Here’s How Heat Shielding Benefits Your Automobile

Key Takeaways:

  • Radiators, fans, shrouds and fluids help cool down your engine. Thermal solutions support reducing high heat on your automobile’s components to prevent overheating.
  • High heat can cause malfunctions of vehicle components, everything from disruption in cabin luxuries to engine failure.
  • Reducing heat in a vehicle’s engine bay and keeping sensors within safe operating temperature extends the life of components.
  • Knowing the temperature drop for an application and heat source type is critical for shielding choice. Most automobile applications deal with radiant heat sources.
  • When selecting a material, weigh the needs of performance, flexibility and cost to meet the needs of an application.
  • Speed of installation and ease of accessibility to components are factors to keep in mind when deciding on a heat protection solution.


 What Is Heat Shielding?

Heat shielding is the method of protecting objects from reaching undesired temperatures by dissipating, reflecting or absorbing the heat before it reaches a protected object. The engine bay of virtually any automobile, whether a battery-operated one, naturally aspirated or anything in between, generates heat. Radiators, fans, shrouds and fluids help cool down the engine, which keeps the vehicle at an operable temperature.

However, the motor still puts off a lot of heat, and the exhaust that leaves the engine often produces high levels of heat inside the engine compartment. This causes unnecessary heat through the underbelly of the car, which can raise the temperature inside the cabin. To remedy this, a thermal barrier can lower the temperature and reflect the heat away from the unintended source. For instance, placing a heat shield externally under the automobile between the cabin and the exhaust.

Thermal barriers also prevent overheating of other internal components of an automobile, including alternators, power steering and the interior of the vehicle. These benefits extend to anything that moves, such as brake and fuel lines, differentials and more.

How Heat Shielding Works

Without proper routing and thermal protection, an automobile can experience a variety of issues. High heat sources can affect cabin luxuries, decrease battery life, reduce fuel efficiency, lead to vapor lock and, in the most extreme circumstances, cause engine failure. Engineers design wire and cable systems to withstand these high heats and to route into “cooler” zones of the engine compartment to avoid overheating of supporting hardware inside the compartment. This hardware often helps to regulate engine temperatures, oxygen and gas mixtures, and vacuum loads, as well as generate continuous power for in-vehicle electrical components.

Why Heat Shielding Is Important

If you ever open up your hood and peer inside the engine compartment, you may find fabric heat shielding or notice several silver-colored covers, wraps and/or metal brackets with wires running on the opposing side of these items. These elements are the heat shielding systems designed into the engine bay to avoid problems of heat generated from the motor, which can occur at any point the vehicle is active — from sitting at a red light to cross-country drives. 

The most common places where flexible heat shielding systems exist are the sensors and/or wires that must pass closely to and interface with the motor itself. Heat barriers applied to these areas can keep equipment within a safe operating temperature. These materials reflect the radiating heat from the motor to cause a lower temperature to exist on the opposing side of the material from the side facing the motor. Keeping the sensor below its max operating temperature can extend the life of the component and ensure that it is performing its task of monitoring the engine. This in turn allows your engine to be used to its fullest potential.

Selecting Heat Shielding Materials

Determining the type of shielding to use is always on a case-by-case basis. It is important to understand the temperature drop needed for a specific application and to know if the heat source is convection or radiant. The majority of automotive applications, deal with radiant heat sources. Because of this, an initial reflective surface is often ideal to reflect the radiant heat from the component. When a further drop in temperature is needed, the thickness and type of backing layer opposing the reflective surface will bring the temperature down further. This is possible by creating distance and air pockets to absorb and dissipate additional heat after the initial heat reflects.

A variety of materials work well with heat reflectance for the automotive industry, such as aluminized coated fiberglass and closures with stainless steel reinforced Kevlar thread. Heat shielding materials can also be equipped with high-temp snaps to cover items like a sensor, preventing the item from malfunctioning due to overexposure to heat.

The use of certain adhesives with some shielding materials can also help ensure the wires themselves do not overheat and melt. A melted cable or wire can be dangerous as it can lead to shorts in the system and electrical difficulties throughout the vehicle.

Moreover, heat shields installed as an added layer against the firewall of a system facing into the engine bay can reduce heat coming through the firewall as well as reduce the air conditioning load to keep the inside of the cabin cool.

When selecting a material, you’ll need to weigh the needs of performance, flexibility and cost to meet the needs of an application.

Heat Shielding Installation

A heat shielding product that is easy to install and conforms to ISO and/or IATF automotive certifications is the primary need for most automotive manufacturers. When installing heat shielding in a manufacturing facility, speed of installation is always a consideration, which means installation involving closures like snaps or adhesives may be the only choice.

Whatever the case may be, there are heat shielding solutions for virtually any automotive application or requirement. Everything from easy-to-install, cut-to-size, adhesive-backed thermal protection to wrap-around heat solutions that can protect diesel exhaust systems from temperatures up to 1,202°F.

Keep in mind, when a vehicle has hoses, wires or other components not yet fully installed, pull-through thermal barrier products, which require no tools for installation, are an alternative option.

Thermal management of automotive systems can be complex, and thermal management of any system can introduce additional challenges. By understanding the basics of heat shielding, you’ll have the knowledge to start narrowing down solutions to shield systems from excessive heat.

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