What is the formula to calculate the weight of a cubic foot of air at sea level?

The weight of a cubic foot of air at sea level is approximately 0.075 pounds. This figure is derived from the density of air, which at standard temperature and pressure conditions is typically around 0.075 pounds per cubic foot.

Factors such as temperature and humidity can influence air density, but under normal conditions at sea level—approximately 68 degrees Fahrenheit and 1 atmosphere of pressure—this value holds true. Hence, when calculating the weight of air for HVAC applications, using this approximation allows for practical assessments in designing and troubleshooting systems.

Understanding this figure is crucial in HVAC, as it plays a significant role in calculating airflow, sizing ducts, and determining system loads, which are foundational aspects of system design and efficiency. Recognizing the correct weight of air helps professionals in making informed decisions about ventilation and air handling.