To cool, or not to cool?

So I have this dilemma, but first, let me explain my "op".

A rubbermaid tub, its about 17 inches wide, 27 inches long, and vertical room isnt an issue as I'm planning on stacking them. It's lined with Reflectix.

I have a sheet of plexiglass a couple inches from the top, with 9 cfl's directly above it. I have an extra 3 cfl's I planned on putting in as well for a total of just under 300 watts mixed spectrum. I bought the plexiglass hoping the heat from the bulbs wouldnt travel to the lower part of the tub.

The top portion has a 50cfm bathroom fan exhausting air from the cfl's, it helps.
The bottom portion has an 8in. intake in one of the walls, the opposite wall has a same size passive exhaust. I tried it with a passive intake and active exhaust, and it was counterproductive as it increased the temperatures.

I also have 4inch ducting coming into the bottom of the tub directly from the houses AC. However, the ac isnt always on. My mother is very nitpicky about the bills she pays, so she tries to use the ac as little as possible. I have no control over it, therefor I can't use it 24/7 to cool my little tubbie. It's on for maybe 4-6 hours a day.

Outdoor temps are around 100~ in this part of cali, my room being 85~. However, with 9 cfl's the temperature of the tub get's to around 93. This is why I'm hesitant on adding more lighting. When the ac kicks in, it cools down to about 77-79 in the tub, but thats only for a select few hours of the day.

Would it be beneficial for me to keep the ac line in, or would the constant ups and downs of the temperature stress the plant to the point were i'd be better off just keeping the tub at 93 or so the entire day.

I need advice, and you guys here are all knowingggg! Thanks for your time, help is appreciated =]

p.s. I'd like to add, without the plexiglass, it was a 109 degrees inside the tub. oi vey.

that just sounds like a shitty situation in general, i say add more exhaust fans to take the hot air out. The changing temps will stress your plant ALOT, and keeping it at 93F will be almost as bad

Zarezhu said:

The bottom portion has an 8in. intake in one of the walls, the opposite wall has a same size passive exhaust.

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umm no offense, but how are you gonna make one of the holes a "passive exhaust" ? I dont think I have ever heard of that before.. A passive INTAKE yes, but passive exhaust? Thats a new one on me. Are you just going to blow air in w/ a fan and have it jsut blow out of the exhaust on its own? Thats the worst way to cool your cab imho.. One active exhaust w/ good fan at the top paired with 1 or 2 passive exhaust holes at the bottom is the best way to keep your cab cool.. Also, your cab can be TOO SMALL ( not saying your is, im just saying in general ) and will not go below a certain temp regardless of what type of ventillation you have.

Well you're right about the passive exhaust thing. I have the intake goin pretty hard, and it blows pretty hard outa the exhaust. I had the exhaust fan up top and active intakes on the bottom, but it kept the temperature a good 3 or 4 degrees higher than if i just had the active intake and "passive exhaust". I've tried quite a few different setups, and this one has been the coolest at 93 degrees.

However, I was also considering frozen gallons of water. I tried it with my previous grow and it dropped temps from 95 to 85 for about 4 hours (a 2 liter bottle), so I'm thinking if I rotate out frozen gallons of water, I can keep temperatures manageable until winter comes around and it's not a good 110 degrees outdoors.

Any other opinions?

What about lowering the ambient temps of the room? ..Do you have a window AC or Central AC ?

I suggest moving your fan back to the exhaust position, and increasing the size of your passive intakes. Also, if you can, make another small intake at the top, on the opposite side to your extraction, since this will pull fresh air straight across your bulbs.

Well the central ac I have ducted, and when it's on it drops down to around 79ish. But it's on and off when my mom chooses. I've been considering buying a window ac, but that's a good hundred or two that I still have to think about before I invest into.

The bulbs are already shielded from the bottom with a sheet of plexiglass and have an exhaust fan taking air straight off of them.

When I had an extra exhaust on the bottom, the passive intake was nearly have a wall of the tub, I'm not sure I can cut away more without losing too much light.

I think the best bet would be a window AC, but is it worth it? It's only another 2 months until winter, what do you guys think

I see your going to have a lot of problems if you don't have a way to cool off the bulbs. and honestly in my opinion that's too small of space too grow in. If i was a plant in that amount of space i would be cramped.

Well I could fit four plants in no problem I know that for sure. It's got like 4x the space of the PC grows I've been reading through.
I think I'll try the frozen gallon of water method and let you guys know how that works, and worst case scenario, I'm off to buy a window ac.
Unless someone has something innovative that I might have completely overlooked? I could take pictures if need be.

How close are your intake and outtake to each other? Are you just circulating the same air? Also, where is your light's air being vented to?

Pics would probably help, if you can get them.

Zarezhu said:

But it's on and off when my mom chooses.

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dammit.. I thought you had your own place.. I do not condone growing weed in your parents house..

Grow up, Move Out, Grow Weed.. In that order

Intake and outtake are on completely opposite sides, and It circulates the air that's through my room I suppose, with a window open occasionally and whatever comes through the ac ducts.

420oldschool. I appreciate your concern, but I have a point to make. I'm a 20 year old about to finish my fourth year at a prestigious college, going to school full time, and working full time. I'm also legal under California's prop 215, and my parents are aware of this as well as my growing. And as soon as I finish my schooling, I do intent to move out, however, I don't believe the whole "growing up" point you're trying to make it necessary.
Thank you for your concern however, have a nice evening.

you know how many kids say the same thing?

GL

I understand, it's cool. I'd maybe be acting impolite too if I was in your shoes.

No more off topic pleaseee, it's a downer.

Just took a glimpse of the seedlings though and they're pretty uplifting <3