Ceramic Metal Halide (CMH)

[Jhhnn]

jhhnn, I had read *in passing* last year that any Mh bulb regardless of the burn rated position was at risk to *drift a bit* in the kelvin/color range.
I never really made much of it until.... I bought a few of those avenger batwing hoods because of the *trapped heat* issues with my parabolic hoods.
afters installing em a week later i thought my 4000K MH i used for bloom were running more blue than yellow, a lot more like my 7400K Mh ultrasuns used in veg .
after 3 wks i saw the difference in growth compared to the other bulbs in the vert position in the para's,
these were the sylvania 1000w metal arc 4000K BT57 bulbs.
I have another grow using plusrite 4000K halides with a BT37 bulbs because the BT 57s won't fit in the 6" cooltubes.

the plusrites had no noticable diff to my eyes burning in the hrz pos.
so that's is a bulb by bulb issue



in my current bloom run I'm a using 6-860w cmh bulbs.
my previous run i used 1 of them.
the do run hotter by quite a lot more.
running 6 now I'm sure the burn temps are hotter.

using my laser temp gun I'm getting 500F from the 860s
while my 1000w sylvies are running 380ish F.

the CMH bulbs definitely run hotter

Interesting. I think one thing we need to recognize is the idea of total energy- lamp output in terms of watts regardless of wavelength. Ultimately, it's all heat, exciting the air that the light passes through & the surfaces that absorb it. In that sense, an 860 produces less heat than a 1000 regardless of lamp type.

It's also important to recognize the interaction between the outer glass envelope & the light generated by the element within. The envelope is transparent to visible & infrared but largely absorbs ultraviolet. Whatever light it absorbs causes it to become "hotter", with that heat being carried away by convection rather than radiation.

So lamp elements that produce more infrared will have cooler envelopes while those that produce more ultraviolet will have hotter envelopes if everything else is equal.

I think that may explain the perception of CMH lamps being "hotter". They are, at the lamp envelope, because that envelope is absorbing more ultraviolet. Some of the spectrum shift away from infrared apparently goes into the ultraviolet range.

Or so it seems to me.

 

[the gnome]

ok, update on those temps I posted above.
i was taking the temps from 24" back,
the intense lite in my face was.. well, intense.
plus the further ways the larger dia. of an area i'm getting info on.

and Jhhnn, I also shot the inner bulb and outer envelope as best i could.
soooo getting 6" away the MH 1000w 4000K I'm now getting 450-460F
this is shooting dead center of the inner bulb,
temps off center, on the outer envelope only I had marginally lower by 20Fish degree's

the 860w 4000K CMH dead center inner bulb gave me whopping 650F+ and more until the laser gun err'd out, so thinking 700F is the limit on my gun.
shooting the envelope gave the same reading.

700F rings a dinner bell with me,
I used to eat at shakeys pizza parlor
their slogan advertised
come eat a shakeys pizza with our nickel thin crust cooked in the 700 degree oven
man-0-man....
shakeys is still sthe best thin crust pizza Ive ever eaten!

 

[rives]

Gnome, I think that you are going to have a hell of a time getting accurate readings like that - the guns are very sensitive to levels of reflectivity and the glass is going to give you problems. You might try setting something at fixed distances from each lamp, maybe paint the object flat black or whatever you have handy so that they are same, and measure how hot the object gets rather than trying to directly measure the lamp. Another option might be a contact-type thermocouple.

 

[LargePrime]

I was getting a small head of rage up about how you cant F'ing....
and there is cool calm rives, explaining how to fix the problem...

We should expect that CMH runs hotter. Remember Philips CANNOT make a latest generation CMH over 315W with the glass tech they have. No other HID tech is pushing the limits of the stuff they make lights out of. ( i wonder if all the smartphone glass innovations 'Gorilla Glass' might make it into CMH tech)

One little science reminder about heat. There is Temp (degrees C), and Heat Volume(Joules or Calories).

One lit match is way hotter (in temp) than, say, the surface of an electric stove on hottest. But you can put a match out with with ones fingertips. One cannot cool, or put out a hot stove top with fingertips.

So if you want to be fair measuring heat, you need to items of similar size and make up and color (often 'black bodies' in science) the same distance and dwell time away, and then measure the temperature OF THESE ITEMS. Never ever try and measure a clear/reflective/white surface with a laser. Even light colors are iffy. And the heat source is gonna be iffy too.

Another note. Those with paler skin will notice these CMH, and even more so the newer ones, throw light you can feel. If you are running open fixture you will FEEL on your skin more light/heat that any other HID I have found. It will pound on you and tan you if you spend time exposed to it. It is a different feeling than other HID i have used. look for it. As a Side note, i think this is why Philips added UV blocking to the AGRO. to protect workers working under them.

Gnome, I think that you are going to have a hell of a time getting accurate readings like that - the guns are very sensitive to levels of reflectivity and the glass is going to give you problems. You might try setting something at fixed distances from each lamp, maybe paint the object flat black or whatever you have handy so that they are same, and measure how hot the object gets rather than trying to directly measure the lamp. Another option might be a contact-type thermocouple.

 

[Jhhnn]

I think it's important to recognize that bulb output is all heat, one way or the other, regardless of the wavelength. 1000w of output puts more heat into the enclosure than 860w, everything else being equal. All the radiant energy is translated into increased molecular motion at the surfaces it encounters, which is heat. It can be no other way.

Our perception of that is another matter entirely. I'll agree that CMH "feels" hotter, but that really flies in the face of the numbers. Perception & reality aren't necessarily the same thing. Those of us who alter our consciousnesses with drugs know that, I'm sure.

 

[the gnome]

Gnome, I think that you are going to have a hell of a time getting accurate readings like that - the guns are very sensitive to levels of reflectivity and the glass is going to give you problems. You might try setting something at fixed distances from each lamp, maybe paint the object flat black or whatever you have handy so that they are same, and measure how hot the object gets rather than trying to directly measure the lamp. Another option might be a contact-type thermocouple.

yeah, it was a pita trying to get the measurements,
putting something next to the bulb for a while and getting temps from that is the way to go.
the last stable temps i could get were around 640f then as i got closer huge flucuations.

but at any rate since no one has shot an 860cmh with a lazer temp gun yet, I figured i give it a go and post results and give you guys something to yak about

seems like phillips woulld have the operating temps listed somewhere ?

side by side i had my 1000w sylvie and the 860w fired up and put my palms up to the lamps at the same time at diff distances
and TBH they seemed to be pretty much the same

 

[Mikell]

Another note. Those with paler skin will notice these CMH, and even more so the newer ones, throw light you can feel. If you are running open fixture you will FEEL on your skin more light/heat that any other HID I have found. It will pound on you and tan you if you spend time exposed to it. It is a different feeling than other HID i have used. look for it. As a Side note, i think this is why Philips added UV blocking to the AGRO. to protect workers working under them.

If I comprehend what your getting at here, you're saying that if I change over to CMH my room will be ginger free?

 

[LargePrime]

If I comprehend what your getting at here, you're saying that if I change over to CMH my room will be ginger free?

Ginger resistant. They can be stubborn.

 

[Drek]

CDM lamps run higher internal arc pressures than normal MH lamps, but less than HPS. Temperature and pressure are linked, meaning the higher the pressure, the higher the temperature. At the same time, ceramic arc tubes are better at reflecting/absorbing a good deal of that heat while lasting longer than quartz. So while the MH puts out less heat, the arc also throws more and doesn't last as long(sodium degradation); The CDM puts out more heat, but the arc is better at reflecting it; throw in the power used at the load(lamp) and that's another variable into the equation. The general order, with all things being equal(which they are not), would be from cool to hot: MH, CDM, HPS.

I'm still very happy with the results I got from my CDM Retrowhite 400..worked awesomely, but then, they were grown awesomely as well.

I believe CDM860 should be running fairly high PAR values; probably in the neighborhood of 1600umol or more, as they produce so much visible light.

I'm still on the fence on how UV effects THC generation. THC, apparently is a molecule good at blocking UV radiation and it has been suggested that it is produced at higher/fully realized quantities when subjected to more UVB, which would make the mogul based CDM's with larger amounts of UVB better, with better strains, at making more potent weed.

Anywho, food for thought.

 

[the gnome]

I'm still very happy with the results I got from my CDM Retrowhite 400..worked awesomely, but then, they were grown awesomely as well.

Anywho, food for thought.

great info Drek
AND
as always your modesty shines brighter than my 1000w 4000K sylvie

 

[Drek]

 

[LargePrime]

CDM lamps run higher internal arc pressures than normal MH lamps, but less than HPS.

I am pretty sure the CMH bulbs, and even the allstarts have higher internal temperature and pressures then HPS

Temperature and pressure are linked, meaning the higher the pressure, the higher the temperature. At the same time, ceramic arc tubes are better at reflecting/absorbing a good deal of that heat while lasting longer than quartz. So while the MH puts out less heat, the arc also throws more and doesn't last as long(sodium degradation); The CDM puts out more heat, but the arc is better at reflecting it; throw in the power used at the load(lamp) and that's another variable into the equation.

CMH is better at holding the metallic salts in the arc tube. That is what gives the increased longevity. And at higher Temps and pressure, more efficiency. I have not read anything about CMH arc tube being more reflective.

The general order, with all things being equal(which they are not), would be from cool to hot: MH, CDM, HPS.

I am not sure what Hot means. But I guarantee that CMH will throw less BTU/system watt than any other HID lighting.

I'm still very happy with the results I got from my CDM Retrowhite 400..worked awesomely, but then, they were grown awesomely as well.

You would be a excellent one to run the newer tech to see if there is much improvement.

I believe CDM860 should be running fairly high PAR values; probably in the neighborhood of 1600umol or more, as they produce so much visible light.

um, PAR is not visible light, but if the 860 could make over 1.8PPF/W for the system everyone would have been talking about them years ago. Saddled with a 1000W mag ballast? no Fing way.

I'm still on the fence on how UV effects THC generation. THC, apparently is a molecule good at blocking UV radiation and it has been suggested that it is produced at higher/fully realized quantities when subjected to more UVB, which would make the mogul based CDM's with larger amounts of UVB better, with better strains, at making more potent weed.

You mean UVA right? Still it is interesting if UV can make more THC. But I worry about human exposure. Also that is a defense mechanism to UV exposure. I am not sure that it is natural for the plant. So I am on the fence too! But science will tell us.

 

[Drek]

I am pretty sure the CMH bulbs, and even the allstarts have higher internal temperature and pressures then HPS. CMH is better at holding the metallic salts in the arc tube. That is what gives the increased longevity. And at higher Temps and pressure, more efficiency. I have not read anything about CMH arc tube being more reflective.

CMH AFAIK, has roughly equivalent arc wall temperatures to HPS at ~ 1200-1300 degrees Celsius. CMH and HPS both utilize ceramic arc tubes and do not suffer from sodium and other salts migrating through quartz. Ceramic is better at containing heat than quartz as well, I do believe.

"CMH arc tubes actually block Radiant Heat from the lamp thus not heating up your tank(aquarium) like MH." - Advancetechlighting

"During their life, sodium and other elements tend to migrate into the quartz tube, because of high UV radiation and gas ionization, resulting in depletion of light emitting material that causes cycling. The ends of the (ceramic) arc tube are often externally coated with white infrared–reflective zirconium silicate or zirconium oxide to reflect heat back onto the electrodes to keep them hot and thermionically emitting.- Wikipedia

Whether or not the zirconium coating aids in the total amount of reflected heat or not, I don't know.

I am not sure what Hot means. But I guarantee that CMH will throw less BTU/system watt than any other HID lighting.

I would tend to disagree with this statement for the simple fact that there are only low/med wattage(mostly) CMH solutions currently available other than the 860W CDM, and from everything I've read(and experienced) and from what others are noticing, the 860 throws a good amount of heat, comparable(give or take) to other 1000w lamps.

The only comparison I've directly had with smaller lamps was my Retrowhite to a Son agro(both philips). The CMH was cooler per say, but the Son agro was rated at 430W. How much heat is thrown, I'm speculating, is also a product of the reflective material/design of the reflector and the bulb orientation.

um, PAR is not visible light, but if the 860 could make over 1.8PPF/W for the system everyone would have been talking about them years ago. Saddled with a 1000W mag ballast? no Fing way.

- A typical human eye will respond to wavelengths from about 390 to 700 nm.[1] - Wikipedia

- Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. - Wikipedia

Par light falls exactly within the visible range of the human eye. I do realize that they are quantified differently.

Pretty sure DNA tested one of the 860 lamps at ~ 1600umol, which I wouldn't at all be surprised at. Other current CMH lamps are putting out ~ 1.9ppf, so the 860 at 1.8 isn't a stretch. It's still a CMH lamp efficiently putting out a lot of visible light, agro or not.

You mean UVA right?

No, UVB. UVB radiation is the high-energy radiation that plants and other forms of life defend themselves against, as to not incur cellular damage. I have read that THC is incredibly good at being a sunblock, and may in quantities, be present(and fully realized as a molecular structure) as a direct result of UVB exposure. ~ 280 - 310nM.

 

[e_24]

As I was surfing the web, I came upon this:

http://www.eyelighting.com/_CE/page...ramic Technology/Cera Arc BT 220-230-270W.pdf

Seems like eye is getting in the game now too. EVEN WIth open rates bulbs.

 

[Drek]

Yes. They are nice lamps. Still slightly less efficient than the best HPS, but a hell of a lot better total spectrum, imo, for overall plant health and visual inspection for the grower, which is also hugely important imo.

Yield, potency, blah blah...are dependent on many variables. Way too many imo, to solely attribute light as being the cause of.

Lighting is WAY overrated. So much so, that it's somewhat sickening in light of how many fights and arguments ensue because of it.

 

[LargePrime]

CMH AFAIK, has roughly equivalent arc wall temperatures to HPS at ~ 1200-1300 degrees Celsius.

Perhaps we are talking apples and oranges. That may be true for the Allstarts, but the CMH elite series are higher pressure and hotter. Remember Philips cannot currently make a larger wattage Elite Lamp, cause the temperature and pressures are too high for the materials we have.

CMH and HPS both utilize ceramic arc tubes and do not suffer from sodium and other salts migrating through quartz. Ceramic is better at containing heat than quartz as well, I do believe.

Some HPS use tubes similar to Philips CMH lamps. And again we can be talking apples and oranges. The more efficient 600W HPS bulbs have lower temps and pressures, which make them more efficient. Moving them more toward the ultra efficient LPS lamps. The 1000W+ HPS lamps may have operating temps like the CMH lamps, but will not have the pressure.

CMH arc tubes actually block Radiant Heat from the lamp thus not heating up your tank(aquarium) like MH; - Advancetechlighting

Not wanting to disagree with Tom, and ya, the arc tube does a better job at reflecting the arc heat back to the arc, which mean less wasted heat/energy trying to maintain the arc, the fact is that hot arc coverts more energy to light than the other techs we are discussing. Its a whole system. Its not like one can just add a ceramic arc tube to another tech and make it more efficient. The whole system has to work.

I would tend to disagree with this statement for the simple fact that there are only low/med wattage(mostly) CMH solutions currently available other than the 860W CDM, and from everything I've read(and experienced) and from what others are noticing, the 860 throws a good amount of heat, comparable(give or take) to other 1000w lamps.

So lets do a thought experiment.
We examine the 2 lamps, one 1000W and one 860W. Now lets postulate that the 1000W makes 50% light and 50% heat (a lamp this good is mostly theory today) so that is 500W of light and 500W of heat.
If the 860W makes ~equivalent light it must make ~500W of light, leaving only 360W of heat.
If this is all true, then the 860W produces about 75% of the heat of a 1000W.
Now we can vary the efficiencies and see what happens to the numbers, but we can see there is no way the 860W can make the light of a 1000W and also make more heat than a 1000W. It gets even better if one looks at the 315W. So I do guarantee that CMH will throw less BTU/system watt than any other HID lighting. But I would love to be proved wrong. Cause then we all have found a better light. https://www.icmag.com/ic/images/smilies/biggrin.gif And remember, Philips has said they CANNOT currently make a higher wattage version of the CMH bulb, as the materials cannot handle the temps and pressures.

The only comparison I've directly had with smaller lamps was my Retrowhite to a Son agro(both philips). The CMH was cooler per say, but the Son agro was rated at 430W. How much heat is thrown, I'm speculating, is also a product of the reflective material/design of the reflector and the bulb orientation.

The heat one will feel with a hand below the lamp perhaps. But all that heat is still in the room. A grow room with 860W in place of 1000W will always be cooler. And so on with a 315W

- A typical human eye will respond to wavelengths from about 390 to 700 nm.[1] - Wikipedia

- Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. - Wikipedia

Par light falls exactly within the visible range of the human eye. I do realize that they are quantified differently.

We are so not getting into Lumens vs PAR discussion. The fact is all the big fat yellow lumens get less use and the skinny red and blue lumens get far more use from the plants point of view. One growing with a high lumen light will not grow as well as a high PAR/W light.

Pretty sure DNA tested one of the 860 lamps at ~ 1600umol, which I wouldn't at all be surprised at. Other current CMH lamps are putting out ~ 1.9ppf, so the 860 at 1.8 isn't a stretch. It's still a CMH lamp efficiently putting out a lot of visible light, agro or not.

1) the 860 is not a CMH lamp like the 315W. Philips said they cannot make a 860W CMH lamp. 2) the 860W may be putting out a lot of light, but 2 of the 315W (346 system wattage PAR 1.95/W) put out more lumen with ~80% of the power.
So that makes it impossible for it to have a par over 1.5.

No, UVB. UVB radiation is the high-energy radiation that plants and other forms of life defend themselves against, as to not incur cellular damage. I have read that THC is incredibly good at being a sunblock, and may in quantities, be present(and fully realized as a molecular structure) as a direct result of UVB exposure. ~ 280 - 310nM.

Well none of these light put out much UVB at all. Except the mogul perhaps.

 

[Drek]

Thanks for your reply Prime, but your information sounds like a lot of the general information I was reading over a year ago. And, no disrespect, but my information is not coming from a subjective viewpoint as much as coming from objective references, which is why I provide references with all my material...and I don't really have that much time to type out pages and pages of debate related conjecture. Show me the references, and I'll stand corrected.

CMH is CDM. Same thing. Retrowhite 'CMH' model number is :
CDM400S51/HOR/K/ALTO.

> http://en.wikipedia.org/wiki/Ceramic_discharge_metal-halide_lamp

Not some, ALL..unless it some strange HPS that designed for some special application not at all pertaining to us. HPS uses a ceramic arc tube, so does CDM. No mystery there.

Show me where HPS(high pressure sodium) will have a higher temperature and a lower pressure than a CDM lamp. Provide objective professional references.

I understand that it's a whole system. No new information for me there...

860w isn't CDM?

> http://www.ecat.lighting.philips.co...mps-with-allstart-technology/928601174701_na/

The visible range contains nearly all the radiation that plants use...nM are nM. Waves are waves.

 

[LargePrime]

In all Philips literature it refers to its current latest generation CMH lamps as the Elite series. This Elite series has a significant improvement over the last generation. But they also have a price for that performance. The newer CMH lamps have there own ANSI spec (182) requiring their own special ballasts.
They are more efficient, have longer lives, and have better spectrum.
The Master Color Elites are the latest generation of the CDM line. But Philips likes to rename things all the time.

The Allstart lamps can run on older tech ballasts. They do not have the system efficiencies, life span and spectrum of the CMH line.

but just looking at the data sheets, here is the 860W CDM
http://download.p4c.philips.com/l4b/9/928601174701_na/928601174701_na_pss_aenaa.pdf
and here is the Agro
http://download.p4c.philips.com/l4b/9/928601172201_na/928601172201_na_pss_aenaa.pdf

Look at the Luminaire design requirements. The Elites all run way hotter than the other CMH lines. The mogul base being the odd one that is both hotter and cooler

 

[Pinball Wizard]

wow! ..special voltage, special lamps with special ballasts. They really got us by the short, curly hairs, now!

 

[Drek]

Look at the Luminaire design requirements. The Elites all run way hotter than the other CMH lines. The mogul base being the odd one that is both hotter and cooler

Who gives a crap about luminaire requirements; I'm not an interior designer. It has no bearing on the engineering facts that make up the technology(the basic design of the arc and it's internals). I'm talking about arc wall temperatures not reflector design specifics? There's also 3 inches of space on either side of the 860 arc to the glass bulb, vs 1/2" on the elite. Of course the 'elite' glass is going to be hotter.

Either way....all of them are CDM's at their root. I'm kinda getting tired of the 'elite'(marketing name) being mystified as some magical wand designed by the elven kings.

CDM, CMH...whatever you want to call it...same salts more or less, same arcs more or less. Don't really care what ballast it is...yes, electronic(designed specific ones) are more efficient but have shorter lives, and besides, I have no plan on running 50 of them. Electronic ballasts are more efficient and extend bulb life...again, no mystery there.

Again, has nothing to do with the basic premise behind the arc that makes a CDM a CDM.