how much loss on aircooled hoods?

[Guest]

how much lumen loss do you think there is with aircooled hoods between the glass and the desighn?

 

[Berry_Coughin']

Pico has a nice writeup on this somewhere on the boards....

 

[Guest]

looks like 2% but im thinking with the savings of heat and the ability to get closer is 0

 

[DIGITALHIPPY]

looks like 2% but im thinking with the savings of heat and the ability to get closer is 0

the reflector shapes the light patern more then anything. some hoods shape better then others.

if you have a free hanging light bulb the lumins are spread 360 degrees so a hood dosent kill the light it concintrates it.

at this point its a matter of efficancy. and a aircooled reflector is the most efficiant. unless your growing stadium.

http://www.icmag.com/ic/showthread.php?t=51325
you should spend about 15 min atleast reading this thread.

 

[Guest]

There was a very informative post in the CMH thread that contained a link to a study done on aquarium halides. In that study it was displayed how much uv is put out by the respective bulbs. They specifically mention that the glass outer envelope of the bulb blocks most UV. If you research the HQI halides used for aquariums they are sold with very strict statements that a glass sheild is needed to block most of the UV or they can damage eyes and skin. A HQI is essentally just the arc tube of a halide bare. Now I don't know about the rest of ya'll but, blocking uv is the last thing I want.

Also, be carefull to buy a high quality hood that uses high quality simax/broscillite(sp?) which is much clearer and will block less. I have seen Pico's thread and disagree. Glass block a lot of light. Now that I made that statement I will look for all the data I collected a couple of years back and get back to ya'll.

Peace

 

[Guest]

http://www.pegasus-glass.com/simax.asp

Optical transmittance of aroun 90 - 92% in the visible spectrum. That is a 8-10% blockage. Too much for me. I would rather dial in my environmentals and use the CMH bulbs (as I do). This allows 4 - 8" above the canopy!

 

[pico]

Interesting find there azeotrope. Do you happen to know what kind of glass is used in the supersun2 reflectors? Hard for me to believe 10% loss when I have tested for myself only 2-3% loss with the glass used in the supersun 2.

 

[clowntown]

I believe there are other significant factors that lead to light loss on air-cooled reflector designs, besides just the glass:

• Ventilation holes that do not reflect
• Design compromise in low turbulence vs effective light footprint

Can we compare hoods that were designed, ground-up, to be non-aircooled and thus made no such compromises in design? I'm not talking about the open-end bat wings, either.

 

[pico]

Most definitely clowntown. I was talking specifically about the amount of light reduced from the glass. No matter the design the final obstacle is the glass and you could easily tell (as I did) how much light is reflected with the glass and without.

Any non aircooled reflector you had in mind for comparison? I did test the original super sun that has minimal aircooling ports for light leaks. I agree batwing is not testing the cream of the crop, but I had them available.

 

[clowntown]

The one that comes to mind immediately are those PL "bowls". Not that it was likely any scientific design, much more likely a coincidence that cheap manufacturing processes and simplicity can produce high reflectivity designs. Or so I heard (that they reflect well).

Those PL hoods has me thinking now, in hindsight: how does the re-strike bend (the "V" at the top of most hoods) affect reflectivity? Those "bowls" don't have a re-strike bend...

 

[pico]

The PL was the first I thought of as well. Never seen one in person. If I get close enough to one I will grab it and test it.

I think the big attraction to the PL design is for greenhouse lighting. In greenhouses most of the time the lights are used for supplemental lighting so you want a small reflector that doesn't block out light from the sun.

Bell has a non aircooled hood. They just sent me the aircooled model to test out and I am not impressed with the design at all. Still haven't done any testing with the light meter, but it doesn't look like it is going to be that great.

 

[clowntown]

I was skeptical about those Bell hoods, too. I'm really looking forward to seeing those numbers, though, regardless of result!

I've seen those PL hoods in at local hydro shops, but never took them seriously enough to ask the staff to demonstrate. Always thought it was more an existing, low-cost, low-price, high-production product that was marketed into this indoor industry as a well-designed all-around hood. I also caught that "greenhouse application" bit as well...

 

[GreenBush 420]

Does anyone know how much light a DIY bake-a-round air cooled hood might block. I am thinking of making some changes and I don't have a light meter to test the best design that optimizes heat control and light output.

Any ideas on the most efficient designs?

 

[Boxy Brown]

Any non aircooled reflector you had in mind for comparison?

how about the non-aircooled radiant reflector by HrydroFarm, its a very well designed reflector.

 

[Guest]

i would love to see the non cooled daystar, supposed to be there new and best hood.

 

[zoolander]

I heard 15% but find this hard to belive when I drop my light 5 or 6 inches away and run 2 600 hps and get some huge dense buds

 

[HerbMan26]

Bell has a non aircooled hood. They just sent me the aircooled model to test out and I am not impressed with the design at all. Still haven't done any testing with the light meter, but it doesn't look like it is going to be that great.

I'd love to see the results from those Bell LR/MV hoods too, which ones do you have pico LR/MV1000 or LR/MV600?

 

[pico]

1000, i am done testing 600s at this point.

 

[HerbMan26]

I'll be keeping a eye open for those results, Hydrofarm's mondo might also be a good one too.

 

[clowntown]

Where are you getting those numbers from, knna?