Regulating Temperature, my next step?

Asskicker

Member
It’s only June, it is going to get so much worse!

Equipment:

1x1x2m tent, 400w light with an open reflector,

Intake fan: 4” Systemair fan, pulling air direct from outside

Out take fan: 5” Systemair fan, attached to a 4” Rhino filter via a metal reducer, pushing air outside the house

I also have a 12” high powered air moving fan, and a 6” clip fan

Problem: The climate where I live has got very warm, and the loft where I keep my tent is 30+ degrees during the day, and 25 on a night. I currently have both in/out fans set to maximum, and the internal fans kicking up a storm inside. Yet, during lights on I can’t get below 29degrees, and lights out I am still around 25-27. I have my lights on while it is dark outside, but they do cross over a couple of hours, it is this period that I really struggle with.

Solution 1: 5” Rhino carbon filter, thus getting rid of the reducer, giving more airflow

Solution 2: Glass panelled reflector with ducting to pull heat straight out.

Solution 3: Air conditioning unit. (too expensive, but probably the best solution)

Solution 4: A twin fan controller?

Solution 5: Any suggestions?

Regarding Solution 2, how would I configure my two fans and filter with a reflector like this? Or would I need a third fan?

Any help or advice would be appreciated. I am putting off switching to 12/12 until this is resolved.

Thanks AK
 

contraptionated

New Member
There is a chance that you are not pulling out as much air as you are taking in through your intake fan. Even though your extractor is 1 size higher than the intake you would not guarantee a negative pressure in the grow room.

For example: If I used a 10" Can Fan HO centrifugal (rated about 800 cfm) to pull air from a Can Filter 150 (a carbon filter that works effectively to around 1260 cfm yet still adds a head loss to the 800 cfm 10" fan) and used a 10" flex duct to vent it outside all in a straight horizontal run of approximately 20' , I would only be extracting roughly 350 cfm (I know this because it is one of many exhaust lines that I measured with , correct me if I'm wrong, I think it's called a Kestrel psychrometer, the thing that you input the diameter of the vent and it gives you a cfm reading).

Now if I had an intake fan of even 6" diameter (2 sizes smaller) there is a good chance I will overpower the exhaust because a 6" will do its fully rated cfm of approximately 400 cfm without a carbon filter and long ducting attached inline. Without negative pressure you will not efficiently remove heat and on top of that you will be leaking odors. That's a big safety issue. Safety first. Also, to better understand how duct sizes effect maximum cfm output , checkout a video on the net about Manual D of ACCA.
 

MYOB

Well-Known Member
ditch the intake fan. Get a good high velocity inline exhaust fan and make the intake twice as large as the exhaust. This will create negative pressure which will pull hot air out and draw fresh air in passively.

An air cooled hood would help. You could run a carbon filter > hood > exhaust.

Exhaust from the top, intake opposite side on bottom.

I would lose one of the circulation fans as well. Have the remaining fan blowing air from the ground up into the canopy.
 
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