1. What is Convection Heat Transfer?

Definition: Convection is the transfer of heat between a solid surface and a moving fluid when they are at different temperatures.

Purpose: This calculator helps engineers and scientists determine the rate of heat transfer due to convection in various applications.

2. How Does the Calculator Work?

The calculator uses Newton's Law of Cooling:

Where:

• \( Q \) — Heat transfer rate (Watts)
• \( h \) — Heat transfer coefficient (W/m²·K)
• \( A \) — Surface area (m²)
• \( \Delta T \) — Temperature difference between surface and fluid (K)

Explanation: The heat transfer rate is proportional to the surface area and temperature difference, with the coefficient h representing the convection efficiency.

3. Importance of Convection Calculations

Details: Accurate convection calculations are essential for designing HVAC systems, electronic cooling, industrial processes, and thermal management in buildings.

4. Using the Calculator

Tips: Enter the heat transfer coefficient (typical values: 10-100 for natural convection, 50-20,000 for forced convection), surface area, and temperature difference. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What are typical h values for different situations?
A: Natural convection of air: 5-25 W/m²·K, Forced convection of air: 10-200 W/m²·K, Water: 50-10,000 W/m²·K.

Q2: Does this work for both heating and cooling?
A: Yes, the formula works for both directions of heat transfer.

Q3: What if I have multiple surfaces?
A: Calculate each surface separately and sum the Q values.

Q4: How does fluid velocity affect h?
A: Higher fluid velocity typically increases h, especially in forced convection.

Q5: What's the difference between K and °C in ΔT?
A: For temperature differences, 1 K = 1°C, so either unit can be used.