ASHRAE Journal - September 2014 - 80

2014 ASHRAE TECHNOLOGY AWARD CASE STUDIES

setpoint. Dehumidification is seldom
72°F Max.
Water Cooled Lab
required in Calgary's dry temperate cliEquipment and
Evap.
Heat Pumps
mate. Cooling coil return water is cascaded
Cooler
to supply the radiant slab and panel loops,
Overhead Radiant
Evap.
Cooling Panels
Cooler
augmented with additional flow from the
Radiant Cooling Slabs
storage tank when required to meet the
load. The radiant panel loop also serves as a
Campus
Cooling Loop
process condenser water network for water68°F
Backup
cooled lab equipment (Figure 4).
Bypass to Charge Cooling
61°F
Slabs Direct at Night
Supply and exhaust air terminal units
Stratified
AHU Cooling Coils
64°F Max.
Thermal
serving each lab, office suite or classroom
and Miscellaneous
Storage Tank 50°F Min.
Fan Coils
are connected to the mains in the corridors.
FIGURE 4: Cooling plant concept.
Each lab may have fume hoods, source capture snorkels, heat capture hoods and general exhaust. During the early stages of the
integrated design process, the team established a new
campus fume hood standard with a lower working sash
height, reducing lab peak exhaust rates by more than
20%. Hood sash alarms remind users to close sashes
when not in use. Snorkels were used to replace hoods
whenever feasible and lab air change rates are reduced
to half when labs are unoccupied.
Lab base cooling is provided by the chilled floor slab;
dual circuit interior radiant panels, also designed as acoustic panels, modulate in either cooling or heating mode,
Radiant tubing from manifolds ready for concrete topping.
avoiding reheat coils or additional supplemental cooling
airflow. The panels are also used as a light bounce surface
for the indirect lighting fixtures. Base heating in perimeter the electrical energy devoted to lighting, and mechanical
energy devoted to removing the heat produced from that
rooms is provided by light shelf/radiant heating panels.
lighting.
Cooling loads in offices or classrooms are lower than
The east-west orientation enhanced access to north
labs, so the chilled slab and displacement ventilation is
and south sun, but adjacent high buildings to the south
sufficient to carry the load. The interior radiant panels
of the site restricted lower floor access to daylight durfound in labs are replaced by acoustic/light bounce panels. Outdoor air rates exceed ASHRAE Standard 62.1-2010 ing winter months. The shape of the site restricted the
length of the building such that the depth of the floor
in all spaces by a minimum of 30% while still delivering
plate was necessarily wider than is optimum for full floor
exceptional energy efficiency. During occupied hours,
occupancy sensors turn empty room lights off and reduce plate daylight penetration. Massing strategies provide
large perimeter openings with external shading devices,
air to 33% of full flow; at night, the ventilation is off.
a central clerestory and light well through the center of
Classroom and office exhaust is collected through the
the building, and glazed corridors to the teaching spaces.
atrium with some drawn through electrical rooms and
A large light scoop at the top of the atrium drives light
communication closets to provide secondary cooling.
deep into the heart of the building (Figures 5a and b).
Daylight and Solar Control
The integrated design process supported by extensive
Daylight harvesting in regularly occupied spaces
energy and solar modeling yielded a distinctive envelope
improved the quality of the indoor environment by
design that minimizes peak solar loads within the buildmaking it more conducive to teaching and learning, as
ing, resulting in reduced mechanical first cost by reducing
well as reducing overall building energy use by lowering the cooling system capacity and complexity. In addition to
80

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ASHRAE Journal - September 2014

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