Sealed Room Question

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Lordgenin

Well-Known Member
Hello Everyone

So I have a sealed room. When lights are on, c02 hold at a steady 1500 ppm.
Once the lights are off the C02 levels drop (Co2 does not run when lights are off)
I have a 50lb tank and it is not using a lot of c02 in my opinion.

In my mind, I would think if my room is @ 1500 ppm right before lights off. Returning it like a 4 hr time frame (light still off) my C02 level shouldn't drop to 600 ppm.
I think my room is not as sealed as I assumed or maybe I am overthinking.

Second question If my room is not as sealed as I assumed, what can I use to find drafts/ where the leak is for the room.

Little info: The room is fully insulated and drywalled and mud then I wrapped the room in Panda film except for the ceiling.

Thanks for your opinion
 
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SourDeezz

Well-Known Member
I wish I had that problem. I'm installing intake/exhaust fans just for lights out so I can get the c02 out of the room.
 
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Lordgenin

Well-Known Member
SourDeezz said:
I wish I had that problem. I'm installing intake/exhaust fans just for lights out so I can get the c02 out of the room.
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Why would you want to do that?
I know C02 is not useable to plants at night time but at least you know when your lights do turn back on you don't have to dump a lot of co2 in the room if you are using a tank or heat to the room too much if you're using a burner.
 
Renfro

Renfro

Well-Known Member
I have always noticed in a sealed room the CO2 PPM rises when the lights are off because the plants put out CO2 in the dark. If the levels drop then you have a lot of leakage thats wasting your tank when the lights are on.
 
Renfro

Renfro

Well-Known Member
SourDeezz said:
I'm installing intake/exhaust fans just for lights out so I can get the c02 out of the room.
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I think having a ventilation system to run for a little bit at lights out can be beneficial as it removes any potential ehtylene gas buildups in the room. I wouldn't however see a need to vent out the CO2 in the dark period.
 
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SourDeezz

Well-Known Member
Renfro said:
I think having a ventilation system to run for a little bit at lights out can be beneficial as it removes any potential ehtylene gas buildups in the room. I wouldn't however see a need to vent out the CO2 in the dark period.
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Yeah sorry, that's what I meant. Going to have the fans run on a timer for about 15 mins after lights out.
 
Renfro

Renfro

Well-Known Member
SourDeezz said:
Yeah sorry, that's what I meant. Going to have the fans run on a timer for about 15 mins after lights out.
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RH% tends to spike for the first 15 - 30 minutes after lights out so the vent cycle can also help with that provided the intake air isn't too soggy.
 
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sf_frankie

Well-Known Member
SourDeezz said:
Yeah sorry, that's what I meant. Going to have the fans run on a timer for about 15 mins after lights out.
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I run an exhaust for 45 mins after lights out to control RH spikes and Ehtylene gas buildup. Also have the ability to turn it on remotely if my dehu takes a crap (which it has!)
 
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Lordgenin

Well-Known Member
sf_frankie said:
I run an exhaust for 45 mins after lights out to control RH spikes and Ehtylene gas buildup. Also have the ability to turn it on remotely if my dehu takes a crap (which it has!)
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I didn't know about that Ethylene gas buildup was a possible thing. I have an Oversized dehu in my sealed room with a 3ton AC so I do not have that Spike when the light turns off.

I stay at a constant 65% RH @ 85F
 
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sf_frankie

Well-Known Member
Lordgenin said:
I didn't know about that Ethylene gas buildup was a possible thing. I have an Oversized dehu in my sealed room with a 3ton AC so I do not have that Spike when the light turns off.

I stay at a constant 65% RH @ 85F
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Are you in Veg or flower? If flowering you should drop your RH a bit to get your VPD dialed in. 85F should be around 58% RH
 
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Lordgenin

Well-Known Member
sf_frankie said:
Are you in Veg or flower? If flowering you should drop your RH a bit to get your VPD dialed in. 85F should be around 58% RH
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I am in flower
The chart that I viewed stated 65% RH for correct VPD.
This is where I don't have a pulse One yet but will get one soon to actually see that the leaf temp is under the light to get more accurate VPD.
@sf_frankie Could you tell me what chart or where you are getting that info?
This is where I got my info from: https://pulsegrow.com/blogs/learn/vpd
They state: " The ideal VPD for the flower stage is closer to the top end of the range, 1.2kPa – 1.5kPa. "
With there VPD calu
I am at a:

VPD Air (kPa) 1.46
VPD Leaf (kPa) 1.20
Leaf temp offset -/+ -2F
 
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sf_frankie

Well-Known Member
Lordgenin said:
I am in flower
The chart that I viewed stated 65% RH for correct VPD.
This is where I don't have a pulse One yet but will get one soon to actually see that the leaf temp is under the light to get more accurate VPD.
@sf_frankie Could you tell me what chart or where you are getting that info?
This is where I got my info from: https://pulsegrow.com/blogs/learn/vpd
They state: " The ideal VPD for the flower stage is closer to the top end of the range, 1.2kPa – 1.5kPa. "
With there VPD calu
I am at a:

VPD Air (kPa) 1.46
VPD Leaf (kPa) 1.20
Leaf temp offset -/+ -2F
Click to expand...
I use this one. It’s kind of annoying that none of them are consistent https://docs.google.com/spreadsheets/d/1M9jGhBA0lc2S8NEsq3q_6Mkpd3yJwedSZ3kfxuK0ZVI/edit
 
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Lordgenin

Well-Known Member
@sf_frankie I see, well I will meet in the middle and go with 61% with a 2% swing.

Thank you for the info, Now I just need to figure out this leak.

Actually I change my mind I will try 58% I am kind of scared of high RH.

Will watch and see if there is any difference
 
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F80M4

Well-Known Member
I have mine set to 1200ppm max and kicks in if it drops below 1000. My co2 regulator is connected to my co2 controller. when lights turn on for me when i walk in the room its in 1000s already. I do not vent out.
 
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rizatk

New Member
is it possible u set ventilation on when lights off n then off when the co2 is blasting ? will the humid go up?
 
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sf_frankie

Well-Known Member
rizatk said:
is it possible u set ventilation on when lights off n then off when the co2 is blasting ? will the humid go up?
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I vent during lights out. Humidity stays stable thanks to my dehumidifier. When I’m venting the humidity drops a bit and then the humidifier shuts itself off.
 
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ChrispyCritter

Well-Known Member
Chances are your only place not sealed is around your door. However based on what you've mentioned it doesn't sound like you have much of a leak. Caulk around all door trim, really everything that's not taped and mudded, and get some foam weatherstripping if your door isn't tight. I don't ventilate my room at night like some do. I have no problems. I use a dehumidifier, which I believe is essential in a sealed room.
 
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sf_frankie

Well-Known Member
ChrispyCritter said:
Chances are your only place not sealed is around your door. However based on what you've mentioned it doesn't sound like you have much of a leak. Caulk around all door trim, really everything that's not taped and mudded, and get some foam weatherstripping if your door isn't tight. I don't ventilate my room at night like some do. I have no problems. I use a dehumidifier, which I believe is essential in a sealed room.
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Dehu is a must for sure! Mine crashed one day and it didn’t take long for the humidity to spiral out of control. Thankfully I have an emergency fan I can switch on remotely to vent to keep it under control.
 
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