Uh...it was just 90 degrees in there...

Dankyspank2456 said:
Gunna give it a shot! 1000w are soo much better than the 600w. Easy tell since theyre side by side. Thanks for the advice!
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Your very welcome man. Sometimes it's the littlest things that we miss. Good luck!

Bigworm4201982 said:
Never would have thought about that, thank you.
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That's one of the great things about this site. Once you learn to differentiate good advice from bad there is lots of great info here and some very helpful knowledgable growers.
 
Thundercat said:
I get what your saying for sure. True 400w of Led is very different then a 400w hps. I would not even think about trying to flower a 4x4 with 400w of HPS. When I eventually switch to LED it will be for more even coverage. I have no intention of lowering the amount of watts I run, but I love the idea of more evenly spreading them over my plants, eventually including side lights. And hell if I want to dim them down I always can .

The comment that I said was bad advice had stated that the OPs wattage was too high for a 4x8 and he should switch to 400w lights. That's crazy, I would much rather see him fix the heat issue and switch to both 1k lights he wanted to run in the first place.
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Yeah, I wouldn't recommend using 12.5W/sqft of PAR. You'll get good results (I used it for a while), but I think the sweet spot is closer to 18-20W/sqft PAR when balancing good use of space vs photosynthetic efficiency. Anything higher is probably overkill. If you had a micro grow and keep plant height below 2ft, then over 12.5W/sqft might be overkill.
 
Kingrow1 said:
Simply because the leaf is as hot with glass as without due to light hitting it.

Im not trying to cool a bulb that burns at hundreds of degrees wirh a fqn, that would be dumb, maybe explode if you actually managed it :-)
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The air cooled hood may not remove the radiation based heat, however it will drastically reduce the amount I convection heat transferred into the room.
I use a fan at canopy level to keep leaf temps happy through evaporative cooling. Which helps convert that radiation heat into convection heat that is then vented out of my room.... So once again the air cooled hood reduces my overall temps in the room. Thanks for playing but I understand the science just fine. You clearly don't for as much talking about it as you try to do.
 
churchhaze said:
Yeah, I wouldn't recommend using 12.5W/sqft of PAR. You'll get good results (I used it for a while), but I think the sweet spot is closer to 18-20W/sqft PAR when balancing good use of space vs photosynthetic efficiency. Anything higher is probably overkill. If you had a micro grow and keep plant height below 2ft, then over 12.5W/sqft might be overkill.
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I don't honestly know the PaR or ppfd of my Hps. I don't know I currently have 62.5w/sqft and I love the growth and quality of my plants. I would be very happy if I could spread 50w/sqft more evenly over my garden. So that will be my goal with LED. I want to be able to put a proper 1200+ ppfd on my plants just like the sun!
 
Thundercat said:
The air cooled hood may not remove the radiation based heat, however it will drastically reduce the amount I convection heat transferred into the room.
I use a fan at canopy level to keep leaf temps happy through evaporative cooling. Which helps convert that radiation heat into convection heat that is then vented out of my room.... So once again the air cooled hood reduces my overall temps in the room. Thanks for playing but I understand the science just fine. You clearly don't for as much talking about it as you try to do.
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Well your getting somewhere now but why couldnt you remove that convective heat from the tent with the same cfm fan you would attatch to a air cooled hood?

No scientific principle changes - theres still the same amount of heat for the same amount of cfm fan draw.

This is the sort of coversation that dosent happen enough with you guys and you see where you bend the numbers to suit your opinion.

:-)
 
Thundercat said:
I don't honestly know the PaR or ppfd of my Hps. I don't know I currently have 62.5w/sqft and I love the growth and quality of my plants. I would be very happy if I could spread 50w/sqft more evenly over my garden. So that will be my goal with LED. I want to be able to put a proper 1200+ ppfd on my plants just like the sun!
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Just estimate. If you assume efficiency is 38% (38W of PAR for every 100W of electricity) then 62.5W/sqft * 0.38 = 23.75W/sqft of PAR.

It's good for making rough estimates of how much power you will need for any lamp where you have a decent estimate of its efficiency. For example, if you wanted the same estimated 23.75W/sqft of PAR with a lamp that's 50% efficient, you'd shoot for 47.5W/sqft of power usage. (23.75W / 0.5 = 47.5W)
 
https://www.rollitup.org/t/nizzas-3x-15-gallon-feminized-big-bud-vision-seed-grow.773447/page-3
check out this set up from when i was younger
2.5ft by 5 ft
400w hps on a mover with 2 dual bulb 4 ft t5 and 2 dual bulb 2 ft t5
not saying 400 w is what u need for a 4x4 just saying its the minimum.. that hps is literally a few inches from the plants but on a mover. later the mover breaks and i think i had 8-10 inches away. just trying to give an example of how you dont need a cool tube and a ton of wattage to get good results!
i would shoot for 600w hid per 4x4 area also keep in mind that height of your grow effects amount of light needed not just length times width

gl OP i hope u figure out how to solve this heat issue without wasting $$
 
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Kingrow1 said:
This just comes from basic first grade science on the bqsic laws of thermodynamics and already someone else has corrected you on the radiation loss of glass so in future please steer well clear of trying to correct me.

Futher to the problem you didnt help, better growers can see the fundamentals before talkkng bro science on air cooled reflectors or assuming everyone needs an ac.

Still he can reduce more if we have some real discussion on that thermometer placement imo...

Youmight think i talk shit when really its your lack of education, keep trying to troll me and you will come off worse by a long shot, use open discussion and you might do a whole lot better :-)
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Where do you put your hygrometer? should mention the low pros cover the VAST MAJORITY of ceiling space in the 4x8 so theres not a place in sight that is not getting some direct light
 
Kingrow1 said:
And just to clarify for those air cooled reflectors dont make any difference to the heat radiation the plant feels so technically do not cool anything.

#barebulbclub :-)
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The vented air removes the convection heat (some) which is a portion of the heat produced by the light so it certainly does help the room temp. Lowering the room temp helps cool the leaves so vented hoods do help with overall room control. Air movement across the canopy helps control radiant heat on the plant surface so it’s a win. I use regular winged reflectors with duct takeoffs built in, they pull convection heat with no reduction in light.
 
Dankyspank2456 said:
Where do you put your hygrometer? should mention the low pros cover the VAST MAJORITY of ceiling space in the 4x8 so theres not a place in sight that is not getting some direct light
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An inherent problem of small enclosed highly reflective spaces lit by a few hundred Watts.

Why wouldnt your tent be pretty xlosecto the intake air? Scientifically speaking if we work out the area and the fan cfm im pretty sure theres not a hell of a difference as the air rushes from your room into your tent and back out in a mere three or so seconds.....
 
Dankyspank2456 said:
So upon waking n checking the temps, the room was up to 90 degrees. Adding a window ac is preffered but out oc the question. simply dont have the space for it.what are some affordable and *efficient* solutions to drop temps ~ 10/13 degrees? Seems alot of people run mini dual hose acs, but those need to be filtered/exhausted. Can you not just lay the exhaust next to the rooms exhaust carbon filter? It runs 24/7.. or does it needs its own separate exhaust?
Lights - air cooled - 1 1000hps, 1 600hps
4x8 tent. Minimum space available... expert opinions greatly appriciated
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lol 32 in nothing they will love it what u run them at when doing co2
 
Budley Doright said:
The vented air removes the convection heat (some) which is a portion of the heat produced by the light so it certainly does help the room temp. Lowering the room temp helps cool the leaves so vented hoods do help with overall room control. Air movement across the canopy helps control radiant heat on the plant surface so it’s a win. I use regular winged reflectors with duct takeoffs built in, they pull convection heat with no reduction in light.
Click to expand...

Im not sure you understand convection as thundercat didnt understand radiatio.... anyone for a pop at conduction next?

The convection from my bulb dont make it far, ehy i have a fan. I could ask by what convection current im heating my leaves but im gona leave you scratching at how us barebulbers do it where you cant quite obviously.

#barebulb420
 
if my mate can grow in a shed in summer in aus with no cooling but inlines and still get a pound u can to was ther yesterday 44.3 in his shed so thats bout 111-112 f use so need the metric system gallons and pounds thats 18th century stuff
 
Dankyspank2456 said:
Whats the difference in set up between a portable ac and swamp cooler?

Its pulling air.. It pulls from just outside the tent inline with the lights, through both lights, through about 6 ft of insulated ducting, (fan), 3 ft ducting, into the next room. The room exhaust is just below the lights...the lo pros are SOOO big, theres no other option.. they throw a ton of light everywhere... highly recomended in THAT regard..
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Many differences between them, including her the author works and how they cool the space.

It would be better for you to investigate these differences yourself than for me to just hand you answers, so that you get a firm grasp of the underlying concepts. Each has their advantages, depending on the situation.
 
Kingrow1 said:
Im not sure you understand convection as thundercat didnt understand radiatio.... anyone for a pop at conduction next?

The convection from my bulb dont make it far, ehy i have a fan. I could ask by what convection current im heating my leaves but im gona leave you scratching at how us barebulbers do it where you cant quite obviously.

#barebulb420
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Lol your fooling yourself if you don't think I understand the science. I've understood the science for years. I've grown bare bulb, and with air cooled reflectors. There is nothing to discuss, air cooled hoods help control and remove heat. I'm sorry that you don't appreciate the benefit, and you certainly can grow without them.

I only have one exhaust fan for my room and it's hooked to my light and carbon filter it works wonders. Typically my temps stay between 75-79.
 
Kingrow1 said:
Im not sure you understand convection as thundercat didnt understand radiatio.... anyone for a pop at conduction next?

The convection from my bulb dont make it far, ehy i have a fan. I could ask by what convection current im heating my leaves but im gona leave you scratching at how us barebulbers do it where you cant quite obviously.

#barebulb420
Click to expand...
It’s all energy and it’s all btu’s, or what ever measurement you want to use. I’m not sure what your arguing about but perhaps you could enlighten me, always willing to learn ;). Tell me about conduction, I’m sure we could have a great discussion on that, I design ground loops for geothermal systems lol.
 
Thundercat said:
Lol your fooling yourself if you don't think I understand the science. I've understood the science for years. I've grown bare bulb, and with air cooled reflectors. There is nothing to discuss, air cooled hoods help control and remove heat. I'm sorry that you don't appreciate the benefit, and you certainly can grow without them.

I only have one exhaust fan for my room and it's hooked to my light and carbon filter it works wonders. Typically my temps stay between 75-79.
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Very few actually know the science or you wouldnt struggle with quantifying heat on this board.

I have no more really to add, the science is there just you keep telling me they work and give no basis.

How much will a cooltube cool an already vented room? Lets talk about that convection properly please not just statements based on some assumption - i too have used both barebulb and cool shade and found that they adhere to scientific principle like ive explained.

Convection.... over to you :-)
 
Budley Doright said:
It’s all energy and it’s all btu’s, or what ever measurement you want to use. I’m not sure what your arguing about but perhaps you could enlighten me, always willing to learn ;). Tell me about conduction, I’m sure we could have a great discussion on that, I design ground loops for geothermal systems lol.
Click to expand...

You aint got to put your loop far if you have a volcano thesedays, crazy icelandics :-)
 
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