Laboratory research facilities have xtremely high energy costs, due primarily to the vast amounts
of 100 percent outside air required to
meet minimum ventilation or air change
requirements. Reducing facility and energy
expenses has become a critical challenge
for both new and existing lab facilities.
Equally important is reducing carbon footprints, meeting green building goals and
providing a better indoor environment.
Until recently, there has been very little
objective data on how reducing or varying
air change rates would affect energy
savings. To address this gap, the American
Industrial Hygiene Association (AIHA)
conducted a major research study on the
indoor environmental quality (IEQ) conditions of 300 lab areas and vivariums that
are using dynamic control of air change
rates. The study demonstrated that laboratories can use lower air flow rates with an
automatic air change rate control system
for well over 97 percent of the time.
Optimizing outside air exchange
The primary reason behind high laboratory energy expenses is the amount of
outside air required for facility ventilation.
Particularly for life sciences labs, air flow is
often dictated by the minimum air change
rate for the space. The number of air
changes per hour (ACH) may be from 6 to
12 in any given laboratory. This (
somewhat arbitrary) ACH rate is often way too
high—if the air in these rooms is “clean,”
or free of any harmful or irritating contaminants, such high air change rates are
often not necessary.
If Your Lab’s Air is Clean,
Why Change it?
A new study says a lab’s air is clean 99 percent of the time,
suggesting lower flow rates can be used, resulting in reduced
energy and expenses.
by Gordon Sharp, Founder & Chairman, Aircuity Inc.
Figure 1 shows the average TVOC level percentages for multiple lab sites. Photo: Aircuity
One approach that has been shown to
effectively and safely vary air change rates
in labs and vivariums is to use a sensor
to detect the air quality for such contaminants as total volatile organic compounds
(TVOCs), ammonia, other chemical vapors
and odors, as well as particulates. When
the sensors indicate that room air is free
of these contaminants, the air change rates
can be reduced, possibly to as low as 2 to 4
ACH for a lab.
Varying air change rates
The AIHA study on laboratory ven-
tilation is believed to be the largest ever
conducted on laboratory and vivarium
IEQ conditions. It covered more than 1.5
million hours of lab operation in more than
300 lab areas at 18 different facilities. The
study collected and analyzed more than
20 million sensor values, including data
on TVOCs, particles ranging from 0.3 to
2. 5 microns, carbon dioxide and dewpoint
(absolute humidity). Facilities in the study
were primarily life sciences and biology-re-
lated areas, along with a smaller number of
chemistry and physical sciences lab areas.
The study used multiplexed sensing,
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