[drudown420]

Hello everyone. Haven't posted in a while because I usually have all the answers Not a newb been growing indoor for years without about every setup you can think of but this is my first legit sealed room in an actual house. 12x12 with vaulted ceilings and central ac. 4 1000w raptors and I actually plan on switching to de cooled hoods soon but that's for a later question. What I wanted to know is I have a 8 inch fan on top of my carbon filter exhausting into the attic and it doesn't seem to be cooling quick enough. Without lights on in mid day it runs at about 82 degrees. Too hot. Should I bump the ac down (thermostat is at 78) or do I need a way bigger fan. I am not currently cooling the lights, which I usually do. I was thinking about running my carbon filter before the lights with a 8 inch fan and a splitter, ducting through the lights into a split onto an 8 inch fan on the other side, and then up into the attic. 1. will this cause a problem with passive/active pressure with the 2 fans? And if not will this be enough? and 2. should I just got with like 10 or even 12 inch fan and leave use 1 for the whole system? Furthermore will I be able to run co2 with this setup? Id really appreciate any help. Right now money is an issue since I haven't had a harvest in about 6 months, but if 1 fan will work better ill sell all my current ones a get a big bad ass one.

[OldPhart]

Originally Posted by drudown420

Hello everyone. Haven't posted in a while because I usually have all the answers Not a newb been growing indoor for years without about every setup you can think of but this is my first legit sealed room in an actual house. 12x12 with vaulted ceilings and central ac. 4 1000w raptors and I actually plan on switching to de cooled hoods soon but that's for a later question. What I wanted to know is I have a 8 inch fan on top of my carbon filter exhausting into the attic and it doesn't seem to be cooling quick enough. Without lights on in mid day it runs at about 82 degrees. Too hot. Should I bump the ac down (thermostat is at 78) or do I need a way bigger fan. I am not currently cooling the lights, which I usually do. I was thinking about running my carbon filter before the lights with a 8 inch fan and a splitter, ducting through the lights into a split onto an 8 inch fan on the other side, and then up into the attic. 1. will this cause a problem with passive/active pressure with the 2 fans? And if not will this be enough? and 2. should I just got with like 10 or even 12 inch fan and leave use 1 for the whole system? Furthermore will I be able to run co2 with this setup? Id really appreciate any help. Right now money is an issue since I haven't had a harvest in about 6 months, but if 1 fan will work better ill sell all my current ones a get a big bad ass one.

OK, you mention sealed room and central AC, then talk about shoving hundreds of CFM of ventilation from the room into the attic. Those are sort of mutually exclusive to each other. If you are going for sealed, you will need a few things: 1) no ventilation from inside to outside. 2) Must have CO2. 3) Must have cooling to cool the room. 4) Depending on environment, will probably need a dehumidifier. 5) Last but not least, you must seal the room! With a central AC you will be blowing the smell/heat/CO2/humidity all over the house. I see a few other issues, like trying to light a 12x12 with 4K; where you should have closer to 6-8K in lights. On the plus side, 4K should be very easy to cool, but will not effectively light more than about 60-80 square feet. Need to rethink what you are trying to accomplish. Unless you are able to seal the room and bring enough cooling into the room in a sealed fashion (dedicated ac/mini split/window ac), I would abandon the sealed room idea. As far as venting is concerned, that would be decided by what temp the "make up" air is. If it is 95 degrees outside and you are blowing all your 'conditioned' air out of the house every 5 minutes... well that just isn't going to work. On limited funds, and assuming it is hot outside; I would not bother with sealing the room and quit venting to the outside (attic) or vent very little. Then I would just crank the central AC for the desired temps. I would then vent the room through the carbon scrubber into a return air duct for the central AC. Expect to need dehumidifier as well. Good luck man, it is all about tuning what you have to work with.

[mushroombrew]

How big is your AC unit?

[drudown420]

Originally Posted by OldPhart

OK, you mention sealed room and central AC, then talk about shoving hundreds of CFM of ventilation from the room into the attic. Those are sort of mutually exclusive to each other. If you are going for sealed, you will need a few things: 1) no ventilation from inside to outside. 2) Must have CO2. 3) Must have cooling to cool the room. 4) Depending on environment, will probably need a dehumidifier. 5) Last but not least, you must seal the room! With a central AC you will be blowing the smell/heat/CO2/humidity all over the house. I see a few other issues, like trying to light a 12x12 with 4K; where you should have closer to 6-8K in lights. On the plus side, 4K should be very easy to cool, but will not effectively light more than about 60-80 square feet. Need to rethink what you are trying to accomplish. Unless you are able to seal the room and bring enough cooling into the room in a sealed fashion (dedicated ac/mini split/window ac), I would abandon the sealed room idea. As far as venting is concerned, that would be decided by what temp the "make up" air is. If it is 95 degrees outside and you are blowing all your 'conditioned' air out of the house every 5 minutes... well that just isn't going to work. On limited funds, and assuming it is hot outside; I would not bother with sealing the room and quit venting to the outside (attic) or vent very little. Then I would just crank the central AC for the desired temps. I would then vent the room through the carbon scrubber into a return air duct for the central AC. Expect to need dehumidifier as well. Good luck man, it is all about tuning what you have to work with.

I'm renting so a wall unit isn't really an option as I can't modify the house anymore than I have. So best bet would be to set the exhaust on a timer? Or not vent at all and just use the ac, co2 and dehumidifier?

Originally Posted by mushroombrew

How big is your AC unit?

Not sure a new unit was just installed in the house but it seems to blow pretty hard

[mushroombrew]

You need to figure out what you are working with. You can't seal a room with "blow pretty hard"

You need numbers. 1000W = 3412btu

So you need a minimum of 15KBTU to seal. 20Kbtu would be better if ambient temps get high.

Go check some labels and figure out what you got...

[dansbuds]

your sucking all that cool air out of the room by exhausting it into your attic ! just scrub the room ,don't exhaust it . if you don't want it completely sealed , have an intake from another room or from outside to get the CO2 the plants need .
you will need an exhaust to get rid of the carbon dioxide , but a small 6" fan on a timer that exhausts the room for 15 minutes twice a day should be fine .

[drudown420]

Originally Posted by mushroombrew

You need to figure out what you are working with. You can't seal a room with "blow pretty hard"

You need numbers. 1000W = 3412btu

So you need a minimum of 15KBTU to seal. 20Kbtu would be better if ambient temps get high.

Go check some labels and figure out what you got...

thanks I will

Originally Posted by dansbuds

your sucking all that cool air out of the room by exhausting it into your attic ! just scrub the room ,don't exhaust it . if you don't want it completely sealed , have an intake from another room or from outside to get the CO2 the plants need .
you will need an exhaust to get rid of the carbon dioxide , but a small 6" fan on a timer that exhausts the room for 15 minutes twice a day should be fine .

Should I just cool the lights then since they are air cooled sealed hoods and run it out the attic or will I still be loosing the cool air.And I have a co2 tank and regulator with monitor.


Thanks everyone

[mushroombrew]

If you want to run air cooled just keep it separate. So pull air in from outside ground level go through the lights and up into attic. Just make sure it is truly sealed.

Then you can(If you got enough AC) seal and cool the room independently of the air cooled
system.

If you have enough AC and can afford it; running without aircooling/glass increases lumens about 12%.

[drudown420]

Originally Posted by mushroombrew

If you want to run air cooled just keep it separate. So pull air in from outside ground level go through the lights and up into attic. Just make sure it is truly sealed.

Then you can(If you got enough AC) seal and cool the room independently of the air cooled
system.

If you have enough AC and can afford it; running without aircooling/glass increases lumens about 12%.

thanks much appreciated. I'm gonna check on the cooling capacity first and make sure I have enough. Getting air into the room might be hard without cutting a hole so I think I might just scrub it or exhaust just a few times a day.

[caljim]

If you are using the homes central heating/cooling you need to keep a cold air return open to move air back to the air handler or it will have a hard time pushing air into a "sealed room". This is why minis are ideal for sealed rooms.