CFM for Cooling 4x600w HPS in cool Tubes?

[koursaros]

Hello there people...

First of all let me show you my firsτ approach...
As you can see in the pic below.. i was planning to have my configuration with one big (and already bought) centrifugal fan named V1.....

this plan was abandoned since i have read the great thread found here named "Ventilation 101" that explain a lot not only about ventilation but also mention that "The plants only needs 3 to 5 Minutes per Air Changes (MpAC)"
(hxxps://www.icmag.com/ic/showthread.php?t=112862)
So.. running the 765cfm fan at it's full speed in order to also keep the lights cool and generally the temperature at the desired levels.. was impossibe.

So i decide to "split" my ventilation...
1 fan will run the carbon filters ONLY...
and 1 fan will cool down the 4 x 600 watt HPS lamps..
See below...

If i place my 1300m3/h - 765cfm (named V1) to Cool tube ventilation system it will be Ok?
too much?
Less than is needed???

Is there any specific formula to calculate the air flow need through a 6" (or whatever inch) cool tube in order to cool down the lights? (in my case the 600w hps connected in series)

Thanks in advance...
Feel free to correct me if i'm wrong at my design...

 

[Fly by Night]

I'd use an 8in filter to match the fan. Rather than Y pipe/splitter, 2 filter etc. And I suppose with 6 in cool tubes, 6in fan ?!? All the best homie

 

[early_bird]

Can your fan handle theese temps :-?

Maybe AKF->FAN->Tube->Tube
And this 2 times is an alternative ? Y-Connector at the End.
Less pressure loss than pushing air through 4 Tubes, you´re loosing propably a lot of air pressure

 

[koursaros]

I'd use an 8in filter to match the fan. Rather than Y pipe/splitter, 2 filter etc. And I suppose with 6 in cool tubes, 6in fan ?!? All the best homie

I suppose that you are talking about my first approach (that was finally abandoned)
The filters and the Cooltubes had been already bought before the fan... and doing the calculations about the desired Cfm for my Tent.. the only capable Fan that was able to push enough air was bigger than 6".. that's why my fan is 8" with adapters...

Can your fan handle theese temps :-?

Maybe AKF->FAN->Tube->Tube
And this 2 times is an alternative ? Y-Connector at the End.
Less pressure loss than pushing air through 4 Tubes, you´re loosing propably a lot of air pressure

Dear early_bird your approach sounds logical... but in ANY way when Cooling the Lights+Filtering the Air together.. you CAN't control the desired 3 to 5 [FONT=Arial, Helvetica, sans-serif]Minutes per Air Changes (MpAC) that the plants need.

That's why i decide to split the ventilation.
About your question "if my fan can handle these temps" you got a point!

The "Tent Ventilation[/FONT] fan" (no interference with lights) is sucking air OUT of the tent.. so there is "Negative pressure" that keeps odors controlled (passive fresh air intake) and the desired [FONT=Arial, Helvetica, sans-serif]Minutes per Air Changes (MpAC) that the plants need.[/FONT]

In my second design the Light fan is also sucking air...
Here you got the point!
If the Lights Fan is sucking air.. it will suck all the HOT air.. pushing the fan to high temperatures...
So.. i will change this..
The "Lights Ventilation fan" will PUSH fresh air through the Lamps..at the begging of the circuit so the HOT air coming out has nothing to do with the fan... Like This..

Thanks early_bird for bringing this to my attention!

But the question still exists...
How i can calculate How much CFM or m3/h the 4 Cool tubes need??

 

[koursaros]

Nobody about the CFM's ?

 

[early_bird]

Take a look at the Ventilation 101, this may help
https://www.icmag.com/ic/showthread.php?t=112862

Pushing through 4 Cooltubes and having 2 90 degree angels will affekt effectivity of the Ventilation system. As bigger as more flexible you are (like on hot summers).

How big you Ventilations System depends heavily on how much temperature delta between inside and outside the growroom you like to achive.

Another point it how flexible this have to be controlled, thinking on day-night temp differences or hot summers compared to cold winters. As more flexible you control over temperature is, as better for growing
Just for example the day-night temperature delta affects the stretch of you plants.