Question on removing glass from air cooled hoods

motoracer110

Well-Known Member
i have grown many many years with are cooled hoods and am wanting to make a Chang but would like some thoughts.

My grow is in a bedroom with 2 1000w air cooled hoods that vent outside. I keep the room at a negative pressure so no bad air can escape into the house and am not able to add a separate ac system. The room stays about 79-81 lights on and 67 lights out. I'm wanting to take off the glass on both hoods and have a each hood have a dedicated intake that pulls air up around the bulb and exhausts out of the room. Do you think this will keep temps low enough and do you think it's worth it to get the extra output from the lights?
 

Owly

Member
It's hard to say exactly how things will change, but it's easy to test. Temp will definitely go up, but maybe manageable.
 

chea.pet

Active Member
Temps will go up about ten degrees. I run open hoods have for five cycles now. You can increase fans, and lower canopy to compensate. Also increased watering will insure plants can take increased heat. Your yield will increase..
 

chemphlegm

Well-Known Member
my temps didnt change. I have an ac unit. my costs went down. I used to vent through the hoods, nd use an ac unit. then removed the glass and sealed the room with c02 no outdoor exchange. never looked back sorta..... i do now regret paying for fancy hoods, knowing the wings or bare bulbe are fantastic
 

chea.pet

Active Member
Bat wings and base bulbs are the best, and I split rooms each has a mini split ac.ac is important each room has aco2 burner. Best yields
 

Owly

Member
Bat wings and base bulbs are the best, and I split rooms each has a mini split ac.ac is important each room has a co2 burner. Best yields

Bat wings are the best? I take it you haven't tried vertical bare bulb yet... but that probably gives the worst gram per lobar hour numbers.
 

chea.pet

Active Member
Bat wings are the best? I take it you haven't tried vertical bare bulb yet... but that probably gives the worst gram per lobar hour numbers.
I have a space in mind to run vortical j just have not had the time to set up yet. With three grows running is hard to find the time,lol
 

Roger A. Shrubber

Well-Known Member
i had a large hood with a 400 watt hps in a tent it barely fit in. i had plenty of vertical room, but it had just a couple of inches between the hood and the tent all the way around. i tried it with the glass out and temps went up about ten points, from around 78 to about 87-88 F., and after a month i didn't really notice a lot of difference in growth. i put the glass back in and turned the fan back down slightly, it got quieter, cooler, and growth seemed the same to me
 

chemphlegm

Well-Known Member
i had a large hood with a 400 watt hps in a tent it barely fit in. i had plenty of vertical room, but it had just a couple of inches between the hood and the tent all the way around. i tried it with the glass out and temps went up about ten points, from around 78 to about 87-88 F., and after a month i didn't really notice a lot of difference in growth. i put the glass back in and turned the fan back down slightly, it got quieter, cooler, and growth seemed the same to me
add c02 to those raised temps and you would
 

Owly

Member
i had a large hood with a 400 watt hps in a tent it barely fit in. i had plenty of vertical room, but it had just a couple of inches between the hood and the tent all the way around. i tried it with the glass out and temps went up about ten points, from around 78 to about 87-88 F., and after a month i didn't really notice a lot of difference in growth. i put the glass back in and turned the fan back down slightly, it got quieter, cooler, and growth seemed the same to me
Lot of factors playing into that. The glass free advantage is pretty slim, like 5% yield boost or something (unless you don't clean your glass). But changing the temp changes lots of things.
At 88F you should be shooting for 75-85% relative humidity, where as at 78 you want more like 65-80%.
 

Roger A. Shrubber

Well-Known Member
it was an experiment, i wasn't sure what kind of an effect it would have, i didn't really expect anything, i was seeing what would happen
 
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