Net ZEB Case Studies - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 480

maintaining an acceptable level of comfort for its users (Lenoir, Baird, and
Garde, 2012).
The lessons learned from ENERPOS will be useful in the design of future
Net ZEBs, especially in tropical climates. The particularly strong link
between comfort and energy design was evident in the design of this
building. Assumptions about comfort and user behavior had a very high
influence on the energy used. Thermal comfort considerations dominated
the energy design of the building and they also pointed out the need in
further research on this important topic, as well as the need to develop
simulation tools that integrate comfort and energy design of buildings in a
more systematic way.
7.5.13.1 Interior Lighting
An improvement could be made on the interior lighting switches of the
classrooms. Daylighting measurements showed that three parallel areas can
be defined. The daylighting is very satisfactory (above 500 lux during the
hours of occupancy) near the windows overlooking the exterior, lower
(below 300 lux a few hours per day) in the middle, and even lower (below
300 lux several hours per day) on the side of the building overlooking the
green patio toward the other building wing. The lights can be controlled
with three different switches such that the darkest part of the room can be
independently lit.
7.5.13.2 Elevator Energy
Data from the energy monitoring system showed that energy consumption
of the elevator accounted for 13% of the overall energy use of the building
(which represents 120 kWh/m 2 ·yr). All the inside lights were constantly on.
A standby mode was activated, reducing the elevator's energy used by half
(reduction of 65 kWh/month).
7.5.13.3 Air-Conditioning
As the air-conditioning of the building is barely used (except for one split
system cooling a technical room), its consumption is minimal. However,
the VRF system and the ceiling terminal units represent 15% of the overall
energy use of the building. In fact, it was discovered that the small display
screens installed in the offices and computer rooms consume 7 W, with a
monthly consumption of 20 kWh.