Ways to deal with high humidity in sealed room with co2

budleydoright

Well-Known Member
Even in a sealed room you must do air exchange. If your not pulling the old air out and bringing fresh air in and just pumping co2 your basically strangling your plants and production will suffer greatly while also inviting mold bud rot and lower production output. Exchange the air every couple hours and get a dehumidifier they are cheap.
So your suggesting that we seal the room, pump it full of nutirent rich (co2) air, scrub the air, have it at the perfect temp and humidity and then periodically pull polluted bug infested air in from outside?

I find it more effecient, cleaner with less mold and mildew when i keep my sealed room sealed. There is absolutely no reason to exchange air with the outside and as soon as you do, you are no longer running a sealed environment.
 

Kite High

Well-Known Member
Even in a sealed room you must do air exchange. If your not pulling the old air out and bringing fresh air in and just pumping co2 your basically strangling your plants and production will suffer greatly while also inviting mold bud rot and lower production output. Exchange the air every couple hours and get a dehumidifier they are cheap.
how does it "strangle " your plants? plants produce o2 in photosynthesis so that is replenished automatically...not supplementing during lights out allows the roots to get the o2 the plants produced during lights on... the only exchange mine ever get is when I open it to water feed and look around....haven not witnessed anything ...imo exchanging air would INVITE molds fungus etc thereby giving a greater chance for Botrytis to take hold as well as other pathogens to infect[h=1][/h]
 

Bob Smith

Well-Known Member
The sentinal controller, even though it says it controls temperature is really made for a fan. The internal relay that switches the outlet on and off probably can't handle the large inductive load presented by an airconditioner. It probably welded the contacts on the relay shut.
The water flowing over the back isn't really a malfunction. The AC should be able to displace all of the water it collects into the condensing coil. Is the AC level? If it's a window unit, often there is a plug you can remove and either put a catch bucket under it or tap a hose on to it to a drain.

to use the sentinal controller to operate anything but the smallest AC you need an external relay with a trigger cord that will plug into it.

I would use the AC and use it's internal t-stat. this is the best way to go unless you really set it up properly. the compressor in an AC also needs to have a 3 minute minimum off cycle. using the internal electronics insures that it is cycling properly.

That will allow you to control the humdity and temp during the photoperiod. when the lights are out, you can vent to the outside or set up a dehuey. Another option is to simply put a small eletric heater in there during the night that will generate enough heat to keep your AC dehumidifying. It sounds really ineffecient, but running a dehuey often does the same thing. Ads enough heat to kick on your AC!
Sentinel controlled my 14K BTU AC just fine.

If you need to run something larger, they have an expansion module for that (to let you run 240V monster ACs).
 

budleydoright

Well-Known Member
Wow 14K on it. Nice. Problem I had killing power to my window shaker to control temps is that it is designed to cycle the compressor on and off, while the fans continue to run. The fan that is on the condensor, flicks condensation into the hot coil providing a little evaporative cooling for the coil as well as disposing of all of the condensate by evaporating it into the air. when this cycle is interupted the condensate starts to overun the fan. Mine sounded like a paddle boat when it would kick on, putting a load on the fan motors and slowing them down. It is also bad for the compressor to not allow the required time between cycles. I believe it is required to allow the pressure between the hi and lo side to equalize.

My window shaker had a 3 minute delay at turn on so it was self protected, but the additional load on the fan motor was taking it's toll.
 

hellraizer30

Rebel From The North
Even in a sealed room you must do air exchange. If your not pulling the old air out and bringing fresh air in and just pumping co2 your basically strangling your plants and production will suffer greatly while also inviting mold bud rot and lower production output. Exchange the air every couple hours and get a dehumidifier they are cheap.
I think you got it rong! Its a revolving circle co2 machine provides co2 that plant uptake, then discharge oxygen!
with good air movment and co2 you should never do a air sxchange!
 

Jersey'sFinest

Active Member
This has me confused as well. I am considering going the "sealed" route for my next room but there seems to be so much conflicting info out there as far as venting and exhausting in conjunction with the AC, dehumid, and CO2. Any experts out there have the skinny? In a "sealed" room, should the CO2, humidity levels, and AC temp be dialed in and then just left alone, or should there indeed be some fresh air coming in and stale air exhausted, and if so, how often and when? Thanks...
 

budleydoright

Well-Known Member
I don't exchange. A sealed room or cea is indeed sealed and does not exchange air with the outside. There isn't neg or pos pressure in the room to push or pull air out. The only time air is exchanged is when the door is opened. Co2 is maintained by a controller, plants produce oxygen in return. Even in our co2 rich enviromnents, the gas is only 1500 parts per million a very small percentage of the whole

There are no rules though, make a system that works for you. If you need to exchange air to balance things out then go for it. Just make sure your air intake has a good filter on it to keep undisrerables out. There are a number of eoom controllers designed to help you maintain that balance by turning your co2 off and fans on etc....
 

sfttailpaul

Active Member
hey guys

we have about a 9x5 room that has 2 1000w hps hooked up to a high cfm fan (cant remember the rating right now) it is intake/exhausted to the outside room. we have 3 fans inside the room to circulate air, we had an a/c in the room but removed it because our environmental controller was/is screwed up and was keeping it on all the time and would spill water out the back and get the floor all wet.

so the humidity this morning with co2 was around 85% with temps around 85 as well. The only thing i am thinking of is going and getting a big bucket of that dehumidifying silica beads. Is there anything else possible?

Everyone is telling you to get a de-humidifier. Do it! Check out Craig's list for an inexpensive source. ALSO, WITH CO2, DEPENDING ON THE STRAIN, YOU CAN LET THE TEMPS GET UP NEAR 93to95 DEGREES. I don't recommend holding the temp there, but you can get away with this extreme swing for bursts, like when it is on. If you're gonna' run CO2, you must get a good atmospheric controller. These will surly cost north of $200.00 but entirely worth the investment. Make sure you have a way to test B 4 paying or a way to get your $'s back if the guy blew it out. C.A.P. controllers are really good and come with a 5 year warranty, so odds are, if it is a once only used 4 grow, it'll most probably be fine.
There are a fair amount of newbie growers who start out like gang-busters only to find that it is more work than they want or can handle. Craig's List has tons of gently used controllers as well as everything else. I see light packages at 2-3 each and every day, usually the reflector, ballast and a (whoopie, big deal; toss it anyway, n/g) a HPS bulb included for around $100.00. Controllers are more rare but also don't sell fast either. May be because many people aren't that sophisticated starting out, give it up, unload the equipment for 15 cents to 50 cents on the dollar. Don't go much higher than 25 cents/dollar unless it is really, really clean and works fine on the spot. People looking to get a deal starting out probably consider that the price is still too high. If you have spare MJ you can probably work out a trade BUT BE CAREFUL the cops shop there too.
Hope this helps a bit. Good advice here! $hit, an ounce of MJ is certainly worth a good controller...
 

sfttailpaul

Active Member
This has me confused as well. I am considering going the "sealed" route for my next room but there seems to be so much conflicting info out there as far as venting and exhausting in conjunction with the AC, dehumid, and CO2. Any experts out there have the skinny? In a "sealed" room, should the CO2, humidity levels, and AC temp be dialed in and then just left alone, or should there indeed be some fresh air coming in and stale air exhausted, and if so, how often and when? Thanks...
You always must have a source of fresh air, no matter what and how you are growing. I have been using CO2 for about 3+ years and absolutely feel it's worth it IF AND ONLY IF you can dial in the on/off cycles along with the fluctuation in temps (if using a gas powered generator), humidity, and etc. It is well worth the investment but I would consider it to be one of the last "bling" one adds to a grow. Simply put, master a regular grow B 4 getting more fancy. The yield will be just fine and it's one less thing to worry about.
Remember that plants NEED Oxygen too, their roots would die rapidly without it. The O2 they give off is in no way near the amount they need replaced. A sealed room is really good to obtain BUT again, you must make arrangements to deal with an exorbitant amount of air exchange... Look at nature whereas she provides a small amount of CO2 and tons more O2 for vegetation to thrive.
 

Kite High

Well-Known Member
You always must have a source of fresh air, no matter what and how you are growing. I have been using CO2 for about 3+ years and absolutely feel it's worth it IF AND ONLY IF you can dial in the on/off cycles along with the fluctuation in temps (if using a gas powered generator), humidity, and etc. It is well worth the investment but I would consider it to be one of the last "bling" one adds to a grow. Simply put, master a regular grow B 4 getting more fancy. The yield will be just fine and it's one less thing to worry about.
Remember that plants NEED Oxygen too, their roots would die rapidly without it. The O2 they give off is in no way near the amount they need replaced. A sealed room is really good to obtain BUT again, you must make arrangements to deal with an exorbitant amount of air exchange... Look at nature whereas she provides a small amount of CO2 and tons more O2 for vegetation to thrive.
preposterous...the plants produce MORE o2 than they will ever use....wow...where do you guys get all these ludicrous ideas...btw o2 ppm are around 200000....while plants do need 02 for roots it is a very small amount that photosynthesis will more than make up for
 

sfttailpaul

Active Member
I think you got it rong! Its a revolving circle co2 machine provides co2 that plant uptake, then discharge oxygen!
with good air movment and co2 you should never do a air sxchange!
Again, proof that there are many varying opinions; everyone is right you know...
You're gonna' have to find your own comfort zone. IMHO, a sealed (not truly possible!) room will become stagnant and the plant's growth vigor will be compromised. This is what I have experienced. Also, it is impossible to have a REAL, actual and totally sealed room. The tiniest hole will allow outside air to enter. Granted this is minimal, but in reality there is no such animal as a "sealed" room. The gaps at the juncture of weather stripping alone, will allow air to enter as well as pests. You'd literally need to build the room with the door sealed like in a submarine, otherwise you'll have leaks. I was a builder of homes/remodeller for over 37 years. I've done fire damage work too and have seen many times, how the smoke will pass through a pin hole in the wall, and lots of it too. Imaging air flow under pressure and the problem compounds.
 

sfttailpaul

Active Member
preposterous...the plants produce MORE o2 than they will ever use....wow...where do you guys get all these ludicrous ideas...btw o2 ppm are around 200000....while plants do need 02 for roots it is a very small amount that photosynthesis will more than make up for
In my opinion, not 100% correct. Plants do NOT manufacture Oxygen. It is the bi-product of respiration. You cannot get O2 where it isn't existing; something is always lost in the process. All forms of energy adhere to this law of Physics. Of course the ratio of CO2 to O2 is quite different, but that stale, stagnant air is a concern as well as the fact that the O2 (primary gas) gets depleted as it is converted by the plant. Again, everyone has their own opinion. I am not wanting an argument to ensue here, seems like some people are hell bent on doing so. It is probably because it has been so quiet here these past few weeks. My thoughts/opinions are simply that you will not arrive at a "sealed" room unless you do a submarine door. Even the computer "sterile" rooms I've built had a tiny amount of leakage and this was a concern due to the need for zero dust (obviously, larger particles than air) and we spent countless hours trying to obtain this to some degree of success, but under a microscope, fresh air IS getting in. Also, Drywall breathes, so why try for an UN-attainable goal? I'd use the fresh air to my advantage. Besides, you'll get CO2 in the end, again, something that gets depleted.
 

Kite High

Well-Known Member
In my opinion, not 100% correct. Plants do NOT manufacture Oxygen. It is the bi-product of respiration. You cannot get O2 where it isn't existing; something is always lost in the process. All forms of energy adhere to this law of Physics. Of course the ratio of CO2 to O2 is quite different, but that stale, stagnant air is a concern as well as the fact that the O2 (primary gas) gets depleted as it is converted by the plant. Again, everyone has their own opinion. I am not wanting an argument to ensue here, seems like some people are hell bent on doing so. It is probably because it has been so quiet here these past few weeks. My thoughts/opinions are simply that you will not arrive at a "sealed" room unless you do a submarine door. Even the computer "sterile" rooms I've built had a tiny amount of leakage and this was a concern due to the need for zero dust (obviously, larger particles than air) and we spent countless hours trying to obtain this to some degree of success, but under a microscope, fresh air IS getting in. Also, Drywall breathes, so why try for an UN-attainable goal? I'd use the fresh air to my advantage. Besides, you'll get CO2 in the end, again, something that gets depleted.
it is a byproduct of photosynthesis...let me tell you that botanically I know that this produces more than enough to supply the use of the roots...furthermore your description of impossible to actually seal a room would therefore negate any need for debate as fresh air exchange according to YOU is always occurring
 

budleydoright

Well-Known Member
My sealed room, is sealed well enough that if my Co2 is off for an hour, the plants will draw it down to 40ppm. With no pressure in the room, there is nothing to push the air out. All air circulation occurs within the room itself. Even when my door is open it is only open into another room indoors. My room hasn't physically exchanged air with the outside since it was put into service. I burn LPG for Co2 during the photoperiod and scrub the air with a carbon filter. When I walk into my room from the hot dusty stale air of the large garage style building, it is literally a blast of cool fresh clean air. Keep in mind that ppm is parts per million, 1500/1,000,000 leaving 998,500 parts of nitrogen, oxygen and the many other gasses that make up our atmosphere.

If your sealed endevour didn't work out, then something was out of balance. My first attempt at CEA, was incredibly difficult and the design of the system was such that success was almost impossible. I didn't have enough cubic feet of atmosphere to support the amount of growth I was trying to stuff in there. the balancing act required to make it work was too much. It's not rocket science, but there are a few design parameters that need to be met.

My new space runs itself and is easier to dial in than a vented system.
 

Jersey'sFinest

Active Member
Budley, just trying to fully grasp the concept here, if you are scrubbing the air with a carbon filter then a fan is pulling the scrubbed air out of the room, correct?
I can only assume that your lights air-cooled as well? From my limited understanding, then, there is no "fresh" air being pulled in, but the heat from the lamps and the stink from the plants are being exhausted out, the CO2 is being regulated within @1500 ppm while the lights are on, the AC is maintaining the optimum temp, and a humidifier and/or dehumidifier is simultaneously holding the humidity at the desired level. Yes?
 

Bob Smith

Well-Known Member
No.

If you have a sealed room, it's a sealed room.

No air in, no air out.............if he's running a filter, he's scrubbing the air and it's recirculating in the room.

Not sure how so many people are failing to grasp the concept of a sealed room.
 

Kite High

Well-Known Member
No.

If you have a sealed room, it's a sealed room.

No air in, no air out.............if he's running a filter, he's scrubbing the air and it's recirculating in the room.

Not sure how so many people are failing to grasp the concept of a sealed room.
thank you!!!
 

hellraizer30

Rebel From The North
There failing to grasp it cause they have never run a sealed room! Even if your room has a bit of leaks
theres no presure from inside or outside to push air in or out thus sealed is achieved. And co2 enrichment
can be achieved :)
 

budleydoright

Well-Known Member
Budley, just trying to fully grasp the concept here, if you are scrubbing the air with a carbon filter then a fan is pulling the scrubbed air out of the room, correct?
I can only assume that your lights air-cooled as well? From my limited understanding, then, there is no "fresh" air being pulled in, but the heat from the lamps and the stink from the plants are being exhausted out, the CO2 is being regulated within @1500 ppm while the lights are on, the AC is maintaining the optimum temp, and a humidifier and/or dehumidifier is simultaneously holding the humidity at the desired level. Yes?
No the 8" fan draws air through the scrubber and blows it back into the room. There is no air cooling on the hoods, no glass or ducting. All of the heat generated by the lamps is absorbed by the airconditioner. If you size your AC right or buy one of the higher end mini splits, your AC will run almost constantly which is more effecient than a cycling unit. It also removes the moisture constantly being transpired into the air. All I have to do is set my AC to the desired temp and my RH is handled, provided the lights are on. Once the load is taken off the ac and it stops running, humidity is handled by a dehuey.

A well tuned CEA system is a magical thing! My room is the same environment year round. It will get even better when I get an inverter mini split. Only thing holding me back is the window ac heats my building nice in the winter. I'll likely just duct the window shakers heat out as it exhasts into a 2k sf storage space.

So I exchange no air to the outside. My room is in a 4k sf building that has no windows, just the air flow designed into the building. you have to go through 3 doors to get outside. so even when the door is open, it's not open to the outside.

CEA is a balance, when things are right it's easy and runs really smooth.
 
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