How much for minium air exchange?

[mikidimini]

Hi, i have 12 x 12 room with 4 x lumatek zeus pro's. My temps are too low and now would like to know what is the minium size of air exchange m3/h i need? Some calculators says 700-800 m3/h but that seems littlebit unnecessary high for me.

 

[troutman]

Normally, a full air exchange every 2 to 5 minutes is enough.
Some people use more air flow if the grow area gets too hot.
If your temp is low then you don't need to vent too much.
I have a dimmer on my 6" inline fan so I can slow it down.

 

[mikidimini]

Does 450m3/h sound too little?

 

[negative37dBA]

Need to know the height then just do the math...so easy.

 

[goingrey]

Normally, a full air exchange every 2 to 5 minutes is enough.
Some people use more air flow if the grow area gets too hot.
If your temp is low then you don't need to vent too much.
I have a dimmer on my 6" inline fan so I can slow it down.

More is also better at preventing mold.

 

[Douglas.Curtis]

Multiply 12x12xheight and then multiply that by 3. That's how many cubic feet per minute you'll want.

That's the recommended rate to prevent mold and provide adequate ventilation. Anything less and you're looking at the beginnings of mold and plant health issues, slower transpiration rates and who knows what else.

 

[AgnesParks]

Normally, a full air exchange every 2 to 5 minutes is enough.
Some people use more air flow if the grow area gets too hot.
If your temp is low then you don't need to vent too much.
I have a dimmer on my 6" inline fan so I can slow it down.




Modtodays is a platform that provides free game applications with mod or hacked versions, providing a unique and interesting experience for players.

Sure, adjusting the air exchange based on temperature is important. The fan dimmer is very smart.

 

[Ca++]

I'm more interested in the RH, followed by temperature. In fact, I have no interest in how much air that actually is.

People seal up rooms for hours on end, using co2. So not exchanging every few minutes isn't a great mold concern. I do wonder where the heat is going though. If you have cold outside walls, then there are extra precautions needed.

A room of plants won't deplete the co2 at any great speed. A monitor is under $20 though, if you want to ensure enough air exchange to not be limiting growth. It's a balancing act though, as decent co2 levels, without the right RH and temp, is of little use.


I'm not sure how most people know how much air they are shifting anyway. I look at fan and filter combinations many use, and while they think they have a 6" fan good for 450, they can't be doing 200 with it. I'm yet to see anyone talk about wind speeds and duct sizes to calculate what's really happening. It's all a bit mute. I have a thread around that helps people calculate ballpark figures, with examples of the kit we see in peoples rooms.

All the air, every minute, is crazy. But again, how would you know you are doing that. People are just not checking.
If your RH won't get silly, then slow it down to get the temp you need. At some point, you may need a dehu~ to dry and warm the room, if you can't lower the speed to warm it, without excess RH.

How about another light. It's a good way to generate some heat. A HID perhaps. Like a vert in the middle, just to cast some IR about.


I really wouldn't worry about the air exchange speed. If you are keeping negative pressure, it's almost certainly enough.

 

[Douglas.Curtis]

Sealed rooms use LOTS of air movement and regular additions of CO2. Successful rooms move about the same amount of air or more as a 2-3 exchange per minute would, even though it's only within the sealed room.

 

[Ca++]

Sealed rooms use LOTS of air movement and regular additions of CO2. Successful rooms move about the same amount of air or more as a 2-3 exchange per minute would, even though it's only within the sealed room.

Why would air movement matter any less, with lower levels of CO2.

 

[Douglas.Curtis]

Why would air movement matter any less, with lower levels of CO2.

Your question is incomplete...

 

[Ca++]

You realise many co2 users deliver it from above, while the circulation fans are turned off for a few minutes?

 

[Call_me_breeze]

Like someone said, CO2 meters are relatively cheap now, as are controllers. You can get a thermostatic controller or a humidity controller or both, I guess. I found controlling a sealed room too expensive with our new electric rates. I had been exhausting before going sealed. I improved the old system by running as much rigid ducting as I could with as few bends as possible. I used a CAP day/night thermostat outlet to control the fan and I had a 50 pint dehu that mostly ran at night, which would raise temps enough to trigger the exhaust fan and the two would keep things right where I wanted and better than I could muster with almost 30 Amps of HVAC and drawing 1 Amp on the fan and 5 or 6 on the dehu for what little time it ran vs 2 dehu non-stop when sealed. I switched to an 8" inline later in flowering just to make sure I was moving as much air as would fit through my ducting. My RH remained around 60%(I've never been able to get it lower without removing all my leaves when measured within the canopy), but my temps were spot on target and I was much happier with the results and the electric bill. I had to take down the grow and get ready to move after 10 years here, can't wait to start building the new space.

 

[Ca++]

There is a lot to be said for good duct runs, and even more for getting suitable fans.
If anyone wants to use one of them cheap ACinfinity RH/Temp controllers, with a decent EC fan, Just shout out.

 

[troutman]

Keep humidity lower than 65% if you want to reduce mold issues.

 

[Douglas.Curtis]

You realise many co2 users deliver it from above, while the circulation fans are turned off for a few minutes?

That is not the information which would make your question complete. What was your question?