ASHRAE Journal - June 2022 - 47

COLUMN RESIDENTIAL APPLICATIONS
In fact, it is often considered as an intentional fl aw in the
integrity of the pressure boundary. But that is only one
element of a mechanical ventilation system and overlooks
the purpose and desired goal of ventilation, which
is the protection of the health of the occupants and the
building. It is complex to value good indoor air quality,
but that doesn't mean we shouldn't try.
A great deal of well documented science exists that connects
indoor air quality to health. It is also fair to say that
poor health impacts productivity: if you're sick you can't
achieve your optimum performance. Therefore, improving
the air quality in a house will impact the productivity
of the occupants. The only question is: by how much?
There are a vast number of studies on the relationship
of indoor air quality to the health and productivity
of offi ce workers. Even before the COVID-19 pandemic
drove us out of our offi ces and back into our homes,
we were spending 90% of our time inside buildings.
Because of the preponderance of working from home,
we can transfer many of the fi ndings relating to offi ce
health and productivity loss to our homes.
Impact of Pollutants on Productivity
Pollutants (see " Pollutants " sidebar) can make the
occupants of homes chronically sick and acutely sick.
And if you're sick, it's diffi cult or impossible to work
productively. Since those pollutants impact the health of
the occupants, the presence of those pollutants impact
productivity. People who do not feel well do not work
well. Studies show beyond reasonable doubt that poor
indoor air quality in buildings can decrease productivity.2
" In the workplace, the economic burden of poor
health includes not only medical and pharmaceutical
expenses but also health-related productivity loss
(HRPL) due to sick leave (absenteeism) and reduced
performance while at work because of uncontrolled diseases
or health risks (presenteeism). " 3 There are a lot of
distractions in working from home and not feeling 100%
can lead to extended " break times " or reduced quality of
performance.
Productivity is a measurement of the rate at which
goods and services are produced per unit of labor.
Health conditions such as fatigue, colds, nausea, headaches,
even kidney failure and cancer effect workers'
performance. The U.S. Centers for Disease Control and
Prevention (CDC) estimates that sinus infection sufferers
miss an average of four workdays per year. 4
Pollutants
For energy purposes we have been working diligently
to tighten up houses, restricting air movement. That
process is like putting the cap on the jar: what's in
there stays in there.
A myriad of elements emit pollutants into the air
in homes. That process is not limited to structural
elements but also to the occupants and what they
transport into the house from the outside world. Many
indoor air pollutants fl oat around in the toxic soup
within the pressure boundary of a house. The main
pollutants include NOx, volatile and semi-volatile
organic compounds (VOCs), SO2, O3, CO, particulate
matter (PM10, PM2.5, PM1), radon, toxic metals and
microorganisms. CDC criteria pollutants are lead, sulfur
oxides, CO, nitrogen oxides (NO, NO2) and ozone.
VOCs can cause eye, nose, and throat irritation; and
headaches. Microorganisms can cause fever, digestive
problems, infectious diseases and chronic respiratory
illness.1 These pollutants are airborne and can be
addressed by mechanical ventilation.
Most of these pollutants are invisible, and their
impact on the building and health of the occupants
can be exceptionally slow. Nature is very patient. It is
a reasonable fi rst step to remove the source of the pollutant
if that is possible. But even though radon causes
cancer and ozone causes respiratory problems, the
sources of those pollutants are not always obvious and
not simple to remove.
Creativity and productivity are the driving forces for
corporate success and health can be assumed to be an
element of human capital that is refl ected in economic
growth.3 An article in WELL points out that indoor environmental
quality in bedrooms infl uences next-day
work performance because sleep is essential for health.
The article says: " Just a few percentage points decrease
in work performance has substantial economic implications
because the cost of workforce is up to 100 times
higher than the cost of a building's construction and
operation. " 5 This factor is skewed due to the preponderance
of working-from-home, which may reduce the
importance of the workplace IAQ, while increasing the
importance of the dwelling IAQ, shifting burden to the
employee. And that raises the question of whether it
would behoove an employer to help improve the IAQ in
their employees' homes.
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ASHRAE Journal - June 2022

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