1. What is a Heat Trace Watts Per Foot Calculator?

Definition: This calculator determines the heat trace power required per foot to maintain a temperature difference in pipes or vessels.

Purpose: It helps engineers and technicians design electrical heat tracing systems for freeze protection or process temperature maintenance.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \Delta T \) — Temperature difference (°F)
• \( k \) — Thermal conductivity (W/ft°F)
• \( D2 \) — Outer diameter (inches)
• \( D1 \) — Inner diameter (inches)
• \( \text{Length} \) — Length of pipe (feet)

Explanation: The formula calculates the heat loss per unit length through cylindrical insulation.

3. Importance of Heat Trace Calculation

Details: Accurate heat trace calculations ensure proper freeze protection, energy efficiency, and prevent overheating of pipes.

4. Using the Calculator

Tips: Enter the temperature difference, thermal conductivity (default 0.25 W/ft°F for typical insulation), diameters (D2 > D1), and pipe length. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is Delta T in heat tracing?
A: Delta T is the temperature difference between the maintained pipe temperature and the lowest ambient temperature.

Q2: What's a typical k value for pipe insulation?
A: Most insulation materials have k values between 0.2-0.3 W/ft°F at room temperature.

Q3: Why do we use natural log (ln) in the formula?
A: The logarithmic term accounts for the cylindrical geometry of heat flow through pipe insulation.

Q4: How do I measure D1 and D2?
A: D1 is the outer pipe diameter, D2 is the outer diameter of the insulation (D2 = D1 + 2×insulation thickness).

Q5: Does this include safety factors?
A: No, you should typically add 10-20% to the calculated value for safety margin and aging effects.