Which variable in the equation Q=CA(2∆P/ρ)^n represents flow?

In the equation Q = CA(2∆P/ρ)^n, the variable Q specifically represents flow, which is typically measured in volume per unit time (e.g., cubic feet per minute, cubic meters per hour). In this context, flow refers to the rate at which air is moving through a particular opening or pathway in the building envelope.

The equation itself is used to describe the relationship between flow (Q) and other factors, including the coefficient (C), the area (A) of the opening, the pressure difference (∆P), the density of the air (ρ), and the exponent (n), which accounts for the non-linear characteristics of flow through openings. Understanding the role of each of these variables is crucial for performing whole-building airtightness testing, as it allows practitioners to calculate the expected airflow based on different conditions within and around the building.

The other variables play supportive roles in the equation. The coefficient is a constant that reflects the specifics of the flow conditions, while the area determines how much open space there is for flow to occur. The density of the air influences how much mass of air is involved in that flow, and the pressure difference is the driving force behind the movement of air. However, it is the flow rate