If you work in manufacturing, process heat is your largest energy cost. The worst part is you’re spending even more because of heat waste.
According to the U.S. Department of Energy process heating consumes more energy in U.S. manufacturing than any other single system. The number is striking: more than 7,000 Trillion Btu per year! That’s roughly 61% of all manufacturing on-site energy use. For individual facilities, the energy used for process heating typically accounts for 2% to 15% of total production costs.
Even a modest improvement in how efficiently your system generates, contains, and transfers heat can translate into real savings without changing your process. Let’s take a look at what process heating is, where it goes and how to utilize more of it.
What “Process Heating” Actually Covers
Process heating is broader than most people assume. It includes furnaces, ovens, kilns, dryers, and heaters used across industries from primary metals to plastics to food processing. It covers fuel-based systems, electric-based systems, and steam-based systems. Virtually any operation that requires controlled heat to transform a material falls under this umbrella.
Process heating operations, include forming, curing, drying, fluid heating, heat treating, and metals reheating. Each one has specific efficiency characteristics and specific opportunities for improvement.
Where the Energy Goes
A process heating system does not deliver all of its energy to the product. Heat escapes, whether that’s from furnace walls and openings, or with hot exhaust or flue gases, no can be 100 percent efficient. Despite that, there are still significant benefits to increasing process heat efficiency. By managing process heat, you can extend the life of your machines, increase overall output and reduce downtime.
The goal of any efficiency improvement program is not to eliminate all heat waste, but to reduce those losses and increase the share of energy that actually does useful work.
The Five Categories of Improvement
The DOE groups efficiency opportunities into five categories: heat generation, heat containment, heat transfer, waste heat recovery, and enabling technologies. These categories overlap in practical application, but they provide a useful framework for identifying where to start. Here’s a brief summary of each category:
- Heat Generation: the process of producing heat energy. It happens when energy from sources like fuel, electricity, friction, or chemical reactions is converted into heat.
- Heat Containment: the process of keeping heat within a specific area or system to reduce heat loss and maintain temperature. It is often achieved using insulation, barriers, or enclosed spaces.
- Heat Transfer: the movement of heat energy from one object or area to another, moving from a hotter place to a cooler place.
- Waste Heat Recovery: the process of capturing heat that would otherwise be lost from a system or process and reusing it for another purpose, improving energy efficiency and reducing energy costs.
- Enabling Technologies: tools, equipment, and systems that help industrial processes use heat more effectively, reducing energy consumption, costs, and emissions while maintaining or improving performance.
Heat containment is the area where most facilities can make meaningful gains quickly and at relatively low cost. Poorly maintained or missing insulation allows heat to escape continuously, adding to energy costs every hour the system runs. Here’s a list of where insulation should be in your facility:
Process Heat Efficiency Opportunities:
- Steam and condensate piping
- Valves, flanges, and fittings
- Boilers and boiler doors
- Heat exchangers
- Process tanks and vessels
- Ovens, furnaces, and kilns
- Ductwork carrying heated air or gases
- Hot water piping and storage tanks
- Turbines and associated equipment
- Any surface operating at elevated temperatures where personnel protection or energy conservation is required
| UniTherm Insulation Systems designs removable and reusable insulation jackets, blankets, and covers for industrial equipment — purpose-built for the heat containment challenge. Products like UniVest® for plastics processing equipment and IsoCovers® for pipes and valves help facilities reduce surface heat loss without requiring permanent modifications. |
If you’re not sure where your facility stands, simply take stock of which surfaces and components are uninsulated or under-insulated. You may be surprised what you find.
Click here to browse our standard insulation solutions
Click here to recieve a quote for a custom insulation project.
Further reading: U.S. DOE, Improving Process Heating System Performance: A Sourcebook for Industry (Third Edition), 2015.