[Groffuwiwi]

Hi guys, me again.

Ok, so I need to get my math sorted out before my next buying spree.

My tent is 1,65m x 0,65 x 1,80. That equates to 1,93m3, which is roughly 68,16ft3

I know that a CF will reduce the extraction by 30%

From various opinions gathered, everyone seems to agree I need a 6" RVK extractor, as I will
be attempting a passive intake.

I've been to a couple of grow shops an local hardware stores, and in one of them I found what I think is an
RVK extractor, that is supposed to be silent... a couple of different models, but prices are significantly cheaper
than in grow shops.

So my noobness asks ye...


1) What exactly is an RVK extractor... what makes an RVK, and why is it better?

2) What is the volume of air I need to extract per hour? Do I add 30% to 1,93m3/68,15ft3 ?

3) how do I choose the right CF size?

4) The extractor also plays a major role in heat control... but if I can't control the extraction speed, how can I control temps?

anything else I need to know?

Thanks a bunch!

[reds]

Right, deep breath....

1. An RVK is just the make,like, Systemaire or RUCK. They are all very good. Someone correct me if Im wrong but I think RVK are German. So decent enginering assured.

2. Rule of thumb is 20 times per hour.At least, id say.

3. If your fan is 6in then your filter should be at least this,if not bigger. If you put a 8in filter on a 6in fan then there would be hardly any resistance, therefore prolonging your fans life.

4. You could get a temp controled fan but they are expensive. Or a fan controller.

Hope this helps alittle,atb reds.

e2a Dont skimp on the filter. Youll regret not gettin agood one like a Rhino.

This post has been edited by reds: 17 May 2012 - 02:16 PM

[Where Angels Play]

Get the 6" high powered ruck,the best filter you can afford (Rhino),buying an 8" filter and a reducer would be perfect and then build yourself a variac.

That set up would be perfect for your space and also give you near total control.

[Groffuwiwi]

Ok then, let me see if I got this right.

So my tent is 1,93m3 ... x20 = 386mm3 and 6" = 150mm and 8" = 200mm (damn metric vs imperial... the roundings never add up right)

The best match I've found so far is the 425M3 RVK-150-E2-A1 which I can get for 90€ locally. I can't find RUCK anywhere.
Next, a filter

The maximum filter size I found is a Koalair 125x200 (270m3/h) for 80€... Isn't there going to be problems trying to suck 425m3/h from the 270m3/filter?

[Floyd]

Hi mate

You have not mentioned what light you are going to use?
This will also dictate your fan size.

Also, is your tent in a room, loft, garage, shed?

[Groffuwiwi]

Ah right!

Someone suggested I update my profile to include this info... but I can't find where to do that. I'm in a slight rush right now, but will get to that ASAP.

Well, actually my tent should be here today or tomorrow (I hope), I initially bought a 600w. But now I am wondering if I should go for a 400w.
The local shop says its ok for me to swap it. Its an interior room without windows, but very well ventilated corridor, somewhere near, around, over or even under southern europe *cof cof*

So I am dreading excess heat, temps are rising daily and its my first run at this. Though I will have a friend helping. In the future, another 400w for full coverage.

What do you guys think?

Fan size!? dear me... I thought the more fans circulating air, the merrier!

[Where Angels Play]

I use a 400w in a 1x1x2m tent with the kit I listed,running passive intakes and I'm yet to turn the fan above 50% (sits at 40% mostly),the tent actualy heats up when I have it open.My first 4" set up struggled along ok but it was a waste of £50.

In the tent I have a 6" desk top fan hung pointing towards the bulb,a 160mm pc fan blowing over the canopy and a small 80mm pc fan on the floor blowing upwards into the canopy

You must atleast match the CF with the fan,the reason I said oversized is perfect is because you would get less air sound,using an undersized one would be pointless because the air wouldn't come out scrubbed.

This post has been edited by Where Angels Play: 17 May 2012 - 03:03 PM

[Groffuwiwi]

When you say fans... do you mean extractor or in tent circulation?

How do you control the fan speed?

[Groffuwiwi]

From reading other threads, I presume you mean the extractor fan...
I've also read about variac, but seems to expensive to buy, and I'm not qualified to build one.

Anyways, I would still appreciate it if someone could explain post #4 from this thread!

[distracted]

Gurruwiwi, on 17 May 2012 - 02:13 PM, said:

Ok then, let me see if I got this right.

So my tent is 1,93m3 ... x20 = 386mm3 and 6" = 150mm and 8" = 200mm (damn metric vs imperial... the roundings never add up right)

The best match I've found so far is the 425M3 RVK-150-E2-A1 which I can get for 90€ locally. I can't find RUCK anywhere.
Next, a filter

The maximum filter size I found is a Koalair 125x200 (270m3/h) for 80€... Isn't there going to be problems trying to suck 425m3/h from the 270m3/filter?

425 is quite low for a 6" fan you can get better than that, but it will do if that is all you can find. The filter is too small. You don't need the filter yet though so you can set up with a fan and start looking further a field for a 150 (6") or 200 (8') fan, as I said in the other thread you can throw this up in the attic if you are tight for space.

The maths is about volumes, you have nearly 2 cubic metres of air in your tent, so going on the recommendation by another member, if you decide you want to change the air completely 20 times an hour then you need to move 400 cubic metres of air an hour, with a 30% load on a matched filter then you want a fan that can do 530 cubic metres an hour to get your 20 air changes unless you upsize the filter and reduce the filter load, then you can go down but the ability to really shift air when it is hot shouldn't be ignored as it is handy to have

To edit your profile, click your avatar, then on the right hand side is a button saying "edit profile" click that and fill all your details in as an when they change

This post has been edited by distracted: 18 May 2012 - 10:24 AM

[Kapusta]

This might help,( or confuse you even further!) It's from the Can Filters website.

 airflow.pdf (92.26K)
Number of downloads: 27

[Groffuwiwi]

Excellent!

Thanks, I'll give it a shot!

[tomcat69]

The maths doesn't make sense - How is changing 2 cubic meters of air 20 times per hour needing to move 400 cubic metres per hour? 2x20 = 40 right? Obviously heat removal would be the reason why anyone goes beyond this rather than actual air replenishment?

This post has been edited by tomcat69: 05 June 2012 - 09:04 PM