First microgrow, temp problem

[MrZ!!]

My first post
I just built my first micro. Its just 100 w cfl but temp keep rising towards 32 C. The cabinet is about 1,5 sqft and 2 ft high and made of 2 mm plastic. On top there is a 120 mm exhaust with a 140 cfm fan conected to a kitchenfan carbon filter 120x120x40mm. Active intake with 80 mm fan. Cant really say I feel a lot of air through the filter but there is some. Tried making more intake holes but they blew air rather than sucked. What to do? I want more lights for my silver bullit auto:-(
Any help appreciated.

Z

 

[MrZ!!]

Without filter it keep temp at 29 even at lowest fan speed. Guess I need an easy permeable filter. How thick must the carbon layer be to be effective?

Z

 

[Aotf]

I would say that your fan has no static pressure and can't push much if obstructed. Pretty common even with a 140cm fan.

This was one reason I started going to mini blowers as my exhaust. They don't have the cfm of a computer fan, but if the blower is capable of venting your space every five minutes, its good to go and they push much more pressure than just about all pc fans.

I ran a 120mm single fan [50+cfm] .10bar [blowers go 1.0+], with a homebuilt scrubber. 12v's and I had to put the cabinet out in the garage for the intake to get cool enough air. Pc Fan just couldn't push air thru the carbon filter efficient enough for my needs.

 

[MrZ!!]

Thanks for replying. My exhaust fan is not a PC fan. Its a 12 v 3,5 amp car engine fan(looks like a 10" cylinder). Feels quite powerfull. Can you do something for static pressure? Sorry for beeing noobish but this is my first indoor grow. I read all about this pc microgrow that seem to work with carbonfilter and pc fan only so it would suck if I couldnt manage to vent a 2,5 cubic feet box:-( I have to solve the odour issue before its too late.
Sorry for the spelling, english is not my main language.

Z

 

[Oregonism]

4 inches @ 140cfm, sounds plenty [quick math in my head only, says a little too much even if done correctly.....]. As far as the intake holes that are blowing air???? Where the damn hell are you cutting them?

Read the link in my sig, vent 1o1

 

[MrZ!!]

So should I use a smaller fan? I tried an axial 90 cfm fan but problem was the same. Seems to work without filter but not with. It felt like a part of the air bounced back from the filter. Maybe a tube shaped filter with larger surface wouldnt restrict airflow as much? Intakes at the lowest level on the side. Would it make a difference if the intakes are close or spaced? They blow in a bad way;-)

 

[Oregonism]

So should I use a smaller fan? I tried an axial 90 cfm fan but problem was the same. Seems to work without filter but not with. It felt like a part of the air bounced back from the filter. Maybe a tube shaped filter with larger surface wouldnt restrict airflow as much? Intakes at the lowest level on the side. Would it make a difference if the intakes are close or spaced? They blow in a bad way;-)

One thing possibly with the intake is the active fan, it could be creating positive force and seems so. Your exhaust should vent your cab just fine with a passive intake.

Second, the axial fan is probably just as weak [pressure wise] as your car fan [which should be axial too]. Though your car fan isn't "weak" at 40watts[?] It does move efficiently, but with little resistance most likely. Especially since those fans, are normally mounted in the front of the car taking advantage of going forward.

For instance just looked my 120mm ADDA: 98cfm @.179 Inches = 44.5 Pa.

This mini blower [aka centrifugal] is rated: 36cfm @1.935 in H20 [480+Pa]
http://www.digikey.com/product-detail/en/BG0903-B047-00S-00/P13442-ND/857935

Big difference to overcome resistance, especially pulling. I would check your fans specs, then you can do the correct calculation to figure out your minimum needs based on your fans "force" not overall output.

 

[TheBatCave]

love it

 

[MrZ!!]

Cant find specs for my fan. Seems like most pc fans comes without specified pressure. Today I removed the active intake and made a cylinder scrubber about 12" long. Works ok and temp istnt that bad. Both intakes suck air and I feel air going through the filter. This must prove working ventilation? T is still around 30+C. Should also mention inside T is 26+ C at the moment(hot as f#%). Perhaps a 5C rise is hard to avoid? Should I get a miniblower instead? Found some similar to the one mentioned but they seem very loud? Would like to put another 100 w in there during flowering but I find it unlikely without fryin the plant.

 

[MrZ!!]

I found the static spec:-( Below 1 at the speed Im running it. That suck for the freekin noice that sucker makes. My wife can use it to dry her hair. Just ordered a fan with 3,2 sp. Hope that works better or I go for a loud ass delta blower. So far my 2" plant seems to like it in 30,5'C but I dont think she would mind another 100 w and less noice.

Z

 

[Oregonism]

I found the static spec:-( Below 1 at the speed Im running it. That suck for the freekin noice that sucker makes. My wife can use it to dry her hair.
Z

Nice, those axial's can be fuggin' deceiving. Pascal rating for us micro-guys is actually pretty damn important beyond just cfm.

Delta makes quality, I looked at EPM Papst. Blowers in my humble opinion get it done. Sometimes they are spendy and noisy [most >50-55db], but I think they are versatile for weird fitting spaces and DIY cabinets.

I am going to have to stack my fans tonight. I usually run uncovered, but in prep for next run, I need the carbon filter on. My fan's are @ 0.179 sp, ouch.

Hope that solves most of it....

 

[MrZ!!]

Thank you for all the usefull information. Used the formulas to calculate my need of ventilation to 30 cfm. With a scrubber i hope I end up in that range since my new fan is 63 cfm. Fingers crossed. I will also increase the size of my intakes to 2x exhaust.

Z

 

[MrZ!!]

Nice, those axial's can be fuggin' deceiving. Pascal rating for us micro-guys is actually pretty damn important beyond just cfm.

Delta makes quality, I looked at EPM Papst. Blowers in my humble opinion get it done. Sometimes they are spendy and noisy [most >50-55db], but I think they are versatile for weird fitting spaces and DIY cabinets.

I am going to have to stack my fans tonight. I usually run uncovered, but in prep for next run, I need the carbon filter on. My fan's are @ 0.179 sp, ouch.

Hope that solves most of it....

Ordered this: http://www.digikey.com/product-detail/en/BCB1012UH-F00/603-1715-ND/3283580

Static pressure at 4 in[H2O]. Low cfm but should be enough for venting a 2 cft micro. How big do you scrubber(m3/h) I could use while maintaining enough cfm? Pretty loud bastard but I thought you could encapsule it in sound absorbing spray foam in a separate box?

 

[Neekz]

Whew 68Db's, goodluck sleepin... But another tip bro, If you have an active intake and scrubber exhaust, I would seal all passive intake holes. The pressure from the intake will help push a little through the filter, but the holes are just bypassing your exhausts straight-up...

 

[MrZ!!]

Whew 68Db's, goodluck sleepin... But another tip bro, If you have an active intake and scrubber exhaust, I would seal all passive intake holes. The pressure from the intake will help push a little through the filter, but the holes are just bypassing your exhausts straight-up...

Didnt plan on running it full throttle. Even at low speed it would kick any axial fans ass. Thanks for the advice on the intake!
Doin a smell test no with a big stinky bud from my outdoor grow atached in front of my circulation fan. So far my diy scrabber seem to work running my fan att 1/2 speed. T is 86 F.

 

[MrZ!!]

So, calculated my active cfm by meassuring exhaust T. Got it to 20 cfm which means I shift air 8 times pr minute. How the fu#% can 100 w cfl heat the air by 5 C in 8 seconds? Soon I give up...

 

[Oregonism]

So, calculated my active cfm by meassuring exhaust T. Got it to 20 cfm which means I shift air 8 times pr minute. How the fu#% can 100 w cfl heat the air by 5 C in 8 seconds? Soon I give up...

20cfm and your shifting air 8 times a minute, wouldn't that put your cf @ [<].7 cu.ft?

Not to tempt fate, but are you calcuating, sq. footage or cubic?

 

[MrZ!!]

20cfm and your shifting air 8 times a minute, wouldn't that put your cf @ [<].7 cu.ft?

Not to tempt fate, but are you calcuating, sq. footage or cubic?

My box is 2,5 cubic ft so if 20 cubic ft goes through my scrubber per minut wouldnt that be 8 changes per minute? All this units fry my brain as im used to mm, cm, dm & m not to mention those bloody celcius:-( No more herb for me which is where I end up anyway since my my yield will be 2 fried sprouts:-(

 

[Oregonism]

My box is 2,5 cubic ft so if 20 cubic ft goes through my scrubber per minut wouldnt that be 8 changes per minute? All this units fry my brain as im used to mm, cm, dm & m not to mention those bloody celcius:-( No more herb for me which is where I end up anyway since my my yield will be 2 fried sprouts:-(

You are right and my math was just downright shitty at that moment. - Yes, it doesn't take much to vent a 2.5 cu.ft cab [.07 cu. meters]

13 cfm [.36 m3/minute] on 5 minute changes @ 2+cfm [.051/m3] every 1 minute is a good mean to start at.

However, that is @ PERFECT static pressure. When you add the filter and heat, you may be right around your range.

-RH%???? What has it been over the last 5-10days, do you data log? That will be a big indicator if you are moving copious amounts of air every day!........

I am opening up the Reefer Manual [big fucking book!] to see if I can get a formula or two, something aint right.

One final solution on slowing the fan down is getting a light dimmer which uses voltage to slow/speed your fan, much cheaper than the actual "fan controller".

 

[MrZ!!]

Dont have a clue about RH at the moment but pots dry rather quickly. Slowing the fan is not a problem since I can adjust the voltage from 5-12 V. I run 7 v now.
I find this bloody disturbing when Ive seen pc setups with 3 times my wattage and just pc fans. Why god? You fu#%^!
I have to vape a sample from my outdoor Annapurna(flash seeds) just to cool down my frustration and because Im worth it