1. Introduction:
Air pollution has become one of the global health hazards in the 21st century. From the report
of the World Health Organization, 4.2 million premature deaths globally every year have been
linked to outdoor air pollution. The major causes of death included 43% chronic obstructive
pulmonary disease, 29% lung cancer, 25% ischemic heart disease, 24% stroke, and 17% acute
lower respiratory infection, respectively. One of the main causes of ambient air pollution is
particulate matter, especially that which is less than 2.5 microns as well as particles of 10
microns in diameter (PM2.5 and PM10). PM can penetrate the lung and enter the
bloodstream, eventually destroying many respiratory, cardiovascular, and cerebrovascular
functions. Over the period 1960 to 2009, the mean population-weighted PM2.5
concentrations were found to have increased by 38%, mainly noted in China and India, which
attributed to global death increase by 89 to 124% while PM2.5 concentration trends were
reduced in Europe and the United States.
Lahore is a metropolitan area with high levels of particulate pollution that often surpasses the
guideline values of World Health Organization (WHO) and the National Ambient Air Quality
Standards (NAAQS) of Pakistan (Pak-EPA 2005). Both fine and coarse particulate matter cause
various types of health concerns (e.g., Stone et al. 2010; Kim et al. 2011; Tsiouri et al. 2015;
Lan et al. 2016). The WHO estimated ∼360,000 premature deaths in Asia each year due to air
pollution (WHO 2008). The environmental degradation, including water and soil, is about 6%
of Pakistan’s GDP, and the indoor and outdoor air pollution contributes nearly half of it
towards the total illness and premature mortality (World Bank 2006). The lack of stringent
implementation of air pollution shows that the exposure to the ambient PM has increased
than previously estimated (WHO 2014a). In megacities such as Lahore, important factors for
the increased exposure to air pollution are the higher intensity of human activities and
emissions from the road vehicles. PM is currently considered to be one of the best indicators
for assessing health impacts caused by the ambient air pollution (WHO 2014a; Yao et al. 2015.
Air quality has a significant impact on human health. According to the WHO, the total number
of deaths attributed to ambient air pollution and its consequential diseases, such as ALRI
(acute lower respiratory infection), COPD (chronic obstructive pulmonary disease), lung
cancer, IHD (ischemic heart disease), and stroke, in Pakistan in 2012, was 60,000This number
increased to 105,000 in 2020 [3]. The high health cost of air pollution-related diseases is 1% of
total gross domestic product (GDP), whereas the total cost of environmental degradation is 6%
of GDP. Around 30 million inhabitants of the urban population are affected by smog. In a study
conducted in 2021, the avoidable mortality of only IHD and lung cancer was over 2 million
people, with the total cost related to this mortality being USD 1000 million in Pakistan.
Pakistan is ranked in the top 10 countries of the world in having the highest concentration of
particulate matter, PM2.5, with an annual mean of 44.21 µg/m3, which is far higher than the
recommended value of 10 µg/m3 by the WHO. Lahore, Pakistan, once called “The City of
Gardens” is seeing its worst environmental catastrophe in the form of smog. The average
PM2.5 concentration in Lahore in 2010 was 121.8 µg/m3, and the value has increased with
each passing year. In 2020, Lahore was ranked as the 18th most polluted city in the world, and
the second most polluted mega-city, based on PM2.5. Dealing with climate issues is now an
unavoidable reality for Pakistan. Data of the source appointment of PM2.5 for Lahore were
only available until 2010, which suggested that vehicles (diesel, 28%, plus petrol, 8%) account
for 36% of PM2.5. Secondary PM in the forms of biomass burning, coal combustion, and
industrial emissions, are accountable for 30%, 15%, 13%, and 6%, respectively.
regulations and the mass transportation system contribute further to the issue of local air
pollution (Biswas et al. 2008). Needless to mention that the particulate matter (PM) also plays
an important role in affecting the global climate (IPCC 2007; Karagulian et al. 2015). The
increasing population and urbanization have led to an increase in numerous industrial sources
as well as the road vehicles (Biswas et al. 2008; Stone et al. 2010; Shah et al. 2012; Rasheed et
al. 2015; Ali et al. 2015; Molina et al. 2017). New evidence related to exposure risk assessment
and global exposure estimates.
2. Area of selection:
According to air quality index (AQI) this is the ranking of different cities of Pakistan.
According to this graph Lahore is the second most polluted city of Pakistan. Now we see the
ranking of most polluted locations of Lahore.
Chattha Park Lahore is the most polluted location the Lahore, that’s why we select the Chattha
Park as a site of our project.
2.1. Chattha park Lahore report:
3. Selection of the HEPO filter:
We use hepo filter of less than 2.5 micron mash. This can easily filter the pm2.5 particles from
the air. Size of the filter select according to the diameter of the fan, and its cubic feet per
minute (CFM).
4. Selection of the active carbon filter:
We use pleated type of active carbon filter. We also use active charcoal filter to remove the
volatile organic compound, smoke etc. size of the filter is decided after the calculation
according to (cfm).
5. Selection of the fan:
We select the fan according to our requirement formula to calculate fan flow rate is;
Q=vA
(1)
(v is in feet per min & A is in square feet)
Q= x/t*A
(velocity = x/t)
Q=V/t
Let suppose t is one min then;
.
Q =V
(2)
If we use filter it also decrease the flow rate so we multiply with x to overcome the filter
friction.
.
Q =V*x
(3)
Where;
.
• Q is the fan flow rate in CFM
• V is the volume which we need to clean in cubic feet
• x is the friction coefficient of the filter
Normally x is the 1.25 for the normal filters.
6. Selection of the solar panel:
According to Fans and Blower Horsepower Equation
1. P = (Q x p)/(229 x ) or.
2. P = (Q x PF)/(33,000 x ) or.
3. P = (Q x Pw)/(6356 x )
(4)
(5)
(6)
Where: P = Power, hp. Q = Flow Rate, cfm. p = Pressure, lb/in2 Pf = Pressure,
lb/ft2 Pw = Water Gauge, Inches. x= Efficiency coefficient.
4. 1hp =745.7watt
7. Our desire calculation:
Now we need to design a air purifier which purify the air at the rate of 190 cfm so accordingly
to equation (3)
Q=Vx
Q= 190*1.25
Q=237.5cfm
As we know that
P= 14.696 ib/in2
x= 85
(blower efficiency coefficient)
by using equation (4)
P = (Q x p)/(229 x )
P=(237.5*14.696)/(229*85)
P=0.179hp
To get answer in watt
P=0.179*745.7
P=134watt
So we need to select the solar panel which gives at least 134 watt.
For 237.5 CFM we use 6 or 8 inch diameter suction blower similarly diameter of active carbon
is same as a diameter of the fan and size of hepo filter is increase 2 to 3 inches from the size of
fan.
8. Results & discussions:
Design parameter already done previously. This air purifier purifies the air at the flow of 190
cubic feet per min. for this purpose 237.5 cfm fan is required. Power required for this fan is
134 watt.
Now we calculate the total area of purification than select the total no. of purifier. Each air
purifier cover 8 feet of radius. Its mean that for better result we use next air purifier after next
16 feet.