The Best NIR Therapy 250 Watt Incandescent Heat Lamps for Pain and DIY Saunas!

electromagnetic spectrum, heat lamp, incandescant, intensity, light bulb, NIR, photobiomodulation, power, red light bulb, Red light therapy, spectrum, watts -

The Best NIR Therapy 250 Watt Incandescent Heat Lamps for Pain and DIY Saunas!

What is the best 250 Watt Near-Infrared Incandescent Heat Lamp? NIR Heat Lamps are a very affordable form of Red Light Therapy that have been used therapeutically for many years! But which brand stands out as the best?

Update! Check out our new 2023 review of heat lamps with updated testing and analysis! Click the Link Here.

As always, we need to test them out to be sure.

Although we can call 250W Heat Lamps a form of Red Light Therapy, it does NOT fit the definition of Photobiomodulation. Where PBM is strictly defined to be a non-thermal interaction of wavelengths and biology.

It is important to recognize the tremendous amount of heat produced by these 250W heat lamps, and not to confuse them with the much lower powered and generally non-thermal LED products. Along with it are important differences in how heat lamps are used and handled safely and effectively.

Regardless, Heat Lamps are a great way to get started with red light therapy. Often they are used for similar purposes such as workout recovery, skin benefits, energy, circulation, wound healing, and more!

These types of heat lamps are also made into the popular DIY Near-Infrared Sauna! Which promotes sweating, detox, and cardiovascular health!

With all these great benefits, which incandescent heat lamp is the best one? Which near-infrared bulb is best to make into a near-infrared sauna?

That is quite the enigma, covered in layers of marketing myths that have confused a lot of people.

Many Incandescent Heat Lamp companies are purposely trying to confuse customers with claims about a fancy wavelength spectrum, claims about intensity, or power. Especially the companies selling 250W heat lamps for therapeutic purposes, it is like they are purposely trying to piggyback their marketing on Photobiomodulation parameters.

In reality, Incandescent light bulbs are easily measured and characterized, but not in the ways these brands want you to think. 

We will cut through to the simple truth in this article, so you can make a clearheaded choice when shopping. Along the way we will dispel many myths and confusing marketing tactics about this simple yet effective technology.

Bulbs we Tested for this Article:

1. Saunaspace ThermaLight

2. Therabulb

3. RubyLux

4. GE

5. Philips

6. Feit Electric

7. Producer's Pride

*note, we have NO AFFILIATION with any of these brands, and purchased these bulbs at full price for testing purposes.*

250W NIR Therapy Saunaspace RubyLux Therabulb GE Feit Philips

The Saunaspace Thermalight, RubyLux, and Therabulb we purchased directly from each companies' website. The RubyLux was $30 and Therabulb was $25 each including shipping, and the SaunaSpace we paid $90 PLUS Shipping - paying more than $100 for a single bulb!

The GE bulb we got at a local Walmart and Zoro Tool online, the Feit Electric we got at a local Home Depot, the Philips we got from, and the Producer's Pride comes from Tractor Supply. All of these bulbs were about $10 each!

So in terms of price, we already are leaning towards the "common" brands.You will also notice that we don't recommend shopping from Amazon for this blog. But that is certainly an option for many of these bulbs.


Incandescence” is simply the emission of electromagnetic radiation (light and infrared) when an object is heated up. Like the embers of a fire, or a piece of metal glowing red-hot. It follows the physical laws of “black-body” radiation defined by Max Planck and other great physicists.

Red Hot Metal Incandescence

Red hot metal is an example of incandescence.

The hotter an object becomes, the more “visible” light it will emit. Hence why we have full-spectrum light coming from the sun, which burns at 5,778 Kelvin.

Incandescent heat lamps are no different, they follow the same laws of physics. And we can use the equations made by Ludwig Boltzmann and Josef Stefan to predict the spectrum of a heated object depending on their temperature.

But how do some of these companies make up such outrageous claims that they have some special spectrum? They cannot defy the basic laws of black-body radiation set by Max Plank, Ludwig Boltzmann, and Josef Stefan. No matter how convincing their marketing may be, they cannot defy the laws of physics.

What they can control:

    1. The type of filament use will determine the “temperature” of the radiation. Normal incandescent bulbs use a Tungsten filament and burn at about 2700K. Even if a particular brand has a special filament for a different temperature, that will only slightly shift the relative spectrum.

    Incandescent Black Body Radiation Spectrum Kelvin Temperature
    Theoretical spectrum for incandescent depending on the object's temperature.

    2. The red coating used might alter the visible spectrum slightly by blocking blue and green light. Similar to wearing blue-blockers, it changes the perceived color and protects the user from uncomfortable brightness or damaging blue light.

    Clear Heat Lamp Vs Red Heat Lamp
    The only difference between a clear heat lamp (left) vs a red heat lamp (right) is that the red coating is blocking the blue and green wavelengths.

      That is it! Unlike LEDs, incandescent bulbs are a very simple technology that emits a very predictable spectrum. It is very difficult to determine if one incandescent bulb has a “special spectrum” compared to another incandescent bulb. They all should be similar in theory and in measurements.

      So lets take a look at the ACTUAL measurements of these bulbs!

      250W NIR Heat Lamp Spectrum SaunaSpace Therabulb RubyLux Philips GE

      Normalized spectrum measured on our Thunder Optics Spectrometer with enhanced range. The spectrometer range ends at 920nm, so we see the spectrum would continue on past that number similar to the theoretical spectrum.

      Here we see the Rubylux, Feit Electric, and GE Bulbs all had practically the same spectrum! Their lines are all stacked on top of each other in this graph. The Philips bulb shows a very similar spectrum even though it doesn't stack on the others. So despite their marketing, the Rubylux spectrum is practically the same spectrum as these generic bulbs.

      The Therabulb and SaunaSpace Thermalight do show they have slightly more output in the Red 600nm-700nm range. Which both of them visually had a deeper red color than the other bulbs which had more of a orange-like hue.

      Therabulb vs SaunaSpace 250W Heat LampThe Therabulb (left) has more of a red hue, while the Rubylux (right) has more of a orange hue. Overall the spectrum are very similar except for these subtle differences.

      However, it really isn't significant enough to justify any extravagant cost, and the SaunaSpace Thermalight certainly doesn't defy physics to produce the special spectral output that they claim. It seems even the Therabulb beats the SaunaSpace at their own game with a relative spectrum having more visible Red.

      The Producer's Pride also has a large amount of visible light emission, but this is also a detriment since they emit a lot more Yellow wavelengths in the 500's, which is visibly much brighter and less pleasant to the eye.

      And I personally like the Philips because it emits the LEAST amount of visible light and is easier on my eyes. The red coating is noticeably darker colored red than the others.

      Power Output:

      We know that solar power meters and laser power meters won't be accurate or appropriate for measuring an incandescent heat lamp.

      So aside from some intricate experimental procedure, we know a simple technique to tell us which bulbs are emitting more intensity than the others. We will rely on our fundamental knowledge of physics, as dictated by the 1st Law of Thermodynamics.

      The 1st Law of Thermodynamics states that energy can not be created or destroyed, but it can change forms. So if we know a Heat Lamp is consuming 250 Watts of electricity, then it must be transforming that power to light and heat!

      Simple! So lets check out these Kill-A-Watt measurements:

      1. Saunaspace ThermaLight - 285-290 W

      2. Therabulb - 264 W

      3. RubyLux - 261 W

      4. GE - 234 W

      5. Philips - 256 W

      6. Feit Electric - 261 W

      7. Producer's Pride - 272 W

      Watch our video to see the testing.

      So what does this mean? Well it looks like SaunaSpace ThermaLight is consuming significantly higher watts than the "250W" rating they claim. This is how they are able to trick their Solar Power Meter into thinking it is 2x some special wavelengths. We already know they don't have some special spectrum, so all they did was crank up the power!

      SaunaSpace Thermalight Power Consumption

      Saunaspace Thermalight consumes 285-290W even though they are advertised as a magical 250 W bulb that emits 2x the intensity of a normal heat lamp.

      This is actually a massive safety issue and explains why Dr. Wilson doesn't recommend the SaunaSpace Thermalight bulb. An extra 40 Watts is a massive heat and fire hazard - especially when you don't warn your customers and they might install it into the wrong type of lamp not rated for that much power. Customers might not be expecting an extra 40 watts of power on their body, eyes, or skin. The normal safety guideline of 18 inches for 250 W bulbs might need to be further away for the 290 W SaunaSpace Thermalight. 

      Other bulbs like Therabulb, RubyLux, Philips, and Producer's Pride are also around 260-271 watts - so they are all in a similar range of power. Which are all higher than expected, but perhaps more manageable to be only 10 Watts higher than the rating.

      I actually had two GE bulbs and both of them were tested around 236W-240W, so maybe the GE is a bit under-powered. Which might be a good thing if you just want to go for the "low and slow" safety aspect.

      Intensity for a NIR Heat Lamp:

      To estimate the intensity, we only need to know two things. The optical watts (milliWatts) being emitted, and the surface area of coverage (cm^2) from the light.

      Since we are using the 1st law of thermodynamics, we will assume all 250 Watts of electrical consumption is being emitted as radiant energy. We multiply by 1000, then that is 250,000 mW of power! That is a lot!

      At 18 inches away, I can measure the beam diameter on the wall as 16 inches (about 40cm).  We convert to area of a circle with pi*(r)^2, so pi*(40/2)^2= 1256.6 cm^2 is the area of coverage at 18 inches away.

      Incandescent Heat Lamp Beam Diameter

      I simply aimed the light at the wall 18 inches away, and then measured the diameter of the primary coverage area on the wall.

      Now we simply divide 250,000 mW by 1256.6 cm^2 to get intensity! So we end up with 198.9 mW/cm^2. So we can say the average intensity at 18 inches away from a standard 250W heat lamp is about 200mW/cm^2 (for the entire spectral output).

      Remember, this is a very rough theoretical calculation. The reality will be different based on a number of small factors and inefficiencies. So we could be wrong by a large margin without verifying by professional testing.

      However, I would wager that this rough estimate of 200mW/cm^2 at 18 inches is MUCH more accurate than the nonsense numbers that some companies are claiming with their solar power meters. Which we already KNOW that solar power meters read falsely high by 2x-4x!

      Flicker and EMF:

      We will cover both Flicker and EMF together, since all the incandescent bulbs exhibit practically the same amount of Flicker and EMF.

      Yes, incandescent bulbs DO flicker! They run on AC power, and will fluctuate in intensity at 2x the Hz of the AC cycle. The magnitude of the flicker is simply "buffered" by the heating and cooling of the filament. In our last review we found a generic incandescent bulb flickers at 9%!

      All of these high-wattage incandescent bulbs showed between 2-3% flicker. Which is very good and low! There wasn't any significant difference between any of the brands.

      SaunaSpace ThermaLight Flicker Measurement

      We measured flicker on our Radex Lupin flicker meter.

      Similarly, the EMF is a non-issue if you are the recommended 18 inches away from the incandescent bulb. One recommendation we have is to add an extra grounding wire to the metal reflector, this way to further reduce the electric field from the bulb.

      Heat Lamp Electric Field EMF not grounded

      Heat Lamps can actually exhibit a HIGH electric field EMF if they aren't properly grounded. This is true for all the bulbs, it depends on the lamp they are put in.

      Check out our YouTube videos to see the EMF measurements!


      Based on Price, Power, and Spectrum my top picks would certainly be Philips or Feit Electric. These lamps had practically the same spectrum and power as the RubyLux, without the extra price tag.

      GE vs RubyLux Spectrum

      The Feit Electric (left) had practically the same spectrum as the RubyLux (Right).

      If you really want to splurge then the Therabulb does have a slightly interesting spectrum and an attractive deep-red color output. But again this would only be a subtle difference in spectrum and doesn't necessarily mean there is any extra benefit.

      And we proved that the SaunaSpace ThermaLight couldn't live up to their physics-defying claims of 2x the output in a 250W bulb. The answer was simple, they jacked-up the wattage on their bulb and used a cheap solar power meter to verify the claim. Compared to a 250 Watt rating they only added 16% more power to get to 290W. Which we don't necessarily want more power from a safety standpoint - especially if the customer is unaware of the deception.

      If you DO want more power for your DIY sauna, you can just buy an extra $10 heat-lamp and add it to your setup! Or again splurge on the 300W ThermaLight bulbs. Save a ton of money and get all that extra power!

      We hope this helped clarify your purchasing decision for heat lamps. All of these incandescent bulbs are functionally and fundamentally the same, just with some subtle differences in spectrum and wattage. 

      More importantly, hopefully you also learned about some of the fundamentals about how incandescent light bulbs work. This way if new companies roll along with more physics-defying claims, then you can spot it and throw some red flags.


      [1] Hot Metal Blacksmith Photo: