, the use scenario, or even the factors used based
predominantly on the previous experience of the design office. The aim of
this section is to explain uncertainties on energy consumption prediction,
during the design phase.
Figure 7.78 and Table 7.22 present a comparison between the energy use
that was predicted during design by end-uses and the measurements taken
in the building while in operation for 2 years (June 2010 to May 2011 and
June 2011 to May 2012). The ratios are given for the net floor area and final
energy (electricity). Overall consumption has been largely overestimated
during the design stage (45 kWh/m 2 /yr instead of 13-14 kWh/m 2 /yr).
Major errors made during the design phase to predict the energy
consumption of ENERPOS were in relation to the split systems used to cool
the two technical rooms, the air-conditioning (AC), the AHU, and the plug
loads.