Intake Fan help

Chefman86

Chefman86

Member
I am going to break down and get an inline fan for an active intake for my 4x4 tent. I have an AC infinity T6 and my temp in my tent is 85 degrees with both LEDs running at full power. I am currently using a passive intake, and want to transition into an active air intake.
My goal is to drop temperatures and reduce a little negative pressure inside the tent.
With everything said, what size intake do I need to get a 4" or 6"? Would you get another AC Infinity (If I do wind up going with an AC Infinity can I plug that into my controller on the T6) or just an inline fan with a speed controller for the intake?
I would like to try and get my temps down from 83-85 to 77-79 (Currently I am in veg now). My RH is anywhere from 50-55%.
What do you recommend?
 
If you are running an exhaust fan with a carbon filter then your intake fan should be as powerful as the exhaust or you'll just end up sucking air thru the intake fan and make it redundant. Can you not open more vents for easier passive intake? A matching intake fan with a speed controller on it would let you match the speed to keep just a slightly negative pressure in the tent. I only have an exhaust fan on a speed controller and a temp/rh one so the fan only comes on when needed. Cool basement temps so even now my intake air is only 64F.

What is the temp of the intake air? You should be able to cool the tent more if the intake air is cool. If it's already warm then a small window AC unit could cool the air in the room you have your tent in and that would really help.

:peace:
 
OldMedUser said:
If you are running an exhaust fan with a carbon filter then your intake fan should be as powerful as the exhaust or you'll just end up sucking air thru the intake fan and make it redundant. Can you not open more vents for easier passive intake? A matching intake fan with a speed controller on it would let you match the speed to keep just a slightly negative pressure in the tent. I only have an exhaust fan on a speed controller and a temp/rh one so the fan only comes on when needed. Cool basement temps so even now my intake air is only 64F.

What is the temp of the intake air? You should be able to cool the tent more if the intake air is cool. If it's already warm then a small window AC unit could cool the air in the room you have your tent in and that would really help.

:peace:
Click to expand...
The intake air is around 75 to 77°. I am in a basement but the part where my tent is is not air conditioned. The lights in my tent really warm things up when I turn all the lights on both LEDs. My temp with both lights running full power is around 85 degrees. I was hoping to get that down with an active intake fan. I don't want to rely on opening vents, because when flower comes I will have to velcro those vents back up. So I was trying to rely on two passive intakes that I was using. I have two 6-in duct tings coming out of each side of my tent that are about five or six feet in length with a piece of filter attached to the end of the ducting and the other end going into my tent on both sides. But I feel that I'm not getting enough air into the bottom of my tent as the T6 is pulling at speed 8 but my temperature is still 83 to 85 degrees. Like I said I thought an active air intake would help. I really don't want to have to buy a window AC unit as my tent is in a basement room that I don't really have room for a window AC unit in.
 
Chefman86 said:
The intake air is around 75 to 77°. I am in a basement but the part where my tent is is not air conditioned. The lights in my tent really warm things up when I turn all the lights on both LEDs. My temp with both lights running full power is around 85 degrees. I was hoping to get that down with an active intake fan. I don't want to rely on opening vents, because when flower comes I will have to velcro those vents back up. So I was trying to rely on two passive intakes that I was using. I have two 6-in duct tings coming out of each side of my tent that are about five or six feet in length with a piece of filter attached to the end of the ducting and the other end going into my tent on both sides. But I feel that I'm not getting enough air into the bottom of my tent as the T6 is pulling at speed 8 but my temperature is still 83 to 85 degrees. Like I said I thought an active air intake would help. I really don't want to have to buy a window AC unit as my tent is in a basement room that I don't really have room for a window AC unit in.
Click to expand...

I hear you about the problem getting AC in your situation. My grow room was built as a cold storage room and is about 7x9x6.5'h in a basement/tall crawl space that's 10x30x7'h. I want to expand and build it as a sealed grow space using a dual hose portable AC/dehumidifier and CO2. Lack of funds atm so am just going to build a separate 5x5 space for now and use that for veg as veg doesn't really need the amount of climate control I have going on in the main room. I'd need another 2 grand or so to set things up how I'd really like it but I don't really need so much and can use the spare bedroom up here for veg space too and have been. Stinking hot there now tho but it'll start getting cooler soon.

I'm not convinced that adding an intake fan is going to be your sol'n tho it should help get air thru the exhaust system as it will reduce the negative pressure and make it easier for the exhaust to move air. You need to move more air thru the tent so a bigger exhaust that can move more air is what I think you need. Get something bigger for that chore and use your existing fan for your intake would be what I would do. Might be too much for your carbon filter if odor is a concern then you'd need a bigger one of those too.

My 6" has been making lots of noise for the last 5 years so I bought an 8" VivoSun for a replacement but haven't used it yet. I bought a plastic 6-8" adaptor for it but damned if the ends on the fan aren't smaller. 7 5/8" instead of 8" so need to DIY something to make the adaptor fit tight as it's on the downstream side so will be under pressure. I really wanted a Vortex S Series 8" but it's twice the price. It doesn't have a built-in speed controller but the VivoSun does so it would be another $40 or more for one of the good ones.

vortex_s800_1.jpg

:peace:
 
Chefman86 said:
The intake air is around 75 to 77°. I am in a basement but the part where my tent is is not air conditioned. The lights in my tent really warm things up when I turn all the lights on both LEDs. My temp with both lights running full power is around 85 degrees. I was hoping to get that down with an active intake fan. I don't want to rely on opening vents, because when flower comes I will have to velcro those vents back up. So I was trying to rely on two passive intakes that I was using. I have two 6-in duct tings coming out of each side of my tent that are about five or six feet in length with a piece of filter attached to the end of the ducting and the other end going into my tent on both sides. But I feel that I'm not getting enough air into the bottom of my tent as the T6 is pulling at speed 8 but my temperature is still 83 to 85 degrees. Like I said I thought an active air intake would help. I really don't want to have to buy a window AC unit as my tent is in a basement room that I don't really have room for a window AC unit in.
Click to expand...
Well, there is something weird going on if you have a T6 fan on speed 8 with a 4x4 tent, that tent should be collapsed by speed 6 unless you have all the other ports open with ductwork for passive intake. I have a T6 in my 4x4 tent on a carbon filter and I never get the speed over 7 with all the ducts open, it pulls so much air thru the tent it is ridiculous. I have a T4 intake fan that I set to kick on if the tent goes over 80 degrees, bringing air from outside directly into the tent.

Use long pieces of 4" or 6" ductwork with 180 degree bends for passive intake in the port holes, that keeps the air flowing and keeps the light out. That way you don't need the flaps open for air flow when you start to flower.

I think you need to get the room temp down or find outside air colder than 77 degrees to bring into the tent and cool it down. I run my lights from 10 pm to 10 am (flower) or 4 pm (veg) and use the colder night temps to bring fresh air into the room and the tent. If I keep the room at 68 degrees the passive intake from the exhaust fan is enough to keep the temps in the tent at 78 degrees. I run the HLG-550 in my flower tent.
 
Driver733 said:
Well, there is something weird going on if you have a T6 fan on speed 8 with a 4x4 tent, that tent should be collapsed by speed 6 unless you have all the other ports open with ductwork for passive intake. I have a T6 in my 4x4 tent on a carbon filter and I never get the speed over 7 with all the ducts open, it pulls so much air thru the tent it is ridiculous. I have a T4 intake fan that I set to kick on if the tent goes over 80 degrees, bringing air from outside directly into the tent.

Use long pieces of 4" or 6" ductwork with 180 degree bends for passive intake in the port holes, that keeps the air flowing and keeps the light out. That way you don't need the flaps open for air flow when you start to flower.

I think you need to get the room temp down or find outside air colder than 77 degrees to bring into the tent and cool it down. I run my lights from 10 pm to 10 am (flower) or 4 pm (veg) and use the colder night temps to bring fresh air into the room and the tent. If I keep the room at 68 degrees the passive intake from the exhaust fan is enough to keep the temps in the tent at 78 degrees. I run the HLG-550 in my flower tent.
Click to expand...
When you say wierd what do you mean? I mean if the fan is running on speed 7 or 8 and I only have (1) porthole on each side of tent open for 6" ducting for passive intake what is going on? Should I send my AC Infinity T6 back for a new one? I don't have any other vents or portholes open....and it isn't collapsing because of negative pressure. there is a good amount of negative pressure but not enough to bend the tent bars or suck itself into collapsing onto itself.
What do you recommend I do to make sure that that T6 isn't defective?
 
OldMedUser said:
I hear you about the problem getting AC in your situation. My grow room was built as a cold storage room and is about 7x9x6.5'h in a basement/tall crawl space that's 10x30x7'h. I want to expand and build it as a sealed grow space using a dual hose portable AC/dehumidifier and CO2. Lack of funds atm so am just going to build a separate 5x5 space for now and use that for veg as veg doesn't really need the amount of climate control I have going on in the main room. I'd need another 2 grand or so to set things up how I'd really like it but I don't really need so much and can use the spare bedroom up here for veg space too and have been. Stinking hot there now tho but it'll start getting cooler soon.

I'm not convinced that adding an intake fan is going to be your sol'n tho it should help get air thru the exhaust system as it will reduce the negative pressure and make it easier for the exhaust to move air. You need to move more air thru the tent so a bigger exhaust that can move more air is what I think you need. Get something bigger for that chore and use your existing fan for your intake would be what I would do. Might be too much for your carbon filter if odor is a concern then you'd need a bigger one of those too.

My 6" has been making lots of noise for the last 5 years so I bought an 8" VivoSun for a replacement but haven't used it yet. I bought a plastic 6-8" adaptor for it but damned if the ends on the fan aren't smaller. 7 5/8" instead of 8" so need to DIY something to make the adaptor fit tight as it's on the downstream side so will be under pressure. I really wanted a Vortex S Series 8" but it's twice the price. It doesn't have a built-in speed controller but the VivoSun does so it would be another $40 or more for one of the good ones.

View attachment 4639102

:peace:
Click to expand...
I'm not sure I understand. If I am doing THE CFM conversion to find out how many CFM's I need to pull out of a 4x4 tent I come up with this...
I don't have ANY 90 degree bends as my ducting is going straight into my 6 inch carbon filter, and then hooked to my exhaust fan (T6), and then a peice of ducting traveling downwards from exhaust letting exhausted air out of tent.
So if I were to get the cubic feet of my tent it would be 106 cubic feet.
Add 20% since I'm using a 6 inch carbon filter, 5% for the 5 feet of ducting I am using, and 5% since I have 500 actual draw watts of LED light I am using.
I get a CFM of 140. That would be the minimum CFM I would need exhausted in a 4x4 grow tent per minute.
My AC infinity T6 inline fan is rated at a 402 CFM....
I'm not sure how that isn't sufficient enough.... I don't think I need to get any bigger exhaust fan....? And definitely not a cheaper one like vivo son for an exhaust...
Would you recommend putting in a small four or six inch active air intake inline fan to help with this problem?
 
Chefman86 said:
I am going to break down and get an inline fan for an active intake for my 4x4 tent. I have an AC infinity T6 and my temp in my tent is 85 degrees with both LEDs running at full power. I am currently using a passive intake, and want to transition into an active air intake.
My goal is to drop temperatures and reduce a little negative pressure inside the tent.
With everything said, what size intake do I need to get a 4" or 6"? Would you get another AC Infinity (If I do wind up going with an AC Infinity can I plug that into my controller on the T6) or just an inline fan with a speed controller for the intake?
I would like to try and get my temps down from 83-85 to 77-79 (Currently I am in veg now). My RH is anywhere from 50-55%.
What do you recommend?
Click to expand...
You need to keep your temps in the 81-83f range when running LED’s to accommodate vpd this is now a proven fact your temps are fine just bump humidity up look into vpd charts that should be every growers bible
 
I have a 8”750 cfm fan sucking air out dialed down to 70% in my 4x4 with a carpet dryer fan blowing in my bottom vent so I don’t suck in my tent it’s worked amazing I had a 4” ac infinity fan hooked up but it didn’t keep up with the stink so I up graded I always go big when it comes to fans you can never have to much air exchange
 
Buddernugs said:
I have a 8”750 cfm fan sucking air out dialed down to 70% in my 4x4 with a carpet dryer fan blowing in my bottom vent so I don’t suck in my tent it’s worked amazing I had a 4” ac infinity fan hooked up but it didn’t keep up with the stink so I up graded I always go big when it comes to fans you can never have to much air exchange
Click to expand...
So I guess my question is with the AC Infiniti T6 inline fan as my exhaust and no active intake fan as of right now, my exhaust fan is fine You're saying I need an inline fan for an active intake? Just making sure I'm understanding what you're putting down
 
And are you recommending me getting a 4-in or 6-in inline fan for an intake? As the inline fan I am using for my exhaust is a 6-inch AC Infinity cloud line.
I've heard you don't want to push too much air with your intake that you're exhaust can't push out? So you want your intake fan to be smaller than your exhaust, the same size as your exhaust?
 
U want just enough negative pressure so no stink escapes the filter do you want all the air going through that filter what I do is get a lighter unzip the tent or open up a vent and light the lighter... if it sucks the flame in even just a little that’s golden ...if it blows the flame away from the tent you have too much intake you don’t want to suck the tent in so u gota adjust to make sure you retain negative pressure I’d say just open up a bottom vent to allow more intake if it’s still sucking the walls in open another one... no reason to buy shit when u don’t need too
 
Buddernugs said:
U want just enough negative pressure so no stink escapes the filter do you want all the air going through that filter what I do is get a lighter unzip the tent or open up a vent and light the lighter... if it sucks the flame in even just a little that’s golden ...if it blows the flame away from the tent you have too much intake you don’t want to suck the tent in so u gota adjust to make sure you retain negative pressure I’d say just open up a bottom vent to allow more intake if it’s still sucking the walls in open another one... no reason to buy shit when u don’t need too
Click to expand...
So you are lighting the lighter right below the carbon filter? or are you lighting the lighter down at the bottom of the tent by the intake portholes and vent holes? The only reason I wasn't using the vent holes with the velcro over them was because in flour I would have to cover them back up with velcro because it wouldn't be light resistant with those velcro patches off better supposed to cover the vents.
So how will I know if I need an intake fan? And if I do need an intake fan should I get a four or six inch?
 
Chefman86 said:
The intake air is around 75 to 77°. I am in a basement but the part where my tent is is not air conditioned. The lights in my tent really warm things up when I turn all the lights on both LEDs. My temp with both lights running full power is around 85 degrees. I was hoping to get that down with an active intake fan. I don't want to rely on opening vents, because when flower comes I will have to velcro those vents back up. So I was trying to rely on two passive intakes that I was using. I have two 6-in duct tings coming out of each side of my tent that are about five or six feet in length with a piece of filter attached to the end of the ducting and the other end going into my tent on both sides. But I feel that I'm not getting enough air into the bottom of my tent as the T6 is pulling at speed 8 but my temperature is still 83 to 85 degrees. Like I said I thought an active air intake would help. I really don't want to have to buy a window AC unit as my tent is in a basement room that I don't really have room for a window AC unit in.
Click to expand...
Why do you want the temp down lower? 82-85 degrees is ideal canopy temperature for LEDs. They don't have the IR that an HPS has.

Edit: Also a few things i myself noticed trying to get optimal atmospheric conditions inside closed areas is:
Are your thermometers calibrated?
Are you relying on a metal temp probe for your temp and is it directly under the light?
I had a couple thermometers that were off by a few degrees as well and I thought I was running hotter than I was until they were properly calibrated.
 
dbz said:
Why do you want the temp down lower? 82-85 degrees is ideal canopy temperature for LEDs. They don't have the IR that an HPS has.
Click to expand...
Really? So 82 to 85 is perfectly fine for veg and flower? If so I'm golden. I just keep hearing from various sources that 82 to 85 is high, and you wanted to be in between like 77 and 79° for optimal temperature
 
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