8 inch inline or 6 inch?

[justiceman]

hey guys I am upgrading my grow space by getting an Everest Grow lab tent and I have a few questions if you would be so kind to answer. It is 3' 11" x 3' 11" x 6' 7"(roughly 16sqft or roughly 105cf). It has 8 inch ports that have ties so you can seal them down to 4 inch. I am assuming that I need an inline fan with a rating that has at least 350cfm but I could be wrong. I run a 400w hps with lumatek digital ballast and a super sun2 6 inch flanged hood. I do plan on upgrading to a 600w in the near future.

Ok so here goes. The hydro store told me I should buy an 8 inch inline(720cfm) instead of a 6 inch inline(400cfm) for exhaust. They also told me to put a 6 inch booster on the bottom for active intake instead of leaving it passive.

Here comes the questions:
1. Would an 8 inch inline fan(with speed controller) be quieter than a 6 inch fan if they were both pushing 400cfm?(I am willing to get the 8 inch and turn it down a bit if it will run quieter then the 6 inch at the same speed)
2. If i just ended up getting the 6 inch inline, would a booster fan really be necessary or could I just leave it passive?
3. Do I have to leave the inline fan running 24/7 or should I put it on a separate timer so that it turns on for 5 minutes every 15 minutes?
4. If my timing is off how many times per hour would it need to turn on to vent the room?
5. If you had the dimension of my tent stated above(roughly 16sqft or roughly 105cf) What kind of ventilation set up would you have?

 

[laserbrn]

hey guys I am upgrading my grow space by getting an Everest Grow lab tent and I have a few questions if you would be so kind to answer. It is 3' 11" x 3' 11" x 6' 7"(roughly 16sqft or roughly 105cf). It has 8 inch ports that have ties so you can seal them down to 4 inch. I am assuming that I need an inline fan with a rating that has at least 350cfm but I could be wrong. I run a 400w hps with lumatek digital ballast and a super sun2 6 inch flanged hood. I do plan on upgrading to a 600w in the near future.

Ok so here goes. The hydro store told me I should buy an 8 inch inline(720cfm) instead of a 6 inch inline(400cfm) for exhaust. They also told me to put a 6 inch booster on the bottom for active intake instead of leaving it passive.

Here comes the questions:
1. Would an 8 inch inline fan(with speed controller) be quieter than a 6 inch fan if they were both pushing 400cfm?(I am willing to get the 8 inch and turn it down a bit if it will run quieter then the 6 inch at the same speed)
2. If i just ended up getting the 6 inch inline, would a booster fan really be necessary or could I just leave it passive?
3. Do I have to leave the inline fan running 24/7 or should I put it on a separate timer so that it turns on for 5 minutes every 15 minutes?
4. If my timing is off how many times per hour would it need to turn on to vent the room?
5. If you had the dimension of my tent stated above(roughly 16sqft or roughly 105cf) What kind of ventilation set up would you have?

I have a 4x4x7 tent. I use an XL Horizontal Hood (the older model) with a 4" flange. I run a 6" 360cfm fan atop my carbon filter and reduce the size to 4" to cool the light.

I am running a 600w in it right now and my temps are just fine w/o air conditioning. I also run a passive intake. I thought it would be a problem, but it's not.

I do run my setup at night when the temps are a little lower, but I don't think it would struggle during the day either. I don't even vent outside, I vent into the bedroom it sits in. The bedroom also has a veg room that has a 4" fan venting 400w's of T5's in there. The two of them combined stay just fine with nothing but an open window.

I do also run an ozone generator for odor so I can leave that window open, but yeah, no problems with the 6" fan on a 600w light in a 4x4x7 tent for me. Check out my journal and see.

 

[LT1RX7 Drifter]

buy the 8 and go passive hes just up selling you on another blower your fine

 

[laserbrn]

buy the 8 and go passive hes just up selling you on another blower your fine

buying an 700+ cfm fan for this size space is laughable. Especially if you are runing an 400w light. The hydro store is definitely trying to upsell you on the intake fan, but they aren't doing a bad job upselling you on that 8" fan either. Definitely overkill.

4x4x7 (approx) = 112 Cubic Ft.

6" 360CFM will exchange the air approximately 3 times/minute. That should be more than enough when coupled with an air cooled light hood.

 

[justiceman]

buying an 700+ cfm fan for this size space is laughable. Especially if you are runing an 400w light. The hydro store is definitely trying to upsell you on the intake fan, but they aren't doing a bad job upselling you on that 8" fan either. Definitely overkill.

4x4x7 (approx) = 112 Cubic Ft.

6" 360CFM will exchange the air approximately 3 times/minute. That should be more than enough when coupled with an air cooled light hood.

Hey thanks laserbrn I thought 700+ might be a little ridiculous haha. So does one leave there exhaust fan on all the time, or should it be set to come on at certain times?

 

[LT1RX7 Drifter]

certain temp

 

[Tiz]

all the time unless you use co2

 

[justiceman]

thanks guys. Hey LT1RX7 Drifter I noticed you said I should just buy the 8 and go passive. Why do you think I should get the 8 over the 6?

So let's say I use co2 just for a theorys sake. Would I then buy a pug in thermostat to control the exhaust fans on/off period.

 

[laserbrn]

thanks guys. Hey LT1RX7 Drifter I noticed you said I should just buy the 8 and go passive. Why do you think I should get the 8 over the 6?

So let's say I use co2 just for a theorys sake. Would I then buy a pug in thermostat to control the exhaust fans on/off period.

With co2 you would use timers to shut the fans off while the co2 is administered.