booster fan vs inline exhaust fan

[budsofmadison]

so i got an ac infininity 6 inch booster fan blowing fresh air into my tent
i have a 6 inch spider farmer exhaust fan blowing air out
with both fans at full throttle, the 6 inch booster fan is blowing more air in my 3x3 tent then what the 6 inch spider farmer exhaust can take out does that make sense should the 6 inch exhaust fan be taking out more air then a 6 inch booster fan can blow in

 

[Scotty 420]

Right on, I got a local buddy his grow is behind mine...my fan runs 4 mins on 2 mins off at the moment on a 24/7 schedule like that. His is set based on temperature which I was weary of but so far it seems to be fine.

Trying to learn where I can dial back to cut costs

I actually just changed my setup because of this very issue. I couldn't come up with a reasonable way to have the fan run on a timed schedule for constant change over while also having a temp/humidity limit. So I bought a 6" duct booster fan with a variable speed controller & mounted it right before my main exhaust. Set the booster fan to a low speed & just plug it straight into the wall so it runs constant at a very low cfm. Main exhaust is left hooked to my controller to maintain heat/rh.

 

[Rootsruler]

Take this for it is worth.
Sorry if already posted;

Ventilation 101 - How to Ventilate Your Grow Space

Ventilation is a vital factor in your plant growth. By supplying fresh air from outside your grow tent, you provide CO2 for your plants, driving their photosynthesis. Expelling the air inside will keep temperature and moisture build-up under control, preventing mold and mildew from inhibiting...

acinfinity.com

If you go by the calculation they posted it comes out to roughly 3 times your base CFM. I posted before that 3 air exchanges a minute is minimum.

 

[MDK]

I actually just changed my setup because of this very issue. I couldn't come up with a reasonable way to have the fan run on a timed schedule for constant change over while also having a temp/humidity limit. So I bought a 6" duct booster fan with a variable speed controller & mounted it right before my main exhaust. Set the booster fan to a low speed & just plug it straight into the wall so it runs constant at a very low cfm. Main exhaust is left hooked to my controller to maintain heat/rh.

I got both a 6 inch exhaust and booster fan as well, I got it hooked up like buds does, booster pushing in bottom and big exhaust fan mounted directly outside the tent up top.

I like your idea though I may have to switch it up and try that out see where I can improve

 

[Rootsruler]

I let the fan passively pull air through the bottom flaps so that it pulls the air through the canopy.

 

[Scotty 420]

If you go by the calculation they posted it comes out to roughly 3 times your base CFM. I posted before that 3 air exchanges a minute is minimum.

If you go by the calculation they posted it comes out to roughly 3 times your base CFM. I posted before that 3 air exchanges a minute is minimum.

Yeah but their calculations also include 20% for a muffler & 50% for lights. I don't need to account for heat from my lights at all I'm running a heater in the tent. So there's 70% off their calculations I personally (& probably a lot of people as well) don't need

 

[budsofmadison]

I got both a 6 inch exhaust and booster fan as well, I got it hooked up like buds does, booster pushing in bottom and big exhaust fan mounted directly outside the tent up top.

I like your idea though I may have to switch it up and try that out see where I can improve

what i realized is my 6 inch exhaust fan ''405cfm'' was taking out more air then my 6 inch booster''205cfm'' intake booster fan could bring in both ac infinity so tonight i switched to an 8 inch ac infinity booster405 cfm fan to bring in air

 

[MDK]

Yeah but their calculations also include 20% for a muffler & 50% for lights. I don't need to account for heat from my lights at all I'm running a heater in the tent. So theirs 70% off their calculations I personally (& probably a lot of people as well) don't need

Would there calculations be for hps lights? Something putting off high heat just to cover all bases? And perhaps people running low temp led would suffice with less?

 

[Scotty 420]

Would there calculations be for hps lights? Something putting off high heat just to cover all bases? And perhaps people running low temp led would suffice with less?

Or depending on where you're growing heat may be an issue, although I would think in most of those cases bringing in outside air via exhaust wouldn't be much help as the only reason I could see to need to be worried about temps would be if your tent was in a warm climate. Which would mean you're just going to exhaust in more warm air. Me personally I'm in a basement that never gets above the low 70's so heat isn't an issue for me. And really based on that article the biggest reason they're advocating for as many cfm's as they are seems to be climate control. Which to me means as long as what you're doing keeps your climate in check you shouldn't need to do more IMO.

 

[Max]

Imo you only need an exhaust fan with passive intake

Agree.my 8’ phresh 720cfm exhaust fan that has a speed controller is plugged into an wifi temp/cool inkbird and comes on when room temp is reached.which is every 1.10 -1m.20secs and extracts the heat and rh..i use heat to control room temps..by using heat with a finned heater which has multible settings I can have it extracting the heat before the rh gets to high and when it’s not extracting the dehuey is helping keeping it in check..it’s just a 5x5 room .while 720cfm is over kill for that room size my thinking was if I get a big ass fan I can have it on low to keep the noise down.I have 2 6’ square shutters for passive ventilation and a big square box on the outside with hepa filters to trap mold spores .I’m in an outside insulated shed so that was a must have..