Electric heaters have widespread applications throughout many industries, where they provide heat for all sorts of reasons. For example, in industrial and manufacturing processes, they can provide heat to warm liquid tanks, help shape or melt material or radiate heat the air to preserve a substance’s molten state. Likewise, in extrusion processes, electric heaters sometimes supplement natural friction to create and support material plasticization. Other processes that benefit from electric heaters include: packaging, foam fabricating, metal fabricating, food processing and water treatment. They also provide heating for comfort to both residential and commercial buildings.
History of Electric Heaters
In the early 1890’s, the American company General Electric began producing the first heaters. These heaters relied on elongated glass bulbs, which had only been invented the decade before, as their heating element. They looked like table lamps. The earliest electric heaters work using bulbs, which were invented by Thomas Edison in 1880. While these heaters did provide some warmth, they were neither durable nor particularly strong. In addition, they were not terribly versatile. To remedy the situation, Albert Leroy Marsh fabricated the alloy chromel. Chromel, also known as nichrome, was the first alloy used as a heating element. Up to 300 times stronger than other alloys of the day, chromel can heat it up to 1400℃, and it resists corrosion. Heaters with chromel heating elements were able to create and disperse heat more efficiently than lightbulb heaters.
Meanwhile, over in the UK, based off of the bulb heater Hebert John Dowsing designed an all-electric cooking system. It featured a copper backing that allowed heat radiation to enter a room gradually. Debuting his invention in 1891, Dowsing is considered the father of domestic heating in the UK.
Another invention of the late 19th century was the electric water heater, developed by Norwegian mechanical engineer Edwin Ruud. His model featured automatic electric heating of stored water. Initially working for the Fuel and Gas Manufacturing Company in Pittsburgh, he eventually started his own company, the Ruud Manufacturing Company, in 1897. His water heater company is successful to this day.
In 1912, manufacturers began producing portable heaters. One of the earliest portable heating technology manufacturers was Charles Reginald Belling. The first patent for central heating was granted to Alice Parker in 1919. Hers was a gas heater. In 1935, another inventor added an electric fan and ductwork to this highly successful model, creating the first forced wall convection heater.
After World War II, radiant heating and the bar heater, also known as electric fire, were invented. Radiant heaters relied on bars of coiled water to work. When current passed through them, the wire would glow orange. Today, we still use radiant bar heaters. However, they are not exactly the same as the first ones. Particularly, they now have different safety standards. That’s because early bar heaters, which were typically portable, were easy to knock over. The result of this occurrence was often a fire and/or injury.
The 1960s saw the development of the storage heater, used in the home and in industrial settings to provide the same amount of heat while consuming less energy. The 70s and 80s experienced a heavier use of electric heat, as the systems were restructured and designed for greater capacities. Modern electric heating systems control heat production with smart technologies, like digital programming and remote controls. Electric heaters have not only made heating easier and more efficient, but have slowed pollution as they’ve decreased our dependence on wood and fossil fuels.
To make electric heaters, manufacturers must make or assemble heating elements, shielding or enclosures, and insulation materials. Heating elements generate heat. They may be simple coils or they may be comprised of elaborate shapes with advanced ceramic insulators to control heat qualities. The choice of what heating element design to construct is made by the manufacturer. The shielding (sheath) improves performance and extends operating life. Insulation retains and absorbs electrical energy so that it may be released as additional heat energy.
Almost all electric heaters feature a sheath made of ferrous or non-ferrous metal materials, like: nickel, stainless steel, aluminum or another conductive material. Manufacturers base materials on which one will best extend operating life and improve performance. Of all the insulation materials, such as minerals, mica or fiberglass, the most common types of insulation are made of or with ceramics.
Design Considerations and Customization
When helping you choose a system or designing a custom electric heating system for you, electric heater suppliers think about a number of different factors. First, they consider what you actually need to heat (A building? A room? Water?) Based on this, they sketch out a basic configuration. Then, they think about specific requirements like: operating temperature, operating efficiency, heater lifespan and permissible/safe watt densities. In addition, use your application specifications to calculate your system start-up power requirement, system maintenance power requirements and operating heat losses. They also consider the environment in which your heater will work. Finally, they take all of this information to decide what heating element material, electric heater type, size, quantity and control system will work best for you.
There is an astonishing variety of heaters available on the market, including crossover styles, a variety that continues to grow daily. Other varieties include: band heaters, strip heaters, process heaters, cartridge heaters, radiating heaters, immersion heaters, circulation heaters, tubular heaters, air heaters, drum heaters and water heaters.
A band heater is a small electric heater that you can attach to nozzles, pipes and tubes for localized heating. It usually provides conductive heat, though it can also provide convection air heating. Band heaters can reach temperatures from around 300℉ to 1400℉. Also known as barrel heaters or knuckle heaters, band heaters are best for use in plastic and metal forming processes like extrusion. They can also be used to clear ice from troughs and gutters.
Strip heaters are small heaters known for their rugged construction and low cost. To work, they can be clamped or bolted to equipment to directly provide heat. They can also heat small spaces inside enclosures. Strip heaters are typically straight and flat like a ruler, but often also feature fins, which offer fuller heat radiation into the air. Manufacturers can also produce circular strip heaters for use around cylindrical objects like tubing. Most often, they’re used for thawing, baking, platens, moisture protection, drying, melting, extrusion and air heating. Strip heaters and band heaters would be exactly alike if not for the fact that band heaters are usually slightly smaller and more flexible.
Process heaters are electric heaters used to heat treat, surface treat, shape and generally process raw materials.
Cartridge heaters a small and cylindrical. They are designed this way so that they can be inserted into small holes drilled into metal parts and materials, where they provide internal heating. The heat they provide may be localized or it may radiate throughout the whole interior of that into which they are inserted. Typically, cartridge heaters are used in manufacturing processes like: extrusion, thermoforming, mold forming, plastic forming, rubber forming, labeling, die cutting, sealing, hot stamping, fluid heating and printing. You can find them inside of machinery like semiconductors, platens, hot plates and shrink wrap machines.
Radiating, or radiant, heaters work using the principles of radiant heat to radiate heat energy. They are straightforward and heat anything within their range.
Immersion heaters are a type of radiant heater. They heat liquids and some solids when they are immersed into them. Like cartridge heaters, they heat the space around them. Immersion heaters are safe and efficient tools for heating large volumes of liquids.
Circulation heaters, as their name implies, are electric heaters that heat the liquid or gas that circulates within an enclosed space.
Tubular heaters are named after their tubular shape. They consist of a coil heating element, a heating element binder in which the coil is encased and magnesium oxide powder, which surrounds the binder. They can be installed or mounted on a wide variety of items and systems. They conduct heat via radiation, convection or conduction.
Air heaters heat air in residential, commercial and industrial settings alike. They may do so within a closed space, like space heaters do, or they may heat large spaces as part of a larger fan system. On top of that, they can be used to heat air for manufacturing and packaging processes, like shrink wrapping. When used to pass air through ducts, they’re also known duct heaters. They work via gravitational or forced air methods.
Drum heaters are industrial heaters used specifically to heat industrial drums. The drums they heat usually hold water, chemical or food products that need to maintain a certain temperature during storage and/or shipment.
Water heaters, just as you’d expect, are used to heat water. There are several types of water heating, including: storage water tanks, tankless heaters, solar water heaters, geothermal heating, gravity fed water heating, point-of-use heating and centralized heating.
Advantages of Electric Heaters
Among the many advantages of electric heaters are: versatility, environmental friendliness, energy efficiency and safety and reliability.
First, electric heaters offer great versatility. They can be used for one small application, one large application or multiple applications. You can adjust coils by shape or size as an application calls for it and you have many options for heating different mediums (water, oil, air, etc.).
Next, electric heaters are far better for the environment than traditional heating methods, like petroleum, natural gas, coal or wood heating. Those traditional processes create pollution in the form of CO2 emissions, smog, fumes, smoke, vapor, chemicals and harmful gases. Electric heaters produce none of those pollutants. Electric heaters make the air cleaner for you, cleaner for your workers or family and friends, and cleaner the entire planet. That’s something we can get behind!
Not only are electric heaters better for health and air quality, but they’re also more energy efficient than their traditional counterparts. All of the energy that electricity uses is converted directly into heat. This contrasts with fuel-based heaters, which waste energy through flue. This level of energy efficiency is good for the environment, and also presents significant energy and operating cost savings for you.
Safety and Reliability
Because electric heaters do not burn fuel, they are inherently much safer than their older counterparts. They are not subject to the risks of explosions, fires and monoxide poisoning. In addition, they do not present the risk of leakage. Finally, because they do not have moving parts to wear out or break down, they are far more reliable. On average, electric heaters last for at least 15 years.
Possible accessories for your electric heater include: a thermostat, a thermocouple, gaskets, seals, baffles and remote temperature controls.
Electric heating is very easy to install. It simply requires a connection to the electrical circuit, so it can frequently be installed in a short span of time. As the heaters can work as stand-alone units or as a system, it is easy and cheap to add heaters to a system at any time, as budgets permit.
Proper Care for Electric Heaters
Cleaning and Maintenance
The biggest threat to an electric heaters health is contamination, followed by excessive temperature cycling. To keep your heater happy, check on it regularly to make sure that it free of contamination, and also keep a log of temperature cycling, so that you don’t overdo it. Also avoid excessive movement.
To optimize your heater performance, make sure that you are working with the best sheath material, maximum sheath temperature and watt density for the job. Compatibility is key.
Depending on the type of heater you plan to purchase, there are different federal/international/industry standards to which your system will have to adhere. For example, residential water heaters in the USA must meet the efficiency standards of the Department of Energy. The standards specific for water heaters vary by heater capacity. Likewise, heaters used in the USA must adhere to EPA emissions regulations. Standards can also vary by state. Other standard code certifications that you may want to look into for your heater include those put out by ANSI, the NFPA and ANSI/NFPA combined (National Electric Code, ANSI/NFPA 70). For more information, reach out to your local government and/or industry experts.
Things to Consider
To get the most out of an electric heater, consider your application requirements, which will determine the material make-up and the power and temperature capacity you want. Different heaters respond differently to the environment you place them in or the tasks you give them. For safety and success, communicate your application intentions and requirements clearly with your service provider. It’s also important that you connect with a quality service provider, or all your efforts will be moot. Find the right provider for you by scrolling up towards the top of this page and perusing the many electric heater manufacturers and suppliers that we have listed there. All of those with whom we work are experienced and trustworthy. Pick out a few, perhaps three or four, in whom you are most interested, and then reach out to them individually with your questions and specifications. Compare and contrast the not only the facts of the conversations, but the tones. It’s important that you choose a manufacturer that can not only deliver the bottom line, but that is also willing to work hard to make sure you’re satisfied. Once you’ve determined which company that is, get started on your project. Good luck!