Help with Fans. Very quick question!

mrtibbs316

Well-Known Member
Hello people.

Very quick question.

I have a 4x4x7 ft tent, and am getting a 6 fan for Extraction, but what do you think is the better size for intake?...

Out take = 150mm\6 inch 720m3ph

Intake option 1

125mm 323m3ph

Intake option 2

150mm 428m3ph

Just not sure which would be best and which one would provide best negative pressure.


I wont really be having major issues with temp, and am more concerned with extracting smell effectively, as well as making sure my plants get enough air.



Thanks people
 

skunkd0c

Well-Known Member
negative pressure comes from the extractor
its better to remove air quicker with a more powerful extractor than using another fan on the inlet
the inlet should be passive imo, using a fan to push air into the space is a waste of power unless you are pushing air directly across/through the lights / cool tubes

peace
 

mrtibbs316

Well-Known Member
negative pressure comes from the extractor
its better to remove air quicker with a more powerful extractor than using another fan on the inlet
the inlet should be passive imo, using a fan to push air into the space is a waste of power unless you are pushing air directly across/through the lights / cool tubes

peace

I am a noob, but surely the more air your plants get, the better?

As long as NP was maintained I would assume your plants would benefit from the additional air.

That's my reason for the extra inlet only.... No air cooled hood in my setup.
 

moving_shadow

Active Member
fans don't do well pushing air, they pull better

so rather have two extractor fans if you really want your plants to benefit from additional air.
 

skunkd0c

Well-Known Member
if you look it up you will find that in order to move air from a space its many times more efficient to suck the air out of the space with an extractor since this removes the air instantly and instantly lowers air presure in the space
if you blow the air to increase air pressure the pressure in the space needs to reach maximum the room/space can hold
before air spills out this is not instant

a powerful extractor will create negative pressure and suck in lots of air while removing the heat and co2 depleted air from the space

if heat is an issue do not try to solve it with active inlets , it could help and work but its wasting power
better to solve heat problems with cool tube reflectors and a much more powerful extractor
with a 2nd fan used to blow cold air through the light system
you can use the 2nd fan to suck air through the light system if you want but then it will need a carbon filter which is extra cost
and reduces the air flow and the heat will come into direct contract with the fan motor

because the air in the light system cool tubes is sealed off from the rest of the air in the growspace the air volume inside the tubes/light is very small so a fan can blow air and not be too inefficient to produce the amount of positive pressure needed in this small space

peace
 
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