is ventilation really a must?

[P@ssw0rd]

it's not the article i read originally but here the same idea from the same guy, starts talking about sealed rooms about half way down the page.

Maximum Yield - Growroom Construction 2004

 

[blackcoupe01]

I mean...I know. I know the normal dogma of this issue...of COURSE ventilation is good for a plant

You answered your own question. Want healthy plants, feed em fresh air, end of story.

 

[TMB77]

You answered your own question. Want healthy plants, feed em fresh air, end of story.

man, i'm a scientist, we dont leave things at "thats just the way things are"

I want to know WHY.

i'm not doubting that there are other components of air besides temp/humidity/gaseous ratio/particulates...(all of which we can control, even if it is pricey) I just want to know what the hell else it is that actually causes stale air.

 

[TMB77]

I like your thinking, I'm trying the sam ething without AC right now. Your problem is that a portable ac will discharge air which in turn will reduce your co2 levels. I think the beast is beaten by making our grow space light cooling as efficient as possible i.e. cool tube, absolutly no leaks, insulated ducting etc. plenty of circulation fans and then there may still be a excessive humidity problem whaich will have to be dealt with. I don't think we need a full 15 min. exhaust every 2 hous, maybe like 2-5min. would do along with a co2 counter and controller along with backdraft dampers.

Good luck mate,
Unity

Well, the AC gets vented to the outside of the room of course, otherwise you're just putting hot air and moisture back in the air, where there would probably be a net decrease in temp, but it would be so inefficient.

also the demumidifier/carbon filter get vented to the outside (actually I guess it doesnt matter if the carbon filter vets vented outside).

with three different things being exhausted out of the room, I dont know how it can technically be a 'sealed' chamber, unless you have some way to prevent air getting sucked back in through these exhaust exits while they arent on.

I'm assuming 'sealed' has to mean having absolute control of the air entering and leaving the chamber, which means some work/valves/construction/planning to prevent backflow. I dont even know the necessary material to do that with.

so basically we're looking for the most control of airflow, and the longest time in between venting times.

but what happens to the gas ratio and net pressure inside the chamber if the three things exhausting out of the room are intermittantly removing air from the space? we're replacing the CO2 until its at the proper PPM, but if there is actually less air particles in the air, that will make the PPM of CO2 kind of meaningless...no? this whole things is getting a bit complicated, I got some research to do.

 

[unity]

Well, the AC gets vented to the outside of the room of course, otherwise you're just putting hot air and moisture back in the air, where there would probably be a net decrease in temp, but it would be so inefficient.

also the demumidifier/carbon filter get vented to the outside (actually I guess it doesnt matter if the carbon filter vets vented outside).

with three different things being exhausted out of the room, I dont know how it can technically be a 'sealed' chamber, unless you have some way to prevent air getting sucked back in through these exhaust exits while they arent on.

I'm assuming 'sealed' has to mean having absolute control of the air entering and leaving the chamber, which means some work/valves/construction/planning to prevent backflow. I dont even know the necessary material to do that with.

so basically we're looking for the most control of airflow, and the longest time in between venting times.

but what happens to the gas ratio and net pressure inside the chamber if the three things exhausting out of the room are intermittantly removing air from the space? we're replacing the CO2 until its at the proper PPM, but if there is actually less air particles in the air, that will make the PPM of CO2 kind of meaningless...no? this whole things is getting a bit complicated, I got some research to do.

I'll chime in on the ac portion You will need to use a mini split system($699up) instead of a package system(portable ac). Difference is, in a split system the condenser sits outside and is connected to the evaporator via a refrigerant line. That way outside air is used to dissipate the heat from the condenser and the evaporator inside will only recycle air

The carbon filter will work fine as long as you recycle the grow space air through it.

You will need GOOD back-draft dampers along with a powerful extraction fan that you use every two hours or so to replace the air.

Add some circulation fans, control your res, automate all this shit, seal every little crack with silicone and you are right there mate

I'm trying it right now (want to get it done without the ac though)

Good luck mate,
Unity


You are one step closer mate!

Unity

 

[Jakebakingcake]

science... hooray!!

 

[Rob Street]

man, i'm a scientist, we dont leave things at "thats just the way things are"

I want to know WHY.

i'm not doubting that there are other components of air besides temp/humidity/gaseous ratio/particulates...(all of which we can control, even if it is pricey) I just want to know what the hell else it is that actually causes stale air.

Thats because there is no stale air
Think about this;
NASA can grow plants in space.
and they can do it "long term"
I would call that a sealed environment.

Astronauts going to mars would need to grow a good portion of their own food. the trip takes 2 years 1 way.

think about it they cant just get rid off all that stale air now can they?

I'll sell you all "air Fresheners" lol if you really think that there is some magic unknown gas that plants need that we are unaware of.

so yes it can be done.

Rob did you use exact co2 usage keeping the co2 at the needed 1200-1500 ppm or just add some unknown co2 amount in there and what size room was it?

Room size over 750 sf.

Co2 Air ppm 1800

we used a full house size air conditioner with the exhaust part outside so no air loss there.
room temp 78-83
you will need a really good Dehumidifier. Id reccomend this one;
DeLonghi DE400P Dehumidifier
you never have to empty the damn things.
also Golden Rod Dehumidifiers work well for smaller areas.
Harbor Freight Tools - Quality Tools at the Lowest Prices

Hope that helps.



Regards

 

[Rob Street]

methane is the only other greenhouse gas that I can even think of and a fart or two should take care of that!

also I just found out that there is an "ongoing greenhouse" project in the new international space station.

this is what they use in space;
http://science.nasa.gov/PPOD/y2003/pdf/LADA_ices_2002.pdf

 

[jimbizzzale67123]

your A/C has to exaust air in order to conditon it so eventually I believe that the air will be vented out and you shouldnt have any problems.

 

[fred flintstoned]

Search this site and others for "sealed room". Use sealed hoods and outside air to cool the lights, venting ONLY this air to the outside. With proper environmental controls, NO room air exchanges are required. Use a charcoal filter/fan combo to filter air inside the room. You will find the dust and air particulates vanish after your first week or so. Search for posts by Jeftek. He's the cultivation editor for several magazines. He is a huge proponent of sealed rooms. Hope this helps.

 

[REEFA]

Man that Nasa Grow setup is sick they can grow that sensi shit up in there space ship and get high like muthaFu*Kers

 

[goatamineHcL]

really if you provide what it needs and it doesnt get too hot you dont have to ventilate i mean it helps but you can totally do it without it or at least without out much