In the field of heating technology, innovation constantly pursues efficiency, safety and versatility. Among numerous advanced technologies, PTC heaters stand out as a unique solution, and their distinctive heating method distinguishes them from traditional heating elements. The inherent characteristics of PTC heaters make them an ideal choice for many application fields.
This article will comprehensively explore the principle of PTC heaters and deeply analyze the wonderful science behind their self-regulating function. We will reveal their many advantages, from improving safety to enhancing energy efficiency, and investigate their wide applications in various industries to help you fully understand this intelligent heating technology.
What is a PTC heater?
PTC heaters, also known as PTC heating elements, consist of PTC ceramic heating components and aluminum tubes. This type of PTC heater has the advantages of low thermal resistance and high heat exchange efficiency, making it a self-regulating, energy-saving electric heater. Its prominent feature lies in safety performance—under any application conditions, it will not produce the surface “reddening” phenomenon like electric heating tube heaters, which can cause potential safety hazards such as scalds and fires.
PTC heaters feature strong bonding force, excellent thermal conductivity and heat dissipation performance, high efficiency, as well as safety and reliability. This type of PTC heater has the advantages of low thermal resistance and high heat exchange efficiency, making it a self-regulating and energy-saving electric heater. One of its prominent features is its safety performance: when the fan malfunctions and stops running, the PTC heater cannot dissipate heat sufficiently, causing its power to drop sharply automatically. At this time, the surface temperature of the heater remains around the Curie temperature (generally around 250℃), thus avoiding the surface “reddening” phenomenon that occurs in electric heating tube heaters.
What is the working principle of PTC heaters?
Constant temperature heating PTC thermistors have the characteristic of constant temperature heating. The principle is that when the PTC thermistor is powered on, it self-heats and raises its temperature, causing its resistance to enter the jump zone.
The surface temperature of the constant temperature heating PTC thermistor will maintain a constant value, which is only related to the Curie temperature of the PTC thermistor and the applied voltage, and basically independent of the ambient temperature. PTC heaters are heating devices designed using the constant temperature heating characteristic of constant temperature heating PTC thermistors.
In medium and low-power heating applications, PTC heaters have incomparable advantages over traditional heating elements, such as constant temperature heating, no open flame, high heat conversion efficiency, minimal influence from power supply voltage, and long natural service life. Their application in electric heating appliances has been increasingly favored by R&D engineers.
Constant temperature heating PTC thermistors can be manufactured into various shapes, structures and specifications, with common types including circular chips, rectangles, strips, rings and honeycomb porous shapes. Combining the above PTC heating elements with metal components can form various types of high-power PTC heaters.
Classification of PTC Heaters by Conduction Method
- PTC ceramic heaters dominated by thermal conduction. Their characteristic is to transfer the heat generated by PTC elements to the heated object through a multi-layer heat transfer structure installed on the surface of PTC heating elements, including electrode plates (conductive and heat-transferring), insulating layers (electrically insulating and heat-transferring), heat-conducting and heat-storing plates (some with additional thermal conductive adhesive).
- Various PTC ceramic air heaters using convective heat transfer with generated hot air. Their characteristic is large output power, and they can automatically adjust the temperature of the blown air and the output heat.
- Infrared radiant heaters. Their characteristic is that they actually use the heat quickly emitted from the surface of PTC elements or heat-conducting plates to directly or indirectly excite the far-infrared coating or far-infrared material in contact with the surface to radiate infrared rays, thus forming PTC ceramic infrared radiant heaters.
The Function of PTC Heaters in Air Conditioners
PTC corrugated heaters for air conditioners are self-temperature-controlled heaters.
- Constant-temperature heating PTC thermistors feature constant-temperature heating performance. The principle is that when the PTC thermistor is powered on, it self-heats and raises temperature, making its resistance enter the jump zone. The surface temperature of the constant-temperature heating PTC thermistor will maintain a constant value, which is only related to the Curie temperature of the PTC thermistor and the applied voltage, and basically independent of the ambient temperature.
- PTC heating elements are designed utilizing the constant-temperature heating characteristic of constant-temperature heating PTC thermistors. In medium and low-power heating scenarios, PTC heating elements have incomparable advantages over traditional heating elements, such as constant-temperature heating, no open flame, high heat conversion efficiency, minimal impact from power supply voltage, and long natural service life. Their application in electric heating appliances has been increasingly favored by R&D engineers.
- Constant-temperature heating PTC thermistors can be manufactured into various shapes, structures and specifications. Common types include circular chips, rectangles, strips, rings and honeycomb porous shapes. Combining the aforementioned PTC heating elements with metal components can form various types of high-power PTC heating elements.
Application Scenarios and Precautions of PTC Heaters
1.Solid constant-temperature heating
1.1 Structure of solid heaters
Figure1： structure of ptc Heater
When heat is conducted through materials with high thermal conductivity (such as aluminum, copper, graphite blocks, etc.), the distance S between the heated solid and the PTC heater should be within 30mm; when heat is conducted through materials with moderate thermal conductivity (such as steel, stainless steel, titanium, thermal conductive ceramics, etc.), the distance between the heated solid and the PTC heater should be within 10mm; when heat is conducted through materials with poor thermal conductivity (such as plastics, non-porous rubber, insulating paper, mica sheets, etc.), the distance between the heated solid and the PTC heater should be within 3mm.
Thermal insulation materials (such as fiber paper, rubber and plastic, foam boards, etc.) must not be used for heat conduction. Using materials with good thermal conductivity and keeping a small distance between the heated solid and the PTC heater will enable the heated solid to obtain a relatively stable temperature.
The ratio of the area of the heat dissipation structure to the heat transfer area of the PTC ceramic body should preferably not exceed 3 times. An excessively large proportion of the heat dissipation structure area will result in unstable temperature of the heated solid.
1.2 Surface Temperature
At an ambient temperature of 25℃±5℃, the temperature tolerance of PTC ceramic heating plates is shown in Table 1. However, if the PTC ceramic heating plate is installed in a heat dissipation structure, the temperature accuracy will deteriorate and the tolerance will increase. The temperature accuracy will decrease when the internal heat transfer of the heater is poor, or when the ratio of the area of the heat dissipation structure to the heat transfer area of the PTC ceramic body is relatively large.
Table 1.
Figure 2 is the PTC heating/heat dissipation balance diagram.
Figure 2 is the PTC heating/heat dissipation balance diagram. The resistance value of the PTC heater increases sharply as its own temperature rises. Therefore, when its own temperature rises, the heating power also drops sharply; when the heating power and heat dissipation power reach a balance, the temperature no longer rises and the power no longer changes. However, when the heat dissipation conditions (such as ambient temperature, air blowing, water immersion, etc.) change, the power and temperature of the PTC adjust again to achieve a new balance.
The factors affecting the surface temperature of the PTC are shown in Table 2.
Table 2.
There are many factors affecting the surface temperature of PTC heaters, so the accuracy of the constant surface temperature cannot be very high. In occasions requiring high temperature control accuracy, a method of using a PTC heater with an additional temperature controller can be adopted. When the external temperature controller malfunctions, the heating surface temperature of the PTC heater will not exceed the set constant temperature, featuring an over-temperature protection function.
1.3 Heating Rate
The factors affecting the heating rate of PTC heaters are shown in Table 3.
Table 3.
1.4 Application Scenarios
Electric mosquito repellents, massagers, heaters, electric soldering irons, electric irons, humidifiers, hair curlers, hair straighteners, laminators, electric aroma diffusers, hot melt glue guns, wax melters, electronic component heat preservation, circuit board moisture removal, etc.
When using PTC heaters for solid constant-temperature heating, the applicable heating temperature ranges from 0°C to 300°C, and the heating temperature at room temperature is 50°C to 300°C. The applicable ambient temperature is -40°C to 250°C. PTC heaters with excessively high or low surface temperatures are difficult to manufacture, and may even lose PTC characteristics.
The operating voltage ranges from 3.7V to 420V, compatible with both AC and DC power supplies. At low operating voltages, the PTC heater has a small room-temperature resistance and a low resistance-temperature change rate, resulting in poorer constant-temperature accuracy. Additionally, low voltage leads to low heating power and slow heating rate, and the heater may not even reach a relatively high temperature.
In terms of safety and reliability, PTC heaters are generally safer than traditional electric heating wires, with higher insulation voltage resistance, smaller and more stable leakage current. In some application scenarios, traditional electric heating wires fail to pass safety certifications, while PTC heaters can meet the requirements. Therefore, PTC heaters are suitable for occasions with high safety requirements. However, not all PTC products from all manufacturers can meet safety standards, so it is necessary to select high-quality PTC suppliers. The main safety and reliability issues of PTC heaters for solid heating are: first, breakdown and burnout of the PTC ceramic body, leading to short circuits and damage to the insulation layer; second, breakdown and leakage of the insulation layer, resulting in electrification of the outer casing.
In terms of cost, for small-area constant-temperature heating, PTC heaters can eliminate the need for additional temperature control and over-temperature protection components. They can be made compact and are relatively easy to install. For large-area constant-temperature heating, PTC heaters provide more uniform heating. The service life of PTC constant-temperature heaters is several times longer than that of traditional electric heating wire heaters, reducing life-cycle costs and maintenance costs.
2.Liquid Heating (including water, diesel, hydraulic oil, etc.)
2.1 Structure of Liquid Heaters
Figure 3 is the structural diagram of the immersed liquid heater.
Figure 5 shows the placement position of the heater in the container. Vertical heating tubes are relatively easy to install, but the temperature of the upper and lower layers of the liquid is not sufficiently uniform. Horizontal heating tubes provide more uniform heating temperature, but during installation, holes need to be drilled in the container, and the mounting holes require sealing treatment. Curved heating tubes also offer uniform heating temperature and do not require drilling, but their cost is relatively high. When the bottom-mounted container heater is installed at the bottom, the heating temperature is quite uniform.
The material of the metal shell in contact with the heated liquid can be selected from: aluminum-silicon alloy, aluminum-zinc alloy, aluminum-magnesium alloy, pure copper, brass, iron (galvanized, etc.), 304 stainless steel, 316 stainless steel, titanium, copper-nickel alloy, etc. The selection of the metal shell material is determined based on factors such as the application purpose, the nature of the liquid, and the liquid’s corrosiveness to the metal. For oil heating, low-cost aluminum alloy shells can be used; for washing water heating, aluminum alloy, pure copper, or brass shells are also applicable; for drinking water heating, 304 stainless steel or 316 stainless steel is suitable.
When the water quality is poor, or for seawater, or for the heating of electroplating aqueous solutions, titanium shells can be used; for highly corrosive liquids, copper-nickel alloy is applicable. In addition, attaching a layer of fluoroplastic to the surface of the metal shell can resist corrosion from most liquids within the allowable temperature range, but the heating power will decrease significantly.
For the container bottom (or side) liquid heater, the heater does not directly contact the liquid, so the liquid will not corrode the heater shell. However, this type of heater has a large volume, low power, and high cost.
2.2 Heating Power
The relationship between the heating power and heating time of PTC heating tubes is quite different from that of traditional electric heating wire tubes. At the initial stage of heating, the power of the PTC heating tube increases from small to large, reaches the maximum value (maximum inrush power), then gradually decreases, and finally stabilizes (stable power for boiling water). The stable power under dry burning conditions is much smaller than that for boiling water (the dry burning power is about 8% of that for boiling water).
The stable power is related to the liquid temperature. The higher the liquid temperature, the smaller the stable power. A standard liquid temperature can be specified according to the actual operating conditions. After the heating tube heats up and the liquid temperature rises from low to high, the power recorded when the liquid temperature reaches the standard temperature is the stable power at the standard liquid temperature.
The stable power is related to the type of liquid. When the liquid is water, the power is relatively large because water has a high specific heat capacity and good fluidity, making it easy to form convection. When heating other liquids, the stable power is generally smaller than that when heating water.
The higher the surface temperature of the PTC heating tube under dry burning conditions, the greater the stable power. However, increasing the surface temperature will lead to increased power attenuation, a higher chance of breakdown of the PTC heating sheet, and degraded performance of adhesives, wires, insulation layers, etc., resulting in reduced reliability.
When the surface temperature of the PTC heating tube under dry burning conditions is the same as the liquid temperature, the heating power is basically zero, that is, it no longer heats. Therefore, the surface temperature of the PTC heating tube under dry burning conditions must always be more than 20°C higher than the liquid temperature; otherwise, heating cannot be achieved. The smaller the temperature difference between the surface temperature of the PTC heating tube under dry burning conditions and the liquid temperature, the smaller the power density of the heating tube, the larger the volume required, and the higher the cost.
A heating tube with a large maximum inrush power does not necessarily have a large stable power. Excessively high maximum inrush power will affect the normal operation of the entire power supply circuit and switches; however, if the maximum inrush power is too small, the stable power will fail to meet the requirements.
2.3 Power Attenuation
Due to quality differences among various PTC manufacturers, users may perceive excessive PTC power attenuation. The PTC liquid heating tubes produced by Dongguan Tiancheng have a power attenuation of approximately 10% after continuous operation for one year, which is completely within the acceptable range for users. However, the PTC products from some manufacturers have a power attenuation of around 30% within one month and 40% to 50% after continuous operation for one year, making them practically unusable. Therefore, it is essential to conduct a power attenuation test when purchasing PTC heating tubes.
Power attenuation is positively correlated with the surface temperature of the PTC ceramic heating sheet. The higher the surface temperature, the greater the power attenuation. In other words, reducing the surface temperature of the PTC ceramic heating sheet can minimize power attenuation, but this will increase the volume and cost of the heating tube.
There are two main reasons for power attenuation: first, the increase in the room-temperature resistance of the PTC ceramic heating sheet/the decrease in inrush current; second, the loosening of the heat transfer structure, which impairs heat transfer efficiency.
2.4 Application Scenarios
Storage water heaters, instant water heaters, electric kettles, hot water dispensers, hot water for vegetable washing, dishwashing, face washing, bathing, foot soaking and foot therapy, auxiliary heating for solar water heaters and heat pump water heaters, electric heating for photovoltaic solar water heaters, hot water cleaning for range hoods and cleaning agents, water beds, heating for electroplating tanks, diesel vehicle fuel tanks and filters, heating for hydraulic oil, lubricating oil and edible oil, steam generation for saunas, beauty treatments, disinfection and humidification, liquid medicine fumigation, heat preservation for aquariums and fish tanks, anti-freezing for water pipes, faucets, pipelines and oil pipes, heating for three-way catalytic converters and urea solutions, hydronic floor heating, heating for oil-filled radiators and hydronic radiators, etc.
The stable heating power can range from 10W to 10KW. However, for heating tubes with high power, a large number of PTC ceramic heating sheets are required, which increases the risk of breakdown of the PTC ceramic heating sheets. In addition, the large insulation area also increases the chance of insulation failure. Therefore, it is advisable to divide the heating system into several heating tubes, each with a smaller power, to reduce failure and waste. The operating voltage ranges from 12V to 420V, compatible with both AC and DC power supplies. When the operating voltage is low but the heating power is high, both the inrush current and stable current will be extremely large, which the power supply may not withstand. Therefore, low voltage should not be used when high power is required.
Electric heating wire tubes have the advantage of low cost but have the following problems: first, after a period of use, the insulation voltage resistance, leakage current and insulation resistance may exceed the standard; second, dry burning is not allowed. If the temperature protection device malfunctions, the electric heating tube will be burned out due to dry burning, and may even ignite surrounding materials, causing fires; third, the electric heating wire may be oxidized and burned out after long-term operation, affecting its service life and even causing electric leakage; fourth, when the water quality is poor with high concentrations of cations (such as calcium and magnesium), scale is prone to form on the surface of the electric heating tube, which impairs surface heat transfer and leads to the burnout of the internal electric heating wire.
PTC liquid heating tubes can overcome the shortcomings of electric heating wire tubes. They have excellent and stable insulation voltage resistance, leakage current and insulation resistance, are resistant to dry burning, have a long service life, and will not be burned out even if scale forms. However, if the PTC manufacturing quality is poor, problems may still occur: first, breakdown and burnout of the PTC ceramic body, leading to short circuits and damage to the insulation layer; second, breakdown and leakage of the insulation layer, resulting in electrification of the outer casing; third, the heating power attenuates with the increase of service time; fourth, excessive inrush current causes failures of the power supply lines and switches. Users of PTC heating tubes should carefully select PTC heating sheets to ensure reliable quality.
3. Air Heating
3.1 Structure of Air Heaters
Air heaters are classified into live-type and insulated-type based on whether the heat sink is energized.
Figure 7 shows a live-type air heater. The heat sink is energized, with the electrode layer of the PTC ceramic heating sheet directly in contact with the aluminum heat sink, and the aluminum heat sink serves as one electrode terminal. Live-type air heaters can easily achieve high power and have relatively low costs; however, since the heat sink is energized, potential safety hazards are likely to exist.
Figure 8 shows an insulated-type air heater. The heat sink is insulated from the PTC ceramic heating sheet, and the heat sink is not energized. Insulated-type air heaters are safer but have lower power and higher costs.
Classified by the structure of the heat sink, there are corrugated structure, finned structure, aluminum extruded structure, compressed air pipeline-type heating, etc. The corrugated structure air heater has a relatively flexible structure, and its length and width are easy to adjust to form various sizes and powers, so as to meet the requirements of various fan sizes, air duct sizes and heating power. The heat sink and PTC heating sheet (or heating tube) of the corrugated structure heater are bonded by adhesive. After long-term use at high temperature or long-term dry burning without air flow, the adhesive may fall off. The length of the finned structure and aluminum extruded structure can be appropriately adjusted, but the width is difficult to adjust. The finned structure gives the impression of being compact and sturdy, and the air resistance is relatively small.
Classified by whether air blowing is required, it is further divided into forced convection type and natural convection type air heaters. The forced convection air heater has relatively large power, but it needs to add a fan, and the fan will generate noise. The natural convection air heater does not need a fan and has no noise, so it is particularly suitable for bedroom heating and under-bed heating, but its heating power is relatively small.
3.2 Heating Power
The variation of heating power with heating time is shown in Figure 9. When first powered on, the initial power is relatively small (usually 1/3 to 1/5 of the maximum inrush power), then the heating power gradually increases to the maximum inrush power, followed by a decrease, and finally reaches the stable power. If heat dissipation is too fast, the heater will always operate at the initial power and fail to reach the maximum power, resulting in a very small stable heating power.
Maximum inrush power = C * Operating voltage / Room-temperature resistance
The value of the maximum inrush power depends on factors such as the room-temperature resistance of the PTC ceramic heating sheet, surface temperature, grain size inside the ceramic body, and operating voltage. The multiple C ranges from 1 to 6: the higher the surface temperature of the PTC ceramic heating sheet, the larger the C; the higher the room-temperature resistance, the larger the C. If a heater contains multiple PTC ceramic heating sheets with different resistances, the maximum inrush current when the heater is powered on in a cold state (at room temperature) will be relatively small; however, when powered on in a hot state (at a temperature approximately 40°C lower than the surface temperature), the maximum inrush current will be relatively large.
Air heaters with a larger maximum inrush power will have a slightly larger stable power. Excessively high maximum inrush power will affect the normal operation of the entire power supply circuit and switches; on the other hand, if the maximum inrush power is too small, the heating power will fail to meet the requirements, and the heating power may even decrease as the air blowing speed increases.
The stable heating power of PTC air heaters is related to the air speed. Generally speaking, the higher the air speed, the faster the heat dissipation, and the larger the heating power. The air speed of ordinary fans is 3~5m/s. The power without air blowing is about 10% of the power at an air speed of 5m/s. When necessary, the heating power can be adjusted by adjusting the air speed. If the inrush power of the heater is close to the stable power at low air speed, increasing the air speed will not increase the power; excessively high air speed may instead reduce the power.
Non-insulated PTC air heaters have faster heat dissipation than insulated ones, so their heating power is also relatively larger. Denser heat sinks increase the wind-receiving area, which also enhances heat dissipation and increases heating power.
Increasing the number of PTC heating sheets will not result in a proportional increase in the stable heating power; the heating power of each individual heating sheet will decrease to some extent.
The relationship between the heating power of PTC air heaters and influencing factors is as follows:
Stable heating power = Heat dissipation coefficient * (Dry-burning temperature － Inlet air temperature)
Heating power is related to the inlet air temperature: the higher the inlet air temperature, the smaller the stable power. When the dry-burning surface temperature of the PTC ceramic heating sheet is the same as the inlet air temperature, the heating power is basically zero, meaning it no longer heats. Therefore, the dry-burning surface temperature of the PTC ceramic heating sheet must always be more than 20°C higher than the inlet air temperature; otherwise, effective heating cannot be achieved. The smaller the temperature difference between the dry-burning surface temperature of the PTC ceramic heating sheet and the inlet air temperature, the lower the heating power density, the larger the required volume, and the higher the cost.
If the outlet air temperature of a heater fails to reach the required high temperature, a second PTC air heater needs to be installed along the air flow direction to increase the outlet air temperature. At this time, the first heater close to the fan has a relatively high power; the second heater far from the fan has a higher inlet air temperature, so its power is much lower, and the stable power is often less than 50% of that of the first heater.
The higher the dry-burning surface temperature of the PTC ceramic heating sheet, the greater the heating power. However, increasing the surface temperature of the PTC ceramic heating sheet will lead to increased attenuation of heating power over time, a higher chance of breakdown of the PTC heating sheet, degraded performance of adhesives, wires, insulation layers, etc., loosening of the aluminum shell, and reduced reliability of the heater.
3.3 Power Attenuation
The main factors contributing to the power attenuation of PTC air heaters include: increased resistance of PTC ceramic heating sheets, loose adhesive, and loose aluminum heat sinks. The PTC products from some manufacturers may experience power attenuation of over 30% within one month, so selecting high-quality PTC is crucial. It is essential to test power attenuation when purchasing PTC air heaters.
Power attenuation is positively correlated with the surface temperature of the PTC ceramic heating sheet. The higher the surface temperature, the more the resistance of the PTC heating sheet increases, the easier the adhesive is to loosen, the more likely the aluminum heat sink is to loosen, and the greater the power attenuation. If PTC heating sheets with a surface temperature above 250°C are used to make air heaters, and they are powered on without air flow, the strength of the adhesive will gradually decrease and loosen after 200 hours. In other words, reducing the surface temperature of the PTC heating sheet can minimize power attenuation, but this will increase the volume and cost of the air heater.
3.4 Application Scenarios
Space heaters, air conditioners, hot air drying of clothes, shoes, hands, desiccants, tea leaves and agricultural products, heating or drying of wardrobes, bookcases, shoe cabinets, rooms, bathrooms, workshops, shopping malls, warehouses, electrical control cabinets, high-speed rail and EMU carriages, electrical equipment and storage items, tunnel ovens, compressed air heating, and battery discharge loads.
The stable heating power can range from 100W to 10KW. Using heaters with smaller individual power can reduce failures and improve qualification rates; multiple heaters can be used when higher power is required. The operating voltage ranges from 12V to 420V, compatible with both AC and DC power supplies. At low operating voltages, both the inrush current and stable current will be extremely large, so low voltage should not be used when high power is required.
Electric heating wire air heaters have the advantages of low cost, high achievable outlet air temperature, and small volume. However, they have the following problems: first, after a period of use, the insulation voltage resistance, leakage current and insulation resistance may exceed the standard; second, they cannot be powered on without air flow. If the fan stops working, the air duct is blocked, or the temperature protection device malfunctions, the heater will be burned out due to overheating without air flow, and may even ignite surrounding materials, causing fires; third, the electric heating wire may be oxidized and burned out after long-term operation, affecting its service life and even causing electric leakage; fourth, if flammable substances adhere to the heater, combustion may occur.
Common Questions About PTC Heaters
Q1: What is a PTC heater, and are they environmentally friendly?
PTC heaters are environmentally friendly due to their energy-saving design. Compared with traditional heaters, they reduce greenhouse gas emissions by lowering energy consumption. Their self-regulating function means they only use the energy needed, thereby minimizing waste.
Q2: Do PTC heaters require regular maintenance?
PTC heaters have low maintenance requirements. Their simple and robust structure reduces the risk of failure. This results in fewer maintenance needs, making them an ideal choice for applications with minimal maintenance requirements.
Q3: Can PTC heaters work in high-humidity environments?
Yes, PTC heaters can operate normally in high-humidity environments. Their moisture resistance allows reliable operation in places such as bathrooms or dehumidifiers. Their durable design ensures efficient performance without malfunctions caused by humidity.
Q4: What are the advantages of PTC heaters compared to traditional heating elements?
PTC heaters are safer and more energy-efficient than traditional heating elements. Traditional heating elements are prone to overheating, posing potential safety hazards. PTC heaters feature a self-regulating function that maintains a safe temperature, making them a better choice for many application scenarios.
Conclusion
PTC air heaters can overcome the shortcomings of electric heating wire heaters. They offer excellent and stable insulation voltage resistance, leakage current, and insulation resistance, can be powered on without air flow, provide automatic protection, and will not catch fire or burn, with a long service life. With their unique self-regulating characteristics and wide range of applications, they stand out as a distinctive and increasingly popular choice. They break through the limitations of traditional heating elements, promising higher safety and performance.
As a supplier of PTC heaters, Anssin continuously provides customers with safe and efficient PTC heaters. Contact us for heating solutions.