Cab Grow fan cycle problems

[mrfake]

There is simply no way a simple fan could pressurize air in a cabinet. sure you feel air coming through it when its unzipped, but as soon as it closes the blades of the fan stop pushing/pulling air because there's no place to circulate it (granted there will be some air pushed through your zippers and exhaust system even though your exhaust fan wont be running). "Air Compressors" work by using a turbine or a piston/cylinder to cram air into a closed volume, zippers make it unclosed. I probably have a fluid mechanics book around that can tell you rate of loss through a thousand pinholes (zipper) but the pressure difference would be way smaller than just elevation difference between sea level and a mountain. Anywhoo... Even though your climate controller kicks ass i think it complicates shit for you. With your intake fan running full-time and door closed, how hot can you get it in there? If it tops out around 90 then I would run the intake fan as long as the light is on, and just exhaust is for 10 mins every 3-4 hours then give it one last dose of co2 as the lights go off and everything goes to sleep. What kind of co2 system do you have? I assume its a bottle/reg/timer setup in which case use a co2 caluclator to figure out how to bring up the levels to +-1500 after every exhaust cycle.

+1 on taking out those drawers and making a dummy face
+1 on using a 250 watt bulb

 

[munch box]

sorry guys i should have shown you this stuff from the begining i suppose. There is already a dummy door in place of the drawers. That is where i keep my resivoir, passive intake, and my digital ballast. My hydroponic system holds 10gallons. It is the V-drip NFT system. scope the modified version of what i got, except i paid much less money.

 

[daddychrisg]

Here is the kicker....Why is your box getting hot in the first place? THE LIGHT, how do you cool down your box? MORE AIR, keep your fan running. How do you keep your co2 in the box? SEAL YOUR REFLECTOR....Simple equation really...I don't think you will achieve the results that you want with a intake fan with out pushing air out of the box......GL I hope I don't seem to harsh, but it is time to make something happen...Fuck the co2, just get the heat down and give your plants fresh air...I think this would be more beneficial to your plants...

 

[daddychrisg]

Have you seen water cooled reflectors before....Pretty sweet!

 

[munch box]

thats what i am doing.
I am using cold air from outside, and cooling the light down, and on the other end of the ducting i have a 200cfm inline fan pulling air through the reflector. and my room is still too hot.

Try to understand that the reflector IS COMPLETELY SEALED. I don't want to say the bulb is freezing cold but everything around it is. the hood, ducting, and probly the reflector too. I don't mean to sound harsh but you need to pay closer attention to whats going on here. The only heat that is coming from inside the box is coming from the pyrex glass beneath the bulb. The glass is completely air tight, Perhaps i need thicker pyrex glass so heat can not penetrate. I have a good reflector, one of the better models look here High Tech Garden Supply

 

[blonddie07]

What is your room temp?? if inside your house is 80... im pretty sure its ganna be 80+ in ur grow cab...

 

[daddychrisg]

What?First you say...
I don't want to say the bulb is freezing cold but everything around it is. the hood, ducting, and probly the reflector too.
Then you say...
The only heat that is coming from inside the box is coming from the pyrex glass beneath the bulb
Two different scenario's you just painted.
Cool the glass by running more air through your reflector...That is the point of an air cooled reflector...To cool off the glass.....More air! I am glad you have a quality reflector to begin with, so use it for what it is made to help you achieve..Cooler temps. If you can't understand this theory, I have nothing more to add on the subject with out getting frustrated with you, LOL.

 

[munch box]

Heat penetrates where air cannot. So when i say air proof, I don't mean heat proof. The temp. of the air before it hits the light is between 36 and 50 degrees F. It travels less than 6 ft., 200 cfm exhaust fan. When the air exits the light, the temp is never over 75. I try to keep my bedroom at 75 as well.

 

[daddychrisg]

More air.....= lower temps on your glass.....
if you don't have your exhaust fan running, it will be very hot, right?

Keep your fan running the entire time you have your light on, and with a powered intake fan, blow fresh air into your grow box...DONE
-OR-
keep doing what you are doing....gl

 

[mrfake]

even if you had a million cfm's going through that light the box would still heat up (but less so). When the light energy (radiation) hits matter it ABSORBS the light energy and converts it to THERMAL energy. While the walls (assuming mylar) wont heat up from light, because its 99% reflective, the plants/cords/pots sure as shit will, then after the radiation excites the plant/pot matter it transfers energy this new found kinetic energy (motion of particles) to the air which in turn transfers it to everything. Think of sitting in the sun, there's no way you are feeling the heat of the sun.. just feeling its radiation.

My point standing is using co2 allows plants to thrive in higher temps than without
it.. If the system balances at sub 90 with the intake and lights on full time then fill the bitch with co2 after every exhaust cycle and let her roll. If it likes to balance warmer than that then you have an overall losing battle with the system; so change the bulb, think about cfl's, or stop growing pot and start popping pills. The first AC was a fan blowing on ice to cool a church. Shit.. put a fan over a bowl of ice water next to your intake fan intake for all i care.

 

[munch box]

the system seems to max out at 87 up above the light. below the light maxes out at 95. At the end of a fan cycle, It takes 50 mins. time to peak at 95F, then the exhaust fan comes on w/ carbon filter. FYI i also have a carbon filter on my intake fan. Seems to eliminate smells from my res. as well as keep my feeding water temps. cool, my ballast too. I need to know how much co2 is being pushed from my cab through the zipper, how frequent should I begin to cycle my co2 during the 50 min. fan off time window. Also at what time, and how much co2 loss/consumption. I set my flowmeter normally at 0.5cfm

 

[daddychrisg]

permalink
even if you had a million cfm's going through that light the box would still heat up (but less so). When the light energy (radiation) hits matter it ABSORBS the light energy and converts it to THERMAL energy. While the walls (assuming mylar) wont heat up from light, because its 99% reflective, the plants/cords/pots sure as shit will, then after the radiation excites the plant/pot matter it transfers energy this new found kinetic energy (motion of particles) to the air which in turn transfers it to everything. Think of sitting in the sun, there's no way you are feeling the heat of the sun.. just feeling its radiation.

Seems to me your theory has a problem....if cold air is running in between the bulb and the glass of the reflector, then the heat will be eliminated for the most part. If you stood in a glass box with an air conditioner unit blowing air in, and a exhaust port, would you feel heat....I don't think so..You will get a tan from the radiation, but you would not feel the heat.
Stop trying to blow air into a sealed box to cool it off...That won't work will it...you have tried this already....Try something new...keep you exhaust fan on the entire time that your light is on and maybe...just maybe your temps will be lower...As I suggested before and how MRFAKE also recommended, put a chunk of ice in the box...it will help...have you thought of trying co2 with dry ice? There is a good section on the DIY.

 

[munch box]

Ok so i was thinking what if instead of using an intake fan, what if i used my portable a/c unit? My only concern would be that it pulls 960 watts! But if its what i gotta do to keep my babies happy, then 8000 btu's is what my baby gets. I will probly go with an adapter piece from home depot that fits nicely over top the vent, then I will stick my ducting strait into the ass end of Katie Holmes grow cab. What do you think?

 

[daddychrisg]

I think it will work...but a simpler method would be to run your exhaust fan while the light is on...

 

[munch box]

With the exhaust fan running full time the temp inside will only go down to a consistant 80F above the light and 82F below the light at most, too hot for no co2, plus the plants flourish more with co2, more forgiving to temp. changes, soil conditions, etc.

 

[daddychrisg]

Tell me this....is your reflector air tight? You have answered yes to this already so I hope your answer is still the same now...82deg with co2 sounds great to me....

 

[munch box]

the only problem is with an EXHAUST FAN and CO2 running at the same time, there is no co2 in the grow cab, the EXHAUST FAN is pushing it all out into my bedroom, and i don't want to breathe that co2 in. Yes my reflector is 100% air-tight thats the whole idea.

 

[daddychrisg]

Wait a sec man, this equation is not adding up...If you have air being pulled through a carbon filter, through your air tight reflector, then out your fan into your room...Then how are you loosing co2 into your room?

 

[munch box]

I do not know how to put it in any simpler terms than i already have, Its almost like your repeating what i say in the form of a question. Thankyou for your input, but I am in search of somebody who knows the answer to the ULTIMATE question...

 

[pandabear]

I do not know how to put it in any simpler terms than i already have, Its almost like your repeating what i say in the form of a question. Thankyou for your input, but I am in search of somebody who knows the answer to the ULTIMATE question...

the Ultimate question?

You mean the meaning of life?

well i know the answer to that question.

It is impossible to have nothing, there is no such thing as nothing, so therefore there is always "somthing" and you dont have to worry about who created it cuz it was always there.



oooooo you mean for your grow cab!

dude i think 95F with C02 is ok for your plants, im actually pretty shure you will be ok with temps ar 95f try it out and unless the plants tell you different you should be ok.