Fan Controllers for both in and out?

[GreenVision]

Hi, in the future grow space I'll be using and active intake, and I'll be using my GAS controller that does both intake and extraction.

 

I'll be placing some small passive intakes in this space so the intake fan doesn't get throttled as it will be smaller than my extraction fan.

 

The extraction is a 12", its currently / usually dialed down to run at no greater than 80%, but to TBH it rarely goes higher than 70% in summer as its such a beast 70% is still 2700cm p/h ish. But I dont want a 12" intake, I was hoping to use a 10" fan with the same concept, run it at 80% max for silent operation.

 

The few times I've looked into it I keep asking myself how the controller will deal with the negative pressure???

 

 

 

As an example, room is 27C and the extractor is running a stable 60% pushing out 2400m3 p/h. The intake is sitting at 70% pushing in 1800m3 p/h, the passive vents taking up any serious negative pressure difference.

 

If for some reason the temps shift, how do I know the controller isn't going to let the extractor fan run down to 30% at 1000m3 p/h whilst the intake fan is now at only 55% but pushing 1250m3 p/h?

 

 

Hoping someone that runs a proper digital controller can shed some light on this. Dont want my setup creating a positive pressure and blasting smell all over the place. Not run and active intake with the controller yet so never had the issue come up until now.

 

Thanks.

 

 

[KC]

You're supposed to run an intake (if you're doing active) that's a lot smaller than your outtake. Afaik the controllers just dial down the extractor and the intake the same percentage. I use a rvk 150L for outtake and a 125L for intake for instance. Remember the outake won't be drawing it's max flow as the carbon filter will be restricting it too so bear that in mind.

 

I wouldn't bother with the passive intakes

[GreenVision]

I'm in the loft so I really need the ability to control the environment. Summer in a loft is a nightmare, I'm going large so if I needed it then it's there.

 

The passive intakes are a precaution, if the outtake exceeds the intake it will throttle the intake fan and could burn out the motor. Especially as I'm going a fair bit larger with the out than the in.

 

I think I'll have to email GAS. Its quite a technical question and I think there may even be a way to programme into the controller which fans it is and have not let the positive pressure ever happen.

 

 

 

[KC]

Your active intake will be fine honestly, there's no way it'll burn out due to the extractor. 

I kind of like the summer, it's the only time my loft is warm enough

 

[sweettooth]

@GreenVision which gas controller do.you have? I have the ec/ac one which does both intake and outtake and it has a built in fan balancer so both fans ramp up and down in sync  maintaining negative pressure at which running a smaller intake will also cause.

 

very good controller

[LK1]

two revolution fans controlled by these controllers will see you right. what fan you got now?

Edited July 13, 2023 by LK1

[Lux_Interior]

I run a 5" in and a 5" out (carbon filter) in a 1.2m tent. I run the extraction flat out all year but I have a simple manual speed controller on the intake that is dialed down, depending on the weather. If your tent looks like its sucking its belly in you are onto a winner. For eliminating smells either chuck a car air freshener up the exhaust ducting or get a few plugin jobbies around the house. I currently extract directly into my home and I have had no "issues".

Edited July 14, 2023 by Lux_Interior
*cough*

[sweettooth]

This is it

 

https://www.globalairsupplies.co.uk/product/g-a-s-ac-ec-digital-fan-controller/

 

you can set how much negative pressure you want as well as light sensitivity if you're using sunrise sunset features and the delay between night and day modes

[GreenVision]

9 hours ago, KC said:

Your active intake will be fine honestly, there's no way it'll burn out due to the extractor. 

I kind of like the summer, it's the only time my loft is warm enough

 

 

 

My extraction will pull about 3600m3 p/h with a filter on it. That said it will only be running about 75% if all goes well, which is 2700m3 p/h. The intake I'm looking into will push a max of approx 2000m3 p/h. With these figures it would be more than possible for the room to start pulling air in from other places, even more so when you take into account that the intake will be split into 4, which will slow down the airflow and reduce the air going in.

 

Honestly, if the intake drops below that beast of a fan pulling air out the air will start to come in from any gaps it can find. So if I put two small intakes in I can control them with bug nets etc, just in case the room tries to pull in more air than the intake is feeding it.

 

When I say burning the fan out I too doubt it will actually "Burn out" as in break down, but the out fan could actually pull air through that intake ducting if its not feeding in enough, when dealing with these airflow numbers. It will make the in fan create noise and not work effeciently.

 

 

 

[GreenVision]

9 hours ago, sweettooth said:

@GreenVision which gas controller do.you have? I have the ec/ac one which does both intake and outtake and it has a built in fan balancer so both fans ramp up and down in sync  maintaining negative pressure at which running a smaller intake will also cause.

 

very good controller

 

 

I have the G.A.S enviro2, but its years old now so im upgrading to the newer enviro4.

 

Plus the enviro2 had a fixed probe, the new enviro4 has a replaceable one.

[GreenVision]

6 hours ago, Lux_Interior said:

I run a 5" in and a 5" out (carbon filter) in a 1.2m tent. I run the extraction flat out all year but I have a simple manual speed controller on the intake that is dialed down, depending on the weather. If your tent looks like its sucking its belly in you are onto a winner. For eliminating smells either chuck a car air freshener up the exhaust ducting or get a few plugin jobbies around the house. I currently extract directly into my home and I have had no "issues".

 

 

 

I run a 12" outtake and will be using a 10" intake.

 

Its going to need accommodate anything I want to have in there, a small area for a few mother plants, a small area for possible breeding as well as the obvious grow space.

[Shumroom]

7 hours ago, GreenVision said:

 

 

I have the G.A.S enviro2, but its years old now so im upgrading to the newer enviro4.

 

Plus the enviro2 had a fixed probe, the new enviro4 has a replaceable one.

I’ve got the v2 so when I saw this my brain went ping!

 

What’s the difference between the v2 and the 4?

 

Atb

 

 

 

[sweettooth]

8 hours ago, GreenVision said:

 

 

I have the G.A.S enviro2, but its years old now so im upgrading to the newer enviro4.

 

Plus the enviro2 had a fixed probe, the new enviro4 has a replaceable one.

That should (i would be very surprised if it didint) have fan balancing on it and wil sort your negative pressure for you, mines the one  down from the envro controler

 

refer to the user manual its all there:

 

 

 

Negative pressure Intake: This will set your intake fan speed below your outtake fan. If you set it at -10% when the outtake fan is at 50% the intake fan will be at 45%. This is to maintain negative pressure in your grow room.

https://addloes.com/core/media/Enviro-Controller-V2-instructions.pdf

 

Aware that is for V2 and not V4 but its the same process

Edited July 14, 2023 by sweettooth

[GreenVision]

16 hours ago, Shumroom said:

I’ve got the v2 so when I saw this my brain went ping!

 

What’s the difference between the v2 and the 4?

 

Atb

 

 

 

 

 

No more AC fan sockets, all 4 sockets can now be programed on separate times.

 

The probe is now replaceable, just unclick and new ones cost about £30.

 

It now has TWO plugs, one for each pair of onboard sockets, so it acts like a 2600w contactor, can take 2 1000w or 4 600w hid lights etc etc.

 

Nice piece of kit IMO.

[GreenVision]

15 hours ago, sweettooth said:

That should (i would be very surprised if it didint) have fan balancing on it and wil sort your negative pressure for you, mines the one  down from the envro controler

 

refer to the user manual its all there:

 

 

 

Negative pressure Intake: This will set your intake fan speed below your outtake fan. If you set it at -10% when the outtake fan is at 50% the intake fan will be at 45%. This is to maintain negative pressure in your grow room.

https://addloes.com/core/media/Enviro-Controller-V2-instructions.pdf

 

Aware that is for V2 and not V4 but its the same process

 

 

It does indeed. The V2 I have does this too, but where I have two different sized fans it looks like its just a case of doing the maths and setting it up correctly.

 

Luckily I have such a higher flow rate on my out than I will the in that as long as I set it up right I should be golden.

 

In short, I wil have to set out a percentage "Map" for both fans and make sure they stay in sync by setting the balance percentage at such a point the intake can never outdoe the outake.

 

Think I'm almost there with now.

 

Cheers.