Should you insulate a pipe or heat trace it? In many freeze-protection applications, that’s the wrong question. Heat tracing and insulation perform different functions, one supplies heat, the other conserves it. The thing that most engineers new to frost protection miss is that most reliable freeze-protection systems use both.

What Heat Tracing Does

Electric pipe tracing is placing an electrical resistance heating element parallel to the pipe. The heater provides heat to the pipe to balance heat loss to colder surroundings.

Several technologies can be used, including self-regulating, series, mineral-insulated, and zone heating cables. Each is suited to different application requirements, pipe lengths, and power considerations.

What Insulation Does

The pipe and tracing elements are then covered with thermal insulation. Insulation reduces heat loss from the system to the surrounding environment, allowing the heat-tracing system to maintain temperature more efficiently.

Insulation used in these applications must be protected from rain and external conditions with an appropriate weather barrier, since wet or damaged insulation loses its effectiveness.

Why Both Matter

Consider a traced pipe without insulation. The heating system supplies energy, but heat can readily escape to the environment. The heat trace ends up working harder than it should, and may not keep pace in severe conditions.

Now consider an insulated pipe with no supplemental heat. The insulation slows heat loss, but it cannot continuously replace the energy being lost from stagnant fluid. Given enough time in cold conditions, the pipe still freezes.

Combining the two allows each technology to perform its intended function:

Heat trace: supplies heat.

Insulation: reduces heat loss.

Controls Matter Too

Heat tracing doesn’t necessarily need to operate at full output under every condition. ASHRAE notes that pipe-tracing systems are designed around worst-case heat loss at the lowest design ambient temperature. Controls can be used to reduce unnecessary energy consumption when conditions are warmer.

For example an ambient thermostat energizes the system as air temperature approaches freezing, rather than running continuously through winter regardless of conditions.

The appropriate control strategy depends on the application and heat-tracing system. The important takeaway is that freeze protection should be designed as a complete system, heat source, insulation, and controls working together, rather than as a choice between insulation and heat.

Building a Complete Freeze-Protection System

If you’re weighing insulation, heat tracing, or both for your piping, UniTherm can help you design a system sized to your actual heat-loss conditions and control strategy — not a one-size-fits-all fix. Contact our team to talk through your application.

This is week 6 of a 10 week series discussing the methods and science of frost protection systems. To learn more or to follow this series click this link: Subscribe to Updates

To find out more information on the frost protection offerings that Unitherm International can provide, go to shop.unitherm.com to view our full listing of products or email quote@unitherm.com to speak to a representative about custom solutions.