Exhaust fan Recomendations?

[Guest]

i have a small 4x4x6 area that needs some exaust asap. i want something cheap and quiet. what can people recomend for me with an area that big? i see things from 20-300 dollars for that sized room. how man CFM's are needed? i thought 100 was plenty. thanks for your time
z-

 

[Villain]

Well I believe that you need to vent a room about 5 times a minute. So you have 96 cubic feet in your grow room so you figure you will need about 500CFM fan. Now if you plan on using a carbon filter then you will need a filter rated for 500CFM and a fan rated for a bit more (like 600 maybe??). I have a filter rated to handle between 125-175cfm, I bought a Vortex 172CFM inline fan and it seems to work great. I will go and see what I can help you come up with and edit my post.

 

[paq]

exhaust

exhaust

Yo I recommend Vortex fans,

-Quiet fans
-25 year warranty
-Lubricated bearings for life

Id go with the 6" or 8".
With you 4x4x6 Id go with the extra 8", but the 6" is a little cheaper and quieter...

I have a 6" thing is awesome, I love it. get one Vortex....

 

[JollyGreen]

Yes Vortex is the shit I have the 6'' aswell.Super Quiet, I highly Recomend it.

 

[Albert Hofmann]

You guys are going a way overboard with the 6" and 8" fans. The minimum room exchange rate is once every 5 minutes, but I like to observe once a minute. My mother room is 5'x4x6 or 120cf with a 4" vortex (172cfm) exhaust and passive intake cooling a 400 halide and 4' 8 bulb T5...room temps are 75-77. Zorkieo, a 4" vortex will be more than enough for your setup.

 

[Villain]

Ok I have a few links for you but they aren't super cheap but then again neither is quality. I first of all suggest something along these lines of this for a filter.
http://www.horticulturesource.com/p.../1511?osCsid=f4233759cee635639bd586bd59f10b46
It is rated to be able to pass 420CFM which I mean come on it's 420 lol. This one is a bit more expensive but is rated for exactly 500CFM max (perfect).
http://www.horticulturesource.com/p.../1430?osCsid=f4233759cee635639bd586bd59f10b46

As for a fan I also have a vortex (4") and honestly I think that it's a bit loud but not too bad. You will need a fan that can push 500CFM max for either one of these filters. This Fantech is a great deal and pushes damn near a perfect amount of air for those filters.
http://www.rewci.com/fa6392cfminc.html
Eco-Plus is ok and if the price fits then you may want one so here is another link.
http://cgi.ebay.com/Eco-Plus-6-inch-Inline-Fan-440-CFM_W0QQitemZ120152302310QQcmdZViewItem

Not that you need to be told but these are not our only options. On the other hand you really should try and get as close to 500CFM as you can with in your budget.

You guys are going a way overboard with the 6" and 8" fans. The minimum room exchange rate is once every 5 minutes, but I like to observe once a minute. My mother room is 5'x4x6 or 120cf with a 4" vortex (172cfm) exhaust and passive intake cooling a 400 halide and 4' 8 bulb T5...room temps are 75-77. Zorkieo, a 4" vortex will be more than enough for your setup.

I thought it was 5 times in a minute not 1 time in 5 minutes. At any rate if what he says is true then you can rest that it will be much cheaper then what I linked you too.
My Grow dresser is only 14 cubic feet total, my filter can handle up 175CFM and my fan does 172. In this dress temps would get up to 78*F using 210w of CFL's (no lie). So I really don't know what to say about that quote.

 

[Albert Hofmann]

If I had to take a guess Villain, it would be that your intake air was in the middle 70's or you have several bends in your vent line and are not moving anywhere near 172cfm. It's definately minimum once every 5 minutes and preferably once every minute, think about it...in a 1000cf room (10x10x10) your math has me needing 4-5 12" vortex fans!! The 1 12" vortex that I do run in my room pulls so hard that I can feel cool air being pulled in through my lightswitches on the other end of the house!..I can't imagine what 5 would do

 

[Guest]

wow thanks for all the help everyone. i will look into it. i appretiate it so much!

 

[Guest]

Is this the best price on a vortex?
http://www.plantlightinghydroponics.com/vortex-inch-inline-fan-172-cfm-p-351.html

anyone konw cheaper?

 

[Villain]

Well you are probably right and my ambient room temps are about 70 so you are right on with that one. So if you want it to be plenty cool in ther for a good price try these and tell me what you think.
Filter
http://www.hydroasis.com/hy/productdetail.aspx?id=1229&product=phat-hydro-filter
Fan
http://www.plantlightinghydroponics.com/vortex-inch-inline-fan-172-cfm-p-351.html
You can get the whole thing for less than 200 shipped not to shabby huh?

Is this the best price on a vortex?
http://www.plantlightinghydroponics.com/vortex-inch-inline-fan-172-cfm-p-351.html

anyone konw cheaper?

Yes just bought the same one from the same place thats a great deal

 

[Guest]

am i going to need a fan speed control on a vortex?

 

[Villain]

I don't use one but like I said it is a bit loud... well the air it moves is loud. The fan itself is really quiet but it moves a lot of air. I would say that if you are really worried about sound then get the controller. If you have a setup like mine that is in your closet thats in your room then you will most likely be fine. I can't hear my fan at all through the two doors, also I have my alarm clock radio on all day, it's just barely loud enough to hear it outside my BR.

 

[venge]

My room size is this: 12'W x 5'D x 7'H, i have a can 100 with 12" inline fan. The air is sucked thru the carbon scrubber and then exhausted out. When this things is running it sucks the air out big time. It actually moves it out too much as it seems fairly loud. I do have a speed control for it and will probably use it. My question is how long does this need to be running? 24/7, set for on a cyclestat for so much time on/off? What aboutwhen I plan to use CO2 in my room (later).

What about when lights are out, do you still exhaust the room as often/continually?

Thanks

venge

 

[Albert Hofmann]

My room size is this: 12'W x 5'D x 7'H, i have a can 100 with 12" inline fan. The air is sucked thru the carbon scrubber and then exhausted out. When this things is running it sucks the air out big time. It actually moves it out too much as it seems fairly loud. I do have a speed control for it and will probably use it. My question is how long does this need to be running? 24/7, set for on a cyclestat for so much time on/off? What aboutwhen I plan to use CO2 in my room (later).

What about when lights are out, do you still exhaust the room as often/continually?

Thanks

venge

You can run it on a thermostat...that's what I do. I also have a 12" vortex and it runs for about 5 minutes and then is off for 10-20 minutes (depending on temps outside) I don't run CO2 anymore, but when I did I would raise the temp on the thermostat to 84 and then the fan ran for 5 minutes on and up to 60 minutes off. Run the CO2 when the fan is off.

 

[venge]

Thx again AH,

Yes I did know that as I have all the equipment in place for that. Obviously getting late and possibly one too many treats for the evening.

Something tells me I have a few more questions for you. lol

Cheers
venge

 

[yamaha_1fan]

I have always heard 5 times per minute but I guess it depends on the size of the room versus lighting/heat

Heres a formula from the OG FAQS

Overheating is a common problem encountered by growers, especially in closet or 'box' setups. High temperatures cause whispy buds and is often a sign of inadequate ventilation, which brings a whole host of other problems.

Whether at the design stage or struggling with an existing problem, the following formula can be useful in assessing your situation. Its pretty basic in terms of heat transfer but from experience has proved to be pretty accurate for our purposes.

The formula is:

Q = V x P x C x dT

where:
Q = Amount of lighting (kW)
V = Volume of air being ventilated (m3/s)
P = Density of air (assume 1.2 kg/m3)
C = Specific heat capacity of air (assume 1.02 kJ/kgK)
dT = Temperature difference between ambient and growspace air in degC

You can use this to determine what the temperature rise in your space will be (dT), or given a desired temperature rise you can use it to work out how much ventilation you will require (V)

To get from CFM to m3/s divide the CFM by 2119.

Examples
Here are some examples of how you could use the formula in three different ways, each using the same basic figures for clarity.

What temperature am I likely to get in my growspace?
Assume: Lighting = 400W (0.4kW), ventilation = 240m3/hr (0.067m3/s) and temperature of air entering room = 21degC

Q = V x P x C x dT
=> dT = Q / (V x P x C)
=> dT = 0.4 / (0.067 x 1.2 x 1.02)
=> dT = 4.87, i.e. 21 + 5 = 26degC in growspace

How much ventilation am I likely to need?
Assume: Lighting = 400W (0.4kW), temperature of air entering room = 21degC and temperature of growspace to be no more that 26degC

Q = V x P x C x dT
=> V = Q / (P x C x dT)
=> V = 0.4 / (1.2 x 1.02 x (26-21))
=> V = 0.065 m3/s i.e. 240 m3/hr

What is the most lighting I can put into my growspace?
Assume: Ventilation = 240m3/hr (0.067m3/s), temperature of air entering room = 21degC, temperature of growspace to be no more that 26degC

Q = V x P x C x dT
Q = 0.067 x 1.2 x 1.02 x (26-21)
Q = 0.41 kW i.e. 400 W

So that’s it, once you get used to using it its very simple really, Just stuff the formula and figures in a spreadsheet and let it do the work.

 

[Guest]

will running an exhaust fan lower humidity a tad bit?

 

[yamaha_1fan]

will running an exhaust fan lower humidity a tad bit?

Someone correct me if I am wrong but what goes out must go in. Basically you need air to come in to replace the air you pulled out. You are not pulling out humidity but air that is humid. If the air coming in is a lower humidity, then you will lower humidity. If the air is the same humidity as whats going out, then I do not think you are are going to lower it by ventilation.

 

[Pistil Whipped]

Your plants are transpiring as they grow, therefore having an exhaust fan will definitely lower humidity. The air in your grow room (without ventilation) will certainly be higher than ambient if you aren't exhausting the moisture the plants release into the air.

Pistil Whipped