Coronavirus
Technology Solutions
WFI Mask Webinar Dealt with Key Issues
More Rapid Air
Changes Spread
the Virus
U.S. Needs to
Provide Aid to
India
ASHRAE Provides
Guidance for
Protecting
Voters
Chinese
Researchers
Create Charged
Nanofiber Media
with Silver for
Anti-Microbial
Function Filti Supplies MERV 16 Air Filters Using Nanofiber Technology
Gyms Need Better
Air Filtration
Generally
Large French
Retailer
Installs Camfil
HEPA Filters
____________________________________________________________________________
WFI Mask Webinar
Dealt with Key
Issues
On Tuesday WFI
held an on line
webinar relative
to masks.
Christine Sun
stated that “the
webinar included
three experts in
the field for
the latest
update on the
facemask market,
technologies and
testing used to
certify the
masks used.
Ms. Janelle
Bentz, Nelson
Labs,
provided
updates on
testing methods,
Dr. Peter Tsai,
University of
Tennessee,
provided
knowledge on the
meltblowing and
electrostatic
charging
technologies,
while
Mr. Bob
McIlvaine,
McIlvaine
Company,
provided updated
information on
the facemask
market.
In addition to
the
presentation, we
also had experts
discussing and
reviewing
important topics
in the Q&A
session. There
was significant
discussion
around the
testing of masks
and where the
market is
heading, plus
questions about
the manufacture
of meltblown
materials for
masks.”
Wendover Brown
of Vogmask asked
the question as
to whether
nanofibers were
efficient enough
to meet the N95
efficiency
requirements. Dr
Tsai answered a
slightly
different
question as to
whether the
nanofiber media
would capture
the virus.
His answer was
an explanation
that the pore
size in the
nanofiber media
is considerably
larger than the
virus. Pore size
in turn is a
function of
packing density
which in turn
determines
pressure drop.
The implication
was that only
the charged
meltblown media
had the ability
to capture the
virus at
acceptable
pressure drop in
a face mask.
This view is
counter to that
of some of the
media suppliers.
They point out
that measurement
is made at 0.3
microns because
this is the most
difficult
particle
diameter in
terms of
capture.
Smaller
particles are
subject to
Brownian
movement and are
easier to
capture.
In addition the
argument is that
the virus
particles are
attached to
either droplets
or fomite which
is larger in
particle size.
So we need
further
discussion of
this subject.
Bob McIlvaine
was asked to
define high
efficiency
masks. He
replied that the
metric should be
fitted filter
efficiency
(FFE). A
combination of
filter
efficiency and
leakage which
would prevent
inhalation of
90% of
the 0.3 micron
particles would
have a 90% FFE.
So the filter
efficiency might
only be 93% but
if the leakage
is 3 % or less
then the mask is
just as
efficient as an
N95 with 5%
leakage.
Realistically
this FFE of 90%
efficiency
should be
considered very
high. Probably
the best that
can be achieved
on the average
is 85% for a
mask in actual
use by the
public. The
reason is that
the way the mask
is worn is very
important.
Averaging less
than 10% leakage
can be
challenging.
Pressure drop is
a bigger problem
with masks than
with filters but
the same
principles
apply.
Particles that
are 0.5μm in
size or smaller
tend to follow
increasingly
erratic paths as
particle size
decreases,
a phenomenon
known as the
diffusion
effect. As such,
HEPA and ULPA
filters are
often rated
according to
their
most penetrating
particle size,
or the size of
particles that
most readily
pass through
them. As
depicted in this
line graph,
filters that
achieve the same
efficiency
rating, in this
case ULPA
filters rated at
99.999%, are not
necessarily
equal in their
MPPS
performance.
There is a need
to evaluate risk
along with
fitted filter
efficiency.
Guidance should
be on a relative
rather than
absolute basis.
For example
until COVID most
visitors and
personnel
in a hospital
did not wear a
mask. Masks were
used by those
involved with
infectious or
vulnerable
patients.
In the future it
is very likely
that everyone
entering a
hospital
including
visitors will
need to wear a
mask to reduce
hospital
acquired
infections
(HAI). This does
not mean that
the visitor
needs to have a
mask with the
same fitted
filter
efficiency as
the nurse
working with
cancer patients.
The CDC is
struggling with
absolutes such
as when to wear
a mask outside
and when to go
without one. The
fitted filter
efficiency is
just one more
variable to be
integrating. So
there can not
only be a choice
of whether or
not to wear a
mask but what
FFE level mask
do you need?
McIlvaine
Company will be
pursuing this
subject with
various people
in the industry
and welcomes
input from the
readers.
This
would include
additional
questions for Dr
Tsai and for
Janelle Bentz
who is an expert
on the testing.
More Rapid Air
Changes Spread
the Virus
Vigorous and
rapid air
exchanges might
not always be a
good thing when
it comes to
addressing
levels of
coronavirus
particles in a
multiroom
building,
according to a
new modeling
study.
The study
suggests that,
in a multiroom
building, rapid
air exchanges
can spread the
virus rapidly
from the source
room into other
rooms at high
concentrations.
Particle levels
spike in
adjacent rooms
within 30
minutes and can
remain elevated
for up to
approximately 90
minutes.
The findings, published
online in final
form April 15 in
the journal
Building and
Environment,
come from a team
of researchers
at the U.S.
Department of
Energy’s Pacific
Northwest
National
Laboratory.
The team
includes
building and
HVAC experts as
well as experts
in aerosol
particles and
viral materials.
“Most studies
have looked at
particle levels
in just one
room, and for a
one-room
building,
increased
ventilation is
always useful to
reducing their
concentration,”
said Leonard
Pease, lead
author of the
study.
“But for a
building with
more than one
room, air
exchanges can
pose a risk in
the adjacent
rooms by
elevating virus
concentrations
more quickly
than would
otherwise occur.
“To understand
what’s
happening,
consider how
secondhand smoke
is distributed
throughout a
building. Near
the source, air
exchange reduces
the smoke near
the person but
can distribute
the smoke at
lower levels
into nearby
rooms,” Pease
added. “The risk
is not zero, for
any respiratory
disease.”
The team modeled
the spread of
particles
similar to
SARS-CoV-2, the
virus that
causes COVID-19,
via air-handling
systems.
Scientists
modeled what
happens after a
person has a
five-minute
coughing bout in
one room of a
three-room small
office building,
running
simulations with
particles of
five microns.
Researchers
looked at the
effects of three
factors:
different levels
of filtration,
different rates
of outdoor air
incorporation
into the
building air
supply, and
different rates
of ventilation
or air changes
per hour. For
downstream
rooms, they
found an
expected clear
benefit from
increasing
outdoor air and
improving
filtration, but
the effect of
increased
ventilation rate
was less
obvious.
Scientists
studied the
effects of
adding varying
amounts of
outdoor air to
the building air
supply, from no
outside air to
33 percent of
the building’s
air supply per
hour. As
expected, the
incorporation of
more clean
outdoor air
reduced
transmission
risk in the
connected rooms.
Replacement of
one-third of a
building’s air
per hour with
clean outdoor
air reduced
infection risk
in downstream
rooms by about
20 percent
compared to the
lower levels of
outdoor air
commonly
included in
buildings. The
team noted that
the model
assumed that the
outdoor air was
clean and virus
free.
“More outside
air is clearly a
good thing for
transmission
risk, as long as
the air is free
of virus,” said
Pease.
When the
infected person
in the office to
the left coughs,
respiratory
droplets
containing viral
particles exit
via the office’s
vent in the
ceiling. Some
droplets exit
the building,
while some are
sent back into
the building and
into multiple
rooms through
the air-handling
unit. A PNNL
team found that
a high
ventilation rate
can increase
viral particle
levels
downstream of a
source room.
(Illustration/Animation:
Cortland
Johnson/Sara
Levine, Pacific
Northwest
National
Laboratory)
The team studied
the effects of
three levels of
filtration:
MERV-8, MERV-11,
and MERV-13,
where MERV
stands for
minimum
efficiency
reporting value,
a common measure
of filtration. A
higher number
translates to a
stronger filter.
Filtration
decreased the
odds of
infection in the
connected rooms
markedly. A
MERV-8 filter
decreased the
peak level of
viral particles
in connected
rooms to just 20
percent what it
was without
filtration. A
MERV-13 filter
knocked down the
peak
concentration of
viral particles
in a connected
room by 93
percent, to less
than one-tenth
of what it was
with a MERV-8
filter. The
researchers note
that the
stronger filters
have become more
common since the
pandemic began.
The most
surprising
finding of the
study involved
ventilation—the
effect of what
researchers call
air changes per
hour. What’s
good for the
source
room—cutting
transmission
risk within the
room by 75
percent—is not
so good for
connected
rooms. The team
found that a
rapid rate of
air exchange, 12
air changes per
hour, can cause
a spike in viral
particle levels
within minutes
in connected
rooms. This
increases the
risk of
infection in
those rooms for
a few minutes to
more than 10
times what it
was at lower
air-exchange
rates. The
higher
transmission
risk in
connected rooms
remains for
about 20
minutes.
“For the source
room, clearly
more ventilation
is a good thing.
But that air
goes somewhere,”
said Pease.
“Maybe more
ventilation is
not always the
solution.”
“There are many
factors to
consider, and
the risk
calculation is
different for
each case,” said
Pease. “How many
people are in
the building and
where are they
located? How
large is the
building? How
many rooms?
There is not a
great deal of
data at this
point on how
viral particles
move about in
multiroom
buildings.
“These numbers
are very
specific to this
model—this
particular type
of model, the
amount of viral
particles being
shed by a
person. Every
building is
different, and
more research
needs to be
done,” Pease
added.
Filtration,
outdoor air
mixture, and
air-exchange
rate are a few
of the factors
in a multiroom
building that
affect levels of
the virus that
causes COVID-19.
(Photo by Roman
Zaiets |
Shutterstock.com)
Co-author
Timothy Salsbury,
a buildings
control expert,
notes that many
of the
trade-offs can
be quantified
and weighted
depending on
circumstances.
“Stronger
filtration
translates to
higher energy
costs, as does
the introduction
of more outside
air than would
usually be used
in normal
operations.
Under many
circumstances,
the energy
penalty for the
increased fan
power required
for strong
filtration is
less than the
energy penalty
for heating or
cooling
additional
outside air,”
said Salsbury.
“There are many
factors to
balance—filtration
level, outdoor
air levels, air
exchange—to
minimize
transmission
risk. Building
managers
certainly have
their work cut
out for them,”
he added.
U.S. Needs to
Provide Aid to
India
U.S.
infectious-disease
expert Anthony
S. Fauci said
Wednesday that
the world has
failed so far in
tackling the
global nature of
the coronavirus
pandemic with a
suitably global
response,
leading to
tragedies such
as the current
outbreak in
India. The nation of more than 1.3 billion is in the grip of a devastating surge, with more than 360,000 new cases in the past 24 hours — another global record — and 3,293 deaths, raising the toll past 200,000. Hospitals and crematoriums have been overwhelmed, and global assistance is only now slowly trickling in.
“The only way
that you’re
going to
adequately
respond to a
global pandemic
is by having a
global response,
and a global
response means
equity
throughout the
world,” Fauci
told the Guardian
Australia.
India’s coronavirus death
toll topped
200,000
Wednesday with
no indications
of slowing down
as shipments of
foreign aid
arrived in an
effort to
supplement
dwindling
medical
supplies. The
help, at least
one official
worried, will
not address the
thousands of
patients turning
up at already
overrun medical
facilities where
staff is
foregoing sleep
and their own
health in an
effort to
provide
treatment.
"The current
wave is
particularly
dangerous,"
Delhi Chief
Minister Arvind
Kejriwal told
Reuters. "It is
supremely
contagious and
those who are
contracting it
are not able to
recover as
swiftly. In
these
conditions,
intensive care
wards are in
great demand."
According to
India’s Ministry
of Health,
nearly 150
million doses of
COVID-19 vaccine
have been
administered
thus far, but
the eligibility
has not been
opened to all
1.3 billion
people.
Currently, India
is only
vaccinating
those over age
45. The country
is relying on
two vaccines for
their rollout,
namely the
AstraZeneca jab
and Covaxin,
which is
manufactured by
Bharat BioTech
Limited.
India is a major
producer of the
AstraZeneca jab,
but has turned
its attention
elsewhere to
address the
crisis at home
which in turn
has hampered
exports that
other regions
were relying on,
such as Africa.
The export ban
is also a major
blow to the
COVAX
initiative,
which had relied
on vaccine
supply coming
from India to
supply dozens of
low-income
countries with
jabs.
ASHRAE Provides
Guidance for
Protecting
Voters
ASHRAE’s
Building
Readiness
guidance
provides
practical
information and
checklists to
help minimize
the chance of
spreading
SARS-CoV-2, or
other viruses at
polling places
in the future.
“Protecting our
voters and poll
workers from
increasing the
spread of
COVID-19 at
polling places
is essential to
protecting the
health, welfare
and safety of
the entire
population,”
said Dennis
Knight, ASHRAE
Epidemic Task
Force vice
chair. “Many
different HVAC
system types are
used in polling
places, so
adaptation of
these guidelines
to specific
cases is
necessary.”
Here is a
summary of key
general
recommendations
related to HVAC
and water supply
systems for
polling places:
Space Selection:
Select a space
with a larger
area for people
to spread out,
and if possible,
a high ceiling
to provide more
volume for
dilution.
Consider space
with operable
windows if there
are potential
ventilation
issues.
Inspection and
Maintenance:
Consider
assessing the
condition of
systems and
making necessary
repairs. All
building owners
and service
professionals
should follow
ASHRAE Standard
180-2018
“Standard
Practice for the
Inspection and
Maintenance of
Commercial HVAC
Systems.”
HVAC Operation:
The HVAC and
toilet exhaust
systems should
be running when
the space is
occupied. If the
HVAC system
cycles on/off
with the
thermostat,
consider running
the fan
constantly
during occupied
hours. If toilet
exhaust is
controlled by
manual switches,
leave the fan
running for 20
minutes after
use, or consider
setting the
switch to “on”
and use signage
that directs not
to change the
setting.
Ventilation:
A good supply of
outside air, in
accordance with
ASHRAE Standard
62.1-2019, to
dilute indoor
contaminants is
a first line of
defense against
aerosol
transmission of
SARS-CoV-2. Pre-
and
post-occupancy
purge cycles are
recommended to
flush the
building with
clean air. If
the polling
place is not
ventilated or
poorly
ventilated and
filter
efficiency is
not good,
consider opening
doors and
windows, and
consider
re-locating all
voting to the
outdoors.
Air Distribution:
Air flow
distribution
should not
cascade air from
the face of a
person onto
others, so take
care in using
personal fans.
Filtration:
Use of at least
MERV-13 rated
filters is
recommended, if
it does not
adversely impact
system
operation. If
MERV-13 filters
cannot be used,
including when
there is no
mechanical
ventilation of a
space, portable
HEPA air
cleaners in
occupied spaces
may be
considered. Also
consider
portable air
cleaners in
locations with
more vulnerable
staff.
Air Cleaning:
Air cleaners
such as
germicidal
ultraviolet air
disinfection may
also be
considered to
supplement
ventilation and
filtration.
Technologies and
specific
equipment should
be evaluated to
ensure they will
effectively
clean indoor air
without
generating
additional
contaminants or
negatively
impacting space
air distribution
by creating
strong air
currents.
Temperature and
Humidity:
It is desirable
to set the
thermostat at
the higher end
of the comfort
zone, 75-78ºF
and maintain
relative
humidity between
40-60%.
Energy Use
Considerations:
In selecting
mitigation
strategies,
consideration
should be given
to energy use as
there may be
multiple ways to
achieve
performance
goals that have
greatly
different energy
use impact.
Control changes
and use of
energy recovery
to limit or
offset the
effect of
changes in
outdoor air
ventilation rate
and filter
efficiency may
reduce or offset
energy and
operating cost
penalties.
Water System
Precautions:
Buildings that
have been
unoccupied could
have stagnant
water, and water
systems should
be flushed to
remove potential
contaminants.
Utilizing ASHRAE
Standard 188 and
Guideline 12 can
help minimize
the risk of
water-borne
pathogens such
as legionella.
Chinese
Researchers
Create Charged
Nanofiber Media
with Silver for
Anti-Microbial
Function
A
nanometer
fiber filter
membrane for
filtering PM2.5,
was
achieved with
multi-needle
electrospinning
equipment. By
adding silver
nitrate to the
spinning
solution, a
polyvinylidene
fluoride
antibacterial
nanofiber filter
layer with high
filtration
efficiency and
low resistance
was successfully
prepared on the
traditional air
conditioning
filter meshes.
Researchers
found that four
key factors
affecting the
filtration
performance.
They include
ambient
humidity,
substrate
meshes, voltage,
and production
rate. Among
them, voltage
and production
rate are the key
factors
affecting the
filtration
performance.
According to the
development
trend of
multifunctional
nanofiber
membranes, the
preparation of
air conditioning
filters with
nanofibers as
the main filter
material was
realized,
producing air
conditioning
filter membranes
with
antibacterial
and deodorizing
functions. This
article provides
a reliable
experimental
basis and
empirical
reference for
the preparation
of nanofiber
membranes based
on multi-needle
electrospinning
technology.
https://aip.scitation.org/doi/10.1063/5.0009170
Filti Supplies
MERV 16 Air
Filters Using
Nanofiber
Technology
Filti,
an air
filtration and
nanofiber
technology
company,
has launched the
9500 Home
Filter. The
patent-pending
9500 Home Filter
is an HVAC
filter
constructed
using nanofiber
technology, an
N95-quality
material that is
proven to filter
95% of
aerosolized,
airborne
particles – like
COVID-19 –
moving through
the material.
Gyms Need Better
Air Filtration
Generally
The more intense
the exercising,
the more air you
need to breathe
in. And, as some
studies show,
the more people
in the gym area,
the more air
pollution levels
increase.
Sources of this
poor indoor air
quality can be
the occupants,
dangerous
chemicals from
cleaning agents
and building
materials, the
HVAC system, and
inadequate
ventilation and
air filtration.
In the case of
Urban Apes, many
of the climbers
use
magnesium-carbonate
chalk to
maintain a good
grip while
climbing. During
peak periods,
the total
particle
concentration
measured in
their gym
therefore spiked
to the
dust-pollution
levels at
industrial
premises. About
half of these
particles were
the tiny PM1
particles that
can get into the
lungs and damage
health. What
this meant was
high
concentrations
of fine dust in
the air – as
well as dry
mouth and eye
irritation from
the dry air
caused by the
properties of
the chalk. Urban
Apes wanted to
improve the
gym’s air and
protect the
occupants’
health, while
keeping energy
consumption low
Camfil filters
and air cleaners
were brought in
to deliver
better air
filter
performance and
achieve the best
possible indoor
air quality. The
CC 6000 Air
Cleaner, a
free-standing
unit, was placed
in the large gym
while the CC
2000 Air
Cleaner, a wall
mounted unit,
was placed in a
smaller room.
The Benefits
Included: •
Significant
improvement in
indoor air
quality and
fewer dust
particles in the
room air
(particle
reduction in
PM1, PM2.5 and
PM10 of 70% and
more) • Improved
comfort levels
for the
athletes, guests
and employees •
Less cleaning of
premises needed
• Less pressure
on their
existing
ventilation
system and
extended filter
lifetime
Large French
Retailer
Installs Camfil
HEPA Filters
A large French
retailing group
includes many
hypermarkets
brands, supermarkets
and DIY shops.
The group
is present in
many countries
in Europe and
between 3,000
and 4,000 people
visit its
headquarters and
training
center located
in the Paris
region every
day.
Further to the
lockdown in
France in March
2020 due to the
COVID-19 pandemic,
this large
retailing
group wanted to
go on welcoming
its staff to the
premises of its
headquarters in
the best and
safest way. The
group wanted to
be able to
continue to
train its new
employees and
franchisees in
its hundred or
so dedicated
rooms.
The control of
the indoor air
quality is a
key factor for
the health
safety of the
staff and
trainees and
also to help
them
feel protected,
reassured, and
confident. There
were many
different types
of rooms
involved:
individual or
two-person offices,
open spaces, or
large
training amphitheaters. The
customer did not
want any work
to be done in
the rooms to
clean the air.
To be able to
guarantee the
continuity of
its activities
and to ensure
the safety of
people with
clean air free
of
airborne particles
and viruses in
the
various buildings,
Camfil proposed
professional air
purifiers
equipped with
HEPA H14 filters
certified
according to EN
1822.
About 180
units of City M
and 350 units of
City S were
installed to
maintain good
air quality in
areas
respectively of
45 square meters
and 75
square meters. To
ensure the
filters’
filtration
efficiency, each
H14 filter has a
serial number,
is individually
tested before it
is shipped and
delivered with
its test report.
All the
employees were
able to work on
the site as soon
as September
2020. All
training and the
annual
negotiation
meetings with
the franchisees
are now
carried out on
the site. Once
the health
crisis is over,
the staff will
continue to
benefit from
clean air and
reduce
allergic reactions
thanks to the
ECARF
(European Centre
for Allergy
Research
Foundation)- certified
City M and City
S air purifiers (ideal
for eradicating
allergies).
Improved air
quality and
fewer
allergies contribute
to less
absenteeism and
better
productivity of
staff.
According to
INRS’ (National
Institute for
Research
and Security),
the City M air
purifier
includes HEPA
filtration
technology and
is highly
recommended to
remove airborne
contaminants
such as the
Covid-19 virus. A
study financed
by the
Auvergne-Rhône-Alpes
region on the
City M
equipped with
HEPA H14 filters
was carried
out in January
2021. This study
confirms the
efficiency of
Camfil HEPA H14
technology with
filtration of up
to 99.9% of the
virus in 20
minutes of use
(10 cycles of
air
recirculation)
and total
disappearance of
infectious
viruses on the
filters at 48
hours. This
allows
for maintenance
of the filters,
without the risk
of contamination
of the
operators.
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