Industrial Heater Guide: Why Open Coil Heaters Deliver Faster Air Heating

When it comes to industrial heating systems, selecting the best industrial heater for your application is a major factor. If the heat does not reach the airflow within a certain time, the entire process becomes inefficient.

This phenomenon is called thermal lag.

When you use traditional electric heaters such as tubular heaters, the heat transfer occurs in multiple stages. The electric current first heats the resistance wire. The heat is then transferred to the insulating powder and the metal sheath before it finally reaches the air.

This delay in the transfer of heat is a major disadvantage of traditional electric heaters. For industries that require faster air heating, open coil heaters are a more efficient solution.

When you use open coil heaters, the resistance wire is exposed to the air flow. The heat transfer occurs immediately by natural convection. This increases the efficiency of the electric heater as the air flows faster without any resistance.

According to a study on industrial HVAC, the use of direct air heating elements can improve the time required for the heat to reach the air flow by as much as 60% over traditional enclosed heaters.

At DHE Heaters, we have developed a unique engineering solution that focuses on the design of the electric heaters. Our experience in the industrial sector has earned us the reputation of being the best industrial heater manufacturer in India.

To understand how manufacturers overcome heating fluctuations in real production environments, read our detailed analysis on thermal instability to production stability in industrial heating systems.

What is an Open Coil Heater?

When you use an open coil heater, the resistance wire remains exposed to the air flow. The resistance wire is not enclosed in a metal sheath.

A standard open-coil heater assembly consists of three major parts.

Resistance Heating Coil

A high-temperature-resistance wire is used in the design.

Nichrome (NiCr) and Kanthal alloy are the two most commonly used materials.
A coil is wound using the nichrome wire.
A coil structure increases the surface area and hence the heat transfer.
When the nichrome wire is exposed to electricity, heat is produced.

Ceramic Insulators

Ceramic insulators support the coil.

These insulators ensure that the coil does not come in contact with the metal frame.
Ceramic materials have the ability to withstand high temperatures.
Ceramic materials provide structural support.

Mounting Frame

A galvanized steel frame and a stainless steel frame are used.

These frames are used to mount the coil and the insulators.
These frames are used to mount the assembly in the air ducts and ovens.

Designing an Air Heater System or Duct Heater? Talk to our engineering staff at DHE Heaters, a leading manufacturer of industrial heaters in India, to know the best heating element for your industrial needs.

Why Open Coil Heaters Heat Faster

Open coil heaters are the best in the industry due to the following reasons.

Minimal Thermal Inertia

There is a minimum amount of material used in the design.
Due to this, the heater attains heat in a minimum period.
Operating temperature is attained in a matter of seconds.

Direct Convection Heating

There is a direct exposure to the airflow.
Hence, the heat is transferred directly.
There is no delay in the heat transfer.
There is no metal used in the design.
Hence, the heat is transferred directly.

Lower Airflow Resistance

Air ducts require efficient air flow for proper functioning.
The open coil design enables free air flow through the structure of the coil.
Air flow resistance is very low.

“In air heating applications, the speed of heat transfer is what defines the stability of the entire process. Open coil heating elements offer one of the best responsive heating elements when clean air is available.”

Industrial Heating Engineer, DHE

To browse through our entire catalogue of the best industrial coil heaters, click here.

Open Coil Heater vs Tubular Heater

Both open coil heaters and tubular heaters are widely used in industrial heating applications. The selection of either of these depends on the environment.

Having trouble deciding between tubular heaters and open coil heaters?

Our team of specialists at DHE Heaters can determine the best solution for your process.

Industrial Applications of Open Coil Heaters

There are many industries that require fast air heating control, for which open coil heaters can be used.

HVAC Air Duct Heating

These types of heaters can be used in air handling units for air duct heating in HVAC systems.

Industrial Drying Ovens

Stable temperature control is needed for drying processes.
Open coil heaters are used for curing ovens, drying chambers, and paint drying ovens.

Plastic Processing

Heated air is needed for plastic processing.
Open coil heaters are used for plastic extrusion, plastic thermoforming, and resin drying ovens.

Air Curtains and Process Air Systems

Open coil heaters are also used for air curtains, environmental chambers, and industrial process air heaters.

Important Design Factors for Open Coil Heaters

Proper engineering is needed for the safe operation of the open coil heaters.

Watt Density

Watt density is the amount of heat produced per unit surface area of the open coil heater.
Higher airflow allows for a higher watt density.
Air flow is used to remove the heat from the open coil heater.
Low airflow and high watt density cause overheating.

Coil Stretch Ratio

Proper spacing is needed for the turns of the open coil heater.
Coils that are too tight will cause overheating due to the heat trapped between the turns.
Coils that are too loose will cause the coils to lose structural strength.

Ceramic Support Spacing

When the resistance wire is exposed to heat, it expands.
Proper spacing is needed for the ceramic supports to keep the open coil heater from touching the adjacent coils or metal parts.

Safety Considerations for Open Coil Heaters

Proper safety considerations are needed for the open coil heaters because the open coil heaters have exposed elements.

Airflow Interlock

Air flow is needed for the open coil heater to operate.
A switch for the airflow is needed to ensure the heater works only when the air flow is on.

Protective Screens

Overheating caused by dust or insulation material coming into contact with the coil.

Proper Grounding

All the metal frames have to be properly grounded. The grounding helps protect the system in case of insulation failure.

Seeking a trusted heating company for industrial air heating systems?

Contact us at DHE Heaters, one of the best industrial heater manufacturers in India, to discuss your heating needs.

Why Industries Trust DHE Heaters

Industrial heating systems require precision and robust materials.

At DHE Heaters, our team designs heating systems for industrial applications.

Our products are specifically designed for performance, reliability, and safety.

Our dedication to precision and robust materials has helped us achieve the status of one of the best industrial heater manufacturers in India.

Our services include:

Designing custom air heating systems
Open coil heater assembly for industrial applications
High-temperature ceramic-supported heating elements
Accurate watt density design for efficient heat transfer
Industrial-grade manufacturing and quality control

Our heating systems are specifically designed to ensure performance and longevity.

Open coil heaters are efficient electric air heaters used in modern industries.

Open coil heaters offer instant heating response, efficient air heating, and accurate temperature control.

Open coil heaters, if designed and used properly, offer effective performance for heating, ventilation, and air conditioning, drying ovens, and other industrial heating processes.

For industries looking for effective heating solutions, choosing the best industrial heater manufacturer in India ensures that heating equipment is designed for performance, safety, and longevity.

Frequently Asked Questions

What are the benefits of using open coil heaters?

Open coil heaters offer faster heat transfer since the heating elements are exposed directly to the air flow.

Are open coil heaters energy efficient?

Yes, they are energy efficient since they transfer heat directly to the air and minimize energy loss.

What are the applications of using open coil heaters?

Open coil heaters are commonly used for heating, ventilation, and air conditioning, drying ovens, air curtains, and industrial air heating processes.

What materials are used for making open coil heaters?

Open coil heaters are typically made up of Nichrome or Kanthal resistance wire and ceramic insulators.