Filter-Hood-Fan Question

Hey guys quick question. I have a relatively small grow box, 24" x 40" x 72". I am buying a 400w HPS with either a cooltube, euro reflector or easycool6... I will also be purchasing a 424 CFM Inline fan with carbon filter combo .

From what I have read it is better to pull air through a carbon filter/air cooled hood, than it is to push it through. I am venting out the top of my box to an attic. Someone with ventilation experience please let me know if this setup will work for me, or if there is some better way of rigging it up.

Also, I know this has been covered on this site, but what is the best value cooltube, euro reflector, or an easycool6?

Thats perfect. If you can put your fan in the attic it would help, Im guessing your getting the combo from HTG? That fan is pretty loud. I wraped mine up in old towels and blankets. No problem now. Good luck and happy growing!

I had the easy cool 6 with a 250 last grow, about the same dimensions..my only advice is to stay under 4 plants and do not veg for longer then 5 weeks. I upgraded to a larger hood/tube and a 400 though..built a custom chamber for it. You will need an active intake as well, under 200 cfm is fine, and if you can vent the hood sepretly, and get another fan for the filter is ideal.

UberSpike said:

Hey guys quick question. I have a relatively small grow box, 24" x 40" x 72". I am buying a 400w HPS with either a cooltube, euro reflector or easycool6... I will also be purchasing a 424 CFM Inline fan with carbon filter combo .

From what I have read it is better to pull air through a carbon filter/air cooled hood, than it is to push it through. I am venting out the top of my box to an attic. Someone with ventilation experience please let me know if this setup will work for me, or if there is some better way of rigging it up.

Also, I know this has been covered on this site, but what is the best value cooltube, euro reflector, or an easycool6?

Click to expand...

Your filter/hood/fan design is perfect.

The fan you are purchasing is a bit large for your grow box, but that's actually very handy because you can purchase one of these also: http://aeroponicsnmore.com/climate-control-ventilation-c-23_5/temp-2v-fan-speed-control-variable-idle-setpoint-p-181 That will run your fan at idle speed during normal operation, but if it gets too hot the fan will automatically kick into high speed and instantly cool your room. I use one and it has worked great and I don't need an AC.

Dirt - I will put my fan in the attic, that's a good idea I just hadn't thought about it before.
Mongo - I have a passive intake that I thought would be more than adequate. The thumbnail shows what my intake looks like.
I know it is ideal to vent the hood/box separately, I was hoping to cut costs by only buying 1 large fan though.
SmokingRubber- I am aware the fan is big, and as nice as having that thing would be, I don't have an extra $120 to drop.
I was planning on getting a $20 Fan Speed Controller from HTG, that way I can run the fan maybe 50-70% to cut down on noise and increase the life of my fan. This should be good right? 50% of 424 CFM is still 212 CFM, my box is 3.5x2x6= 42 ft^3. From there I figure I can manually adjust the Fan speed depending on temps without having to spend over $100.

Mongo, my main question to you is why stay under 4 plants? This will be my first hydro grow (have had success in soil but I'm tryin to step it up here), but I was thinking I could get 6 girls in a homemade 30gallon dwc/bubbleponics system I have already created. I have 7 sqft of space to grow in, I thought 1sqft/plant under a 400w was enough as long as you don't veg them for too long.

By the way, all of your help is greatly appreciated, everyone on here is so helpful, thanks again!

This passive intake would be the entire width, 40", of my box.
I was thinking I would run a 2x4 across the middle for support, meaning that each level would be about 3".
Alot of air can be moved through a 3x40 passive intake if I am not mistaken

UberSpike said:

SmokingRubber- I am aware the fan is big, and as nice as having that thing would be, I don't have an extra $120 to drop.
I was planning on getting a $20 Fan Speed Controller from HTG, that way I can run the fan maybe 50-70% to cut down on noise and increase the life of my fan. This should be good right? 50% of 424 CFM is still 212 CFM, my box is 3.5x2x6= 42 ft^3. From there I figure I can manually adjust the Fan speed depending on temps without having to spend over $100.

Click to expand...

It sounds good on paper, but you're not in there constantly watching the temperatures. It could spike and you may not know about it for hours. I assume you work during the day?

I bought a fan speed controller first, just like you. I was constantly fighting the temperatures. Plus, that controller made my fan hum like a mf. I don't know why, I had a good one that was not supposed to do that. When I hooked up the temp controller, I was pleasantly surprised that the hum went away and so did my constant temperature struggle.

Extra heat in your grow room can cause major problems. Any tool that you can purchase for $120 that prevents that problem is WELL worth it imo. How much do you think your crop is worth?

Personally, I've invested several thousand in my grow and I can't afford to have it fail because I was scared to spend a couple hundred. It's all or nothing. Failure is not an option.

Thanks for the input, I just really don't have the extra funds right now to splurge on something like that. I do work during the day, and I live in a cold climate, so the outside temps will be below or around freezing for most if not all of my grow. My apartment is kept at a (IMO) comfortable 65, so I figured if I got the fan working so that the temps inside the box were below 75 during the day and then around 65, ambient temp, during the night, I should be alright. I am aware this will take some calibration on my part, which I was hoping to do during a weekend. With the constant temp of my apartment (65) I thought that once I had it setup correctly, maintaining a solid grow room temp wouldn't be a big deal. Do you still think it is worth it to spend the extra $100?

As far as the worth of my crop, I will be growing mostly for myself and girlfriend, but we currently (since i stopped soil growing circa 8 months ago) spend maybe $200/month on MJ, so I guess the crop would be worth at least that assuming I can keep a constant stash for us. I am not looking to deal, so once it's up and running I would say this project will be worth $200-$250/month to me.

Plus the added benefit of not having to deal with questionable people with ever more questionable prices, and of course the joy of growing... I just love it

It sounds like you're growing for the right reasons.

Here's what I can tell you that I've learned. Nothing is constant. The plants grow and the outside environment changes. You can fine tune it today, and find them roasting their ass off tomorrow. Do I think it's worth an extra $100 to automate the whole process? HELL YEAH!

A 400w bulb won't fry the girls too quick. You may be okay with just a controller. I wouldn't chance it though since you'll be running this through the summer months too?

A friend of mine uses one of these: http://www.amazon.com/Lutron-TT-300NLH-WH-Credenza-Dimmer-White/dp/B0000DI241

It's only $13 and it will work just fine until you can afford the temp controller.

HEre is the pic of my termo-controler. Sorry I couldnt figure out how to do it im PM.
Dirtfree

remember that air behaves exactly like water.
heat rises...

put the temp sensor where its hot... not on the floor close to the outlets......

example- you cant see the thermocouple(tiny temp sensor) in the pic, but see how the lights are on unistrut rails? the rail allows me to raise and lower the lights according to how i want them in relation to the canopy. since the top oif the canopy is what will get cooked first if you have high temps, that is the same level that my temp sensor is, the top of the canopy. temps exceed 80f it kicks on the 240v intake exhaust fans (no passive system here) and vents the entire cab in less than 1-2 secs...lol.
but the concept is pretty simple. you want the temp sensor where its hot, so it will do its job.
leave the temp sensor on the floor or away from the canopy there might be a 30-40 degree temp difference between the top of the canopy and the floor.

I think this one is better.

I keep mine as close to the canapy level as possible.

That's nice, but it's an on/off switch. I don't want my room/light exhaust turning off. I want constant fresh air and constant hood cooling (during light's on). My fan runs at an "idle" speed until the temp gets to 80. Then it automatically kicks into warp speed and cools the room back down to 75. Plus, I can put the sensor anywhere in my grow room.

An on/off only works well if you've got 2 exhaust fans installed. One fan is always on providing constant fresh air. The other fan can be on/off and only kicks on to cool the room. Of course, then you would need 2 carbon filters. The cost of 2 fans and 2 filters quickly outweighs the cost of the single variable temp controller.

SmokingRubber said exactly what I was thinking. I want a constant supply of fresh air to my growbox, at least during the daytime (lights on) period. This leads me to probably the simplest question I have asked all day but I can honestly say I don't know the "norm".
I was planning on keeping my fan on all the time, even if it is on at a very low level. With my large passive intake I don't like the idea of the fan not being on, aka allowing air to freely flow out of what is designed to be the intake. I was planning on running my fan constantly, which is just another reason that I went ahead and got the big 424 cfm fan, hoping I can increase the life of the fan by not running it full blast.
Is it a bad idea to be constantly running the fan?

First, I don't suggest growing in an apartment. Second, I run my fans constantly. I have 1 144 cfm fan intake,1 424 cfm fan exhausting the hood and chamber (but only during the winter) in the summer I add a can fan 243/filter combo. It all exhausts out of the house along with my clothes dryer. My chambers are in the basement, but here in the south that doesn't save me from the heat.
I had a cabinet built to about those dimensions last year, using the easy cool 6 a 250 and a 105 for supplemental..humidity was a huge problem. When I built my new chambers 4x4x7 with a 4" rise off the floor my humidity problems were solved...but like I said bro, I don't think growing in an apt is a great idea.

Mongo, Although I truly do appreciate your concern, I think you're getting the wrong idea. I do not live in an apartment building or an apartment complex. I call my living situation an apartment, but in reality I live in a house that is divided into two parts, first and second floor. Our landlord is pretty legit. She stops by once a month or so to make sure we haven't completely destroyed the place, as long as I'm paying rent she's happy. I get the good ol "hey, how are you? Have a great day," and then don't see her for another month or two. My neighbors downstairs smoke more herb than I do, so I don't imagine them being concerned about the smell... Despite this, I am hoping to keep the odor to a minimum with a small grow box, larger than needed fan, and a carbon scrubber (mostly for the times I have visitors aka rents/inlaws over).
I have also taken into account the fact that my landlord could hypothetically key into my apartment while I am at work, but I have my grow box inside of my closet in my room.
I have a pad lock on my closet when I am gone. (That is where I keep my valuables )
The closet has doors that allow good airflow, the whole doors are essentially downward slanted vents and there is no light escaping the grow box so there is no reason to be suspicious. The vent up to the attic is my only concern; however my landlord is a 45+ yr old woman that has no business climbing into an attic. She pays me to do most of the repairs anyhow, so if anyone will be going up there it will most likely be myself.
Overall, I have lived here for almost a year, and yes, the fact that I was living on someone else's property was the reason I took an 8 month hiatus from growing (I grew soil before), but I have gotten to the point that I am very comfortable with my situation and have no doubt that I can not only grow successfully, but also without causing any alarm.

After re-reading this post I can see how it would be taken the wrong way; therefore, I would like to re-iterate that I really am thankful that you're looking out for me, sounds like you have your head on a swivel and don't want to see people get busted.
I just wanted you to know that as long as that carbon scrubber works it's magic during the last and most stenchy part of flowering, I shouldn't have any problems.

Edit: Also, I don't live in the south... Humidity will not be a problem, especially now while it is winter. I haven't tested it out yet, but if anything I will have to buy a cheap walmart humidifier to keep the humidity up. I could most likely run the humidifier 24/7 in my bedroom (where the intake comes from), but I will cross that bridge when I get to it.