CALL ON: +91-7720088723


Selecting the Right Fan for Enhanced Air Quality: Part II – Key Parameters to Consider

Selecting the Right Fan for Enhanced Air Quality: Part II - Key Parameters to Consider

In our previous article, we discussed types of fans and recommendations for choosing the right fan selection for the right application. When we need to consider selecting the right fan for enhanced air quality, some key and important parameters need to be taken into consideration, We will discuss here the key parameters for selecting the right fan for enhanced air quality as well as explore more about configurations and types of drives for fans, which have a significant impact on the performance of the system as a whole.

Selecting the right fan: List of Key Parameters: ​

For enhanced air quality, we considered the key parameters for selecting the right fan, which are listed below.


Capacity involves flow rate based on actual cubic feet per minute (acfm) to the fan inlet.The water gauge measures flow rate and pressure requirements at standard conditions (0.075 Ibm/ftl) using FTP and FSP. If the required pressure is unknown under non-standard conditions, density correction is made to ensure accurate measurements.

  • Air stream Handled Through the Fan
  • Explosive or flammable material
  • Corrosive Applications
  • Elevated air stream temperatures

Air stream handled through the fan:

It involves the following:

Air Stream and fan to be used

Explosive or Flammable Material:

Always use spark resistant construction (use explosion proof motor if motor is in air stream. Always stick to the standards set by the National Board of Fire Underwriters, the National Fire Protection Association, and governmental regulations.

Corrosive Applications:

It may require a protective coating or special materials of construction (stainless, fiberglass)

Elevated Air Stream Temperatures:

Use the correct materials for construction, arrangement, and bearing types because the maximum operating temperature affects the strength of the materials.

Physical Limitations:

Physical limitations must be considered in fan selection. Fan size, inlet size and location, fan weight, and ease of maintenance are the important things to be considered along with performance requirements.The most efficient fan size may not fit in the available physical space.

Drive Arrangements:

In a packaged fan system, the drive arrangement, i.e., the motor, is provided by the manufacturer, but if you purchase an assembled unit, then you must make drive arrangements according to the motor type, such as:

  • Direct Drive
  • Belt Drive

Direct Drive provides a compact assembly with constant fan speeds, ensuring optimal motor performance despite variations in impeller geometry and motor speed.

Belt drive offers flexibility in fan speed. This can be done by altering the drive ratio. Some applications need flexibility in fan speed because it requires changes in system capacity or pressure requirements due to changes in process, hood design, equipment location, or air cleaning equipment.


Fan noise, generated by turbulence within the fan housing, varies by fan type, flow rate, pressure, and fan efficiency. Noise ratings must be obtained from the fan manufacturer, as each fan design is different. Most fans produce a "white" noise, a mixture of all frequencies, and radial blade fans also produce a pure tone at a frequency equal to the blade passage frequency (BPF). The backward inclined impeller design is generally the quietest, but non-uniform air flow at the fan inlet or outlet can increase fan noise level. Most fan manufacturers publish sound ratings, such as sound power levels for eight ANSI standard octave bands in decibels (dB). The surrounding environment affects the sound level, and the decibel unit is not interchangeable for sound power or sound pressure. Sound pressure levels are usually measured in dB using the "A" weighting scale, which closely reflects the human auditory response to noise of various frequencies.

Safety and Accessories:

Safety guards are required as per the latest government norms implemented everywhere. All the danger points, such as the inlet, outlet, shaft, drive, and cleanout doors, must be checked as per the safety guidelines. Accessories can help with installation as well as maintenance requirements. Examples of accessories include drains, cleanout doors, split housings, and shaft seals.

Flow Control:

To control the airflow of a fan, there are some accessories to be installed, such as dampers, variable-pitch blades, and speed control.


Dampers are part of the air stream so they are installed directly on the fan inlet or outlet. Dampers are made up of material, which may not be acceptable for material handling fans.

Advantages of Dampers:

  • Dramatic Power Supply and Noise Reduction
  • Simple installation.
  • Lower initial costs.

Dampers are of two types:

Outlet Dampers:

The selection of outlet dampers depends on the required resistance, with parallel and opposed blades available for optimal control.

Inlet Dampers:

Inlet dampers reduce fan output and operating horsepower by pre-spinning air into the fan inlet, ensuring power savings for extended periods of operation.

Variable Pitch Blades:

Variable-pitch impellers enable manual or automatic changes to blade pitch, allowing for pneumatic or hydraulic adjustments while the fan is operating.

Variable Frequency Drive (VFD)

In flow control, a VFD (variable frequency drive) is also used as an accessory to control the flow of a fan, so the VFD is also an important parameter in fan selection.VFD applications vary fan speed and fan static pressure by controlling voltage and frequency between the electric power source and fan motor. The fan speed varies linearly with line frequency, with most VFD applications using direct drive arrangements. Belt drives are occasionally used.

VFD's intended usage requires understanding of the building's power supply and other electrical equipment usage. In applications with 80% or more system air flow, an inlet damper may be a better choice.

In short, the following parameters are more important in selecting the right fan:

When we think about a clean air system, there are numerous factors to be considered for optimal performance of the system. The selection of fans is one of them. Here are some factors responsible for these fan selections:.

Volume Flow Rate:

Make sure the fan has sufficiently high air speed and air flow for optimal performance of the system.


The amount of pressure needed to move air through the ducting and any filters,dampers, or other obstructions in the ventilation system.

Type of Air stream Handled:

The type of air that needs to be moved.

Space Limitations:

Available amount of space for the fan.


The fan’s efficiency depends on the design and type of fan.

All the above factors are most important in selecting the right fan or blower for the clean air system.

How can you select the right parameters among all to select the right fan?

With so many deciding factors and parameters, how can one choose the right parameters to choose the right fan for a clean air system? Here, Filter On’s expert guidance came into play. Filter On assesses requirements and gives you expert guidance to choose the right fan for a clean air system.

Filter On will assess:

  1. Statically and dynamically balanced fans, optimized with careful selection of operating points.
  2. Optimal VFD ensures further power savings.
  3. Fans are selected for optimized performance and require less power.

Thus, Filter On uses their 40+ years of expertise to help you decide the right fan for a clean air system.

In the next article we will explore more about fine tuning of fans for optimum performance of the system.

Filter On India has been working towards “Mission Zero Pollution” for the last 40+ years as a clean air solutions partner for industries. We specialize and have expertise in welding fumes, oil mist, coolant mist, dust collection, soldering, laser marking, laser cutting, plasma cutting, fumes in fastener manufacturing, ball point tip manufacturing, oil quenching, kitchen fumes, etc. Filter On has 70+ clean air solutions, so you can contact us for more information about our solutions. You can reach us through the web or visit us at our corporate office at Pune and our virtual locations at Delhi, Bangalore, Ahmadabad, Hyderabad, or Chennai locations.


Optimizing Air Quality: An Extensive Guide to Fan Selection for Clean Air Systems (Part I)

Optimizing Air Quality: An Extensive Guide to Fan Selection for Clean Air Systems (Part I)

We discussed the selection of filtration systems in the previous article. Fan selection is most important in ventilation when we talk about air-moving devices, selection of fan is most important because it has impact on the overall performance of the clean air system, However fan selection is difficult task, so some expert guidance is necessary. Here in this article we will discuss types of fans, some guidelines about how to choose right fan for right application? Etc..

Classification of fans for fan selection

Fans are the primary air-moving devices in industrial applications, so they have been classified into three basic groups:

  • Axial Fans
  • Centrifugal Fans.
  • Special Type Fans

Axial Fans

Industrial Tube Axial fan
Industrial Axial fan

Axial fans are used for high flow rates at lower resistance. Axial fans are of three types:

  • Propeller Fans
  • Tube axial Fans
  • Vane axial Fans

Propeller fans are essential for general ventilation, utilizing blade types like disc or propeller blades for low resistance. Performance is sensitive to resistance, affecting flow rate.

Tube axial fans, also known as duct fans, are fans designed to move air against moderate pressures, typically with narrow or propeller-type blades in a short cylindrical housing.

Vane axial fans, typically mounted in cylindrical housings, are highly efficient and typically used in clean air applications due to their higher pressures.

Types of centrifugal fan

Forward Curve (Squirrel Cages):

Squirrel cages, with their low space requirements and quiet operation, are ideal for low to moderate static pressures in heating and air conditioning work but not recommended for dust or particles that could cause unbalance.

Radial Impellers:

Radial impellers offer a variety of blade shapes, ranging from high efficiency to heavy impact resistance, designed for exhaust systems. These radial blades, with medium tip speeds, handle both clean and dirty air, ensuring efficient material conveying velocities.

Backward-inclined or backward-curved impeller blades

These blades are inclined oppositely to the direction of fan rotation. These types of fans have higher speeds, efficiency, and relatively low noise levels with non-overloading horsepower characteristics.

These impellers have two types:
  • Single-thickness blades and
  • Airfoil blades.

Special Type Fans:

Special Type Duct Fans

Special-type fans, such as in-line centrifugal and vane axial fans, feature backward-inclined blades and similar performance curves to scroll-type centrifugal fans.

Thus, it is very important to choose the right type of fan for the right kind of application. For example, choosing a forward-curved fan for fume and dust handling will definitely be the wrong choice, as it would lead to the deposition of particles on forward-curved blades and thus imbalance.

How do I select the right fan for the right application?

In conclusion-
  • Choose an axial fan for low-pressure and high-volume clean air ventilation applications (like underground parking or tunnel exhaust ventilation).
  • Choose centrifugal forward-curved fans for fresh air low-pressure applications. You will find these fans most commonly used for small AC units, coolers, etc.
  • Choose centrifugal backward-curved fans for medium-pressure and low- to high-volume applications. These are most commonly used for industrial fume extractors, dust collectors, AHUs of central AC systems, etc.
  • Choose centrifugal radial fans for material movement like pneumatic conveying, dust handling systems, powder handling systems, etc.

In the next article we will explore more about configurations and type of drives of fans which has a significant impact on performance of the system as a whole.

Filter On India has been working towards “Mission Zero Pollution” for the last 40+ years as a clean air solutions partner for industries. We specialize and have expertise in welding fumes, oil mist, coolant mist, dust collection, soldering, laser marking, laser cutting, plasma cutting, fumes in fastener manufacturing, ball point tip manufacturing, oil quenching, kitchen fumes, etc. Filter On has 70+ clean air solutions, so you can contact us for more information about our solutions. You can reach us through the web or visit us at our corporate office at Pune and our virtual locations at Delhi, Bangalore, Ahmadabad, Hyderabad, or Chennai locations.


Understanding CO2: Pollution, Impact And Proactive Solutions.

Understanding CO2: Pollution, Impact And Proactive Solutions.

In today’s world, air pollution is a huge and serious issue. Alarming sea levels and the effects of global warming are seen everywhere. Carbon dioxide (CO2) is a major pollutant among all pollutants. It’s effects on the health and environment are problematic in nature. When we talk about industrial pollution, it is one of the problems as well, so in this article, we’ll discuss CO2 and the role of CO2 in air pollution. Its impact on industrial workers as well as industries, the environment, preventive measures, compliance, etc.

What is CO2?

Carbon dioxide is a chemical compound with the chemical formula CO2. It is made up of molecules that each have one carbon atom covalently double-bonded to two oxygen atoms.

CO2 as a Pollutant

Carbon dioxide is a major pollutant in air pollution. When talking about air pollution, this greenhouse gas has a major portion in it.

Sources of CO2 Pollution in the Industrial Indoor Work Environment

There are numerous sources of CO2 pollution. We are here discussing CO2 and its effects on the workplace environment and workers health.

There are mainly four types of sources of CO2 often seen in the indoor industrial environment.

Respiration from employees.
Burning of fuels
Industrial Operations
Goods Transportation

Respiration from Employees

In a close work environment, mostly in offices, CO2 is mostly generated by respiration among the employees.

Burning of Fossil Fuels

The burning of fossil fuels for the operation of machinery is another way of generating CO2, and if there is low ventilation, the CO2 can be hazardous to the workers.

Industrial Operations-

Industrial operations, i.e., processes like welding, cutting, and brazing of metals, generate CO2 because fumes from these processes are more hazardous to the health of the workers. These processes produce more CO2, and without proper ventilation and fume collection systems, in most of the industries, workers face various health issues due to CO2 pollution.

Goods Movement-

Goods movement or transportation in a closed environment where trucks and cranes are used for goods movement in large premises generates CO2 generated through vehicles, which is harmful for the workers and employees who used to work there.

Thus, CO2 as a pollutant plays a major role in industrial indoor air pollution.

Impact of Carbon Dioxide (CO2) on Health:
Short-Term Health Effects:
Exposure to high carbon dioxide levels can cause:

Suffocation by displacement of air: The suffocation-exposed person has no warning and cannot sense the oxygen level is too low, so it leads to a breathing issue.

Incapacitation and unconsciousness: At high concentrations, carbon dioxide can cause unconsciousness and respiratory arrest within one minute.

Headaches: Excessive amounts of carbon dioxide inhalation can cause headaches.

Vertigo and double vision: Carbon dioxide exposure can cause vertigo and double vision. At high levels of exposure, the carbon dioxide itself can cause vertigo, dizziness, nausea, and other symptoms like double vision.

Inability to concentrate: High exposure levels of CO2 lead to concentration problems while working; suffocating environments can cause an inability to concentrate, which results in productivity loss.

Tinnitus: According to one study, chronic tinnitus is related to multisensory environmental hypersensitivity, including CO2 thresholds. Another study reports that tinnitus has been reported in hearing loss secondary to carbon monoxide poisoning.

Seizures: Carbon dioxide (CO2) can increase brain excitability, which can lead to spontaneous seizures.

Breathing in high amounts of carbon dioxide may be life-threatening.

Touching liquid carbon dioxide can cause frostbite or blisters.

Carbon dioxide can cause frostbite when anyone is in contact with solid CO2 (dry ice) and vapors off-gassing from dry ice.

These frostbite blisters on the skin may begin to feel warm—a sign of serious skin involvement. If you treat frostbite with rewarming at this stage, the surface of the skin may appear mottled. And you may notice stinging, burning, and swelling. A fluid-filled blister may appear 12 to 36 hours after rewarming the skin.

Long-Term Health Effects: Prolonged exposure to carbon dioxide may cause:

Changes in bone calcium-induced respiratory acidosis induced by an elevated carbon dioxide (CO2) environment should provoke hypercalciuria with related total body and subsequent bone calcium losses. often leads to osteoporosis.

Changes in body metabolism: In the human body, carbon dioxide is formed intracellularly as a byproduct of metabolism.

Levels of CO2 Exposure to Health

Safe exposure limits for carbon dioxide (CO2):

According to the US Health Department, carbon dioxide is not generally found at hazardous levels in indoor environments. The MNDOLI has set workplace safety standards of 10,000 ppm for an 8-hour period and 30,000 ppm for a 15-minute period. This means the average concentration over an 8-hour period should not exceed 10,000 ppm, and the average concentration over a 15-minute period should not exceed 30,000 ppm. It is unusual to find such continuously high levels indoors and extremely rare in non-industrial workplaces. These standards were developed for healthy working adults and may not be appropriate for sensitive populations, such as children and the elderly. MDH is not aware of lower standards developed for the general public that would be protective of sensitive individuals.

In the Indian context, the exposure limits for CO2 are as follows: CO2 < 1000 PPM (home) < 5000 PPM (workplace-short duration).

Proactive Solutions for CO2 Emissions in Industries

Measure your CO2 levels in industries.
You can measure CO2 levels at your workplace by using a CO2 sensor. The most common type of sensor is the non-dispersive infrared (NDIR) sensor. This sensor measures infrared light in a sample of air. NDIR sensors are popular because they have a long life, are fast, and have low cross-sensitivity to other gases. They can measure CO2 concentrations with high accuracy across a wide range of volumes. The measuring unit detects the CO2 concentration and converts it into a digital display.

Use renewable energy solutions.
You can use renewable energy solutions for CO2 reduction from traditional energy sources. Sources like solar energy and wind energy can reduce the carbon footprint and make industries self-sustainable in the long run.
Use ventilation solutions.
Using ventilation solutions such as local exhaust ventilation, an adequate amount of air flow through windows, and proper placement of machines that are responsible for CO2 generation with effective measures can reduce the carbon footprint in industries.

Use extraction solutions.
Clean air solutions like fume extraction, oil/mist collectors, dust collection systems, and laser cutting extraction solutions can reduce CO2 exposure in industries, which helps workers get proper ventilation at work and can have a positive impact on their productivity.

Filter On India has been working towards “Mission Zero Pollution” for the last 40+ years as a clean air solutions partner for industries. Filter On has 70+ clean air solutions, so you can contact us for more information about our solutions. You can reach us through the web or visit us at Pune, Delhi, Bangalore, or Chennai locations.


Breathable Workspaces: Understanding PM 2.5 and PM10 Pollution

Breathable Workspaces: Understanding PM 2.5 and PM10 Pollution, Knowing Safety Limits, and Implementing Solutions for Worker Health

Today, air pollution is a very sensitive subject for everyone. In every country, cities, and now small villages, are also affected by air pollution due to various pollutants. PM2.5 and PM10 are two of the major pollutants. In industrial environments, PM2.5 and PM10 are present due to various industrial processes. In this article, we are discussing PM2.5 and PM10 as pollutants, their impact on industrial workers, safety and solutions to overcome pollution from them, and government norms and regulations about PM2.5 and PM10 in an industrial context.

What are PM 2.5 and PM 10?

Particulate matter (PM) is a fine, microscopic matter suspended in air or water. PM2.5 and PM10 are the two types of particulate matter.

What is PM2.5?

Particulate Matter (PM) 2.5 is a very small particulate matter with a microscopic size of 2.5 or smaller.

What is PM10?

Particulate Matter (PM) 10 is a small particulate matter with a diameter of a microscopic size of 10 or smaller.

PM2.5 and PM10 as pollutants

PM2.5 and PM10 are small particulate matter that is totally microscopic, so they are inhaled by humans.

PM2.5 Sources

Natural Sources:

>> Forest Fires
>> Volcanic Eruptions
>> Earthquakes

Artificial Sources

Industrial Sources :

Industrial sources include paper pulp industries, oil refineries, brick kilns, power plants, municipal waste treatment plants, industrial fossil fuel burning, and gasoline sources such as sulfur dioxide and nitrogen oxide.

Household Sources :

>> Construction Sites
>> Smoking
>> Cooking, Frying, and Not Maintaining Kitchen Chimneys
>> Wood Burning
>> Biomass Burning


>> Emissions from Vehicles

PM10 Sources :

There are various sources of PM10 pollution.
The natural sources include sea salt, dust, etc., whereas man-made sources are as follows:
  • smoke, dust, and dirt from unsealed roads, construction, landfills, and agriculture

  • pollen

  • mold

  • smoke from wildfires and waste burning

Industrial Sources

>> materials handling
>> crushing and grinding operations
>> power generation

In the home, PM10 comes from many sources, some of which are as follows:

>> outdoor sources leaking in through spaces around doors and windows

>> stoves

>> space heaters

Apart from these sources, some of the industrial processes also produce PM2.5 and PM10.

Welding :

Welding is a general process that is carried out in most manufacturing industries. During the welding process, PM2.5 and PM10 are generated when hot metal vaporizes, cools, and condenses into small, solid metal particles. Welding aerosols can be coarse (PM 2.5–10) or fine (PM 0.1–2.5). Welding produces visible smoke that contains harmful metal fumes and gas by-products. Welding workers are exposed to significant amounts of the metal fume PM2.5 during the welding process.

Plasma Cutting-

Plasma cutting generates the highest concentrations of PM2.5. Most aerosols generated during plasma arc cutting are PM 2.5. The fumes and gases generated by plasma cutting depend on whether the cutting is dry or wet.

Some of the other processes are also responsible for PM2.5 and PM10 generation, like diesel exhaust.

Health Effects of PM 2.5 and PM 10.

Particulate Matter (PM) 2.5 and 10 have very serious health effects on humans, mainly those who are most in contact with them. In industries, these pollutants are generated from various industrial processes such as welding, brazing, cutting, etc. So the adverse health effects of these pollutants are as follows:.

Short-term health effects of PM10 can include:

>> Difficulty breathing
>> Coughing
>> Eye, Nose, and Throat Irritation
>> Chest tightness and pain
>> Fatigue
>> General Respiratory Discomfort

Long-term exposure to PM10 can cause more serious health concerns, such as:

>> Lung tissue damage
>> Asthma
>> Heart Failure
>> Cancer
>> Adverse birth outcomes
>> Chronic obstructive pulmonary disease (COPD)
>> Premature death

Health Effects of PM2.5

>> Short-Term Health Effects of PM 2.5
>> Irritation of the throat and airways
>> Coughing
>> Breathing Difficulty

Long-Term Health Effects of PM 2.5

>> Heart and lung disease
>> Bronchitis
>> Emphysema
>> Nonfatal heart attacks
>> Irregular heartbeat
>> Asthma and more intense flare-ups
>> Decreased lung function
>> Early death

Safe Limits for PM 2.5 and PM 10.

There are two types of absorption limits for PM 2.5 and PM 10, as follows:

>> General (Ambient Air) Absorption Limits for PM2.5 and PM 10
>> Industrial Processing Absorption Limits for PM2.5 and PM 10

General (Ambient Air) Absorption Limits for PM2.5 and PM 10

As per CPCB India’s Central Pollution Control Board’s norms, the general (ambient air) absorption limits of PM 2.5 and PM 10 are as follows:

Industrial Process Absorption Limits for PM 2.5 and PM 10.

The industrial process absorption limits for PM2.5 and PM10 as per OSHA standards are as follows:

Solutions to PM 2.5 and 10 in the Industrial Environment

Many countries seek to reduce PM2.5 and PM10 air pollution. For example, in 2019, India joined the United Nations Climate and Clean Air Coalition with the stated goal of reducing particulate matter pollution by 20 to 30 percent by 2024. The country launched the National Clean Air Program in mid-2019.

Solutions on PM 2.5 and PM 10 for Industries

Use Eco-Friendly Process Materials: Industries must use eco-friendly process materials for their processes, such as in welding, where we must use water-based fluxes or electrode coatings, which can reduce the environmental impact of welding. These materials help reduce the fumes generated and waste produced during the welding process.

Use Industrial Air Filtration Systems: Industrial air filtration systems such as welding fume extractors, oil mist collectors, laser marking fume extractors, soldering fume extractors, and dust collectors must be used for air filtration in an industrial work environment to reduce the impact on workers of PM 2.5 and PM 10.

Use Monitors for Measurement of PM2.5 and PM10 Pollution in Industries: Use PM2.5 and PM10 monitors for measurement of the severity of workers health.

Use PPE Equipment While Working: Use personal protective equipment like masks, helmets, hand gloves, and PPE attire while working to reduce PM 2.5 and PM 10 exposure.

Reduce Burning Fossil Fuels: Reducing fossil fuel use and switching over to renewable energy sources can reduce the exposure to PM2.5 and PM10 in industries because the burning of fuels is a major source of PM2.5 and PM10 pollution.

Reducing the use of wood burning: reducing the burning of wood is the best solution to reducing PM2.5 and PM10 pollution.

Filter On India has been working towards “Mission Zero Pollution” for the last 40+ years as a clean air solutions partner for industries. Filter On has 70+ clean air solutions, so you can contact us for more information about our solutions. You can reach us through the web or visit us at Pune, Delhi, Bangalore, or Chennai locations.