400W @ 83F or 600W @ 89F

[ElGrandeMongo]

The heat problem is mostly gone now (it gets up to like 77F now only). I followed DarkWeb advice and moved the exhaust fan to pull. The suggestion could have gone without his sarcasm though, I defintely do not know anything about pneumatics OR hydraulics and thus I definitely DO need to be *spoon fed* as he put it on topics I have never taken a course on in my life.

@Buddernugs who would spend $285USD on ANOTHER light when they've already got a perfectly good 600W HID (and also a 240W LED)? I don't sell this weed I grow, why are peoples advice always to go buy more expensive shit .. or buy 2 of them? You guys are either selling the weed you grow or you don't know what financial responsibilities in life are.

Another thing that came to mind as I thought more on this, I'd put the 200CFM fan exclusively over the light, and the 400CFM as your room exhaust.

 

[guitarguy10]

Another thing that came to mind as I thought more on this, I'd put the 200CFM fan exclusively over the light, and the 400CFM as your room exhaust.

Yeah I've considered flipping them around but honestly the 200CFM creates SIGNIFIGANT negative pressure. It's a 2'x4'x5' so it only has 30cuft to exchange. I'm worried that with 400CFM it would tear seams on the tent, and having the 400CFM on the light means I dont have to run it at full speed (only like 4/10 speed actually), so it's much quieter.

 

[ElGrandeMongo]

Yeah I've considered flipping them around but honestly the 200CFM creates SIGNIFIGANT negative pressure. It's a 2'x4'x5' so it only has 30cuft to exchange. I'm worried that with 400CFM it would tear seams on the tent, and having the 400CFM on the light means I dont have to run it at full speed (only like 4/10 speed actually), so it's much quieter.

Wouldn't it be just as easy to run the 200cfm through the light, and adjust the ac infinity to manage the room as needed? That way if your temps do happen to be up, you have more ability to increase the actual airflow in the room. Also, this has been on my mind so it might be of value to you. Look into bracing the walls of your tent. Have seen it done on here before, where they run an extra crossbar horizontal midway across height of the tent. Would help two ways... first with stress on the tent fabric/seams, and second you regain those few inches of space where the walls shrink in.

Also, not a huge difference in the overall math, but 2x4x5 = 40cu ft

 

[guitarguy10]

Wouldn't it be just as easy to run the 200cfm through the light, and adjust the ac infinity to manage the room as needed? That way if your temps do happen to be up, you have more ability to increase the actual airflow in the room. Also, this has been on my mind so it might be of value to you. Look into bracing the walls of your tent. Have seen it done on here before, where they run an extra crossbar horizontal midway across height of the tent. Would help two ways... first with stress on the tent fabric/seams, and second you regain those few inches of space where the walls shrink in.

Also, not a huge difference in the overall math, but 2x4x5 = 40cu ft

You're right, I can't do simple math!

I sort of have the bracing aspect covered because I built the screen's frame to fit tightly against the poles, but all that stretching and contorting of the tent material has still lead to several pin hole light leaks. It's what you get for buying the cheapest tent you can find I suppose, but it is already inside of a closet, so the exposure to any light is already very low.

I might consider flipping them around next grow, but for now everything seems good leaf temp like 75-80 and when lights go off it only goes about as low as 73, and they are looking good so far at 3 weeks.

 

[DarkWeb]

You don't want a wind tunnel. But a fan controller on the larger fan turned down would be quieter. I don't use a controller so I can't give any first hand experience. Your temps are fine though.

 

[Cvntcrusher]

Whats your intake exhaust situation?

I run
1 365W COB LED
2 105W QBs
2 110W LEDs

I have a 203CFM inline fan mounted on a bucket that I put ice and water in. With ducting for my intake.

And a 4" CF and 203 cfm inline fan for my exhaust.

I run both of the fans at 50% when lights are on.

And my temps never get above 85⁰ in my 4x4. Normal temps are 79⁰ w 40% rh.

Thats 800W of LEDs and I don't break 85⁰ F

What I'm saying is how can we help you improve your intake/exhaust situation so that you can run more power without running high temps

 

[ElGrandeMongo]

You don't want a wind tunnel. But a fan controller on the larger fan turned down would be quieter. I don't use a controller so I can't give any first hand experience. Your temps are fine though.

His AC infinity should have one built in.

You're right, I can't do simple math!

I sort of have the bracing aspect covered because I built the screen's frame to fit tightly against the poles, but all that stretching and contorting of the tent material has still lead to several pin hole light leaks. It's what you get for buying the cheapest tent you can find I suppose, but it is already inside of a closet, so the exposure to any light is already very low.

I might consider flipping them around next grow, but for now everything seems good leaf temp like 75-80 and when lights go off it only goes about as low as 73, and they are looking good so far at 3 weeks.

Those pinhole light leaks were probably present in the tent before negative pressure. They're just cheaply made as you say. My smaller tent has tons of minor pinholes along the seams and no actual exhaust fan pulling out of there. There's no direct sunlight in the room anyway so I don't worry about it. Have doubled up blackout curtains on the window to the room. Would probably apply just the same to you as you're growing in a closet?

 

[evergreengardener]

90 is hot but it's not crazy hot. Is it a consistent 90 or does it fluctuate, like with your house's AC or something?

200W is a lot of light to give up just to save a few degrees of heat.

Not to mention he wouldn’t be switching to a 400w he is just dimming down a bulb which isn’t good for the bulb and messes with the spectrum don’t dim hid lighting

 

[guitarguy10]

I'm not dimming anymore now that I have fixed the temps, I am running the bulb at 600W and getting good temps no higher then 80F leaf temp in the hottest spots. I think 600W is sufficient for 2'x4'.

I'm not talking about the pinhole leaks at the seams and I have noticed new leaks that I'm sure weren't there before. But as I say it's not
that big of a deal since the tent is already in a closet which is only open a crack (well about 6" to allow ducting out) in a bedroom with blackout blinds and often no light on. Although that has recently changed a little as the other side of my closet has become the space for a mother plant, so there is a light right next to the tent and I'm observing closely to make sure there doesnt seem to be any light leaks that are affecting my plant, only time will tell on that though.

@Cvntcrusher I have a passive air intake. I have tried using a 4" inline fan as an active intake and the temps in the tent were much worse then simply to have a passive intake with this diy filter I made to make sure all the air entering the tent is clean. I know this sounds counterintuitive (to me it does at least), but I monitor my tents temp and RH with an arduino through which I can plot in real time those values and turning on the fan temps go up, turning it off they go down, reproducibly. So I took intake fan off and temps are down *shrug*

 

[ElGrandeMongo]

I'm not dimming anymore now that I have fixed the temps, I am running the bulb at 600W and getting good temps no higher then 80F leaf temp in the hottest spots. I think 600W is sufficient for 2'x4'.

I'm not talking about the pinhole leaks at the seams and I have noticed new leaks that I'm sure weren't there before. But as I say it's not
that big of a deal since the tent is already in a closet which is only open a crack (well about 6" to allow ducting out) in a bedroom with blackout blinds and often no light on. Although that has recently changed a little as the other side of my closet has become the space for a mother plant, so there is a light right next to the tent and I'm observing closely to make sure there doesnt seem to be any light leaks that are affecting my plant, only time will tell on that though.

@Cvntcrusher I have a passive air intake. I have tried using a 4" inline fan as an active intake and the temps in the tent were much worse then simply to have a passive intake with this diy filter I made to make sure all the air entering the tent is clean. I know this sounds counterintuitive (to me it does at least), but I monitor my tents temp and RH with an arduino through which I can plot in real time those values and turning on the fan temps go up, turning it off they go down, reproducibly. So I took intake fan off and temps are down *shrug*

600w in a 2x4 is killer. I've done 600w in a 2x4 once. The buds were HUGE. It's 83w/sqft. Pretty extreme so far as lighting goes.