PLoS ONE,
Год журнала:
2024,
Номер
19(3), С. e0296803 - e0296803
Опубликована: Март 1, 2024
Existing
research
of
non-unidirectional
cleanrooms
generally
suggests
that
lower-side
return
air
outlets
provide
better
control
effect
on
indoor
particle
concentration.
As
a
result,
there
has
been
relatively
less
focus
outlets.
However,
installing
oriented
towards
operators
as
emission
sources
can
reduce
the
impact
process
layout
and
improve
space
utilization,
while
also
from
upper
workbench
area.
To
investigate
characteristics
outlet
for
(abbreviated
H
),
this
study
compared
concentration
distribution,
non—uniformity,
purification
efficiency
oultet
traditional
L
)
by
experiments
CFD
simulations.
Based
theory
mass
conservation,
expression
required
supply
volume
under
equivalent
cleanroom
conditions
was
derived.
Under
corresponding
experimental
simulation
conditions,
differences
range
2.0%
to
12.7%
12.4%
33.2%
,
these
gradually
decrease
with
exchange
rate
(ACH)
increases.
The
results
show
ACH
=
20
is
sufficient
cleanliness
requirements
when
one
person
in
cleanroom,
higher
35
needed
are
two
persons.
Although
have
certain
potential
reducing
increasing
remains
most
effective
method
Compared
ranges
non-uniformity
coefficients
0.50
0.67
0.45
0.53,
respectively.
average
coefficient
differs
11.9%,
not
significant
difference
uniformity
more
than
changes
per
hour.
use
only
requires
an
additional
11%
achieve
same
cleanliness,
demonstrating
its
effectiveness
controlling
It
suitable
workbenches
restricted
floor
usage
or
requiring
flexible
layouts.
explores
width
sources,
larger-sized
facilitate
discharge
distribution
inside
room.
Energies,
Год журнала:
2024,
Номер
17(4), С. 855 - 855
Опубликована: Фев. 12, 2024
Before
the
COVID-19
pandemic,
ventilation
in
buildings
was
not
always
given
its
due
importance.
The
World
Health
Organization
has
highlighted
important
role
of
air
exchange
with
outdoors
improving
quality
buildings;
should,
therefore,
be
equipped
mechanical
or
adequate
conditioning
systems.
This
paper
aims
to
investigate
different
retrofit
solutions
for
conditioning,
evaluating
them
terms
energy
consumption
and
cost
impact
increased
outdoor
rates
on
countering
propagation
COVID-19;
latter
is
main
novelty
paper.
As
a
case
study,
we
take
an
existing
office
building
located
Central
Italy
that
previously
system
(a
primary
introduced
during
study).
analysis
conducted
using
dynamic
simulation
software
after
validation
through
bills;
economic
analyses
were
considering
external-air
rates.
An
optimal
number
changes
found
mitigate
risk
infection,
finding
line
international
literature.
increase
leads
rise
costs.
These
values
evaluated
systems
operational
schedules.
drawbacks
can
made
less
significant
by
combining
interventions
energy-efficiency
measures
applied
envelope.
Energies,
Год журнала:
2024,
Номер
17(11), С. 2769 - 2769
Опубликована: Июнь 5, 2024
Air
conditioning
systems
can
play
a
positive
or
negative
role
in
the
spread
of
COVID-19
infection.
The
importance
sufficient
outdoor
air
changes
buildings
was
highlighted
by
World
Health
Organization,
therefore
these
should
be
guaranteed
mechanical
ventilation
adequate
systems.
proposed
case
study
concerns
optimal
number
to
limit
contagion
for
school
building
Central
Italy.
Wells–Riley
model
is
used
assess
risk
airborne
infection,
while
energy
consumption
calculated
dynamic
simulation
software.
scope
paper
offers
an
innovative
method
define
strategy
building’s
HVAC
system
design
reduce
infection
with
limited
increases
and
greenhouse
gas
emissions.
Results
show
that
desirable
approach
one
which
same
low
value
set
all
rooms.
This
new
results
significant
savings,
compared
most
common
ones
(setting
high
rates
rooms)
counteract
Finally,
zero-emission
target
verified
introducing
suitable
photovoltaic
offset
pollutant
Energies,
Год журнала:
2025,
Номер
18(6), С. 1526 - 1526
Опубликована: Март 19, 2025
The
operation
of
Heating
Ventilation
and
Air
Conditioning
(HVAC)
systems
in
densely
occupied
spaces
results
considerable
energy
consumption.
In
the
post-pandemic
context,
stricter
indoor
air
quality
standards
higher
ventilation
rates
further
increase
demand.
this
paper,
retrofit
a
partial
recirculation
all-air
HVAC
system
serving
university
lecture
room
located
Southern
Italy
is
analyzed.
Multi-Objective
Optimization
(MOO)
Multi-Criteria
Decision-Making
(MCDM)
approaches
are
used
to
find
optimal
design
alternatives
rank
these
considering
two
different
decision-makers,
i.e.,
public
private
stakeholders.
Among
Pareto
solutions
obtained
from
optimization,
alternative
identified,
encompassing
three
Key
Performance
Indicators
using
new
robust
MCDM
approach
based
on
four
methods,
TOPSIS,
VIKOR,
WASPAS,
MULTIMOORA.
show
that,
era,
baseline
scenarios
for
infection
reduction
that
do
not
involve
introduction
demand
control
strategies
cause
consumption
negligible
values
up
59%.
On
contrary,
involving
decrease
between
5%
38%.
findings
offer
valuable
guidance
retrofits
education
similar
buildings,
emphasizing
potential
balance
occupant
health,
efficiency,
cost
reduction.
also
highlight
significant
CO2
reductions
minimal
impacts
thermal
comfort,
showcasing
substantial
savings
through
targeted
retrofits.
Journal of Aerosol Science,
Год журнала:
2023,
Номер
175, С. 106285 - 106285
Опубликована: Окт. 14, 2023
The
airborne
droplets
released
by
humans
while
speaking
or
coughing
are
the
main
sources
of
human-to-human
contagion
for
transmissible
diseases.
Due
to
recent
SARS-Cov2
pandemic,
indoor
transmission
in
classrooms
and
other
environments
is
an
interesting
topic
investigated
scientific
community.
In
this
work,
thermofluid
dynamic
conditions
droplet
transport
was
analysed
a
large
University
Classroom
(UC),
as
function
inlet
airflow
occupancy
rate.
These
parameters
assume
relevant
role
design
stage.
However,
their
effects
on
were
not
deeply
literature.
Therefore,
different
analyzed,
such
as:
full
occupancy,
which
represents
condition
where
no
social
distancing
enforced;
half
representative
distancing;
empty
UC,
be
considered
term
comparison.
novelty
work
related
analysis
combined
effect
thermal
plume
UC.
numerical
model
dynamics
simulation
validated
previous
emission
retrieved
from
High
volumetric
always
beneficial
reduction
risk.
An
important
aspect
plume,
cannot
ignored
if
rate
assumes
significant
value.
Moreover,
evacuation
age
indicators
assess
cleaning
time.