Self-Regulating vs Constant Watt Heating Tape: Which One to Use?
Energy efficiency, control and application differences between the two heating tape types.
Heating tapes come in two main types: self-regulating and constant watt. They differ in how they respond to temperature, which affects where each one can be used safely and efficiently.
Self-regulating heating tape
The heating element is a conductive polymer core between two bus wires. As the pipe gets colder the core conducts more current and gives out more heat; as the pipe warms up, it gives out less. Each point along the tape adjusts independently.
Because of this, self-regulating tape can be cut to length on site, can cross over itself where the maker permits, and carries a lower risk of overheating. It is often used for freeze protection and for temperature maintenance at moderate temperatures.
Constant watt heating tape
A constant watt tape produces the same heat output per metre whatever the pipe temperature. It is simple and suits uniform heating, but it does not adjust itself, so it must be controlled by a thermostat. Without control it can overheat, particularly where it overlaps or where flow stops.
Comparison
- Output: self-regulating changes with temperature; constant watt is fixed.
- Control: self-regulating is more forgiving; constant watt needs a thermostat or controller.
- Cutting to length: self-regulating can be cut to length in the field; constant watt types are often made to a set length.
- Temperature range: constant watt types are available for higher temperature work; check each product's limits.
- Cost: self-regulating tape usually costs more per metre; constant watt is often cheaper.
Which should you use?
For most freeze protection and low to moderate temperature maintenance, self-regulating tape is the usual choice for its safety and ease of installation. For higher temperatures, long uniform runs or where the cost is critical, constant watt tape with proper control may be chosen. Tell us the pipe size, length, insulation, ambient temperature and the temperature you need to maintain, and we will help with the selection.
Key Takeaways
- Self-regulating tape adjusts its own output; constant watt does not.
- Constant watt tape needs a thermostat.
- Send us pipe details to select the right tape.
This article is general guidance. For a recommendation for your own application, contact our engineering team. View heating tape →