A couple of fan questions

[cough_cough_eer]

I have a 265cfm inline fan . I'm wanting to vent a 400 watt hps(for temp control) and use a carbon scrubber, probably about the size of a 5 gal bucket .I plan on using 6 inch ducting conected to a Y shaped duck with the fan sucking the air out into the attic. Will this one fan do the job or will I need to buy another fan? could I use a 4 inch ductwith a reducer or would it be better with the 6 inch? The growroom is in a bathroom and already has an exhaust fan, I was wanting to replace that fan with my new fan, or should I mount the new fan lower, ya know closer to the plants?

Any help will be appriciated I'll probably have more questions later

my room is 6 x 5 x 7H, I have 6 plants,400wattHPS

 

[BuzzBob]

Hey CCE! --

Well, allow me to respond from my "On the Learning Curve" point-of-view. That'll give you some insights, and will also get your thread back on the Active Topics list. Then maybe someone will come along and tell me I'm fill o' chit, correct me, and in the end give you what you need!

First, I believe I have read that good ventilation should turn the room's air over roughly twice per minute. Your room is roughly the same size as mine, and is about 210 cu. ft. So, while the fan you have will turn the air once, it will not do it twice...

As far as the ductwork, etc. I am not sure... I believe with larger ducts, higher air volume passing through will make less noise. That said, I don't recall reading a duct size to cfm recommendation anywhere... Good question!

To get the most bang {cooling} for your cfm, I would suggest air cooling the light. You know, attach the exhaust pipe directly to your light hood, and draw air across the lamp, and up the exhaust. If that is not feasable, then mount the exhaust line over the lamp, as the hot air will rise.

As a side note... Are you planning on flowering with the entire room? If so, that 400 watt hps probably won't be enough... I, too, have a 400 hps, and only plan to flower in approximately 8 sq ft of... Which gives me 50 watts per sq. ft.


Hope that helps!

-Bob

 

[cough_cough_eer]

Hi buzz bob

Hi buzz bob

thanks for replying to my questions. I did want it back up on the active topics list.I think it got put away as soon as I posted it.

yes - I did cut a hole in my hood for air cooling, right now I have a 4 inch vent connected to my bathroom exhaust fan and glass on the bottom to keep the heat inside. I am still waiting on a plug for my fan as it did not come with one. if it donsnt come soon, I'll just go to home depot and make one.

flowering- I usually only have about 4-5 females . I would like to have another light but i only grow for personal use and I usually harvest more than I can smoke. but 2 400 watters would be perfect for that room.

 

[cough_cough_eer]

anyone else have any comments or suggestions. My HVAC skills are very limited.

 

[cough_cough_eer]

anybody?

 

[bartender187]

I think you should be fine. A 265 cfm inline should be able to vent your light fine, and since its a centrifugal fan it should easily be able to take the pressure from the filter. Try it out, and run it for a day to see how your temps are. If its not enough check out this website, they offer cheap squirrel cage blowers.

www.surpluscenter.com

bartender187

 

[Guest]

265 cfm is fine strait off the light housing. I had one that was close to that setup and heat from the light was not a problem.

I stepped up the next round though to a 440cfm because I was trying to create a vacuum affect between two rooms.

Were going into fall so your ambiant temps are not going to be such a bitch to overcome.

When all else fails, run it and see what happens

Tex

 

[cough_cough_eer]

hey, Thanks for the replys, bartender and tex,very helpful. I plan on setting this up on sun, then we will see what happens., but now I know to make room for another fan if needed.

One more Question--- I have an air conditiner vent that blows cool air into the room, do you think I'm gonna need an intake fan also ,or will the air conditiner be suffiecient?

bartender---- that website does have great prices, I thinking about buying more inline fans to put on my air conditiner vents to help cool the rest of the house
tex-- I usually dont grow in the summer becouse of the heat, but I came to this site and got all these free seeds and good genetics, i just could not help myself. I did a test grow becouse i couldnt decide what to grow first.

see buzzbob--- nobody told you that you were full of poop. you have definietly done your homework.

 

[BuzzBob]

HiYa CCE!

Ayuh, I did not expect anyone to really slap me down or anything, 'cause that's just not the way of things around here. But I kinda felt that sionce I was speaking from research, and not first-hand knowledge, I should throw in a disclaimer of sorts.

Plus, it set the stage for others {TK and 'tender in this case} to come along and provide either supportive posts, or contradictory information.

Note: I have been watching this thread, as I too am still in the throws of determining what ventilation I'll need here pretty soon! So good information!!


I hope you have what you need now, CCE!

-BuzzBob

 

[cough_cough_eer]

hi buzz bob
your so funny i enjoy all of your posts.
but I'll definently let you know how it works out.

 

[bartender187]

Hey CCE, your AC will help loads to keep your tempurature in check, but I would still make some intake holes, so your fan as has enough fresh air to run at full CFM. You dont need a fan, passive intake and active exhaust works very well.

bartender187

 

[cough_cough_eer]

Thanks bartender,
with my current set up my temps are 90-95 , so it sounds like when I hook up this fan should get it down to the 80's. Good thing for my grow its been an exceptionaly mild summer.

 

[Guest]

My advice is to put the carbon scrubber at the end of the line in the attic, and vent directly from the hood. As BuzzBob said, you get the most out of your fan by venting the light, as well as more space in the growroom by moving the scrubber.

Using a Y adapter for a scrubber and a light will be hard to tune in, you will probably have to use a dampner. Also, 6" duct may be overkill for this light. I would go with 4", it what most air cooled hoods are setup for these days.

I aircooled 2 400Ws in a closet, and 1 1000W an another closet, without running AC. I can set a pint of Ben and Jerry's on top of any one of them while I work with my plants and it won't melt!

Don't forget circulation, it is nearly as important for your plants as ventillation.

Hope this helps.

 

[cough_cough_eer]

thanks Phototropic

thanks Phototropic

Let me see if I got this right

put carbon srubber in attic,run a vent tube from the scrubber to the light, get another vent tube, put on other side of light (remove glass from light) and run that vent to the fan and back out the attic.

I'll try to post an illistration later.

 

[Guest]

I reread what I wrote and wasn't very clear.

Air is extracted directly from hood. It extracts the room air as well as cool the light. Next inline is your fan, then up to the attic to to the carbon scrubber. You can quiet things a bit more if you put the fan in the attic too (so long as it can't be heard where its shouldn't).

If your hood has louvers on the side (like the one in the pic) leave the glass. If not, you may want to try taking it off.

The benefit here is that most of the heat doesn't get the chance to accumlate in the room, it gets sucked right out.

Add a small fan for circulating the air and you should be good to go.

This pic shows how my closet is ventilated. Essetially I did the same thing I am recommending you try, except I put the fan and the scrubber in another room rather than in the attic.

 

[cough_cough_eer]

I made some diagrams of ideas I've gotten from this thread.

this is what i got from phototropics idea. I like it real well but unsure my fan can handle it (265 CFM) I would probably leavethe srubber in the grow room . not sure about going into the attic (scarry up there)

Click for Larger Image

this illistration showa my first idea, but agian not sure if the fan will do the job

Click for Larger Image

This illistration shows what I was thinking about doing in the event I need a 2nd fan.I am unsure about connecting 2 fans to one vent though. both fans will be venting to the outside but not sure if its ok to put 2 fan in the y shaped duct

Click for Larger Image

 

[BuzzBob]

G'Morning CCE! --

You know me... Lurk'n around, look'n for tid bits here 'n there...

Actually, here is what I got from phototropic's description:

Click for Larger Image

In your diagrams, it seems to me that you would be drawing unscrubbed air out your exhaust, via the cooling run from the light.

Phototropic's concept is that you exhaust your room via the light, and then out through the scrubber at the end of the line.

Does that make sense? I need more coffee...

 

[cough_cough_eer]

Hi buzzbob
I need my coke (a cola) and I dont have any.but anyway,enough of my problems

I thought the same thing as you did at first but I thought it was better if the fan was to pull the air though the srcubber and not push though it. or does it really matter


one more question---does the air need to be vented to the outside or can I just vent into the attic.?

 

[BuzzBob]

Hi CCE,

I have read discussions on Blowing vs Sucking {such talk! }, and fan back-pressure, etc. For the most part, I believe, it is moot point. Others may have a different opinion...

As for attic venting... I think into the attic is fine. Especially if the attic has the normal eve vents.

At least that is what I have currently planned. i.e., Running a vent line from the grow room in the basement, up through the corner of a closet in an unused bedroom, into the attic, to a scrubber which is located right next to the furnace/hot water heater vent pipe.

The idea of placing the scrubber next to the furnace/hot water heater vent pipe is to keep a localized infrared footprint in my attic. i.e., one hot-spot. -- I know, I know... Too paranoid!

 

[Guest]

I agree with BuzzBob. You have been right on the money Buzz, you sure you haven't done this before? : )

The only way to scrub the air clean it to either suck or push ALL the air through a carbon scrubber.

The problem with keeping the scrubber in the growroom (diagram 1) is that you will need to use an inline carbon scrubber. They are not available commercially, and I have yet to see a diagram or build plans for an inline version at OG or here.

By adding a Y adapter (diagram 3) you are at best scrubbing 50% of the room air.

My guess is that you would get the same results from 1 fan the way I have recommended (BuzzBob diagram), as you would if you used 2 as in (diagram 3). If you are going to add another fan, I suggest 2 runs up to the attic. The Y adapters lose lots of airflow (CFM).

I know attics are scary, (trust me you wouldn't want to go in the one I was in last week) but you only have to go up there once!

Nice diagrams, and planning, both of you. I love to see people using their brain before they just go out and do something!

Good luck and shout if I can help!