Yet another: Ventilation Question! YAY!

[ItsAllOver]

Preface:
So, I read (read: scanned through) the Ventilation 101 thread.
I think it's great, but it was a bit (a lot) over my head for a cursory glance, which is, honestly, what I'm willing (have time) to give it right now. One of these days I'd love to read it thoroughly, do some homework, and have a full understanding of this topic.
However, for the time being I am leaving it alone and calling myself comfortably ignorant. Feel free to throw that in my face.

This question goes out to anyone that reads the above preface and considers it worth their time to help me anyway. And I'd be willing to bet someone is, because I love ICmag, and that's why.

So...

I am intending on running a single 8" 747 cfm Vortex inline fan through a Y-connector to cool both:

(1) - 55"x55"x84.5" Silver Edition Hydrohut with 1000w aircooled hood, which has 6" inlets. We will be pulling through a 6" CanFilter 100 filter.

(1) - ~3'x4'x7.5' Pandafilm room with a 600w aircooled hood (6" holes) - Pulling through a 4" Canfilter in here.

The 8" fan will be located against the ceiling, pointing straight up into the attic. Then comes the 8" Y-connector. I'll be reducing and using exclusively 6" duct on the 1000w side. On the 600w side I'll have to be reducing down from 8" to 6" from the Y-connector to hook up to the hood, and then reducing again to connect the 6" hood to the 4" canfilter.

Is this going to work? Is my smaller room going to be competing with the bigger room for air movement? I'm sorry, but this issue confuses the hell out of me. I would just set it up and see what happens, but I hate doing something without a little research/question-asking first.

I have access to a 142cfm CanFan which has been used in the past with the 600w hood and filter, but I was sort of unhappy with the heat, and surely it could be better. Could I incorporate this fan into the design to overcome any possible issues? Maybe put it after the hood on the 600w side to increase airflow, but taking advantage of the larger fan, too? Now of course this fan is 4", creating bottlenecks in my duct size, which sucks, but I imagine it might work. Will this wear out my smaller fan?

Ghetto? Maybe, but I'm cobbling together to increase the size of my op.

And once again, thank you to the emergent order and collective knowledge of the masses!
Peace

 

[guest 77721]

I think the heat issues with the 600W light and the 4" filter will be the same when you hook it up to the larger fan. It appears that the 4" filter and 142CFM fan is undersized. The 142 Canfan and the 747 Vortex both produce the same backpressure so when blocked by a scrubber will produce similar results.

If you can get the 600 light cooled right now, it will work when connected to the 8" system. If you can tell me the room temp and measure the growbox temp and the exhaust temp, I can tell you what your effective air flow is. Also any specs or model numbers on the fan and filter would help.

 

[ItsAllOver]

I measured the room temp at 79.2 and the grow tent temp at 82.4 with no carbon filter attached. When I flower, I will have the info with the scrubber, however I will probably have the 8" vortex 747 hooked up by then.
I don't feel like (sorry, I appreciate your willingness to help) taking my exhaust down to measure the temp there. It would be a major PITA.
However, I think you still might be able to help me with the broader questions that I have.

- So you think that the 4" canfilter for the most part is what caused the high temps on my last run? It would surely have a major impact on the amount of air being pulled through the system.

- Considering this, could I leave that filter in place for this grow and use both the 747 and the 142 to cool that side? Meaning:

747 cfm fan -> Y-connector -> Side 1) 6" duct to 1000w hood -> 6" duct to 6" canfilter AND Side 2) 6" duct reduced to 4" 142 cfm fan -> 4" duct then increase to 6" 600w hood -> reducer -> 4" duct to 4" canfilter

That is a ridiculously bottlenecked 600w side with all the reducers, but that's all I can think to do if I want to try and use the 142 cfm fan, too. (will this harm the fan?)
First, though, I'm going to try running just the 747 to both sides and see what temps and air flow look like. That way I can use 6" duct exclusively except going to the canfilter on the 600w side.
OK thanks for checking in on me!
I'm just trying to get it all set up to see what happens. I'd think that the two sides would get about what they need.

 

[guest 77721]

The more I look at this, the worse it looks. I was looking at the specs for an 8" filter connected to an 8" fan. Reducing the 1000W airflow down to 6" will make it run hot too.

Your best bet would be to get a single 6" fan and both hoods together with no scrubbers attached. This gets the heat right out of the lights with no restrictions. The 600W light needs 190 CFM and the 1000W needs 310 CFM for a grand total of 560 CFM.

Take your 142 CFM fan and connect the 4" filter and another 4" filter. You'll save some $$$ on the filters and the large fan and have guaranteed cooling.

 

[ItsAllOver]

So what is the problem using an 8" fan and a 6" filter? The 6" filter doesn't allow enough air in to make use of the fan's cfms?
I'll take reduced efficiency if it works. I don't really have the ability to just play around with things like you're describing, otherwise this would be a whole lot different. The equipment listed above (and I'm not sure about filter size, honestly, it could be an 8", but as the hood is 6" I will have that bottleneck no matter what.) is what I have available. After this grow, I might have enough saved up to get things going in a more efficient way.
It would be cool to have a dedicated bulb cooling fan and one for scrubbing air, with the hoods sealed and everything, but if I go that far, I'm going to go with CO2
Anyway, I'll make a post in here describing how the system I described above works, because that's about the only option I have.

Thx for your