exhaust fan, realy HIGH temps!

Jlee1990

Well-Known Member
my last two plants because it was just too hot and had no cooler air coming in. i have just bought a 4'' exhaust but will this lower the temps? because they are 40 degrees afte an hour of it being on :/. and any ideas and advice will b realy appriciated :)
 

Metasynth

Well-Known Member
How are you bringing fresh air in to the grow area? Are you drawing air from the same place that you're exhausting into? Do you HAVE some sorta fresh air intake?
 

Jlee1990

Well-Known Member
ive got one exhaust fan which i havent tried yet, and i open the door to get fresh air into the grow space every now and then?
 

Jlee1990

Well-Known Member
yee i no mate thats why my last two plants died :(, but i want to know if this new exhaust fan i bought will bring the temps down?
 

Metasynth

Well-Known Member
ive got one exhaust fan which i havent tried yet, and i open the door to get fresh air into the grow space every now and then?
You're gonna wanna use that exhaust fan, cut some sorta passive intake holes so you can bring a constant stream of fresh air into the room, or else the exhaust fan isn't gonna do anything...You want to be able to exchange the entire volume of air in your grow area at least once every few minutes, preferably more frequently. So you need to set that exhaust fan up towards the top of your grow area, to vent out the hot air as it rises, and you need some sorta intake for fresh air towards the bottom of the room, drawing in cooler air from floor level. Intake, you don't need a fan, just some holes will do, because the exhaust fan should be running 24/7, and create slight negative air pressure in the grow area.e
 

Clonex

Well-Known Member
yee i no mate thats why my last two plants died :(, but i want to know if this new exhaust fan i bought will bring the temps down?
sorry i sounded sarcy was not my intention ,
you need a fresh air intake for cooling/co2/fresh air , an Exhaust may drop temp a couple of degrees but not much without the fresh air,i take it your adding a carbon filter on the exhaust ? i would advise more research , you must have ...
1 good light
2 good soil
3 fresh air
at the very least.
:-)
 

Jlee1990

Well-Known Member
create the holes where mate? and its a relief i dont have to buy another fan for the intake. what do you think the temps will drop too? because my seedlings have just sprouted and keen to get them under the light
 

Clonex

Well-Known Member
create the holes where mate? and its a relief i dont have to buy another fan for the intake. what do you think the temps will drop too? because my seedlings have just sprouted and keen to get them under the light
to draw fresh air in from outside you Will need another fan.
 

Jlee1990

Well-Known Member
well ive got a normal fan that i can have blowing air in to my airing cuboard from the top of my stairs, thats it i have no other way to do it.?
 

Metasynth

Well-Known Member
Ok, what sorta lighting are you using, and where exactly is your grow area located, how large of an area...

You do NOT need another fan for the intake, the exhaust fan with draw air in passively, and as long as the ambient room temperature outside your grow(the area you draw air from) remains cool, it'll be fine. The exhaust fan will blow the hot air out of the top of your grow, and make the intake holes towards the bottom, close to the floor, since cool air falls and warm air rises.
 

Jlee1990

Well-Known Member
its in my airing cuboard at the top of my stairs, its about 2ftx2ftx6ft . it isnt near any windows or anything and the ambient temp normaly is about 18-19 degrees if we dont have the central heating on all the time. so all i need then is this exhaust fan ive got?
 

Metasynth

Well-Known Member
Yep, it's a 6ft tall cupboard? So have the exhaust fan high as you can, blowing hot air out, and 6 ft below that, at the bottom of the cupboard door, you are gonna wanna cut some holes for passive air intake...though you might want to build a light trap to prevent light from leaking in during the flowering cycle...Just make sure the passive intake holes are big enough...you have a 4 inch exhaust fan, so cut a hole slightly larger in diameter than that, say 5 inches, and that should help...And what kind of lighting are you growing with?
 

Clonex

Well-Known Member
its in my airing cuboard at the top of my stairs, its about 2ftx2ftx6ft . it isnt near any windows or anything and the ambient temp normaly is about 18-19 degrees if we dont have the central heating on all the time. so all i need then is this exhaust fan ive got?
He's right , but it would be better -
 

Jlee1990

Well-Known Member
do you mean cut the intake holes into the sheeting at the bottom? because thats all im using, a sheeting wrapped around inside the airing cuboard. and im using a 400 dual spectrum light with ballast
 

Clonex

Well-Known Member
You don't necessarily know that, mate...We know very little about his grow, or even the m3/hr rating on his fan...
Sorry i just tried this method when i first started and pulled my hair out as it was not enough , ended up buying an intake anyway , not trying to be argumentitive , soz :-)
 
Top