1. What is By-Pass Factor?

By-Pass Factor is the inability of a coil to cool or heat the air to its temperature. It represents the fraction of air that passes through the coil without contacting the heat transfer surface.

2. How Does the Calculator Work?

The calculator uses the By-Pass Factor formula:

Where:

• \( U \) — Overall heat transfer coefficient (W/m²·K)
• \( A_c \) — Surface area of coil (m²)
• \( m_{air} \) — Mass of air (kg)
• \( c \) — Specific heat capacity (J/kg·K)

Explanation: The formula calculates the exponential decay of temperature difference across the coil based on heat transfer characteristics.

3. Importance of By-Pass Factor

Details: By-Pass Factor is crucial in HVAC system design as it affects the efficiency of heating and cooling coils. A lower bypass factor indicates better coil performance.

4. Using the Calculator

Tips: Enter all values in appropriate units. All inputs must be positive values greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical range for By-Pass Factor?
A: Typical values range from 0.05 to 0.3 for most cooling coils, with lower values indicating better performance.

Q2: How does coil configuration affect By-Pass Factor?
A: Coils with more rows and closer fin spacing generally have lower bypass factors due to increased surface area and better air contact.

Q3: What factors influence the Overall Heat Transfer Coefficient?
A: Fluid velocities, material properties, fouling factors, and temperature differences all affect the overall heat transfer coefficient.

Q4: How does air mass flow rate affect By-Pass Factor?
A: Higher air mass flow rates generally increase the bypass factor as there's less time for heat transfer to occur.

Q5: Can this calculator be used for heating coils?
A: Yes, the same formula applies to both cooling and heating coils, though the heat transfer characteristics may differ.