1. What is an Air Mass Flow to Volumetric Flow Calculator?

Definition: This calculator converts air mass flow rate (in pounds per hour) to volumetric flow rate (in gallons per minute).

Purpose: It helps HVAC engineers, mechanical designers, and technicians convert between mass and volumetric flow rates for system design and analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Volumetric flow rate (GPM)
• \( W \) — Mass flow rate (lb/hr)
• \( \rho_{air} \) — Air density (lb/ft³, default 0.075)

Explanation: The mass flow rate is divided by the product of air density and conversion factors to get volumetric flow in gallons per minute.

3. Importance of Flow Rate Conversion

Details: Proper conversion between mass and volumetric flow is essential for accurate system sizing, performance calculations, and equipment selection in air handling systems.

4. Using the Calculator

Tips: Enter the mass flow rate in lb/hr and air density in lb/ft³ (default 0.075). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is air density important in this calculation?
A: Air density affects how much volume a given mass of air occupies. Changes in temperature or pressure will affect density and thus the conversion.

Q2: What's the standard air density value?
A: Standard air density at sea level and 70°F is approximately 0.075 lb/ft³.

Q3: When would I need to adjust the air density?
A: Adjust for high-altitude locations, extreme temperatures, or pressurized systems where air density differs significantly from standard conditions.

Q4: How do I convert the result to other units?
A: For CFM (cubic feet per minute), multiply GPM by 0.1337. For L/s (liters per second), multiply GPM by 0.06309.

Q5: Does this calculator account for humidity?
A: No, it uses dry air density. For precise calculations with humid air, use adjusted density values.