Air cooled hood question

I have read that the glass can block up to 10,000 lumens and UV light. If you're just running the single light you may want to try with the glass removed eventually. The light runs slightly hotter like that but it will still draw lots of air across the bulb with the glass out the bottom.

Vented hoods also require less light distance. You'll be able to get the light closer to the plants then with an open reflector. That's one reason you mostly see big open reflectors in commercial or large room grows. They have more headroom for open reflectors to spread the light footprint more.

 

1000 watt hps is 140,000 lumens. You're not going to notice the 10,000 the glass is blocking with your naked eye or the UV that it's blocking. That doesn't mean it's a myth. Ed Rosenthal wrote about it extensively in his growers handbook. He and others also discussed the importance of UVB radiation to potency of final product. There's been scientific papers written on this. It's a fact UVB increases resin production. You only really want to add it for the last 3 weeks or so of flowering.

Just passing on advise that might help you grow better bud if you want to try it. I noticed you had no replies. Thought I'd throw 2 cents.

The glass on the hood most certainly blocks all the UVB radiation from the light. Do UV Sun Rays Go Through Windows?
" Normal glass blocks all of UVB but allows UVA to come through."

My buddy just replaced both of his 1000watt hoods with sunsystem vented hoods like yours with glass in the bottom. He bought a light meter at the same time and the vented hoods have better spread than the cheap gull wing he was using. He's also able to get higher lumen output to hit the plants since he can get the light much closer. He has intake air coming from his crawlspace and the exhaust dumps in the attic. He almost can't keep his room warm enough now since it's winter. The vented hoods made a huge difference. He's running UVB bulbs on the sides of his reflectors so no need to remove the glass. Cannabis

 

It's a trade off. Better spread, bigger footprint with a large umbrella type reflector, more light output per light, huge heat problems, large light distance requirements.

Vented hoods smaller light footprint, smaller light distance, 50% less heat in the room.

I've been helping a dude plan a large scale 40' container grow room. There's stats out there for how many btu's it takes to cool vented hoods and open reflector hoods. A rule of thumb air conditioning requirement for a 1000 watt hps vented hood is 4,000 btu's of cooling power. The same light with a large umbrella open reflector requires 6,000 btu's to cool. 50% more cooling power.

The vented hood only roughly has a 4x4' footprint though and the open hood can be stretched to 5x5 or 6x6 with a large reflector. This allows you to run less lights in large scale grow spaces. That's another reason you see them in large commercial grows. If you're able to run 9 lights instead of 12 or 14 with open reflectors the vented aren't saving you much. In small scale tent grows with no ac vented is generally the only way to go because heat is such an issue.

 

@realdealz28 - I run the same type and with a good fan can have them a foot away from my flowers with a 1000w HPS

I run 2 of the 1,000w lights daisy chained together with flexible vent and stay reasonably cool except for 100 degree days.

Bottom line is that they do work very good. I do not have any issue with the glass blocking light.

J

 

I switched from an open hood 400watt to the first pic you posted and went to 1000watts my temps dropped 13 degrees from a 400watt open to a 1000watt tube

 

My flower room is a small spare bedroom at the far end of the house so noise isn't really an issue so I've only got the single wall vent - not insulated. I do keep 2 quilts tacked up covering the door from the inside so that muffles things pretty good.

@Freedom1 is absolutely correct and you'll really enjoy the airflow through the hoods keeping things nice and cool.

J