Good Filter and Inline fan.

jarvild said:

I am cooling a 4x4x7 Grow box with a Amazon Ven-Tech 190 cfm fan filter combo with a 600 watt hps bare blulb and a 40 quart dehumidifier inside. Input air is 68 degrees. Max temp runs 82 degrees when both light and dehumidifier are running. Average temp about 76 degrees

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Maybe my fans suck. I went with fancy schmancy *silent* fans. Perhaps they should not be used this way....

Jiji...you were around in a thread I started a week or two ago about my problem. What's your take...poor fan choice?
The fans I was using are here:
http://www.hvacquick.com/products/residential/AirFlow-Boosting/Inline-Air-Booster-Fans/S-P-TD-SILENT-Series-Inline-Fans

For the 4x4, i was using two of the TD-100XS wired to the HIGH setting.

Are you pulling through a filter? Length of your duct,elbows? Those fans don't look like they can handle much static pressure.

jarvild said:

Are you pulling through a filter? Length of your duct,elbows? Those fans don't look like they can handle much static pressure.

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Yes. One of two fans was pulling through the filter. Filter was in the tent. Had about a 4 foot run with one loose elbow into the fan. Exhaust from the fan had no ducting. There seemed to be good air pressure. If I stood in front of it it would blow my hair. But I see the static pressure chart now...yikes...does not look very good.

Hot Diggity Sog said:

My *other* tent is 4x4 but I only had a 200 CFM exhausting and I could not manage the heat so it's been taken down for the time being.

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4x4 will need 2 400CFM fans and cool hoods if you want low temps. I have mastered my 4x4 but it wasn't cheap I have to run Portable AC. Nvhak49 I would get ipower fans super tough and quite.

Mainlinekush said:

4x4 will need 2 400CFM fans and cool hoods if you want low temps. I have mastered my 4x4 but it wasn't cheap I have to run Portable AC. Nvhak49 I would get ipower fans super tough and quite.

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This is Nvhak49's thread and I don't mean to hijack it but do you mind if I pick your brain for a few minutes?

Could you just provide an overview of your 4x4 configuration for us?

[/QUOTE] is Nvhak49's thread and I don't mean to hijack it but do you mind if I pick your brain for a few minutes? [/QUOTE]

Sure bro I'm using the 4x4 6.5 foot modle set up for 6 inch intake on floor and 6 inch exhaust at ceiling.
I'm using a ipower 6inch exhaust fan that is outside tent. My filter runs to my first hood then inline to second then to ceiling for exhaust outlet. Then the ipower fan pulls it out of my garage through my wall heater exhaust out let.
I'm using 6 in flanges that allow me to cut everything to spec and seal it with hose clamps.

So far I spent $200.00 or so on 2 ipower fans and a carbon filter, and 25 ft of duct foil.
Fan speed controller $19.00
I spent $135.00 on the 17x24 cool hoods from ebay.
digital thermostat controller $28.00
AC unit $250.00

my intake fan is a floor stand modle only a few feet from my tent it's mounted to 12x6 intake hood that pulls in the cool air from 12,000btu ac unit.When my ambient temp is 68 my tent will be only 72 with lights on and ac.

temps go to 77 w/o the ac or when garage gets really hot.

I hook up a speed controller to my 6inch intake fan incase I turn it down for back pressure.

All my AC and heat is plugged into home made thermostat controllers I set the temp run the wire to my tent and let the garage do all the work.

Mainlinekush said:

This is Nvhak49's thread and I don't mean to hijack it but do you mind if I pick your brain for a few minutes?

Sure bro I'm using the 6.5 foot modle set up for 6 inch intake on floor and 6 inch exhaust at ceiling.
I'm using a ipower 6inch exhaust fan that is outside tent. My filter runs to my first hood then inline to second then to ceiling for exhaust outlet. Then the ipower fan pulls it out of my garage through my wall heater exhaust out let.
I'm using 6 in flanges that allow me to cut everything to spec and seal it with hose clamps.

So far I spent 200.00 or so on 2 ipower fans and a carbon filter, and 25 ft of duct foil.

I spent 135.00 on the 17x24 cool hoods from ebay.

my intake fan is a floor stand modle only a few feet from my tent it's mounted to 12x6 intake hood that pulls in the cool air from 12,000btu ac unit.When my ambient temp is 68 my tent will be only 72 with lights on and ac.

temps go to 77 w/o the ac or when garage gets really hot.

I hook up a speed controller to my 6inch intake fan incase it's cool so I turn it down.

All my AC and heat is plugged into home made thermostat controllers I set the temp run the wire to my tent and let the garage do all the work.

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[/QUOTE]

So you are pulling with a 400 CFM from inside to outside but then you are also blowing into the tent with 400 CFM? How do you maintain negative pressure that way?

So you are pulling with a 400 CFM from inside to outside but then you are also blowing into the tent with 400 CFM? How do you maintain negative pressure that way?[/QUOTE]

The exhaust has alot of duct to set lights low but it still draws the incoming air nicely. That's when I turn my intake down to like 80% the tents pressure doesn't balloon the tent
As long as you duct it well and use same size fans you should be able to control the pressure.

Okay. Thanks for the info and detailed description man...it helps!

One final question:

When you have to open your tent and do work like watering, smell is escaping. Do you find that the smell dissipates after a short period of time or does it wreck your garage?
That is one of my delimnas right now...I have to *also* control that situation.

Hot Diggity Sog said:

Okay. Thanks for the info and detailed description man...it helps!

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Yeah I'm going to repot my girls this week and give tent a good sweep and cleaning up. I'll take some more pictures. Those hoods saved me and portable ac was my only option windows in my garage are super narrow won't fit a ac unit
I think when it comes to ventilation get Everything done right it will last for years. I swear by environment and care and overall cure of our medicine.

It smells in garage....but 5 feet from door nothing. I climb on my roof and I can barley smell the flowers. I have better circuit breaker in my garage otherwise I would love to have a room instead.

I dont know about the Phat / Rhino thing. You can still purchase the normal Phat filters in the US.

@Hot Diggity Sog I think you had a couple things going against you

Using tents there are quite a few variables so what works for one may not work for others

However there are some good formulas to give you a baseline

You can estimate how many cfm of exchange per CU ft and guestimate your delta T or difference in temperature

Although, it gets tricky when your using a bunch of lights and restrictive carbon filters.

Centrifugal fans work best under pressure. According to vendors numbers (biased info) generally axial hybrids move more air with less electricity with zero pressure.

Under 6 inch fans efficiency drops a lot, and if thats too much airflow you can always purchase a variac.

IMHO, its easy to keep the delta T whithin 10-15 degrees ambient

I think your problem was that your ambient air wasn't constant. Instead of evacuating heat outside, you were heating up ambient air.

- Jiji

Hot Diggity Sog said:

This is Nvhak49's thread and I don't mean to hijack it but do you mind if I pick your brain for a few minutes?

Could you just provide an overview of your 4x4 configuration for us?

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No worries

cheap and effective I use the ventech 4in inline fan and filter for right at 100$ and have been running both fans for well over a year and I religiously change filters every 6 months whether i need to or not

Mainlinekush said:

Yeah I'm going to repot my girls this week and give tent a good sweep and cleaning up. I'll take some more pictures. Those hoods saved me and portable ac was my only option windows in my garage are super narrow won't fit a ac unit
I think when it comes to ventilation get Everything done right it will last for years. I swear by environment and care and overall cure of our medicine.

It smells in garage....but 5 feet from door nothing. I climb on my roof and I can barley smell the flowers. I have better circuit breaker in my garage otherwise I would love to have a room instead.

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Hey man so yeah thanks for the info I really took it to heart. But, I just invested in a raptor 8 air cooled hood, a sg ballast and a tent. 4 inline fans, duct for everything, nutes you know the drill..so I had to improvise. But before anyone throws out some negative vibes, let me tell you it is working way better than I could have ever imagined. I also have a window dilemma, they are the stand up style and the only AC I have is a window mount. So after setting up I must stay on a tight budget to make everything work for a harvest or two.

I built a manifold on the back of it out of styrofoam insulation and heat retarded expand foam. Those newer ACs throw a LOT of heat. And I have zero in the tent.

I put a 250cfm duct fan in the manifold blowing the air it release through the duct. Simply ran the duct to the window that's nearby, made a manifold in the window, and turned it on. I've had zero issues with climate since. It's on a controller and both the AC and fan that goes with it are on a timer that is 15 minutes short of the light cycle.

The exhaust however, uses the same size fan and runs around the clock. No filter where this is the veg tent. The hood has a dust filter on one side and is ducted out of the tent to yet again a 250 cfm inline fan.

But again thanks for your help it's nice to see someone taking there time to get the NOOBS up to par. I appreciate it, happy growing as always.