Ceramic vs Incoloy vs Carbon: Far infrared heater types

In my previous post about far infrared heaters, I’ve explained my opinion on importance of heaters in an infrared sauna design. Now, my goal is to make you more confident when choosing heater type and configuration for your far infrared sauna. Understanding why you should prefer one heater over another can be extremely hard, especially when sauna companies say about excellence of their heaters without giving specific details about them (sometimes, when browsing infrared sauna site you can find it difficult to get any detail on heater, even it’s type). I’m going to give answers to more specific questions regarding infrared heaters to make you feel more comfortable in the field of far infrared sauna heaters.

In general, there are three different types of heaters used. They differ by material of which the heater’s surface is made:

  • ceramic;
  • metal (incoloy or aluminium);
  • carbon.

Ceramic is the most popular type of heaters, as it has high emissivity (degree with which material can emit electromagnetic waves), is durable, and ceramic heaters can have large surface area. However, they are more fragile than other types of heaters, so additional precautions must be taken when transporting such heaters.

Metal heaters are less fragile than ceramic ones, also durable, typically made in tubular form and have the least surface area of these three types of heaters. Metal used is usually aluminium or incoloy (special alloy, which oxide have high emissivity). On the surface this metal is highly oxide to make emissivity higher.

Carbon heaters are less common type of heaters. They are usually made as thin (about 1mm) carbon plate or film, sometimes enclosed in fiberglass. They are flexible and less fragile than ceramic infrared heaters and have largest surface area of all three types. Carbon also has high emissivity.

Heaters can also be distinguished by their shape:

  • tubular heaters (metal, some ceramic heaters);
  • flat heaters (ceramic, carbon).

Tubular heaters have the advantage – all infrared they emit can be reflected in one direction with reflectors in which they are usually enclosed. Tubular heaters have smaller surface area than flat heaters.

Flat heaters have larger surface area, put have the problem of heat that emitted from the back of such heater – it dissipates and lowers the overall efficiency of the heater.

Another thing to say is that quite often mixed types of heaters are used – for example, incoloy with ceramic coating, or sand-filled ceramic. By mixing and modifying different technologies infrared sauna manufacturers are trying to improve different characteristics of heaters – efficiency, durability, warm-up time and so on.

All infrared heaters get their heat from electrical current which flows through some isolated conductor inside. Typically it is a metal coil embedded in a heater material. Without current there is no heat and no intensive infrared radiation.

The technical information above gives you an idea of how far infrared heaters work and differ. More important question is: what it means for a person taking a sauna? The answer is simple: in a quality made heater, material doesn’t matter much. More important characteristics are surface area and volume of the heater.

Let’s take a tubular metal heater with small surface area and a flat ceramic heater with large surface area. They both consume the same amount of electricity, let’s say 200 watt. In both heaters almost all or this energy is emitted as infrared radiation. Amount of energy emitted from 1 sq. cm. of surface area depends on the temperature of the surface. Surface with high temperature emit more infrared than surface with low temperature. From these we can draw a conclusion: to emit the same 200 watt as a flat heater, tubular heater should have higher temperature, because it has small surface area, while the flat heater has large surface area.

So heater with smaller surface area will always be hotter than heater with larger area which consumes the same amount of electricity. Also, as I wrote in facts about infrared heaters, lower temperature means longer peak wavelength, so heater with lower temperature emits radiation closer to far infrared (not much, though). If there is a health difference between near, mid and far infrared is still in question.

On the other side, from heater volume depends how fast it will warm-up and how fast it will cool-down. If heater is massive it takes more time to heat it to the necessary temperature. Heater warm-up time should not be confused with sauna warm-up time. Sauna warm-up time depends heavily on the overall power of heaters installed, on the volume of the sauna and on speed of air circulation. Slow warm-up and cool-down can be a plus in sauna models which use turning heaters on and off to maintain constant temperature in a sauna. In such models, slow warm-up and slow cool-down lead to more gradual change in intensity of heat when heaters turn on and off.

Conclusion

Tubular heaters (both ceramic and metal) have, usually, short warm-up time, small surface area and high temperature, they emit rays closer to mid-infrared.

Flat ceramic heaters have slower warm-up, larger surface area, lower temperature and emit rays closer to far-infrared.

Flat thin carbon heaters have fast warm-up, largest surface area, lower temperature and emit rays closer to far-infrared.

Tags: , , , , , , ,

4 Responses to “Ceramic vs Incoloy vs Carbon: Far infrared heater types”

  1. Paul Says:

    Your comment “Flat thin carbon heaters have fast warm-up,” is completely false. Have you actually tried out a sauna with carbon fiberglass heaters? It takes a lot longer than other types of heaters to get warm and heat the cabin.

    It does not sound like you know what you are talking about.

  2. Paul Mernon Says:

    Paul,

    Looks like you are thinking about sauna warm-up time where I talk about heaters warm-up time. They are completely different things. Let me recite the part of the post above (important points are made bold):

    Heater warm-up time should not be confused with sauna warm-up time. Sauna warm-up time depends heavily on the overall power of heaters installed, on the volume of the sauna and on speed of air circulation. Slow warm-up and cool-down can be a plus in sauna models which use turning heaters on and off to maintain constant temperature in a sauna. In such models, slow warm-up and slow cool-down lead to more gradual change in intensity of heat when heaters turn on and off.

    I think that carbon heaters, because they are thin and thus have little volume, will reach their working temperature (which is lower than for other heater types) relatively fast. It doesn’t mean that a sauna will reach preset temperature quickly.

    Also I don’t agree that a sauna with carbon heaters takes a lot longer to get warm. Can you give the reasons why a sauna of certain wattage, size and construction with carbon heaters will take longer to warm-up than exactly the same sauna, installed in a same room, but with ceramic or any other type of heaters? Doesn’t amount of heat emitted from heater depend on its power, not from material of which the heater is made of?

    I do not advocate any specific heater type, I just want to disprove the statement I believe is wrong. Please provide your arguments; don’t say that I don’t know what I’m talking about; show that you know what you’re talking about.

  3. Shelly galde Says:

    Where can I find a far infrared heater for a 10×10 room? I do not need a sauna kit. I need to heat a 10×10 room to 100 to 115 degres to do hot yoga. This is the only thing that has ever improved my health. I have tried many heaters from Menard’s and Home Depot. I can only get the room to 90 degress and the information about whether or not these heaters are infrared is sketchy at best. I have tried contacting the suana manufactureres about buying their heaters without the kit and they are not helpful.

    Thank you

  4. Rich Says:

    This carbon vs. ceramic thing is confusing. Most of the older saunas have used ceramic and we know it works. Now comes along carbon and claims to be better. A lot of people are adamant that ceramic is better and carbon does not even come close. And if this picture is true

    http://www.cedarbarrelsaunas.com/infrared-heater-comparison.html

    then carbon elements are really lousy. You are way better getting a ceramic heater sauna which are much cheaper.

    Any thoughts?