IAQ News

CFM in HVAC Systems is an Important Metric for Maintenance

Cubic feet per minute (CFM) is a measurement used to quantify the flow rate of air or gas in a system. It represents the volume of air that passes through a specific point in the system in one minute. CFM is commonly used in various industries, including HVAC (Heating, Ventilation, and Air Conditioning) systems, to assess airflow rates and ensure proper ventilation. CFM in HVAC systems plays a crucial role in determining the effectiveness and efficiency of the ventilation process. Proper ventilation is essential for maintaining indoor air quality, controlling temperature and humidity levels, and ensuring the comfort and safety of occupants in a building. Importance of CFM in HVAC systems
  1. Ventilation: Proper ventilation is essential to maintain a healthy and comfortable indoor environment. CFM helps to ensure that an adequate amount of fresh outdoor air is brought into the space and that stale or polluted air is removed. This process helps reduce indoor air pollutants, control humidity, and replenish oxygen levels.
  2. Air distribution: CFM plays a significant role in distributing conditioned air throughout a building ...

How Flooding Affects Commercial Buildings

Historic flooding occurred in New England as a result of a mid summer weather system that dumped torrential rain from Vermont to New York's Hudson Valley. Officials say the storm has already wrought tens of millions of dollars in damage. In New York, Gov. Kathy Hochul said at a news conference Monday the storm sent “cars swirling in our streets” and dumped a “historic” amount of rain. “Nine inches of rain in this community,” Hochul said during a briefing on a muddy street in Highland Falls. “They’re calling this a ‘1,000 year event.’” (source: Associated Press) For facility managers it's important to understand how flooding affects commercial buildings to ensure occupant safety. Flooding Affects Commercial Buildings Environmentally The environmental impacts of floodwaters on commercial and institutional buildings cannot be overstated. While there are many different concerns, four critical areas of how flooding affects commercial buildings are explained below.
  1. Structural Damage: Floodwaters can cause significant damage to the structure of buildings, weakening foundations, walls, and floors. This damage can compromise the integrity and safety of the building.
  2. ...

Wildfire Smoke and Building HVAC Systems

Wildfire smoke can infiltrate a building's HVAC (Heating, Ventilation, and Air Conditioning) system through various pathways, including outdoor air intakes, cracks, gaps, and openings in the building envelope, and leaks in the ductwork. Once inside the HVAC system, the smoke particles can be distributed throughout the building, affecting indoor air quality and potentially causing health concerns for occupants. How Wildfire Smoke Gets In The following are some mechanisms by which wildfire smoke can enter and circulate within a building's HVAC system:
  1. Outdoor Air Intakes: HVAC systems often draw in outside air to maintain indoor air quality. If the building's outdoor air intakes are not adequately filtered or located in proximity to the wildfire smoke source, smoke particles can enter the system.
  2. Building Envelope: Smoke can infiltrate a building through cracks, gaps, and openings in the building envelope, such as windows, doors, and poorly sealed joints. Once inside, the smoke can be pulled into the HVAC system through pressure differentials.
  3. Ductwork Leakage: If there are leaks or gaps in the HVAC ductwork, smoke particles can infiltrate the ...

Different Types of Air Handler Units in Commercial HVAC Systems

As a facility management professional it is essential to have a comprehensive understanding of different types of air handler units (AHU) used in commercial HVAC systems. This document aims to provide a comparative analysis of three commonly used air handler units: Chilled Water Air Handler Unit, Package Air Handler Unit, and DX (Direct Expansion) Air Handler Unit. By exploring their unique characteristics, working principles, and applications, we can gain valuable insights into their suitability for various HVAC system configurations. Chilled Water Air Handler Units A chilled water air handler unit is a type of HVAC system that uses chilled water as a medium to cool and dehumidify the air. It consists of a cooling coil, a supply fan, filters, dampers, and a heating coil (optional). The chilled water coil removes heat from the air, and the supply fan circulates the conditioned air throughout the building. Chilled Water AHU Maintenance:
  • Regularly clean or replace air filters to ensure optimal air quality and airflow.
  • Inspect and clean the cooling coil to remove any dirt, debris, or microbial growth ...
/ IAQ Learning Institute

How often should commercial ductwork be inspected and cleaned?

The frequency of inspection and cleaning of commercial ductwork can vary depending on several factors, including the type of facility, the level of contamination, and local regulations. However, a general recommendation is to have commercial ductwork inspected every two to five years and cleaned as necessary. Commercial Ductwork Components The components of HVAC ductwork or air conveyance systems typically include:
  1. Supply Ducts: These are responsible for delivering conditioned air from the HVAC system to various areas of the building.
  2. Return Ducts: They collect air from the occupied spaces and return it to the HVAC system for reconditioning.
  3. Air Handling Units: These units condition and circulate the air, filtering it, and adjusting its temperature and humidity.
  4. Registers and Grilles: These are the visible openings where air enters or exits the duct system and are usually located on walls, ceilings, or floors.
  5. Plenums: These are large boxes or chambers connected to the HVAC system where the air is distributed or collected.
  6. Diffusers: These are devices that distribute conditioned air into the occupied spaces, ensuring proper airflow and temperature ...


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