HVAC systems are essential in regulating heat, airflow, air-conditioning and ventilation of commercial and residential buildings. A significant function of the HVAC system is improving the quality of air in a building – a factor that directly affects the health and productivity levels of those residing within. It reduces the amount of humidity to a level that is comfortable and safe. The HVAC systems are a worthy investment as they contribute to energy savings in the long run. In this article, Crosstown Plumbing, a leading plumbing supplies wholesaler in New Jersey, explains how to measure HVAC air flow.
The standards and guidelines prescribed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) are a good place to start when measuring the airflow in your HVAC system. ASHRAE Standard 41.2 offers information regarding air velocity and airflow measurement, specifically.
According to the guidelines, the accuracy of airflow measurement is largely dependent on the location of said measurement. Thus, the airflow transducer must be placed:
- 7.5 duct diameters downstream
- 3 duct diameters upstream from any obstructions.
Another recommendation while measuring is to steer clear of bends or junctions in the ducts. Turbulence from fans or other machinery can also affect the accuracy of the measurement.
Parameters of measuring a HVAC system
Indoor air quality
Reports suggest that approximately 3.8 million people die due to household air pollution globally every year. With alarming statistics such as this one, it is imperative that indoor air quality is tested and in line with international safety standards. Adequate ventilation, eliminating pollutants, and comfortable humidity levels are essential when measuring indoor air quality.
It is recommended to use indoor air quality sensors to detect the presence of contaminants such as carbon monoxide, particulate matter, VOCs, formaldehyde, and radon.
Evaluating the airflow and velocity of a ventilation system offers an insight into the overall balance of a commercial or residential building. Experts use an anemometer to measure the average air speed in a ventilation system. This measurement is then multiplied by the area of the duct in square feet to understand how air is flowing through the duct.
Heating and cooling systems
There are several instruments that are used to measure flow and surface temperature of heating and cooling systems, which in turn, determine the hydroponic balance of the system. This balance, which is directly correlated to thermal comfort, avoids the building from over- and under-heating or over- and under-cooling.