ventilation help

GibbsIt89

GibbsIt89

Well-Known Member
my veg. room is 6'x9'x7.5' which is... 405cf
& my flower room is 6'x12'x7.5' which is... 540cf

the pic is of how i want to set everything up but i dont know what sized fans to buy.. and i dont want to spend a fortune.. i found some cheap duct fans:

there is an 8" that runs 500cfm for $30
there is a 6" that runs 250cfm for $25
and a 4" that runs 80cfm for $20

but they are "not compatible with carbon filters" so it says.
http://www.htgsupply.com/products.asp?categoryID=7&subcategoryID=39


the high velocity 4" exhaust fan and carbon filter combo is $120 and the fan runs 170cfm (cheapest one)
http://www.htgsupply.com/viewproduct.asp?productID=52531


and id rather not go bigger becuz of price.. so im really left kind of clueless as to how i should balance all of these on timing and what size inlets to get HELP PLEASE!:dunce:
 

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GibbsIt89

GibbsIt89

Well-Known Member
do i want the room pressure to be higher or lower? and to what extent

if i use the 170 cfm exhaust and two 500 cfm inlets the pressure will be high by : 330 cfm
if i use the 170 cfm exhaust and two 250 cfm inlets the pressure will still be high: 80 cfm
if i use the 170 cfm exhaust and two 80 cfm inlets the pressure will then be low by: 90 cfm

this of course being the pressure in the flower room.
the veg room will be balanced unless someone suggests otherwise.

these inlet fans can't be used with a speed adjuster to control the cfm either.
 
GibbsIt89

GibbsIt89

Well-Known Member
the ad for the exhaust fan&carbon filter combo says: for a carbon filter to be most effective you want your grow room to be exhausted through it for 5mins, or slowly exhausting

so 12'x6'x7.5= 540cfm divided by 5min. is 108cfm and this 4" fan is 170cfm so it'll take about 3.5mins to fully exhaust the room (as one cycled air flow)
 
fabfun

fabfun

New Member
i see that it says it is not compatible but i dont see why it wouldnt be i mean if it has the cfms it should work
 
marijuananation

marijuananation

Well-Known Member
GIBBS.. ONE THING TO REMEMBER IS THAT MARIJUANA LOVES NEGATIVE PRESSURE, AND PESTS DO NOT LIKE NEGATIVE PRESSURE.
Get the higher CFM fan.. you will be better off with more air than not enough air.. if you need extra control because you think you might have too much air you can get a fan control module for cheap from most hardware stores
 
GibbsIt89

GibbsIt89

Well-Known Member
marijuananation said:
GIBBS.. ONE THING TO REMEMBER IS THAT MARIJUANA LOVES NEGATIVE PRESSURE, AND PESTS DO NOT LIKE NEGATIVE PRESSURE.
Get the higher CFM fan.. you will be better off with more air than not enough air.. if you need extra control because you think you might have too much air you can get a fan control module for cheap from most hardware stores
Click to expand...
thats awsome news man thanx! this is what it said tho *Can not be used with Blower/fan speed controller, not compatible with carbon filters

but once again i dont know why.. mayb just not with the one they sell idk.. those of course now are the only things that are bothering me.. i will call them tomoro
 
fabfun

fabfun

New Member
i say start a new post asking if anyone uses that fan with carbon filter or call supplier and ask them but they may say same as ad so they may not be help but if they grow they will tell u the truth hopefully lol

GibbsIt89 said:
thats what i was thinking, doesnt make sense, just attach some ducting and some tape, there yuh go.
Click to expand...
 
GibbsIt89

GibbsIt89

Well-Known Member
fabfun said:
i say start a new post asking if anyone uses that fan with carbon filter or call supplier and ask them but they may say same as ad so they may not be help but if they grow they will tell u the truth hopefully lol
Click to expand...
ya i'll c what they say when i call them tomorrow..
 
GibbsIt89

GibbsIt89

Well-Known Member
http://www.businesslights.com/vortex-inch-449-cfm-high-power-inline-fan-p-1444.html

i found this one.. just need a carbon filter for it.. then i can get those cheap 8" duct fans as inlets still and the pressure in the flower room will still be high, but only by 51cfm.

although, still by effectively using a carbon filter the room needs to be slowly exhausted and its only 108cfm for those 5 mins so i dont know how well the carbon filter will work for it considering it will be exhausting fast at 449cfm cuz the room is 540cfm
 
jondamon

jondamon

Well-Known Member
Ok so i think this will help you out a little more.
I have had to do it by ducting it out of the window as you cannot cut holes in the ceiling as you are in a groundfloor room.
If you can cut holes in your walls into other rooms then this would REALLY REALLY HELP! As you could change the position of the exhausts and the intakes. The Intakes could be near the window and the exhausts could go through a wall into another room of the house therefore keeping everything under control.

The problem that most people have is exhausting the hot air somewhere and the biggest mistake most people make is to exhaust the air into a room too close to their grow room which causes an ambient air temperature increase.

The picture is pretty self explanatory.
This would be the ideal scenario if you could exhaust outside that way you could draw in ambient house air from your living areas which also has a higher Co2 ppm then outdoor air.

The fans may seem a little extreme but it is done on the following forumla.

Total volume of growing area in CFM x 1.25 or 25% to allow for the reduced power of the fan with the filter attached.

Hope this helps you out bro and any questions you have about it then fire away.

J
 

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marijuananation

marijuananation

Well-Known Member
GIBBS:

This fan will most likely be alot more efficient if you were planning on placing a carbon filter on it, as the Vortex fans are the true industrial strength inline fans and this will last for years without any maintenance.

Specifications: 449 CFM - 2600 RPM - 0.80 Amps - 100 watts
 
GibbsIt89

GibbsIt89

Well-Known Member
marijuananation said:
GIBBS:

This fan will most likely be alot more efficient if you were planning on placing a carbon filter on it, as the Vortex fans are the true industrial strength inline fans and this will last for years without any maintenance.

Specifications: 449 CFM - 2600 RPM - 0.80 Amps - 100 watts
Click to expand...
ya i def. like this fan!
 
GibbsIt89

GibbsIt89

Well-Known Member
jondamon said:
Ok so i think this will help you out a little more.
I have had to do it by ducting it out of the window as you cannot cut holes in the ceiling as you are in a groundfloor room.
If you can cut holes in your walls into other rooms then this would REALLY REALLY HELP! As you could change the position of the exhausts and the intakes. The Intakes could be near the window and the exhausts could go through a wall into another room of the house therefore keeping everything under control.

The problem that most people have is exhausting the hot air somewhere and the biggest mistake most people make is to exhaust the air into a room too close to their grow room which causes an ambient air temperature increase.

The picture is pretty self explanatory.
This would be the ideal scenario if you could exhaust outside that way you could draw in ambient house air from your living areas which also has a higher Co2 ppm then outdoor air.

The fans may seem a little extreme but it is done on the following forumla.

Total volume of growing area in CFM x 1.25 or 25% to allow for the reduced power of the fan with the filter attached.

Hope this helps you out bro and any questions you have about it then fire away.

J
Click to expand...

Jondamon is KING lol thanx bro
 
jondamon

jondamon

Well-Known Member
lol the KING has just arrived in the nick of time.


Hey B your the KING OF COOL.


want to add anything to help GIBBS out?


ive pretty much took the design from my UGM mags and designed the room as per the recommendations with the difference of the exhaust fan location.

They recommend going filter fan ducting out through exhaust. But you taught me better than that bro!



J
 
GibbsIt89

GibbsIt89

Well-Known Member
""They recommend going filter fan ducting out through exhaust. But you taught me better than that bro!""

whats that about? lol n thanx again.
 
GibbsIt89

GibbsIt89

Well-Known Member
"""Ok so i think this will help you out a little more.
I have had to do it by ducting it out of the window as you cannot cut holes in the ceiling as you are in a groundfloor room.
If you can cut holes in your walls into other rooms then this would REALLY REALLY HELP! As you could change the position of the exhausts and the intakes. The Intakes could be near the window and the exhausts could go through a wall into another room of the house therefore keeping everything under control."""





i will c if i can do this.. would it make things cheaper u think? lol like would i still need 2 exhausts or just one then?
 
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