Question about recylculating air

[nemgrower202]

I want to build a sealed grow room with a fan and a carbon filter(1500cfm) which recirculates the air inside the room. An ac unit will send air from the outside into the room.
I don't want to vent outside because I am growing in a hot climate and i want to save energy. My question is do I need to have a co2 generator or is that unnecessary and how do I counter the positive energy, as in how do i vent some of the air out?
I always used to grow in cold climates so this is a new issue for me.

 

[Aqua Man]

I want to build a sealed grow room with a fan and a carbon filter(1500cfm) which recirculates the air inside the room. An ac unit will send air from the outside into the room.
I don't want to vent outside because I am growing in a hot climate and i want to save energy. My question is do I need to have a co2 generator or is that unnecessary and how do I counter the positive energy, as in how do i vent some of the air out?
I always used to grow in cold climates so this is a new issue for me.

I run a sealed room and equipment will vary based on the size.

1.What type of AC unit are we talking about? Most AC do not bring in outside air and will only circulate the air from inside the room so positive pressure should not be an issue.
2.If you are running a truly sealed room you will need to supplement Co2. Depending on the size of room you may want different equipment to provide Co2 none the less you will need a Co2 controller to run it effectively.
3.You will need a way to evacuate the Co2 at lights out or ensure that Co2 levels are not to high as plants produce Co2 at night.
4. You will need an adequate dehumidifier and a small humidifier if you plan on using it from seed/clone to harvest. Also you will need a controller for this because humidity is an issue in a sealed room.

 

[Jimster]

I want to build a sealed grow room with a fan and a carbon filter(1500cfm) which recirculates the air inside the room. An ac unit will send air from the outside into the room.
I don't want to vent outside because I am growing in a hot climate and i want to save energy. My question is do I need to have a co2 generator or is that unnecessary and how do I counter the positive energy, as in how do i vent some of the air out?
I always used to grow in cold climates so this is a new issue for me.

If you have outside air coming in, then you will need the old air some way to be removed, sort of like blowing up a balloon. You will either need an out-of-tent vent OR a recycling system with the carbon filters to control smell. A totally sealed room is great if you have the equipment and setup to do it and make it worthwhile, but it is also much more difficult trying to regulate fluctuating temps and humidity levels, like was mentioned in an earlier post.
Depending on your AC system, it might not be necessary to vent it if it is used as a closed system and NOT bringing fresh air in, just recirculating the old air and cooling/removing water from the air. To save energy and heat, I would defiantly recommend a LED lightsource. Depending on your location, swamp coolers are a great alternative to air conditioning if you have low humidity levels where you grow... although they aren't much good in the humid southeast!

 

[JWM2]

Inkbird is your friend. Get a heat controller and humidity controller. You can buy them in a combo pack on amazon. It’s $70 on sale right now for both. They are normally $39.95/ea.

 

[nemgrower202]

I used to grow in canada and now I am starting to grow in spain so conditions are way different.
After thinking about the problem I think I will turn on the light at night and off during the day and just use massive air circulation to keep the grow room cool, any other alternative is just too expensive and/or elaborate.

 

[FTCG]

@nemgrower202

A portable air conditioner should not break the bank, you can find a good one for $250-300. And if this is a bedroom we are talking about, you don't need to vent outside. You can seal the window up with and vent the air conditioning unit through the ceiling. Much more stealth that way.

A carbon scrubber will be good to keep things fresh and to pull fibers and mold etc... out of the air, keeping your buds clean.

A co2 burner is not necessary, but one of the main reasons of a sealed room is to supplement co2, apart from keeping bugs out.

I would use any positive pressure to my advantage, as the plants grow better under higher atmospheric pressures, and slightly higher temperatures. Which I would only recomend with co2 supplementation.

You should be fine running cooler temps around 70-75 degrees without co2. Keep in mind the co2 rises quite quickly when you are in the sealed room dealing with the plants. It's motivation to get work done and keep the plants happy.

No need for co2 if you keep busy with the plants.

Add it once you are comfortable, after using a co2 meter to see the DAY/NIGHT trends the room goes through, and assessing the plants needs.

 

[nemgrower202]

I am planning on setting up a 10 light grow room.
At first I was thinking of doing a sealed system with an ac and the carbon filter circulating the air inside the room instead of venting outside.
My second option is just to use an intake fan with a hepa filter and to vent the carbon filter outside and to use massive air exchange to keep the room cool and grow at night.
Discretion is not an issues since it is a legal grow.
So which one of the 2 ideas you think would work better?

 

[Aqua Man]

I am planning on setting up a 10 light grow room.
At first I was thinking of doing a sealed system with an ac and the carbon filter circulating the air inside the room instead of venting outside.
My second option is just to use an intake fan with a hepa filter and to vent the carbon filter outside and to use massive air exchange to keep the room cool and grow at night.
Discretion is not an issues since it is a legal grow.
So which one of the 2 ideas you think would work better?

I grow in a sealed room and i can say having a sealed room it's a lot more of a PITA but can be more beneficial once you get everything dialed in with Co2. Being new i would go dirt/coco media with a vented room. That said I have never grown indoor dirt/coco but i can say a sealed room in hydro takes a lot of adjusting and tinkering to get it right but like i said there are some really nice benefits once you do.

 

[FTCG]

Do both. It will provide much better control over your grow room. Extra cooling, and extra humidity control. Use proper reflectors and maximize your footprint.

You can add co2 later after setting up a meter and observing your plants needs. With the intake you will at least always ambient co2 levels, until you are ready to supplement.

1000w's or 600w's?

Also, what are the room dimensions?

I find using just intake and exhaust with no co2 enrichment, gives you the typical bud. Nothing special.

Co2 enrichment is the way to go.

Set up a hybrid system to make grow room management easier on yourself. And to give you more control over the parameters of the room.

You'll need quite of bit of cooling for 10000w's.

 

[nemgrower202]

Room is 4m x 13m x 3m height. It is going to be in deep water culture. I already have a lot of growing experience.
So you suggest using a sealed room with co2 and a ac unit? I dont see quite understand that concept, i never looked into it.
The hps light will be air cooled.
An ac would need 25000 btu to cool that size room.

 

[nemgrower202]

How do you circulate the air in a sealed room and do you use a carbon filter?

 

[FTCG]

Sealed room to keep the co2 levels higher than outdoor levels. It produces a higher potency product.

Of course you A/C will be exhausting hot air, and you have fans for circulation.

I was saying to set up the A/C, as well as having a filtered intake, and a carbon filtered exhaust, this wouldn't run all the time during the day, just here and there to take some load off your A/C.

If your unit is powerful enough to cool 10000w's, then you don't need the exhaust.

The only difference with co2 in a sealed room, and using and intake and outake, is the potency of the finished product.

If you are looking for that extra 5% THC, you will need to supplement co2, and make sure you don't exhaust it all before the plants have their way with it.

Wall-mount fans circulate air in a sealed room just like any other. And a carbon filter just scrubbing the room will help with and mold issues, and keep the air fresh and clean.

Since you are using air-cooled reflectors, it shouldn't be a problem with cooling. It would be counter intuitive to add co2 and pump it right out the grow room.

So your best bet is to forget about a sealed room and co2, and opt for the exhaust route. Intake and outtake on top of the air cooled reflectors.

 

[nemgrower202]

Ok so after reading your advice (thanks guys) and looking at both sealed rooms and non sealed rooms I finally understand it.
Now i have to run the budget for both sealed and non sealed rooms.
For the non sealed room it will cost 6000 Euros to setup.
The sealed room I will do the calculations shortly and see how much more expensive that is.
From what i see i would need massive amounts of co2 for that size room.

 

[1diesel1]

Use a package unit, Carrier, Trane, York. You need to do some calculations for tonnage. With a package unit you install the supply and return into the room. You will not pull outside air into the room unless you install a economizer. Seal the room install all duct work scrub your carbon filter and run co2. Get a titan 2 co2 system where you install your sensor you need to be able to move the sensor at the top of the canopy so you don’t waist. Remember co2 is heavier than air.

 

[Aqua Man]

Just to add to the others lists of do's dont's.

If your going sealed in a room that size a Co2 burner is probably your best option.

As for controllers you will want individual or a unit that is rated for your equipment and will :

Provide Co2 ppm from at least 500 to 1500 ppm preferably with day and night cycle or light sensor. This is because you don't really need Co2 in veg other than to supplement. Depending on lighting you crank it up at the flip (I run 1200ppm) and then personally lower back to supplement at 3 weeks before harvest (some do 2 weeks before harvest and some all the way)

Provide control of both heating and cooling not one or the other.

Provide control of humidification and de-humidification not one or the other.

An exhaust fan to run for set interval(s) after lights out to evacuate Co2.

If your going hydro then RDWC is probably your best bet there are pro's and con's but RDWC makes for a lot less work. Can make things a bit tougher running multiple strains at once or encounter pythium. The benefits far out weight the con's in my opinion.

Don't forget a chiller. I run LED since its cooler but there are pro's cons to that as well. You could always do air cooled lighting with outside intake and exhaust.

So many dam things I will stop there.

 

[nemgrower202]

Thanks guys, i took everything into consideration and got everything down except for the
" An exhaust fan to run for set interval(s) after lights out to evacuate Co2. ", that is new information that i haven't run across anywhere. I will look into it now.
Also, the co2 controller i prefer one with a timer as to not bombard the room with co2 as soon as the lights go off and not to stop only once they go off but half an hour before to let the plants adjust.

After running all the calculations co2 seems a better option, the cost for a non co2 room is 5700 euros and a co2 one is 7050 euros so not a big difference.

 

[FTCG]

That sounds like a good idea to me. A regular venting system running at night will bring in fresh air and keep co2 levels low at night time. Build the sealed room, but also set up and intake and outtake for use as you need it.

Not everything has to be electronically controlled. You can manually set many aspect of the grow room. And equipment can always fail.

Don't waste money on product you don't need.

 

[nemgrower202]

What do you mean by a "regular venting system"?

 

[nemgrower202]

Do you absolutely need to add exaust fan to evcuate co2? All the setups I found so far don't have any exhaust fans they just keep the co2 inside.

 

[FTCG]

No you don't. The plants eat up the co2, so turn your co2 off 2-3 hours before the night cycle and in a 10kw room your co2 levels will be back down to around 400-500ppms.

The venting is just for you, to increase control over your environment. For example, if you water your plants and the room get really humid. Or if humidity spikes at night time, you are going to want to expel the humid air and replenish with dry air to mitigate and mold issued etc...

You dehumidifier may not be up to the task by its self. And maybe your A/C needs a little help dropping temps down a few degrees.

Having a ventilation system can minimize electrical consumption and be that extra help you need to maintain a proper environment at will.

The ventilation can run every 5 minutes for 1 minute, or every 20 minutes for 4 minutes etc... Just for extra control.