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Chapter

Indoor Air Quality in Health

Care Units (Case Study:
Namazi Hospital, Shiraz, Iran)
Forough Farhadi, Saeid Chahardoli and Mehdi Khakzand

Abstract

Indoor air quality (IAQ) represents an important research focus due to its direct
and substantial implications on human health outcomes. Existing research showed
that substandard IAQ exacerbates the effects of airborne diseases. The objective of this
chapter would be to explore the correlation among indoor air quality (IAQ), location
of air outlet valves, and fluctuations in IAQ indicators within the cardiovascular care
unit (CCU). In this regard, a combination of experimental and numerical methods has
been utilized. These included direct IAQ measurements within the unit and the appli-
cation of computational fluid dynamics to simulate indoor air conditions based on the
collected experimental data. In this specific circumstance, the state of the air outflow
valve and the condition of the air change rate significantly affect the enhancement of
IAQ levels. To confirm this hypothesis, existing literature was thoroughly reviewed
according to IAQ guidelines. In a similar vein, the study included measurements of
emissions such as CO2, CO, PM2.5, and PM10. Additionally, it examined the associa-
tion relating to IAQ , air outlet placement, and dynamics of the emissions within the
patient’s room.

Keywords: indoor air quality, building performance, healthy indoor spaces, infectious
diseases, computational fluid dynamics

1. Introduction

Indoor air quality (IAQ) in healthcare facilities has the greatest significance due to
its enormous effects on patient well-being, staff productivity, and overall health out-
comes [1]. Airborne diseases highlight the potential to enhance healthcare settings’
preventative procedures [2, 3]. Comprehending and managing prevalent indoor pol-
lutants can mitigate the potential health risks and adverse health consequences asso-
ciated with indoor air contaminants [4, 5].
World Health Organization (WHO) estimates that air pollutants cause up to 7.3
million fatalities annually, of which 4.3 million are due to indoor air pollutants [6].
Recently, the Harvard School of Public Health conducted a study that noticed a
correlation between mortality rates attributed to infectious diseases and the rising
levels of particulate matter concentration [5, 7, 8]. The impact of IAQ is particularly
1
Advancements in Indoor Environmental Quality and Health

consequential for these individuals as those with compromised immune systems could
be exposed to potentially life-threatening infections within hospitals due to poor air
quality [3, 9, 10].
Studies and efforts related to this field emphasize how poor IAQ magnifies the
effects of airborne pathogens [11–13] and the enormous risk that respiratory infec-
tions carried by aerosols pose, particularly in compact, inadequately ventilated spaces
[14]. Finding the causes of the rising transmission of airborne diseases and their
mortality rate has drawn recent scientific attention. The damage caused to human
health varies, and this issue depends on particle pollutants’ concentration [6, 15, 16].
Preventing or managing airborne infectious illnesses would be improved by IAQ
research, characterization, and increased interest in creating healthy indoor settings
[17]. Standards have been established for assessing IAQ in a building for its intended
purpose. As an example, the EPA has developed a series of specific reference pro-
cedures to precisely gauge the levels of individual pollutants [18–20], and the World
Health Organization (WHO) set a comparison of different indoor air quality guide-
lines [21–23]. These methods provide outstanding accuracy and precise time mea-
surements, yet they present challenges such as the requirement for quality control
assessments, frequent calibration, significant costs, and the necessity for an operator
possessing specialized expertise [24–26]. Given the damaging impact on IAQ and
individuals’ vulnerability within healthcare facilities, addressing this concern in treat-
ment areas holds paramount significance.
Recently, computational fluid dynamics (CFD) has potential techniques for ana-
lyzing particles’ behavior in a room [27, 28]. It is influenced by a number of variables,
including airborne contaminants, ventilation systems, and building layout [29, 30]. To
maintain a balanced airflow and avoid recirculating contaminated air, the placement
of air outflow valves is essential [31].
This issue should be considered in hospitals in order to control and monitor the
microbiological quality of indoor air [32, 33]. At present, there exists a dearth of
understanding among individuals concerning the assessment, recognition, and possi-
ble health consequences of indoor air quality (IAQ) [34–36]. Hence, the ongoing
monitoring and regulation of indoor air quality within hospitals are integral compo-
nents of infection prevention strategies and the promotion of a healthful indoor
environment.
Recent studies investigated the importance of IAQ monitoring according to guide-
lines [31, 36, 37]. Abdel-Salam et al. investigated PM10, PM2.5, and CO2 experimen-
tally for 24 h in urban homes in Egypt based on WHO guidelines [21]. Kephart et al.
investigated NO2 measurements for 48 h in Homes in Peru based on WHO guidelines
[38]. Woolley et al. studied CO concentration from Wednesday to Friday evenings for
48 h in home residence apartments based on WHO guidelines in the United Kingdom
[39]. Amadeo et al. studied O3, NO2, SO2, and PM10 measurements from December
2008 to December 2009 in schools based on WHO guidelines in Guadeloupe (French
West Indies) [40]. Shen et al., Huang et al., and Abdel-Salam investigated IAQ
measurements based on EPA guidelines [41–43]. Poulin et al. studied IAQ measure-
ments based on Canadian IAQ guidelines [44].
Also, Singh et al. investigated PM2.5 for two weeks of measurements in a com-
mercial shopping complex (CSC) based on NIOSH guidelines in Delhi.
Branco and colleagues conducted a study on indoor air quality (IAQ) and discov-
ered that children sensitized to common aeroallergens had an increased likelihood of
developing childhood asthma when exposed to particulate matter [45]. These factors
can have adverse effects on human well-being, potentially causing disruptions to daily
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Indoor Air Quality in Health Care Units (Case Study: Namazi Hospital, Shiraz, Iran)
DOI: http://dx.doi.org/10.5772/intechopen.113724

life [25, 46–48]. Connections have been demonstrated to exist between particular
indoor exposures, even when they are at low levels. This can pose health risks,
particularly for individuals who have not developed prior sensitivities [49–52].
Groulx et al. have concluded that alterations in outdoor air quality significantly
affect the composition of medical air administered to patients. They also emphasize
the crucial significance of monitoring and controlling the quality of medical air within
healthcare facilities [53]. In their study, Jung et al. examined levels related to signifi-
cant airborne pollutants, which encompassed CO, CO2, O3, total volatile organic
compounds (TVOC), formaldehyde HCHO, and particulate matter (PM2.5 and
PM10). Their research revealed that inpatient rooms had significantly elevated levels
of CO2 and TVOC compared to nursing stations, clinics, and clinic waiting rooms [54].
In contrast, Nair et al. [55] verified that pollutants including particulate matter
(PM10, PM2.5), NO2, SO2, CO, O3, and CO2 elevate the risk of contracting airborne
illnesses, resulting in prolonged infectiousness of airborne viruses and contributing to
an unhealthy environment.
Recent studies used short-period monitoring as a technique to analyze the quality
of indoor air [21, 38, 56]. Piexoto et al. [57] experimentally investigated CO2 and CO in
the fitness center. Related activities in healthcare facilities induce specific emissions.
This condition may become harmful if it exceeds the acceptable limits and may
accelerate the virus’s contagion [58–60]. As a result, the particles transferred with the
incoming air would affect the transmission of infectious diseases. Recent studies based
on IAQ measurements show that this experimental system is an effective method to
help us understand the status of the environment and can prevent the chances of
infectious transition and mechanically or naturally reach the appropriate IAQ. This is
effective because it can lead to more healthy spaces, especially in healthcare facilities.
Within this context, the crucial role of maintaining indoor air quality in infection
control becomes evident. Inspired by the above-mentioned facts, the objective of this
study is to contribute scientific insights into indoor air quality (IAQ) within
healthcare facilities. This will be achieved through experimental measurements of IAQ
indicators, which will then be compared to the acceptable limits established by IAQ
guidelines. Research focused on health underscores the growing importance of
comprehending the interplay between the built environment and the transmission of
infections [61–63]. Examining the dispersion and mobility patterns of indoor particles
can improve indoor air quality and promote the sustainable and healthy development
of indoor environments. Recently, government agencies have implemented regula-
tions and enforcement measures to enhance environmental health by controlling
outdoor air pollutants. Different guidelines have been established to help monitor the
air quality both indoors and outdoors [64].
Since 1979, WHO has consistently addressed indoor environmental conditions in
numerous reports [65], with the objective of ensuring adequate indoor air quality,
particularly within hospital facilities [66, 67].
According to WHO, numerous indoor air pollutants can adversely impact both the
indoor environment and human health [68]. Airborne pollutants, including VOCs,
PMs, SO2, CO, NO, PAHs, microbial spores, pollen, allergens, and more, are the
primary contributors to the deterioration of IAQ [69]. In their study, Kim et al. have
come to the conclusion that high levels of PM10 have the potential to transmit indoor
infections in closed spaces [36].
As awareness of the significance of indoor environments for human health grew,
scientists began proposing various recommendations. These recommendations
include establishing optimal air exchange rates within specific timeframes, regulating
3
Advancements in Indoor Environmental Quality and Health

the subsequent emission of air pollutants from various products, and establishing a
foundation of guidelines and references for indoor environmental considerations [70].
Achieving an ideal air changes per hour (ACH) is crucial in IAQ within healthcare
facilities to maintain efficient ventilation and reduce the danger of airborne pollution.
In previous research, it has been established that low air changes per hour (ACH)
and insufficient ventilation negatively impact occupants’ health. Recent analyses have
revealed that ACH rates in many European countries range from approximately 0.35–
1 ACH [71], while in China, they vary from about 0.35 to 0.78 ACH [72]. These earlier
studies predominantly concentrated on aspects like achieving net zero energy build-
ings (NZEB), optimizing thermal comfort, and reducing energy consumption, which
often led to lower ACH rates. However, a significant knowledge gap exists regarding
the design criteria. This gap relates to determining the ideal ACH thresholds and
achieving the best air quality with the lowest health risk for occupants.
In this chapter, we have conducted numerical simulations to replicate fluid
dynamics using the RNG k-e turbulence model and to analyze the motion of particles
using the discrete particle model (DPM). These simulations are employed to investi-
gate the behavior of particles within the unit and their interaction with the surround-
ing fluid. The study’s findings should provide an extensive understanding of the
ventilation system design by air outlet valve height on particle dispersion and removal
in situations when high outdoor contamination loads are an issue.
This chapter is based on CO, CO2, PM2.5, and PM10 measurements in a patient’s
room in the CCU of Namazi Hospital in Shiraz, Iran. Based on previous research, IAQ
measurements have been compared to IAQ guidelines (EPA, NIOSH, WHO, and
Canadian). This study aims to understand the air quality inside Namazi Hospital,
particularly in the Cardiovascular Care Unit. We’re looking at how the direction of air
outlet valves affects the indoor air quality and its potential impact on preventing the
spread of diseases.
The study follows this sequence: (i) Experimental measurements are carried out,
(ii) the obtained results are compared to IAQ guidelines, and (iii) the findings from
this investigation are analyzed utilizing CFD computational design.

2. Method

This study is based on experimental data collection, CFD modeling, and analysis,
commencing with a real-world case study. Namazi Hospital has been chosen for a case
study due to its location in a congested area of Shiraz, Southern Iran, with a dry and
warm climate. Measurements were undertaken both indoors and outdoors within the
CCU (critical care unit). The sampling encompassed pollutants like CO, CO2, PM2.5
and PM10. Monitoring was carried out during typical daily activities and under con-
ditions representative of occupancy, following the ISO 4224 standard. To simulate the
patient’s breathing zone accurately, the measurement devices were positioned on a
level surface at a 1-m height, maintaining a minimum distance of 1 m from any doors
or active heating equipment. The devices used were calibrated before and after mea-
surements.

2.1 IAQ sampling and analysis

The sampling devices were securely positioned in locations equipped with elec-
tricity, shielded from direct sunlight and rain within a protective shelter. They were
4
Indoor Air Quality in Health Care Units (Case Study: Namazi Hospital, Shiraz, Iran)
DOI: http://dx.doi.org/10.5772/intechopen.113724

positioned at a height of 1 m above the ground to ensure unobstructed access for the
sampling inlets and sensors, thus preserving the integrity of the sampling process. The
levels of CO, CO2, PM2.5, and PM10 were simultaneously measured alongside other
air parameters both indoors and outdoors at 10:20 AM and 6:20 PM on Monday,
March 1, 2021. The following measurements were conducted using the following
equipments: IAQ for CO (Aeroqual, model S200, N/A), AQ100 for CO2 (Aeroqual,
model S200, 250313-2307), DustTrak for PM2.5 and PM10 (model ISI, 21221), and a
flow meter (model N/A) (Figure 1).
Measurements have taken place in Room 6, which has an area of 14.5 m2 and
occupants on every shift. This room is mechanically ventilated by 2 inlets with a
velocity of 2.5 m/s, dimensions of 2525 cm, and an outlet that has a dimension of
5050 cm. Windows and doors were closed during the measurement period. The
results have been compared to IAQ guidelines (EPA, NIOSH, WHO, LEED, and
Canadian).
This study centers on the utilization of computational fluid dynamics (CFD) and
particle tracking to model indoor air quality (IAQ) within healthcare environments. In
this context, the Reynolds-averaged Navier-Stokes (RANS) equations serve as the
foundation for describing turbulent, incompressible airflow. To address various tur-
bulence scales effectively, a customized RNG k-ε model is employed.
In this research, both Eulerian and Lagrangian methods are simultaneously used to
model indoor airflow and particle trajectories. The particle motion equation includes
gravity and drag forces. The accuracy of particles’ simulation is ensured by integrating
RANS models with the model of discrete random walk (DRW).
Regarding the deposition of particles, wall-normal turbulent velocity fluctuations
play a crucial role. Particle deposition on surfaces is assumed when particles hit the
walls.
For computational simulations, ANSYS-FLUENT 18.2 software is utilized, with an
Intel(R) core (TM) i7-6800 CPU @ 3.40 GHz processor and 32 GB RAM. The airflow
conditions include a velocity of 2.5 m/s and air density of 1.225 kg/m3. Particle sizes
range from 1 to 10 μm, with a density of 2000 kg/m3. A one-way method is employed
due to diluting particle concentration.
The study also examines particle deposition on walls in a patient room using a
Eulerian-Lagrangian approach and validates results against other literature. Various
pollutants are monitored in this mechanically ventilated room.
Figure 2 illustrates how the velocity magnitude’s competitors vary across diverse
computational grids when employing the realizable k-ε model. Grid independence

Figure 1.
Created the room geometry description drawing and the fine unstructured mesh.

5
Advancements in Indoor Environmental Quality and Health

Figure 2.
Grid independence for velocity magnitude with 100; 500,000; and 1,000,000 grids.

shows the domain with 1 million mesh has the best accuracy for fluid flow simulation.
The velocity profiles have been acquired and are being compared across varying grid
resolutions at heights of 1, 2, and 3 m. Additionally, for the solving of the governing
equation, the SIMPLE algorithm, as well as the finite volume method, are employed.

2.2 Mathematical equation and model description

The Reynolds-averaged Navier-Stokes (RANS) equations are applied to describe

turbulent airflow that remains incompressible. Within this context, we observe the
utilization of the continuity and momentum equations [73]:

∂U i
¼ 0, (1)
∂xi
" ! #
∂U i ∂P ∂ ∂U i ∂U j
ρU j ¼ þ μ þ ρui uj , (2)
∂xj ∂xi ∂xi ∂xi ∂xi

Here, U i stands for the fluctuation velocity, and U and P stand for the average
speed and pressure, respectively. In addition, ( ui uj ) and μ are the fluid viscosity and
the Reynolds stress tensor, additionally, ρ is density.
Yakhot et al. [73] developed the RNG k-model by applying a process of
renormalization to the Navier-Stokes equations, taking into account diverse scales of
turbulent motion. RNG k-model’s transport equations are provided as:
  
∂ ∂ μt ∂k
ðρkui Þ ¼ Gk Yk þ μþ , (3)
∂xi ∂xi σ k ∂xj
ε2
  
∂ ε ∂ μt ∂k
ðρεui Þ ¼ Cε1 Gk Cε2,RNG ρ þ μþ , (4)
∂xi k K ∂xi σ k ∂xj

here:

1 ∂ui ∂uj
qffiffiffiffiffiffiffiffiffiffiffiffi  
2
Y k ¼ ρε and, S ¼ 2Sij Sij , Gk ¼ S μt , Sij ¼ þ , (5)
2 ∂xj ∂xi

6
Indoor Air Quality in Health Care Units (Case Study: Namazi Hospital, Shiraz, Iran)
DOI: http://dx.doi.org/10.5772/intechopen.113724
 
3 η
Cμ η 1 η0 1 k
Cε2,RNG ¼ Cε2 þ η ¼ 2Sij Sij 2
, η ¼ 4:337, β ¼ 0:012, (6)
1þ βη3 ε 0

The importance of demonstrating particle dispersion inside buildings has led to

specific concentrations being determined for simulating diffusion and deposition.
Lagrangian particle trajectories offer advantages as they enable the tracking of ran-
dom particles within the computational domain while also facilitating a straightfor-
ward interaction between the particles and walls, thanks to well-defined boundary
conditions. In the present study, both Eulerian and Lagrangian methods are employed
to simultaneously compute the indoor flow field and particle trajectories. Gravity and
drag force are included in the particle motion equation as follows:

p
dui CD Re p p
¼ ui ui þ g i , (7)
dt 24τ

Combining the particle velocities yields the particle position as follows:

dxi p
¼ ui , (8)
dt

RANS models are used to calculate the kinetic energy of turbulence, mean flow
velocity fields, and turbulence dissipation rate. They combine realistic simulation of
particle motion with precise modeling of fluid flow fluctuations. The following equa-
tions [74] are used in the DRW model for this purpose:

u0 ¼ ζu0rms , v0 ¼ ζv0rms , w0 ¼ w0rms (9)

Ref. [74] Research has indicated that achieving precise forecasts for the velocity of
sediment particles moving through a duct necessitates the consideration of turbulent
velocity fluctuations in the wall-normal direction within the near-wall region.
Lecrivain et al. [75] wrote the equation [11]. To accurately model particle deposition,
complicated wall turbulent flow is represented as follows:

a1 yþ2
qffiffiffiffiffiffi  
02
u2 ¼ u ∗
, for yþ < 30 (10)
1 þ b1 yþ þ c1 yþ2:41

here, c1 = 0.0014, b1 = 0.203, and a1 = 0.0116 y plus can be described by,

yu ∗
yþ ¼ (11)
v

3. Result

This study relies on the collection of experimental data at Namazi Hospital. The
findings magnified the importance of keeping levels of CO, CO2, PM2.5, and PM10
concentrations low for various health-related purposes, possibly even in transmission
of SARS-CoV-2. Results showed the measurements of CO and CO2 concentrations
have been lower than acceptable limitations offered by IAQ guidelines (EPA, NIOSH,
7
Advancements in Indoor Environmental Quality and Health

WHO, LEED, and Canadian). Also, indoor and outdoor measurements of PM2.5 and
PM10 have been above LEED and EPA guidelines.
Utilizing CFD as an analytical tool, its influence on indoor air quality and ventila-
tion has been investigated and specifically applied to facilitate particle dispersion in an
intensive care unit (ICU), with a primary research objective of assessing how varia-
tions in outlet valve heights impact indoor air quality. In space, on Monday, March 1,
2021, at 10:20 a.m. and 18:20 p.m., we measured the pollutants CO, CO2, PM2.5, and
PM10 in the room at two separate times of day.
For the simulation phase, we employed ANSYS Fluent to model the room based on
its actual dimensions. The inlet velocity in this room was 2.5 m/s. The entrance valves
measure 25 by 25 cm, while the output valves measure 50 by 50 cm. The grid inde-
pendence computation determined that an unstructured mesh with roughly 1,106
cells should be installed. Then, to replicate airflow in the room, we used RNG k. Based
on the outcomes of the simulation, we found that the airflow velocity was higher
when the exit valve was placed 20 cm from the wall.
The domain was then filled with particles that were 1, 2.5, 4, 7.5, and 10 mm in
diameter. By altering the location of the outlet valve, we successfully reduced con-
tamination in the room equipped with an airflow ventilation system. Different air
outlet valve heights have an impact on the flow field and particle deposition. This
issue has been investigated by using velocity contours and streamlines. The outcome
shows that a higher exit valve would result in particle entrapment in the space. As the
height of the outlet valve decreases, the flow of air would increase, and the particles’
concentration would be removed. Therefore, the chances of infectious transmission
will be reduced.
The calculated ACH for the case studies, based on a room area of 61.41 m3
(3.45 m  4.45 m  4 m), two inflows totaling 0.062 m2, an inlet velocity of 5.5 m/s,
and an airflow rate of 0.15 m3/s, falls within the acceptable IAQ range at 8.8 ACH
(Figure 3).
Based on the simulation results, the inlet valve is strategically situated at a height of
20 cm, accounting for the natural tendency of cold air to accumulate at lower levels
and facilitating its exit through the lower outlet valve. Additionally, the higher airflow
velocity, as represented by the yellow color in Table 1, signifies efficient air move-
ment. This observation, coupled with air change rates meeting industry standards,
promises improved indoor air quality.
Figure 4 show the dispersion of the particles inside the room and illustrate how
convenient it is for particles to exit the room if they are placed at 20-cm height.
DPM concentration at the 20-cm outlet height varies with time. Initial seconds
exhibit high emissions near the outlet, but after 90 s, CFD indicates substantial
particle removal from the room. This indicates effective ventilation dynamics.

Figure 3.
A contour velocity magnitude for the model at the z/x plane located at the center surface.

8
Indoor Air Quality in Health Care Units (Case Study: Namazi Hospital, Shiraz, Iran)
DOI: http://dx.doi.org/10.5772/intechopen.113724

Date Indoor Outdoor

(Time)
PM2.5 PM10 CO CO2 PM2.5 PM10 CO CO2
(Mg/m3) (Mg/m3) (ppm) (ppm) (Mg/m3) (Mg/m3) (ppm) (ppm)

10:20 0.005 0.011 1.16 913.0 0.017 0.023 4.03 668.0

18:20 0.005 0.012 0.16 796.0 0.006 0.015 5.17 774.0

Table 1.
Indoor and outdoor measurements [31].

4. Discussion

Figure 4.
Particle dispersion inside the room.

The comfort, productivity, and health of building inhabitants are directly impacted
by indoor air quality. Indoor pollution, which has been linked to 4.1% of global
fatalities in recent decades, can have immediate or long-term health consequences.
Recent studies utilizing indoor air quality (IAQ) and computational fluid dynamics
(CFD) demonstrate how useful this experimental approach is for assisting architects
in producing improved designs. This method provides crucial information about
airflow patterns and their effect on pollutant particles, enhancing architects’ under-
standing of IAQ. This approach is effective as it bridges the gap between technological
analysis, such as the CFD results, and architectural design.
A good indoor air quality is important in operating rooms where contaminated air
can cause surgical site infections. An appropriate ventilation strategy, underscored by
a comprehensive understanding of airflow patterns and pollutant dispersion, is essen-
tial for controlling and reducing indoor pollution while optimizing the performance of
the ventilation system. This study employed computational fluid dynamics to analyze
airflow patterns and the spread of airborne contaminants within indoor settings.
In recent research, there has been an emphasis on the surveillance of indoor air
quality [27, 76, 77]. Ascione et al. [78], in a study on university classrooms in Italy, by
investigation of IAQ measurements proposed new scenarios and provided supporting

9
Advancements in Indoor Environmental Quality and Health

evidence regarding the effectiveness of the systems responsible for thermal comfort
that wouldn’t pollute airflow. Additionally, they assessed the appropriateness of cer-
tain air distribution strategies, such as ceiling squared and linear slot diffusers, in
comparison to conventional methods. Leconte et al. [79] conducted an experimental
assessment of airflow and inventive active air ducts impact IAQ in a residential
building. Cetin at al. [80] examined efficiency of varying air exchange rates on the
dispersion and settling of indoor particles within a ventilated room.
Dobson et al. [81] investigated the quality of indoor air based on WHO guideline
limits, in residential homes in Scotland, Florence, Greece, Milan, and Catalonia. The
findings indicated that, in the context of this study, only a small number of house-
holds achieved complete smoke-free status. Lewis et al. [82], by investigating PM2.5
measurements from December 2011 to January 2012 in 105 residential homes in India,
found out that in houses in which traditional stoves were used, pollution levels still
remained above WHO guidelines.
Can et al. [83] studied NO2, O3, and VOCs for 7 days in a university in Turkey, the
lifetime cancer risks for individuals employed within the department, including fac-
ulty members and technicians, exceeded the acceptable risk threshold established by
the USEPA. Shen et al. [41] surveyed the IAQ within healthcare facilities, and based
on the research findings, proposed the potential use of AgZ filtering as a means to
manage bacteria and fungi parameters in hospital settings for indoor air quality
management.
Baurès et al. [84] explored the levels of chemical and microbiological
compounds present in the indoor air of two hospitals in France, which found that
these concentrations (aldehydes, limonene, phthalates, aromatic hydrocarbons),
exist in the space even low and are related to ventilation efficiency. Baboli et al.
[85], conducted an investigation into the airborne transmission of infectious
diseases at Razi Hospital in Iran, specifically chosen for this study. The findings
corroborate the presence of airborne transmission of SARS-CoV-2 bioaerosols indoors.
On May 7, 2020, Kenarkoohi et al. [7] conducted research into the transmission of the
COVID-19 virus among confirmed COVID-19 patients within the indoor air of hospi-
tal wards.
These investigations clearly showed a strong influence on IAQ monitoring and
controlling to achieve healthy spaces. There has been limited research conducted on
indoor air quality (IAQ) within healthcare facilities. Furthermore, certain scholars
propose exploring strategies for regulating and reducing pollution levels. The aim of
this study is to assess the indoor air quality in Namazi Hospital’s critical care unit
(CCU) and to confirm whether the room is healthy or not for patients, also, reduce the
possibility of the transition of infectious diseases by non-polluted air.
We came to the fact that the indoor and outdoor measurements of PM2.5 and
PM10 have been higher than the guidelines’ limitations. This condition can make
it easier for infectious diseases to spread, especially those that are transmitted
through contagious means. This matter has the potential to be for the corrupted
HVAC filters and misfunctioning outlet valves or HVAC systems. Indoor and outdoor
air should be monitored frequently for early detection of possible ventilation prob-
lems. This investigation suggests that frequent IAQ monitoring can lead to healthier
spaces.
The ACH (air changes per hour) in numerous European countries for residential
buildings ranges from approximately 0.35–1 [71]. However, the recommended proto-
col to minimize airborne infection transmission, especially during the COVID-19
pandemic, suggests a minimum of 12 ACH [86].
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Indoor Air Quality in Health Care Units (Case Study: Namazi Hospital, Shiraz, Iran)
DOI: http://dx.doi.org/10.5772/intechopen.113724

5. Conclusion

Recent studies showed the impact of IAQ on the transmission of infectious dis-
eases. Also, how monitoring and controlling IAQ can be effective. Therefore, the IAQ
of the CCU of Namazi Hospital was studied both experimentally and conceptually to
understand the indoor air quality and its consequences on outlet valve height. It was
found that the IAQ with respect to CO, CO2, PM2.5, and PM10 was critical in the
patient room due to room procedure’s significance and the count of individuals pre-
sent. If the IAQ indicators were above the guidelines’ limitations, the chances of
catching airborne diseases would increase sharply. In conclusion, frequently monitor-
ing indoor air will be more effective in making a better IAQ and reducing the likeli-
hood of infectious diseases transmission becomes more probable. Secondly, an
observation revealed measurements of PM2.5 and PM10 within the patient’s room in
the critical care unit (CCU) in Namazi Hospital were above IAQ guidelines limita-
tions.
Based on ANSYS Fluent output, particle concentration remains trapped when the
outlet is at 380 cm due to airflow pressure. At 200 cm, emissions escape, while at
20 cm, substantial airflow removes particles. The highest deposit fraction occurs at
380 cm, resulting in the lowest air quality. Conversely, placing the valve at the bottom
yields better particle removal.
We came to the fact that if the outlet valve position is above the ground height,
mechanical ventilation systems will not provide enough air renewal throughout the
patient room’s interior space. And this would lead to the trapped and built up condi-
tion of the air pollutants, especially in highly polluted locations. Therefore, the IAQ
will be lowered, and the likelihood of spreading infectious diseases will increase. It is
advised to use these principles since lowering the particle deposition fraction is
needed more than other options. Setting the exit valves lower can significantly alter
the air in the space and help with incoming flow egress. By managing this matter, we
could enhance our effectiveness in reducing the probability of airborne disease trans-
mission within vulnerable environments such as healthcare facilities. There were few
studies with interventions to improve IAQ , IAQ monitoring in healthcare spaces, and
investigating the impact of IAQ on health based on IAQ guidelines.

Acknowledgements

We would like to express our gratitude to Namazi Hospital, particularly the Occu-
pational Health Department, for their invaluable cooperation and guidance that sig-
nificantly contributed to this research.

Conflict of interest

The authors declare no conflict of interest.

11
Advancements in Indoor Environmental Quality and Health

Author details

Forough Farhadi, Saeid Chahardoli and Mehdi Khakzand*

School of Architecture and Urban Design, Iran University of Science and Technology,
Tehran, Iran

*Address all correspondence to: mkhakzand@iust.ac.ir

© 2023 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of
the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided
the original work is properly cited.
12
Indoor Air Quality in Health Care Units (Case Study: Namazi Hospital, Shiraz, Iran)
DOI: http://dx.doi.org/10.5772/intechopen.113724

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