A Guide to Energy Efficient Industrial Oven Design

Energy costs are a significant consideration when purchasing an industrial oven. While the initial purchase price is important, the long-term operating costs of the equipment can have an even greater long-term impact. Thoughtful design can improve the energy efficiency of industrial ovens, helping manufacturers reduce operating costs and maximize their return on investment.

Understanding Industrial Oven Efficiency

When comparing industrial ovens, efficiency claims can be difficult to evaluate because efficiency is measured in several different ways. Rather than focusing solely on efficiency percentages, manufacturers should consider the total operating cost of the equipment. Utility rates, production volume, process temperatures, cycle times, and throughput requirements all contribute to the actual cost of operating an oven. A properly designed industrial oven should not only meet process requirements but also minimize wasted energy.

Choosing the Best Heating Method

The foundation of an energy-efficient oven begins with selecting the appropriate heating technology for your application.

Gas vs. Electric Heating

In many areas, natural gas costs less than electricity per unit, making gas-fired ovens a popular choice for applications with significant heating requirements. Ultimately, the best solution depends on the operating schedule, process requirements, utility rates, and overall project goals. 

For smaller ovens or applications with limited operating hours, electric heating may be a practical option. Large industrial ovens, particularly those operating at elevated temperatures or processing heavy workloads, are often gas-fired due to their substantial energy requirements. Evaluating local energy costs and comparing projected operating expenses can help determine which heating source is the most economical choice.

Convection vs. Infrared Heating

Another important design consideration is the method used to transfer heat to the product. Convection ovens utilize heated air circulated throughout the work chamber to transfer heat to the product. Infrared ovens transfer radiant energy directly to the surface of the product.

Neither technology is inherently more efficient than the other. The optimal solution depends on the product being processed, production requirements, and thermal characteristics of the workload. For some applications, convection provides the most effective and economical solution. In others, infrared heating may offer advantages. It is important to review the specific process requirements to determine the most energy-efficient heating method.

Design Features That Improve Industrial Oven Efficiency

Once the heating technology has been selected, several design features can help reduce energy consumption and operating costs.

Increased Insulation

Insulation is one of the most effective ways to reduce heat loss from an industrial oven. Additional insulation helps retain heat within the work chamber, reducing the amount of energy required to maintain operating temperature. Thicker insulation can also improve temperature uniformity by minimizing heat loss through the oven walls. Although increasing insulation slightly increases the initial cost of the equipment, the long-term operating savings can be substantial.

Door Limit Switches

Batch ovens experience unavoidable heat loss during loading and unloading operations. When an oven door is opened, heated air escapes from the chamber. Without proper controls, the heating system will operate at full output while the door is open, unnecessarily sending wasted hot air into the factory. Door limit switches automatically reduce burner firing rates or temporarily disable electric heaters while the door is open, minimizing unnecessary energy consumption during loading and unloading.

Direct-Drive Recirculation Blowers

The recirculation system is a critical component in convection oven performance. Belt-driven blowers experience efficiency losses associated with the belt drive system. Direct-drive blowers eliminate these losses by coupling the motor directly to the blower shaft. In addition to reducing energy consumption, direct-drive systems are much quieter and require less maintenance because there are no belts to inspect, adjust, or replace.

Heat Spill-out Reduction

Every opening in an oven is a potential source of energy loss. Reducing unnecessary heat loss helps improve overall system efficiency and lowers operating costs. For conveyor ovens specifically, special attention should be given to product entry and exit openings. Features such as high-temperature curtains, powered air seals, and vestibules can help minimize heat spill-out while maintaining process requirements. 

Lightweight Load Carts and Fixtures

The product is not the only thing being heated during a process cycle. Load carts, racks, fixtures, and tooling absorb energy along with the product. Designing these components to be as lightweight as practical reduces the thermal mass that must be heated and can contribute to lower energy consumption over time.

Wisconsin Oven E-Pack™ High Efficiency Industrial Oven Design

Many of the design features discussed above can be incorporated into a single integrated solution. Wisconsin Oven's optional E-Pack™ High Efficiency Oven Upgrade combines several of these energy-saving design features into one package. The E-Pack™ high efficiency upgrade includes thicker insulation, door limit switches on batch ovens, combustion air filters on gas-fired models, insulated floors where appropriate, and pressure sensors that help maintain balanced chamber pressure. 

These design features can provide measurable cost savings over the life of the equipment. A gas-fired batch oven equipped with the E-Pack™ upgrade and chamber dimensions of 8' wide x 12' deep x 8' high, operated 55 hours per week, can deliver annual savings of more than $5,000. An electrically heated oven with the E-Pack™ upgrade, a 4' x 4' x 4' chamber, and 40 hours of operation per week can provide annual savings of more than $1,600.

By understanding the design features that contribute to an energy efficient industrial oven, manufacturers can make more informed purchasing decisions, maximize their return on investment, and reduce long-term operating costs.

Interested in an Energy Efficient Industrial Oven for your Application?

Wisconsin Oven works closely with manufacturers to design industrial ovens that meet their process requirements while minimizing energy consumption and operating costs. If you are interested in a high efficiency batch or conveyor oven for your process, our team can help identify the design features and options that best support your application and production goals. Contact our team today to get started!