PFO LED lighting

[midgetwaiter]

Originally Posted by StirCrazy

because of the efficiency the will be less heat, but how much we don't know.. I do know the luxton stars get so hot they need a heat shield to prevent the LED from burning out and I can only imagine that a 5 watt version would need that also sense a 1 watt version does. so there will be heat thrown out. now sense they use 40% less energy then you are looking at a heat difference of 40% (at least) but how much of this was through the ballast? I would say 1/2 sense I know how hot my ballast get. light is radiation of energy which when comes in contact with a surface will change to heat, the question is how much. weather you have 250 watts of radiant light from a MH or 250 watts of radiant light from and LED it is still the same amount of energy (assuming 100% efficiency) and will have the exact warming effect. now I am only taking about the radiant component, not the convection or conduction types. Convection is the big one that we have a problem with in closed hoods but can be solved with power venting, but you can vent all you want and Radiant heating will not be affected.


so like I said before.. will it run cooler, probably... how much... don't know.

Steve

You don't need heat sinks on luxeon stars because of the amount of heat they produce alone, you need it because of the amount heat it produces compared to the surface area of the device.

The radiant heat transferred by the photons striking a surface is not a significant concern and will almost completely be nullified by evaporation at the water's surface.

The amount of problem heat generated by lighting in aquariums will always be proportional of the efficiency of the light source and the water will be heated by convection. I don't care how many fans you put it a hood with two 150 watt HID lamps, the temperature in the hood will be significantly higher than ambient. Air is a shitty heat conductor and pushing it around with fans doesn't work very well. For example, this is why big transformers are submerged in oil.

Ideally you should be able to touch the surface of one of those LEDs at full power and not hurt yourself. I suspect that either PFO will manage to maintain that kind of surface temp or that the lamp life will suffer significantly. A hot LED is not a happy LED.

[G1GY]

Originally Posted by midgetwaiter

The radiant heat transferred by the photons striking a surface is not a significant concern and will almost completely be nullified by evaporation at the water's surface.

Air is a shitty heat conductor and pushing it around with fans doesn't work very well. For example, this is why big transformers are submerged in oil.

.

While air is not a good heat conductor, you can only saturate a given amount of air with water untill the air can't hold any more. A fan will move the wet air away and allow more dry air to become saturated during evaporation. Without doing this.............. evaporation (and free cooling) stops. (This is in the case of the aquarium itself.)

As far as the fixture itself:

While air itself is not a good conductor, moving it over a heated surface does provide an excellent cost effective vehicle to move heat away from the fixture.

Yes big transformers are filled with with oil for cooling, but the outside of this oil filled gallery is also designed as a heat sink(Largest surface area possible in a given space.) to transfer the heat from the oil to............... You guessed it! Air.

[jess]

I'd really like to see the spectrum of light they put out. Generally LED's have a very narrow frequency band for each colour. I wonder how many different colours they are using in the light.

Halides should have a much broader frequency band.

[TheReefGeek]

How exactly does it use 40% less energy?

The new PFO fixture is 300w

This is supposed to be comparable to a 250w MH setup.

Seeing as I pay for electricity by the Kilo-watt-hour, if I run both these fixtures ofr 10 hours a day, won't the PFO cost me MORE?

What am I missing?

[jess]

From a pure power usage point of view your right, they won't make much of a difference on the electricity bill if ran for the same amount of time. I'm not sure how the MH are rated but assuming that the bulb is using 250W and then assuming the ballast has an 80% efficiency then the actual input power to the MH balast should be around 300W anyway.

MH obviously lose alot more power to heat generation through the light and ballast than LED's. So on a Watt vs Watt basis the LED lighting should produce more light output and less heat output due to it's high efficiency. I'm no lighting expert by any means but what worries me is the narrow spectrum of light produced by LED's.

The 300W LED light should run quite a bit cooler which is a nice bonus.

I'm sure someone else here has a better explanation.

[andresont]

Originally Posted by reeferaddict

I saw a brochure at Safari yesterday for these - pretty pricey... BUT imagine not having to replace bulbs and the overall energy savings! If anyone's getting one of these puppies, let me know... I want to see with my own eyes!

http://www.solarisled.com/

Thank you for your comments. Our control board is sprayed with a protective coating for saltwater as well as all the circuit boards in the unit. We do not have a heat problem with our units. The maximum inside temperature next to the LED's is 40 Deg C. (The hottest point). Not only are they fan cooled and don't produce the heat of metal halides, they also have an internal RTD unit that will shut the entire unit down if it gets to hot.

Our unit has only 12V dc in the hood not high voltages like it takes to fire metal halide lamps. This continues to reduce the risk of fire and shock.

We are constantly changing/improving the Solaris as well as the new LED fixtures we are developing with feedback from people like you. We appreciate your comments and if you have more please send them to us. For your information, the unit has been almost entirely redesigned since our first showing at the Chicago IMAC because of customer suggestions. The outside may look the same, but the inside is dramatically different.

Thank you,
Patrick Ormiston



Sent: Wednesday, July 12, 2006 5:38 PM
To: Patrick Ormiston
Subject: LED's
Thank you for being first and pushing research forward, I think this light can eliminate all aqua lights in the future,

I have a question/recommendation though, Would you consider moving controlling CPU away from the heat and aquarium top also away from moisture. Looking at Giesemann lights they are catching fire and CPU’s are failing because of overheating. Why not take “Tunze” for example and keep CPU/controller away from aquarium top where it is subjected to harsh environment.

Just my two cents for what it worth

[OCDP]

Originally Posted by andresont

Looking at Giesemann lights they are catching fire and CPU’s are failing because of overheating

Any links to how and why they are catching fire? I just bought a Giesemann Nova II and it hasn't had any problems. Is this a really common problem? Does this happen in the all-in one fixtures? Or in the pendants?

Sorry to hijack.

[andresont]

Originally Posted by OCDP

Any links to how and why they are catching fire? I just bought a Giesemann Nova II and it hasn't had any problems. Is this a really common problem? Does this happen in the all-in one fixtures? Or in the pendants?

Sorry to hijack.

I am sure your fixture will be ok , however in all-in one fixtures I hear many are catching fire and / or burning their CPU's because of heat accumulation and especially because of poore step down transformer from 220Volts down to 110. This is done by unquolified tech back East, this is not my place to say who or name the names. All i can tell you can find out more by visiting big "pet shop " on north road and talk to manager he will be able to tell you some more.
the step down transformer is not secured properly in the fixture plus overheat problem and CPU's do not like that.
This is a year old info so I am sure somthing might have been changed and design improved,

[OCDP]

Thanks for the reply .

So it sounds like this is all in the all-in-one fixtures, not the pendants. Thank goodness hahaha....

[untamed]

I've very interested in this lighting system for my 400 gallon under construction right now. I had planned 6 x 250W MH w/flourescents and a chiller....but if I could avoid all that it is pretty tempting.

I have the same problem as everyone else. I can't afford to be a test subject. I know that MH will work, but I have yet to see anyone's longer term results on only LED.