True or False....HQI MH's run cooler than other MH's.

[Anonymous]

I was told that HQIs run brighter and cooler than regular MH's. Is any of this true?

I'm tormenting myself with which to choose.

1.Icecap 440w VHOs
2.2 150w HQIs
3.2 175w MHs

Over a 55 gallon with anemones. I saw a great aquarium in The Reef Aquarium by Sprung and Delbeek which had an anemone tank under 5500K MHs.

Now Icecap claims to use only 260w of electricity for 440watts.

But electricity is not my priority. Heat is.

So if it is true that 440w of VHO is as hot as 440W of MH than it would make sense to get MH.

BUT I only have a max of 6inches of clearance. SO,wouldn't HQIs make more sense?

I feel I would be happy with any of them. But the heat is my highest priority.

Any input would be appreciated.

Thanks in advance,

Dan

 

[pez]

1) I don't know if HQI MH lamps run cooler, temerature wise, than mogual MH lamps. I would suspect the smaller envelope might let them run cooler, but the gas still has to ignite and burn at a specific temperature. No way around that.

2) Watts are watts. 440 watt of VHO is no different than 440 watts of MH. If you want to talk about intensity, lumens, par, etc., it's a whole different story.

3) Watts = volts * amps. The claim that you are referring to is impossible (if you read exactly what you wrote). However, I think their claim is more on the lines of "burns brighter with less electricity." Word for word it has little to do with watts. However, 440 watts is 440 watts. The truth is there is loss in any ballast, so 440 watts of output power will really more like 480 watts of input power. Icecap's claim really means their electronic ballast is more efficient than a tar ballast. Duh.

4) With 6" of clearance, you are going to have problems regardless of the techonology you choose. You need A LOT of light - you have to get the heat away from the tank some how. I'd give some serious thought to more clearance or a lot of fans.

Hope this helps.

-Tom

 

[Sarc]

Hi

I have an open topped tank, i had a 400W single-ended MH over a 1.2m (55gal) tank. I then swopped to a 240gal tank but that is another story.

The heat was never a problem for me, even in the middle of summer. I didn' use fans and yes the outside temperature did get hotter than 90 degrees. I did however have the hood off the tank when the mh was running (it was my main light source and so the hood was always off). This helped disperse heat so if you can do that, then go for the HQI. I have a HQI on my 240gal tank. They are nice but i found that the single-endeds allowed me to keep the corals happier. The HQi puts out a lot of UV and i had to put a shield up, but even with the shield, the corals need a long acclimatisation time to get to high light areas (softies) and i haven't put any at the top yet (except porites).

Go for HQI tho, try out the 250W version. I know of a 2Kq version that i can get, double-ended.

HTH
Chris

 

[bigtank]

The 150w HQIs are much brighter than any 175w MH. I use 2 on a 70g tank (48" long) and my animals, including a bubble tip anemone, are doing great. Mine are 10k AB, which have a little pink to them, but otherwise look good.

If you want SPS in there, the 250s would be a better choice of course, but the 150s can support anything. Just my .02.

 

[Anonymous]

Tom,

I wasn't trying to compare the lights intensity but the heat involved. More like comparing the heat of 440w VHO to the heat of a 400w MH. Are there any differences in the amount of heat produced by either of these units? Would they both burn at about 120 degrees(not actual temp,just guessing)?

The electricity is not the issue. But the Icecap claim is that it uses 260 watts to produce 440w of light. Not my claim,it is theirs. Duh!

Dan

 

[Iron]

get the 2 hqi 150. if this is your only lighting it won't get to hot. a small fan will take care of it. the 440w of vho will heat up also. The halides maybe alittle hotter but way more light.

 

[kjb]

Not to confuse the issue but... I thought that the actual HQI bulb did run hotter than a regular mogul bulb, but is much, much smaller, within a more enclosed case and shielded with UV glass, and so the total overall heat varriance is negligable. At least it is a moot point since either lamp will need ventilation if you are in a hood.
At least, that's what I was thinkin'...

 

[Sardaukar]

Actually, Watts = Joules per Second. Just thought id let you know.....

 

[Anonymous]

Thanks.

 

[pez]

Dan,

Although I have no hard data, I would suspect MH lamps burn much hotter than FL lamps. You can touch a running FL lamp; I would never recommend that with a MH lamp.

watt info: http://whatis.techtarget.com/definition/0,,sid9_gci294147,00.html


-Tom

 

[canadawest]

I'm no expert either, but I would question the statement that "440 watts of VHO produces the same temperature (heat) as 400 watts of MH"

I know my 440 watts of VHO over my tank gets warm, but I can touch any one of the bulbs. A 400watt MH lamp on the other hand will produce a nasty 3rd degree burn in no time if you lay some skin on it!

I'd say that watts are not a fair comparison of heat produced. Keep in mind this is just my opinion, and has not been tested scientifically for accuracy!

 

[Diablo]

I have to concur with canadawest... there is no doubt that the HQIs will burn significantly hotter than the VHOs. I would still use them, however. Place a toughened glass shield between the lamps and the tank, use a small fan in the area betweeen the lamps and the shield. Do not blow air directly on to the HQIs... the lamps need to burn at a certain temperature, otherwise it effects their color and lifespan.

Sardaukar:
Amps = Coulomb/second
Volts = Joules/Coulomb
Amps * Volts = Joules/second = Watts
Even though both Amps and Volts are derived units, it is perfectly correct to say Watts = Amps * Volts

 

[Barbie]

The heat output would also be spread out over the whole bulb in a VHO system, while the halides have it concentrated in a much smaller area, fwiw...

Barbie

 

[Anonymous]

Thank you all again.

 

[Josh's Reef]

Barbie you hit it on the head!!!! The Mh will run a lot hotter,because its much more compact. Hqi and reg. Mh of the same intensity will run close to the same temp. I was told by Rich at marine ecosystems that the 400 mh's will run about 1350 degrees at the iner envelope and pruduce 350 degrees of heat at the bulb surface. SO DON'T TOUCH IT!!
For exact specs you can call PFO, OR ANY MANUFACTURER.

 

[Scott D Passe]

Hi all,

As an engineer, let me take a crack at this.

What we are really talking about is efficiency. I.e. the lamp that produces the most usable light (PAR etc) per watt of electricity, also produces the least overall heat. Energy that is put into a lamp as electricity leaves it as combination of heat (bad) or as usable light (good). (This is somewhat of an oversimplification, as there are other forms of energy such as UV and RF, but these are not “major” components)

HQI lamps produce the most light per watt of input.

IceCap florescent ballasts are efficient because:

1 The ballasts themselves are more efficient because high frequency switching power supplies use smaller magnetic inductors that are more efficient than the large iron core inductors (transformers) that operate at 60 Hz.

2 High frequency current causes the phosphors in the lamps themselves to emit light more efficiently. (Cooler, brighter)

It is a myth that HQI and MH less efficient than other forms of lighting. Watt per watt, they produce less heat than other forms of lighting. The bulbs are hot because the concentrate their heat in a small area as opposed to spreading out that heat over a long bulb envelope. An analogy to this is comparing a soldering iron (say 25 watts) to a space heater (say 1500 watts). Which is hotter? Which produces more overall heat?

For “large” tanks, with light loving critters, HQI or MH is often the only choice because of light per square foot issues.

Regards,

Scott Passe

 

[Sardaukar]

You are correct Diablo...My apologies....I should be ashamed of myself, im in Physics AP in High school.....ah well, its summer...my breain is in hibernation mode ;-)