do I leave my exhaust fan on?

Rayman522

Active Member
A couple sources say to leave it on all the time. But why cant I hook it up to a enviroment controller and it only comes on when the humidity or temp is too high? would that be enough fresh air? room specs are 7 ft long 3ft wide 7 feet tall. only using flourescents.

thanks
Raymankiss-ass:hump::weed::cry::evil:
 

klmmicro

Well-Known Member
I am looking at the same thing. I will probably go with a standard duct fan that runs to cool my light, but am considering setting up a t-stat to control the internal temp of my tent. I was talking with a few growers that told me 200 CFM is about perfect for my 3.25x3.25x6.5 foot tent. My dad did the calculation and sort of laughed...that would exchange the entire space air in about 30 seconds.

My thought is, environmental control on the main exhaust fan and then have a circulation fan to keep things moving internally.

What type of controls are you considering?
 

7th1der

Well-Known Member
I am looking at the same thing. I will probably go with a standard duct fan that runs to cool my light, but am considering setting up a t-stat to control the internal temp of my tent. I was talking with a few growers that told me 200 CFM is about perfect for my 3.25x3.25x6.5 foot tent. My dad did the calculation and sort of laughed...that would exchange the entire space air in about 30 seconds.

My thought is, environmental control on the main exhaust fan and then have a circulation fan to keep things moving internally.

What type of controls are you considering?
Not sure yet! Wanted to get the fan first.
 

dhhbomb

Well-Known Member
u wouldnt have to have it all on all the time but every like 5-10 minutes so u can have and exchange of air so the plants have fresh air
 

mannurse801

Well-Known Member
If a 171 CFM is a strong fan for a 7 ft long 3ft wide 7 feet tall area, am I trippin for trying to get a 197 CFM Soler & Palau for my little cab?

I forget where, but there is a calculation to use to find the right CFM for the cubic feet of your room. As long as I get 4 good air exchanges per hour, that is all I need, but I have a cool room, and lights bring it up to good temperature. Just calculate, 7x3x7=147. So a fan of 171 cubic feet per minute is recirculating your air a little more than once per minute basically...

How big is your box?
 

sandmonkey

Well-Known Member
I have my fine wired to a thermostat, so if it gets too cool the fan shuts off.

As long as there is air intake vents, you can leave it running all the time.
 

Twistyman

Well-Known Member
A couple sources say to leave it on all the time. But why cant I hook it up to a enviroment controller and it only comes on when the humidity or temp is too high? would that be enough fresh air? room specs are 7 ft long 3ft wide 7 feet tall. only using flourescents.

thanks
Raymankiss-ass:hump::weed::cry::evil:
More a matter of how many plants in an area ...IMO....I turn my off during dark periods..(2 plants)..
 

LinearChaos

Active Member
I have a fantech fr150 243cfm fan in a Homebox L (40"x40") with a 400w hps and I leave the fan running 24/7. It works great, pulls the sides or the tent in so I know there is good suction/airflow, and it's one less part I have to buy. Haven't had any issues so far, even when I was in veg and the light was on longer.
 
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