Coronavirus
Technology Solutions
The Foundation
of COVID
Mitigation
Strategy Should
be Mask
Effectiveness
Cummins is
Making Masks
with Uniquely
Charged
Meltblowns
Outdoor Air
Reliance in NY
is not a Great
Winter Solution
________________________________________________________________________
The Foundation
of COVID
Mitigation
Strategy Should
be Mask
Effectiveness
The strategy to
defeat COVID
should be based
on use of highly
efficient masks.
All other
options are more
costly and less
effective with
the exception of
total lockdowns.
The virus spread
with near normal
activity but
correct use of
CATER 95 masks
will be less
than if there is
a partial
lockdown and use
of ASTM 20
masks.
The strategy
which treats all
masks as equal
makes little
sense. It is the
equivalent of
saying that
whether a room
has one occupant
or 100 the risks
are the same. In
fact if all
occupants are
wearing CATER 95
masks the risk
is equivalent to
the room with
one unmasked
occupant. If
every one of the
100 people is
wearing
an ASTM
20 mask you have
the equivalent
of 71 unmasked
people. This 70
to 1 ratio means
that mask
efficiency
should be the
cornerstone of
COVID policy.
The following
examples were
calculated based
on available
information for
various types of
masks. The net
efficiency
equals the media
efficiency less
leaks.
Masks are worn
by the both the
transmitter and
the recipient.
So the total
virus inhaled
becomes a
function of the
removal in the
two sets of
masks.
The CATER 95
mask is
therefore 71
times more
effective at
preventing virus
inhalation than
is an ASTM 20
mask. Granted
that fitness and
other variables
are not
precisely
quantified but
this is a
reasonable
comparison.
Another approach
is to compare
combined
efficiency.
If the decision
is made on a
basis of
comparative
efficiency it is
easy to argue
that a less
efficient mask
is better than
nothing. At
least an ASTM 20
will remove 29%
of the virus if
worn by all.
But when
you consider
that it allows
71 times as much
virus to
penetrate as
does a CATER 95
mask this is a
powerful metric
and one that can
be used in a
total plan which
includes social
distancing,
HVAC, and
lockdowns.
Rigorous Social
distancing
including
prevention of
large gatherings
could have an
effect of
reducing virus
inhalation by
40%.
If
partial lockdown
is combined with
ASTM 20 masks a
total reduction
of 79% might be
achieved. It
could be argued
that if everyone
wore CATER 95
mask you could
eliminate most
social
distancing. In
the case of bars
fan filter units
and directional
air flow would
be needed
because of the
need to remove
masks while
drinking or
eating.
The value of
CATER 95 masks
is even greater
compared to
alternatives
when you
consider that
air pollution,
wildfires and
other air
contaminants are
equally
important.
Hypothetically
let’s assume a
total load which
is 200% of the
COVID. So the
COVID load could
equal 50% of the
contamination
(100), colds and
other virus
related
infections are
10% (20) and air
pollutants and
other air
contaminants are
40% (80).
The graph
then reflects a
total
contaminant load
of 200
It is clear that
the benefit of
CATER 95 masks
is far superior
to the
alternatives
when all
pollutants are
considered.
Social
distancing does
not reduce the
amount of air
pollutants
inhaled.
Mask efficiency
should be the
basis of all the
social
distancing,
lockdowns,
school, bar and
restaurant
openings. If
everyone wears a
highly efficient
mask there will
be the ability
to return to
near normal
activities while
reducing the
COVID spread.
Ignoring mask
efficiency is as
illogical as
saying social
distancing of
one foot or one
mile should be
treated equally.
The mask
protection has
been proven in
every pandemic.
Doctors were
kept safe from
EBOLA by wearing
masks and taking
other
protections. The
highly
efficient masks
provided the 99
% protection but
other PPE
assured that the
protection was
99.9999%.
“Because of our
expertise in the
automotive
filtration
industry, we
believed we
could adapt to
supply the
filter media
used in the face
masks worn by
healthcare
providers, which
are also in high
demand across
the nation,”
Christopher
Holm, director
of filter media
technology and
IP at Cummins,
said in a news
release posted
yesterday.
Oak Ridge’s
Carbon Fiber
Technology
Facility
meanwhile worked
with Peter Tsai,
the inventor of
N95 filter
media, to
develop a novel
in-line charging
device that
could be placed
on the precursor
production line
to
electrostatically
charge
melt-blown
material made of
polypropylene or
PP.
Electrostatically
charging the
material with
millions of
microfibers
layered on top
of each other
creates a filter
material able to
remove more than
95% of submicron
particles and
viruses such as
the one that
causes COVID-19.
“We reached our
target goal in
only a few weeks
on pilot scale
melt blowing
capability at
the CFTF and had
the capability
to produce
filter media for
9,000 masks per
hour when we
connected with
Cummins for
potential
technology
transfer and
scale up,” said
Merlin Theodore,
director of the
CFTF at Oak
Ridge. “Cummins
was an ideal
partner to scale
what we had
accomplished and
helped us
produce material
that passed all
required testing
for filter
media.”
ORNL’s research
team designed
and manufactured
a custom
electrostatic
charging device
for Cummins,
assisting in the
installation of
the device on
the company’s
Cookeville
facility
production line.
“Their research
has made it
possible to be
where we are
today,” Holm
said. “We can
manufacture
material that
has passed all
the required
testing for N95
filter media.”
Two months ago,
Cummins had
never produced
filter media for
face masks.
Today, it’s
already shipped
material to
multiple
customers across
the country for
the production
of millions of
masks.
BelEmsa, one of
the leading
manufacturers of
disposable
hygienic
products, has
increased mask
production to
200 million
pieces per month
in Europe,
according to
Aleksandr
Kolesnov, the
first deputy
director of
BelEmsa in an
article in
Nonwovens
Industry.
The DOD’s
Defense Assisted
Acquisition Cell
led this effort
in coordination
with the
Department of
the Air Force’s
Acquisition
COVID-19 Task
Force. This
effort, funded
through the HHS
Coronavirus Aid,
Relief and
Economic
Security (CARES)
Act, supports
domestic
industrial base
expansion for
critical medical
resources.
Lincoln, RI Buys
Air Purifiers
for Schools
All told,
Lincoln Public
Schools have
spent roughly
$1.2 million in
unbudgeted funds
responding to
the COVID-19
pandemic.
Lincoln schools
received four
separate grants
to assist with
safely reopening
in the COVID
environment.
The first source
was the
Coronavirus Aid,
Relief and
Economic
Security (CARES)
Act – money
specifically
allocated to
elementary and
secondary
schools for a
wide range of
activities,
including the
prevention,
preparation for
and response to
the coronavirus.
Gov. Gina
Raimondo awarded
Lincoln with
$472,779 to help
fill a gap in
state aid to
education.
Essentially,
McNamee said the
state shorted
Lincoln in
education aid
this year but
replaced the
shortfall with
CARES Act
Elementary and
Secondary School
Emergency Relief
funds.
Secondly, the
state of Rhode
Island was
provided with
roughly $1.25
billion in
federal
coronavirus
relief funds
under the CARES
Act. Of that
number, Raimondo
allocated $50
million for the
schools, with
Lincoln
receiving
$570,908.
Lincoln spent an
additional
$64,234,
provided by the
Council on
Elementary and
Secondary
Education, to
purchase
portable air
filtration units
and make
improvements to
all of the
schools’
existing air
filtration and
ventilation
systems.
In total,
Lincoln schools
received
$1,159,916 in
COVID relief.
Outdoor Air
Reliance in NY
is not a Great
Winter Solution
My feet are
starting to
freeze,” a
Brooklyn
public-school
teacher tweeted on
December 9, when
she had two
classroom
windows open
despite the
temperature
outdoors
dropping to 31
degrees. Despite
the weather
getting colder,
she said
teachers in her
building have
been told to
keep the windows
open
indefinitely.
It’s the same in
schools across
the city, where
scores of NYC
elementary
teachers and
students are
bundled up in
frigid
classrooms to
prevent the
spread of the
coronavirus.
Is this the best
that New York
City schools can
offer? Until the
city upgrades
hundreds of New
York City school
buildings, the
short answer is
yes. Ventilation
systems in the
buildings built
in the early
1900s “basically
rely entirely on
open windows,
like the whole
one wall of a
classroom is
just all
windows,” said
Edward Olmsted,
an industrial
hygienist, whose
job it is to
make sure that
an indoor space
has good air
quality with no
mold or other
contaminants.
Olmsted serves
as a consultant
for the United
Federation of
Teachers (UFT)
and has been
working on
fixing school
ventilation
issues since the
summer. A lot of
these prewar
school buildings
built during the
Spanish flu
pandemic were
designed to keep
airborne
illnesses at bay
with steam
radiators overheating
rooms and the
windows always
open — but a
century later,
that doesn’t
always work in
practice. The
city’s
Department of
Education also
issued new
guidance that
when the room
temperatures are
uncomfortably
cold, custodians
should raise
boiler settings
and preheat the
building — but
this still
leaves teachers
and students
shivering in
class.
Newer school
buildings have
better
ventilations
systems, but the
problem is that
schools — old or
new — now need
the kinds of
systems found in
hospitals.
“Nobody builds a
regular building
that way, so
suddenly
everybody is
being asked to
upgrade their
ventilation
systems, to
really perform
like it would in
a hospital,”
Olmsted said.
“[But] you can’t
just easily make
a few changes,
turn a few
screws, or
change a couple
pieces or parts,
and suddenly
it’s a hospital
system; it can’t
be done.” A
typical fan
system’s filter
is rated MERV 8,
while hospitals
usually have
MERV 15 or 16
filters (the
higher the MERV
numbers, the
smaller the dust
particles it can
filter out).
Experts are now
recommending
MERV 13 filters,
which remove
about 90 percent
of the aerosol
that could carry
infectious virus
particles.
The DOE is now installing
thousands of
MERV 13 filters,
prioritizing
buildings with a
central HVAC
system or no
windows. The
agency is also
installing
30,000 High
Efficiency
Particulate Air
or HEPA purifier
units in
classrooms,
which capture over
99 percent of
particles in the
air.
Once these
purifiers are
installed,
classroom
windows don’t
need to remain
open, said a DOE
spokesperson.
The agency
expects to
deliver an
additional
30,000 purifiers
by January,
according to an
internal memo
sent to DOE
custodians. Once
the 60,000 units
are installed,
this should
cover most of
the classrooms
that need it,
said the
department.
But some parents
are skeptical.
“I am not
confident that
those air
purifiers will
be enough to
circulate the
air. I am not
confident that
if they do show
up, they will be
working,” Naomi
Peña, director
of the Community
Education
Council for
District 1 and
public-school
mom, told me.
She may have a
point. According
to the EPA,
both filters and
air purifiers
are effective at
filtering out
coronavirus
particles, but
by themselves
are not enough —
they should be
used in
conjunction with
mask-wearing,
social
distancing, and
other common
safety
practices — like
opening windows.
Though Peña’s
children are
studying
remotely, they
see their
classmates at
the school via
Zoom. Her
11-year old son
was puzzled to
see one of his
friends wearing
a coat inside
the classroom
and asked her,
“Why can’t he
just come over
to our house so
he can be warm?”
And he has a
point, Peña
says. “When it’s
cold and you’re
wearing gloves
and a coat … How
can you possibly
learn?”
Doug Engel
analyzed the
changes in
thinking
relative to HVAC
strategy to
fight Covid in
the December
issue of
Facility
Executive.
As he
points out
ASHRAE’s
Epidemic Task
Force (ETF) has
been at the
forefront of
providing
actionable
recommendations
for mitigating
the airborne
transmission of
COVID-19 in
buildings.
Initially ASHRAE
recommended
maximizing the
outside air
intake of
mechanical
systems and
minimizing
recirculation.
It encouraged
opening windows
and increasing
ventilation with
fans.
High-efficiency
filtration was
an additional
key
consideration,
with guidance
urging an
upgrade to a
minimum of MERV
13 filters for
central HVAC
systems. In the
absence of
central systems,
or if they could
not accommodate
high-efficiency
filtration, then
it was
recommended that
“demonstrated
safe and
effective”
in-room air
cleaners be
employed.
Since the
Spring, however,
several
developments
have contributed
to a shift in
thinking
regarding early
guidance. Dr.
Bill Bahnfleth,
Professor of
Architectural
Engineering at
Penn State and
Chair of the
ASHRAE ETF,
recently shared
in a widely
attended October
webinar that
early guidance
from the ETF in
April was driven
by perceived
risk and
possible
effectiveness.
He referred to
the initial
recommendations
as
“conservative”
and that they
“did not factor
in cost and
operational
impacts.” Also,
he outlined key
factors that
have prompted a
re-evaluation of
the guidance and
previewed new
core
recommendations
that will be
forthcoming from
ASHRAE.
KEY FACTORS
Risk
estimations. Increased
use of tools
that estimate
airborne
transmission
offers a
quantitative
prediction of
risk. There are
a number of
estimators, but
the most widely
used is The
COVID Airborne
Transmission
Estimator,²
created by
Professor
Jimenez of the
CIRES
(Cooperative
Institute for
Research in
Environmental
Sciences) at CU
Boulder. This
estimator, and
others, rely on
the Wells-Riley
model, an
accepted
industry
standard
approach for
assessing the
risk of airborne
infection in
buildings. The
Wells-Riley
model takes into
account factors
such as the size
of the building,
number of
occupants,
number of
infected people,
and the amount
of time infected
individuals
spend in the
building.
Equivalent
filtration
effectiveness. In
numerous
presentations,
Prof. Bahnfleth
has emphasized
high efficiency
filtration, and
reiterated that
guidance in the
recent webinar,
“We have
evidence that
better
filtration is as
effective as
ventilation and
lower cost.” He
referenced this
analysis
conducted by
Prof. Brent
Stephens and
Parham Azimi for
the Built
Environment
Research Group
at Illinois Tech
that shows the
relative cost of
outside air
ventilation in
different U.S.
locations versus
filtration.
The graph below
shows that the
most
cost-effective
and efficient
approach to
reducing
infection rates
is using a MERV
13 filter, and
that outdoor air
increases cost
at least four
times as much to
achieve the same
benefit.
Energy,
economic, and
operational
considerations. Prof.
Bahnfleth also
spoke to the
fact that ASHRAE
has taken a
closer look at
the energy,
economic, and
operational
impacts of HVAC
strategies for
COVID
mitigation,
particularly its
guidance on
ventilation. As
many in the
industry have
pointed out,
maximizing
outside air
ventilation is
expensive and
energy
intensive—the
often-cited
“energy penalty”
associated with
conditioning
increased
amounts of
outdoor air. It
is even more of
a concern during
the
energy-intensive
winter months.
Additionally,
there are other
environmental
considerations
that need to be
factored in: PM
2.5 from
pollution and
the smoke from
wildfires
plaguing the
western U.S. are
two significant
concerns.
Relative
humidity also
plays a role, as
research
emphasizes³ the
need to keep
relative
humidity between
40-60% to both
reduce the
transmission
risk of the
virus and to
support the
respiratory
health of
building
occupants.
Equivalent
outdoor air
changes. The
Air Change Rate,
e.g., the rate
at which the air
in a specific
space is
replaced with
clean air is
typically
expressed in Air
Changes per Hour
(ACH). ACH has
been assumed to
refer to outdoor
air exchanges.
However, with
limitations of
HVAC systems,
the superiority
of highly
filtered air
given
environmental
issues such as
pollution/smoke,
and new
consideration of
energy impacts,
experts are now
promoting
“equivalent
outdoor air”
changes. These
equivalencies
can be achieved
by deploying
high-efficiency
filtration,
in-room HEPA
filters, as well
as innovative
approaches such
as sorbent-based
filtration.
A helpful tool
for school
facility
managers is the
Harvard-CU
Boulder Portable
Air Cleaner
Calculator for
Schools. It
simplifies
decision making
around deploying
in-room air
cleaners and can
also be adapted
for office and
retail
settings. Experts
from the Harvard
T.H. Chan School
for Public
Health recommend
5 ACH per hour,
but provide
ranges, with 4-5
ACH as Good, 5-6
as Excellent and
6 ACH as Ideal.
SIMPLIFYING
GUIDANCE
The ASHRAE ETF
will likely
share new core
recommendations
before the end
of 2020, with
the goal of
updating
guidance to
reflect the
above factors,
and to simplify
recommendations
across its
various
subcommittees.
From the preview
Prof. Bahnfleth
offered,
the
update will
likely
emphasize:
·
Use of minimum
outdoor air as
required by
Standard 62.1
·
Employ
high-efficiency
MERV 13
filtration
and/or
stand-alone HEPA
air cleaners for
recirculated air
·
Achieve
equivalent air
changes using a
combination of
outdoor air,
filtration, and
air cleaners
·
HVAC controls
that achieve
exposure
reduction goals
while minimizing
associated
energy penalties
ENERGY,
ECONOMIC, AND
CARBON
With the renewed
focus on cost
from increased
energy
consumption,
there is a need
for a tool to
help calculate
costs of various
ventilation and
filtration
approaches.
While risk is
the paramount
consideration,
models providing
a more complete
picture allows
for more
informed
decision-making
Doug says
his
company, enVerid,
has released the
enVerid COVID-19
Energy
Estimator, an
open-source,
vetted tool
building upon
Prof. Jimenez’s
COVID Airborne
Transmission
Estimator. This
tool performs
predictive
calculations for
energy
expenditures. In
addition to
enabling a
comparison of
energy use among
HVAC strategies,
it offers
insight into
anticipated
carbon emissions
associated with
each approach.
For example,
building
engineers
evaluating a
50,000 square
foot office in
Boston with 250
occupants and
design supply
air of 50,000
CFM can compare
two
approaches—switching
to 100% outside
air (OA) or
upgrading to
MERV 13
high-efficiency
filters and
bringing in
minimum OA as
per ASHRAE’s
Indoor Air
Quality
Procedure
(IAQP).
As shown in the
table below, the
Energy Estimator
shows both
strategies will
deliver over
five effective
air changes per
hour (ACH),
considered
excellent by the
Harvard School
of Public
Health, but the
100% OA strategy
will cost
$85,827 per year
compared to
$12,261 per year
for the
MERV13/IAQP
approach. When
reviewing the
carbon impacts
of the two
approaches, the
Energy Estimator
shows the 100%
OA strategy will
generate 325
metric tons of
CO2 per year
versus 28 metric
tons for the
MERV 13/IAQP
approach.
This graph shows
findings that
the most
cost-effective
and efficient
approach to
reducing
infection rates
is using a MERV
13 filter, and
that outdoor air
increases cost
at least four
times as much to
achieve the same
benefit. (Graph:
Provided by
enVerid)
AN UNDERUTILIZED
APPROACH
Given the
current focus on
IAQ, it makes
sense that
building
management and
engineers take a
close look at
ASHRAE’s Indoor
Air Quality
Procedure. In
its Standard
62.1, ASHRAE
defines two
procedures for
mechanical
ventilation: the
Ventilation Rate
Procedure (VRP)
and the Indoor
Air Quality
Procedure
(IAQP). VRP
defines
ventilation
requirements
based on space
size and
occupancy
without
factoring in the
efficiency
benefits
afforded by air
cleaning
technologies.
Alternatively,
IAQP is a
performance-based
ventilation
approach that
achieves the
same results
with less
outside air, and
therefore a
reduction in
energy expenses,
particularly
when employing
air scrubbing
technology.
Designing HVAC
systems using
IAQP combined
with sorbent-based
air cleaning and
high-efficiency
filtration
significantly
reduces first
and operating
costs without
increasing the
risk of airborne
transmission of
viruses. When
put to the test
utilizing the
Wells-Riley
equation
described above,
it was found
that same
relative risk of
airborne
transmission can
be achieved with
improved
filtration and
reduced
ventilation when
ASHRAE’s 62.1
IAQP is used
with sorbent-based
air cleaning
technology.
Using this
approach,
savings from
reduced
ventilation can
more than offset
the cost of
increasing
filtration (see
graph below).
·
ASHRAE’s
contaminants of
concern,
including
formaldehyde,
are scrubbed out
of the air.
·
By using less
outside air, it
is easier to
maintain
relative
humidity (RH) in
the 40-60% range
which experts
posit inhibits
the spread of
viruses. In
winter we are
concerned with
the dry air and
introducing more
outside air
would likely
cause the RH
figure to drop
below 40%.
·
Air scrubbing
reduces fine
particulates (PM
2.5) from
pollution or
smoke, while
ventilation
increases them.
Particulates
inflame the
lungs, making
catching the
virus
potentially more
likely and its
impacts more
severe.
·
Certain air
scrubbing
technologies can
also reduce CO2
levels. Research
from
Harvard points
to the
degradation of
cognitive
function when
CO2 levels rise
in indoor air,
an issue of
particular
concern in
schools and
offices.
·
Ozone exists in
outside air and
is known to
damage the lungs
and exacerbate
chronic
respiratory
conditions.
Building
engineers
evaluated a
50,000 square
foot office in
Boston with 250
occupants and
design supply
air of 50,000
CFM using the
enVerid COVID-19
Energy
Estimator. This
open-source,
vetted tool
performs
predictive
calculations for
energy
expenditures.
(Chart: Provided
by enVerid)
COVID-19 has
thrust IAQ
issues into the
spotlight.
Controlling
airborne
transmission of
the virus is the
most pressing
task, yet there
are a host of
IAQ
considerations
that need to be
addressed.
Facilities need
to employ
effective and
energy efficient
solutions to
respond to the
pandemic today,
and to future
proof for the
next crisis.
Additionally,
for many,
addressing IAQ
must also be
managed within
the context of
lowering a
building’s
carbon
footprint. This
is a tall order,
but all within
reach.
The complete
article is found
at
https://facilityexecutive.com/2020/12/indoor-air-quality-and-the-pandemic/
|