Passive V In-Line Ventilation???

[NorthofEngland]

In both my tents I have the most simple of In-Line fans for inputting cool air.
A PASSIVE SYSTEM that is a length of 6" ducting, that takes air from a area of cool. rich atmosphere,
and delivers it to the bottom/centre of my 4 x 4' area.
In the 8 x 4' I do this same technique twice.
It's just a length of ducting, with bends to prevent light, that goes into the tent through a low vent hole (with string ties).

This has been fine, up to now.
But I cannot help but think there must be reasons to buy and use a second (or even a third) RvK to work as an 'air in' in-line fan???

WHEN DOES A GROW ROOM BENEFIT FROM HAVING A FAN DEVOTED TO AIR-IN???

WHEN IS A PASSIVE AIR-IN SYSTEM INADEQUATE???

In my 8 x 4 I already have a 6" RvK for 2 x 600w Closed Reflectors
and a 8" RvK, with 8" Carbon Filter, to ventilate, deodorise and cool the tent.
A third IN-LINE would need a damn good reason.
(3 fans would be noisy, vibratey and inconvenient for plug space, ducting and wiring everywhere....).

EDIT
I don't actually have the 2 closed hoods, yet.
They are amongst my top priorities for equipment needed for when the winter temperatures change to spring/summer).

 

[Southerner]

Its all about temp/humid control, and smell if you care; you do/buy what you have to to get your numbers locked in.

 

[cc2012]

Aye up NorthofEngland, I've been thinking about the very same thing..."Passive V In-Line Ventilation" well in regards to my Main GR at the moment it's only Inlet (Fresh Air) in is a 4" hole in the window board I've fitted...The Little window opener where I've located the Hole,plate and Ducting is open say about 2" so nice amount of fresh Air available what I was thinking of adding..is one of these in the 1st instant just to ensure a little more Air trickle...



4" hydroponic axial air fan
105 M3/Hour
62 CFM
£13.99 + Free PnP off FleaBay

What do reckon...just to pull a bit more in? if not this route...might use a Bigger Inline Fan with a....



Then maybe have 1 x Ducting taking Fresh Air to the Floor of the GR and the other side taking Fresh Air to the Cool-Tube I ain't yet got...

Peace

 

[NorthofEngland]

Aye up NorthofEngland, I've been thinking about the very same thing..."Passive V In-Line Ventilation" well in regards to my Main GR at the moment it's only Inlet (Fresh Air) in is a 4" hole in the window board I've fitted...The Little window opener where I've located the Hole,plate and Ducting is open say about 2" so nice amount of fresh Air available what I was thinking of adding..is one of these in the 1st instant just to ensure a little more Air trickle...

View attachment 2994634

4" hydroponic axial air fan
105 M3/Hour
62 CFM
£13.99 + Free PnP off FleaBay

What do reckon...just to pull a bit more in? if not this route...might use a Bigger Inline Fan with a....

View attachment 2994663

Then maybe have 1 x Ducting taking Fresh Air to the Floor of the GR and the other side taking Fresh Air to the Cool-Tube I ain't yet got...

Peace

I don't know, Brum.
I never get any negative pressure = the tent walls are never sucked in....
I really cannot think of a convincing reason to use a THIRD RvK in my tent....???

BUT I've only been growing since mid November, last year. So I haven't had to cope with higher temperatures.
(Keeping temps up during lights off as been a bigger problem than keeping temps down during lights on - but when the summer comes....???)

Another reason for consider an input fan is that, apart from the very basic fan speed controllers, the environment controllers (with thermostats and humidistats) are all designed to work with 2 fans. Input and extraction.
And I like the idea of trying an Eco Evolution Environment Controller.

But my priorities are 2 ventilated hoods for the summer months.

I have a 6"RUCK, which will be with a 6"Rhino Filter in my VEG tent
a 8"RvK, a 8" Phresh Filter, a 6" and a 8" FAANTRONIX Filter
a 12" RvK.
20m of 6" Ducting
10m of 8" Ducting
a 8 to 6" reducer and
a 12 to 8" reducer.
Plus 2 basic dimmer switch fan speed controllers.

I'll probably ventilate the 2 hoods with the 8"RvK
and ventilate the tent with the 12"RvK (maxed down through the fan speed controller???
(a 8 x 4 x 6 = 5.76m3
x 1.25 x 60 = 432m3/h
A 12"RvK can handle 1300m3/h

 

[cc2012]

BUT I've only been growing since mid November, last year. So I haven't had to cope with higher temperatures.(Keeping temps up during lights off as been a bigger problem than keeping temps down during lights on - but when the summer comes....???)

Yeah I hear ya, I picked up a 800w Mini Oil Filled heater from BM Bargains for less than £20 and on the half setting its keeping the GR at about 19° lights off and when lights on my Temp is about 21-22° at the moment I just have 2 x Fans(6" & 12") in the GR and the passive intake hole/ducting..

Last summer I was using my Closet/cupboard and the Temps after being on half hr was hitting the 30°s had to have the Door open all the time when it was lights on...This Year though I've moved the Grow into small bedroom
(8' x 7' x 9') or something like that, Baked at the mo

I've kinda been working my way through Grows and just getting the Bits as and when I can(Funds)

Def thinking about getting a small inline fan for the Intake...instead of it being passive...though will be happy just to have the GR dialed in...last Grow...when I first moved into the bedroom had some real issues with Humidity!!

Peace