Temperature Problems in Rubbermaid Grow Box

Hello All, I am new to this forum and forums in general! So an mistakes I make I apologize for them. Here Is my issue and I hope someone out there has the answer. I have created a grow box out of 2 30 gallon rubbermaid tubs I lined it with tin foil (yes I know bad idea, I am going to Spray paint it flat white as soon as I trouble shoot this heat issue.) I am using CFL's I have 6 100watters rated at 23 watts per bulb for one plant. I have a three socket light fixture hanging by chains and split each socket with "Y" Splitters. Also I have Two 3" computer fans rated each at 33 CFM for exhaust fans at the top right side of the top tub and i have drilled 2 2" passive intakes on the left bottom side of the bottom tube. I also have a desk fan blowing into the passive intakes. I also have a small vertical oscillating desk fan inside the box for "Wind." The temperature in the closet i have the box in stays around 75 steady RH20% I have sealed off the window in the room cause it's also a control room for a recording studio for acoustical purposes. The Temperature in the box stays between 85 and 95 degrees and a RH at a steady 20% and that is far too hot!! With the lights off it gets down too 75 This is where i need help I cant get the temperatures any lower in that box with the lights on! Any Ideas how to solve my temperature problem?? I already have a girl growing in there for about 5 day. She seems to be doing really good right now, shes not gonna be very good to me if i dont give her some good temps soon. HELP!! Thanx Guys!!! I'll post some pics ASAP of my setup as well! and my baby girl! (I hope)

Ditch the foil. Even if you don't paint it yet. It isn't reflecting anything but heat. The computer fans should be ok for that size container. But then again 3 inch is pretty small. You are positive they are blowing out instead of in?

Thanx for the reply, thats what I figured the foil would do since it is meant for "Cooking." I will ditch the foil. The fans are blowing out. I can feel a nice breeze of hot are pumping out of them. Should i put more fans?

metalgodusa said:

Thanx for the reply, thats what I figured the foil would do since it is meant for "Cooking." I will ditch the foil. The fans are blowing out. I can feel a nice breeze of hot are pumping out of them. Should i put more fans?

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you dont need any more fans, i've seen setups like your describing have no problem at all with two 3'' comp fans. the trick is to make sure you have a real good seal on your lids and where the top tote sits on the bottom tote.
but honestly, if your plant is not showing any heat stress, then dont worry about it, besides, 90 degrees is not really that bad, i've grown plants indoors in 105 degrees. some plants are more tolerant than others.
have fun with it though

paint the wall of the tub flat white, what type of power supply are running your fans? might have to step up the power to the fans a little more volts or more amprige. i am using a 18 volt for 2 5 inch comp fans and they hummmmmm, doesnt hurt them and they move some air.

otwa2002 said:

paint the wall of the tub flat white, what type of power supply are running your fans? might have to step up the power to the fans a little more volts or more amprige. i am using a 18 volt for 2 5 inch comp fans and they hummmmmm, doesnt hurt them and they move some air.

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Yeah, I ditched the foil and painted the inside all flat white, it acctually reduced the temp. by 5 degrees. I have learned tin foil is baaaad. Glows like a huge blue christmas bulb, but thats ok, us Card holders dont mind! I just got some random 12v AC to DC power supplys that would work with these fans. I wasnt aware that the more voltage would move these babies, im not that electrition savvy. I will Check it out when i get home.

How did your grow go in those temps work out, do you have any pix of the final product im curious to see. I concurr on the air tightness around the tub any innovetive Ideas that may work to make some sort of gasket around the tub? I will have pix of my setup as soon as I get a camera.

metalgodusa said:

How did your grow go in those temps work out, do you have any pix of the final product im curious to see. I concurr on the air tightness around the tub any innovetive Ideas that may work to make some sort of gasket around the tub? I will have pix of my setup as soon as I get a camera.

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https://www.rollitup.org/harvesting-curing/159974-orange-crush-51-days-flowering-3.html that grow was actually my first and best, we still have some nice nuggets from that one plant, we never really worried about temps or humidity, never checked ph. it was always over 100 with the lights on, and the plant seemed to love it.
glue the top tote on to the bottom tote's lid, i used liquid nail. for the lids, i used weather strip on the bottom of the lid and bungee straps to hold them down tight

Pretty much all aluminum reflectors are better are reflecting IR light(heat) than visible light, and they do even more poorly at UV light than either! But hey, you can still use aluminum foil to get a more even sun tan(you get a tan based on UV light).

You don't have tin foil. You don't live in the early 1900's.
It's aluminum. It's a thicker layer of aluminum than on the surfaces of aluminized Mylar, and is used in numerous... nay countless applications.

Even though many metals have a high solar reflectance, if emissivity is low the material will not reject heat effectively. For example, polished aluminum foil has a very high solar reflectance, but its emissivity is low, so it retains heat. Note its placement in the lower portion of the graph. The best performing materials for cooling load reduction, which have both high albedo and high emissivity, are in the upper left-hand section.

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What they seem to fail to mention is the absorption of aluminum is minimally 3%. Whoops. At best the emission is equal to what it absorbs. Cool. No heat is retained. And lower quality aluminum surfaces will absorb around 10-15% of the light. Still better than white paint(20% absorption).

According to this chart aluminum foil is 85-97% solar reflective, according to my eyes. White paint is 80%. BTW, a higher IR emissivity means it will not hold onto heat! Also, the hotter an object, the more reflectance produced.

TeaTreeOil said:

Pretty much all aluminum reflectors are better are reflecting IR light(heat) than visible light, and they do even more poorly at UV light than either! But hey, you can still use aluminum foil to get a more even sun tan(you get a tan based on UV light).

You don't have tin foil. You don't live in the early 1900's.
It's aluminum. It's a thicker layer of aluminum than on the surfaces of aluminized Mylar, and is used in numerous... nay countless applications.

What they seem to fail to mention is the absorption of aluminum is minimally 3%. Whoops. At best the emission is equal to what it absorbs. Cool. No heat is retained. And lower quality aluminum surfaces will absorb around 10-15% of the light. Still better than white paint(20% absorption).

According to this chart aluminum foil is 85-97% solar reflective, according to my eyes. White paint is 80%. BTW, a higher IR emissivity means it will not hold onto heat! Also, the hotter an object, the more reflectance produced.

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So are you saying that I should be using Aluminum Foil? Should I be using some sort of DIY Reflector with CFL's?

i use windsheuld reflectors and they work perfect
i also just use 1 30g rubbermaid stood up on handle sides
i cut whole at bottom for fan blowing in and up
i use heat lamp fixtures tht clamp on another whole on top
and like aero dynamics at te bottom inside u feel coll air comong from bottom an on top u can feel hot air blowin ou....
kudos to
DIY rubbermaid grow box :youtube

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