ASHRAE Journal - December 2013 - 30

2013 ASHRAE TEcHnology AwARd cASE STudiES

conditions permit, the office/laboratory
Table 1 Simulation results excluding the process load compared to the actual invoices.
system can switch to free cooling mode in
suMMary
order to increase indoor air quality. This
Baseline Case
ProPosed Case
invoiCes
eui
double deck system was deemed approMonths
Without ProCess
Without ProCess inCluding ProCess
kWh eq /M 2
priate to respect the desired comfort for
kWh eq
kWh eq
kWh eq
the occupants while compensating for the
April 2011
149,976
82,872
123,233
27
exhaust air rates. Several sensors are presMay 2011
115,308
82,672
196,651
47
ent to control the operating mode and to
June 2011
111,424
86,282
97,946
23
maintain the temperature and humidity
July 2011
122,655
95,780
106,829
26
inside their acceptable ranges.
August 2011
123,071
93,253
122,400
29
The ventilation requirements in the
September 2011
82,342
75,964
114,676
27
laboratories are extremely strict. The
October 2011
145,539
79,380
132,998
32
laboratories must maintain negative presNovember 2011
199,303
82,407
204,801
49
sure at all times, provide very high air
December 2011
294,470
99,437
189,015
45
exchange rates, and no cross-contaminaJanuary 2012
332,114
106,485
171,045
41
tion between incoming and exhaust air is
February 2012
281,744
94,178
196,937
47
acceptable. As a result, the laboratory ventilation system is capable of supplying a
March 2012
232,438
95,668
151,970
36
ventilation rate of 10 air changes per hour
Total
2,190,386
1,074,378
1,798,502
430
during occupied hours and 6 air changes
per hour during unoccupied hours and ensures that no the installed airflow exceeds the ASHRAE standard at
harmful gases and odors migrate to the surrounding
normal occupancy densities. For example, in each labospaces by maintaining negative pressure.
ratory with a ceiling height of 2.9 m, the average ventilaA runaround type heat recovery system is used to
tion rate is 0.066 L/s·m2 (0.013 cfm/ft2), as opposed to
Standard 62.1-2004 which requires a rate of 0.019 L/s·m2
recover heat from the laboratory exhaust. Having an
(0.004 cfm/ft2), considering normal occupant density.
efficiency of 45%, this type of heat recovery system
For the exhibition hall, the variperforms less than other types
able volume air handling system
available on the market; howsupplies air to only one large zone.
ever, this type of system does not
In this case, under floor air distriallow any contaminants from the
bution was an appropriate stratexhaust air to be reintroduced
egy considering the 4 m ( 13 ft)
into the outdoor air supply. This
ceiling height, the amount of natheat recovery system reclaims
ural lighting, and the space usage
90 kW in the winter and 21 kW
(constantly changing artwork disin the summer. Other efficiency
plays). Air stratification elevates
measures for the laboratory venInner court, mirror pond and collections.
the temperature from 16.7°C to
tilation system include frequency
nearly 29°C (62°F to nearly 84°F)
inverters to control the fan motor
at roof level. During mid-season, this system can also
speeds as well as occupancy sensors, carbon dioxide
operate in natural cooling mode, where 100% outdoor
sensors and scheduling controls to lower the ventilaair is introduced into the space for cooling, thus saving
tion rates when the spaces are unoccupied. Because
energy.
of the laboratory equipment, heating and cooling
Montreal has several outdoor air sampling stations
is entirely provided by a ceiling distribution system
and, the values are below the EPA's established guidewith a ventilation effectiveness (Ez) of 1.0 in the summer and 0.8 in the winter.
lines. Even though, each HVAC system is equipped with
When comparing ventilation rates established by
a filtration media with MERV13 minimum efficiency
ASHRAE Standard 62.1 and the installed ventilation rates and is part of a regular maintenance program. With the
imposed by the owner's requirements and space use,
exception of the laboratories, where negative pressure
30

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ASHRAE Journal - December 2013

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