Designing an effective heat Trace System: a step-by-step guide

Heat trace cable is a critical component to maintain the required temperature of pipes in various industrial applications. Effective heat trace design ensures optimal performance, precise temperature controls and energy efficiency. This guide outlines four essential steps to help you design a reliable and efficient heat trace system.

1. Basic heat loss calculation

The first step in designing a heat trace system is to calculate the basic heat loss from the pipe. This involves finding the temperature difference between the ambient environment and the desired pipe temperature. Using this temperature differential, you can refer to a heat loss table to find the basic heat loss for the specific pipe size and insulation thickness. This calculation provides a foundation for selecting the appropriate heating cable.

Calculate temperature differential using our pipe heat loss calculator

2. Insulation adjustment

Once you have the basic heat loss calculation, the next step is to adjust it based on the type of insulation used. Different insulation materials have varying thermal properties, which can affect the overall heat loss. By consulting an insulation adjustment table, you can find the insulation factor for the material in use and multiply it by the basic heat loss. This adjusted heat loss value, known as QF, gives a more accurate estimate of the heat required to maintain the desired pipe temperature.

Calculate the insulation adjustment, using our pipe heat loss calculator

3. Correct for indoor location and wind speed

Environmental factors such as indoor location and wind speed can significantly impact heat loss. If the pipe is located indoors, you should multiply the adjusted heat loss (QF) by a factor of 0.9 to account for reduced heat loss in a controlled environment. Additionally, the heat loss table typically assumes a 20 mph wind speed. For outdoor installations, you need to add a 5% margin for every 5 mph increase in wind speed above 20 mph. This correction ensures that the heating system can compensate for additional heat loss due to wind exposure.

Calculate heat trace watts per foot

4. Select the appropriate heating cable

The next step is to select the heating cable that matches the calculated heat loss and the pipe’s maintenance temperature. Different heating cables have varying thermal outputs and are designed for specific temperature ranges. Constant wattage heating cables for example, provide a continuous power output regardless of the surface or ambient temperature, whereas self-regulating cables adjust the heat output according to the ambient temperature. For metal pipes, you can use thermal output ratings to find the cable that meets or exceeds the required heat loss at the maintenance temperature. For plastic pipes, additional considerations such as the use of aluminium tape to enhance heat transfer may be necessary. Ensure that the total cable length accounts for in-line components like valves and flanges, which require additional heat tracing.

Discover our heat trace product range

5. Ensure the right connection accessories for your environment

The final step in designing a heat trace system is selecting the appropriate controls and connection kits to match the application and environmental conditions. Key considerations include temperature control needs, operating environment, and regulatory requirements. For example, outdoor or hazardous locations may require weatherproof or explosion-proof accessories, while simple indoor applications might only need standard accessories.

Choose controllers that match your system's complexity - thermostats for basic on/off control or advanced electronic controllers for precise temperature management and monitoring. Similarly, ensure power connection kits, end seals, and splice kits are compatible with your heating cable and designed to prevent common issues like moisture ingress, especially in outdoor installations.
By selecting high-quality, application-specific accessories and consulting with experts if needed, you can ensure your heat trace system is safe, reliable, and optimized for performance in any environment.

By following these five steps, you can design an effective heat trace system that ensures reliable temperature maintenance and energy efficiency. Proper calculation and adjustment of heat loss, along with the selection of suitable heating cables, are crucial for achieving optimal performance in heat tracing applications.