Whether it’s your workplace, a commercial space, or a public facility, proper airflow and air circulation are key components in an overall air quality improvement approach for any building. Airflow and air circulation can be improved by using high-quality air filtration systems, making sure that your HVAC system is running properly, and utilizing both mechanical and natural ventilation. This article will discuss the role of airflow and air circulation in maintaining cleaner air and explore ways to improve air quality in your building.
The Importance of Proper Airflow and Air Circulation in a building
The movement of air inside a defined space is referred to as airflow. It’s the quantity of air that passes through a specific area, measured in cubic feet per minute (CFM). Air circulation refers to the distribution of air within an indoor environment. Airflow is a quantitative measurement and air circulation is qualitative. They both help improve indoor air quality and without adequate airflow and proper air circulation, pollutants like PM2.5 and other pollutants, allergens, mould, and volatile organic compounds can accumulate, creating an unhealthy indoor environment.
How does proper airflow and air circulation improve indoor air quality?
The Key Benefits of Proper Airflow and Air Circulation:
- Building ventilation helps dilute and remove particulates such as dust, pollen, PM2.5, and harmful gases by bringing in outdoor air. This process dilutes contaminated indoor air when outside air is not highly polluted. As the air circulates through the air filtration system, the contaminants are trapped by air filters. The higher the quality of the filter, the more contaminants are captured.
- It reduces the risk of negative health conditions caused by poor air quality, including asthma, allergies, and poor cardiovascular health. It also increases oxygen levels, which can improve the health of building occupants.
- Distribution of Conditioned Air: Proper airflow and circulation ensures that warm or cold air is evenly distributed throughout buildings and building floors, and this reduces temperature variance, making buildings more comfortable.
- It reduces humidity levels by circulating air throughout the building, resulting in more consistent heating or cooling. This can save energy by reducing the need to crank up HVAC systems to compensate for inadequate airflow.
- It removes excess moisture and hinders the growth of bacteria and mould. Additionally, odours, higher rates of virus transmission, a feeling of stuffiness, and off-gassing may occur in environments with high humidity levels.
- It leads to a more comfortable environment. Studies have shown that cleaner air leads to better cognitive function and better concentration.
Inadequate airflow and circulation allow tiny, harmful particles to stay suspended in the air and to be present in rooms for a longer period, which can lead to poor air quality and a variety of negative health issues.
The Role of Ventilation Systems
Ventilation systems in conjunction with good air filtration, are designed to bring outside air into a building and to recirculate air. Poorly designed or malfunctioning systems can lead to poor IAQ. A well-designed air filtration system and building layout allows continuous airflow and circulation which can ensure good indoor air quality (IAQ).
Natural Ventilation: Windows, vents, and air intake systems are all used for natural ventilation and airflow. However, if the air outside is polluted, or for example, there are very high winds or if it is hot or cold outside, using natural ventilation becomes a less attractive option. That is when mechanical ventilation becomes even more crucial.
Mechanical Ventilation: Mechanical ventilation brings in air from outside and filters and conditions it as it comes into a building. It is vital to make sure you have a properly designed, leak-free HVAC system that allows an adequate amount of air changes per hour in a room (ACH) and that you use a high-quality air filter to capture dust and other pollutants.
Common Problems in HVAC System Airflow and Circulation
An inefficient HVAC system, cluttered rooms or hallways, poor room layouts, and long corridors, can all contribute to restricted airflow and poor air circulation in a building.
Although advanced air filtration systems provide excellent air quality, issues with airflow and circulation can still occur. If the air ducts or vents are blocked, it can hinder airflow, preventing enough outside air from entering the building and disrupting filtration.
Clogged or Dirty Air Filters, HVAC components
Clogged air filters can significantly reduce airflow, requiring the air filtration system to work harder and causing poor system efficiency. High-quality air filters capture smaller particles and improve air quality and HVAC system performance.
Dust build-up in the air filtration system leads to increased pressure, which decreases airflow and reduces the amount of outside air intake.
Fans, blowers, and coils covered in dust and debris do not perform as well, leading to reduced airflow and increased wear of the HVAC system.
High Pressure Drop
A high-pressure drop occurs when airflow is restricted, leading to poor performance and increased energy costs. To address this, select filters that feature the lowest average pressure drop, while maintaining effective filtration.
Improper Filter Selection
Using the wrong type of air filter or an improperly sized filter can restrict airflow. The filter must be appropriate for your HVAC system’s specifications. It is crucial to choose a filter with a suitable MERV rating or a HEPA filter for environments such as sensitive areas in healthcare and pharmaceutical facilities.
Air Filter Bypass
At times, air can bypass an air filter if the filter or frame is not properly fitted. It is important to make sure that air does not bypass the filter by using the right size filter that fits properly in the rack, install it correctly in the proper orientation, and choose high-quality air filters. Make sure you regularly check seals for any cracks or breakage.
7 Ways to Improve Airflow, Air Circulation, and IAQ in Your Building:
- Install High-Quality Air Filters: Use a minimum MERV 13-A air filter with the lowest resistance to airflow. Choose an air filter with the lowest average pressure drop to ensure that you will get maximum airflow during the entire life of the filter, not just the first month or so.
- Follow industry standard ventilation rates: following ASHRAE and CSA recommended fresh air intake rates is crucial.
- Use exhaust fans, supply fans, and controlled ventilation to improve air exchange and help with pressurization control.
- Keep Vents, ducts, and fans Clean: regularly clean your HVAC system, vents, and air ducts to prevent dust buildup.
- Open windows and inside doors: In suitable climates, open windows can provide ventilation. Open doors inside buildings can help with cross ventilation, helping with airflow, and improving heating and cooling efficiency.
- Older buildings can be retrofitted with better air filtration systems and can be remodelled to eliminate dead spots and to improve airflow and air circulation throughout the buildings.
- Monitor airflow in your building to ensure that you have good IAQ. Monitors can help you improve airflow and save energy. Monitoring systems include sensors and building monitoring equipment with real-time analysis (building monitoring systems (BMS)).
How do air changes per hour (ACH) affect indoor air quality in a building?
Adequate air changes per hour (ACH) allow for the dilution and removal of harmful particles from buildings before they penetrate deep into the human body. A minimum number of ACH along with proper air filtration and air dispersion must be achieved. Without it, harmful particles can still linger in a room.
ASHRAE Standard 62.1-2016 outlines minimum air ventilation rates for various building types based on building or space usage. ASHRAE recommends 0.35 ACH or 15 cubic feet per minute (CFM) per person for residential spaces. For commercial spaces, it varies depending on the building type. For example, hospitals require higher ventilation rates, and hallways require less.
The Centers for Disease Control and Prevention (CDC) suggests 5 ACH for buildings in general, and recommends MERV-13 or higher air filters. It recommends 12-15 ACH for more sensitive areas such as long-term care facilities.
The Canadian Standards Association (CSA) recommends different ACH of outdoor air depending on specific room type. CSA standard Z 317.2 is specific to healthcare.
Conclusion
Problems, such as dirty or clogged filters, poor air filter selection, leaky or improperly built ducts, or blocked vents, can cause problems with airflow and air circulation. Air quality suffers as a result of these problems and system efficiency is degraded. It is critical to choose the right filter type, such as a MERV 13-A rated filter, change air filters before they reach the end of their life, and make sure ducts are appropriately sized and sealed in order to increase airflow.
Furthermore, adequate ventilation and unobstructed vents may greatly improve airflow. Better circulation and airflow can also be achieved by minimizing pressure drops, avoiding filter bypass, and keeping HVAC equipment clean. Achieving efficient, effective airflow management requires proper maintenance, real-time airflow monitoring, and HVAC system design optimization.
Would you like to improve the air quality in your building today? Start by contacting Camfil for a complimentary site survey for your commercial building, public building, or other facility. Use this contact form
About Camfil Canada Clean Air Solutions
For more than 60 years, Camfil has been helping people breathe cleaner air. As a leading manufacturer of premium clean air solutions, we provide commercial and industrial systems for air filtration and air pollution control that improve worker and equipment productivity, minimize energy use, and benefit human health and the environment. Read more about Camfil Canada
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Sources:
ASHRAE
CDC: Health & Safety Legislation
CSA Z 317.2
Media Contact:
Phillip Ilijevski
Camfil Canada Inc.
T: 437-929-1161