Gustafson explains. “These come mostly from paint, indoor
Find the Source of the Complaint
building materials and even copy machines.”
Temperature and humidity aren’t problems in themselves
but can detract from both overall comfort and create the
conditions for even bigger problems – particularly mold – to
develop. High humidity leads to mildew, which can make
your occupants sick, Gustafson says. ASHRAE Standard 62
recommends a relative humidity of 30-60% to discourage
pathogens and allergens from growing.
Taking persistent complaints with a grain of salt isn’t an
option – a pattern of comments about the same concern
indicates a real problem. Start by questioning the individual
and anyone sitting nearby to gather details about the problem. What exactly did it smell like? What symptoms are they
having? This information can give you clues about where
to look next – the answer may be a quick fix that doesn’t
require further investigation.
“For example, if you get an occupant complaint about
smelling natural gas, right away you would want to iden-
tify all of the appliances in the building that use natural
exacerbate any problem. Poor exhaust and stuck dampers can
allow unwanted gases or pollutants to build up in a space.
“Carbon dioxide is the main pollutant that people moni-
tor because it’s generated regularly and aggressively by
human activity,” notes Herm Gustafson, Product Marketing
Engineer for Onset, a manufacturer of data loggers that
can measure CO2 and other IAQ-impacting contaminants.
“One of the spaces that has become increasingly targeted for
CO2 monitoring is workout spaces because of all the meta-
bolic activity present. Schools are also good candidates for
monitoring because the buildings are notoriously outdated.
There may be too many kids in classrooms and there gener-
ally isn’t space in the budget for the latest building automa-
tion system, which means they don’t have a way to set up
demand controlled ventilation.”
Volatile organic chemicals (VOCs) are also common,
though off-gassing tends to fade with time. This might be
a concern if you’re renovating, painting or bringing in new
furniture, carpet or cabinetry.
“Basically anything you can smell is generated by a VOC.
That could be cleaning chemicals or even food, because
VOCs are generated when something boils or vaporizes,”
TOMASZ BIDERMANN / SHU TTERSTOCK.COM AND ONSE T
Indoor climate data loggers can measure a variety of air quality information. If your facility has demand controlled ventilation, make sure these sensors are up to date – accurate readings ensure responsive ventilation.
Retrieve the data on a regular basis so you can look for patterns.
One measurement may not tell the whole story, however – for
instance, the red graph indicating a CO2 spike below could use
some additional context. Compare it side by side with other
factors measured in the same space to get a clearer picture. The
graph at bottom shows the same CO2 measurement in blue, but
with temperature (red) and relative humidity (green) added. The
extra information will help you figure out why the CO2 spiked on
May 22 and then remained low for days while the temperature
rose and fell and the humidity spiked again two days later.
UPDATE YOUR DATA-GATHERING PRACTICES