beaster: Room design - sealed vs. vented

[Beaster]

Hi folks, 2nd post, first thread my boy Delta Force referred me to this wonderful site, he talks about you guys all the time, then again if you know him...he just talks a lot j/k bro

Anyways, I'm planning on converting a 12x8 section of my shed into a 2000w grow room....We, calyxlover and myself have tons of ideas and challenges to work through....

First order of business....sealed or vented. Like i said the space is 12x8 and in a detached shed, electricity won't be an issue, but water will(one of these challenges i was talking about). It's a basically a clean slate, stick built with 2x4's that are 16" on center.

What are your thoughts on both types of rooms...pro's... con's of each?

also, any co2 information would be appreciated....

 

[green_tea]

if you are doing sealed, YOU HAVE TO USE co2.

12x8 can do a lot more than 2000W too!

break it down to 2 rooms of 12x3 and you can get 4 600W's in there.(in each room)
on a flip flop and you have a 4800W system. the 2ft extra is for a walkway. use pull out trays too and oyu can pull em out 2 ft and attend each 3x3 area pretty easily.

not sure where youd put your veg area though... could always cut up one of the 12x3 rooms into 9x3 and 3x3 for a veg room.

 

[Green Force]

i say start small gorw big trust me you will be happy you did and prolly save a lot of money in the long run =) take it from the little exsperence i do have =) and hey check out my grow that i run now

 

[suedoe]

I am planning a similar setup, 8x10 shed so a little different. I plan on running a sealed room with a\c. I'm going with a 12,000 btu portable a\c. I know people recommend a window unit and just building a box for it, but I like the easy way. I am going to run 2 x 600 watts in Super Sun 2 hoods and cool them with outside air via inline fans. I'm gonna run co2 using hydrofarms co2 injector. I can always add another 2 x 600's later if I wanted. My current problem is I think I will have to have my lights come on at night because of the hot temps here. I don't want to cool my lights with my a\c because then I would loose co2. Just something you might wanna think about...

 

[Beaster]

thanks for the input guys, the 8x12 needs to hold everything, the actual light footpring will probably in the 4x8 area. I understand if the room is sealed i will need co2. However, i have zero experience with co2. Whereas sound and smell are very important to me and that it is a shed in the middle of my yard, I feel a sealed room may be the way to go.

 

[Whatever]

If a free standing structure like that I'd be inclined to go with a closed system. I set up a grow space for a buddy in his detached garage and the influence of the weather was extreme in the middle of winter and summer. In the summer the sun is beating down on it, possibly, and you will require an ac. If an open system you will at least need one for the lights off cycle which will be during the day. No other way to deal with it. In the winter freezing cold so drawing in outside air for an open system is difficult to heat while retaining decent air flow. I understand I don't know what part of the country you are in so guessing. If in the south someplace then difficult to keep the space cool at night in an open system when the lights are on.

It's gonna look funny having an ac sticking out the side of a shed though. Maybe a portable ac for inside the room but no experience with those.

A problem with having a grow space in the middle of the yard is picking up pests as you walk through. Mites are the big one and thrips are also easy to pick up. A problem with thrips is they also fly so when you open the door they can get in that way also. When I help friends set up open systems now I install some small micron filter socks on the intakes and it really cuts down on pest problems. It's a similar material as that used to make bubble bags and you can get it by the yard.

I'm still debating whether to recommend to my buddy to go with a closed system for the winter and open in the summer. We're up in the mountains so it really cools off at night. He still needs an AC in the summer lights off during the day otherwise it would cook. Winter temps are regularly below freezing so closed in the winter would help as all heat generated by the lamps and ballasts could be used. Open in summer cause air is free...lol.

Something like that...

 

[Beaster]

I will definately need an a/c in the summer and a heater of some sort in the winter but because I plan on insulating the hell out of it for sound and climate I should be able to maintain it. There is also an 8x10 section that is going to be retained as my workshop. I think i should be able stick an a/c on the connecting wall.

 

[BonsaiBud]

As for portable ACs: you need a twin hose type. The ones with a single hose are worthless and violate the laws of thermodynamics. They don't even work as dehumidifiers.

If you insulate well enough, you should be able to heat with grow light waste heat in the winter. Use multiple chambers with high wattage lights and flip-flop or just use 2 timers. The plan would be to run lights during coldest 12 hours of the night during the summer. You could also use a gas burning CO2 generator in the winter for extra heat. No reason to let any energy go to waste in the winter.

Since you have the shop room, you could keep a set of "clean room" cloths and shoes in there. Change every time. Or, you could put in a path of concrete slabs so you don't walk on the lawn/dirt.

 

[BonsaiBud]

As to your question: use air cooled hoods and some dampers so you can heat with that lamp heat in the winter and exhaust it in the summer. Sealed in winter when heat is needed. In summer, you pump outside air in and then push it across all the lights, then right out a dryer vent. HEPA filters everywhere but don't put one of those fancy blue and chrome hot-rod type cone filters on the outside where someone will see it. Make a little chamber for it. Suck in through some wooden slats.

 

[FullMetalJacket]

As for portable ACs: you need a twin hose type. The ones with a single hose are worthless and violate the laws of thermodynamics. They don't even work as dehumidifiers.

If you insulate well enough, you should be able to heat with grow light waste heat in the winter. Use multiple chambers with high wattage lights and flip-flop or just use 2 timers. The plan would be to run lights during coldest 12 hours of the night during the summer. You could also use a gas burning CO2 generator in the winter for extra heat. No reason to let any energy go to waste in the winter.

Since you have the shop room, you could keep a set of "clean room" cloths and shoes in there. Change every time. Or, you could put in a path of concrete slabs so you don't walk on the lawn/dirt.

A dual tube portable AC will not create a truely closed enviroment. It mixes air it treats with air it exhauts from cooling the units. I would go with a window unit and build a partician inside the shed so that it is not protruding and can still be vented. Also in my prior closed grows i also need a dehumidifier because if i used the AC for cooling and hehumidification my area got to cool.

personally i would get a

window AC - small heater - dehumidifier and a CHHC-1 controller. The chhc-1 is only like 500 and controls all of the forementioned items independently. Make sure you insulate well and use properly clean the shed before beginning the grow. The lights will of set heat as will a Propane co2 genertaor if you go that route. Fortunately heaters are cheap in case the ligh/co2 geneartor are not sufficient. I prefer bottled co2 (tanks) for safety, stealth, and ease of use....

I agree that the threat of pests would increase but cannot speak well to this.

 

[Beaster]

in a room this size, 8x7x10, how much co2 would i go through each grow? I am concerned about getting the bottle filled being suspicious. what types of places file co2 tanks? paintball? home brewery? aquarium?

 

[saintgr8one]

welding supply companies

 

[green_tea]

FMJ, with portable ACs, can you take em apart and basically mod them to be sealed?

I would think modding a portable AC unit ends up being easier than modding a window AC unit (to seal it 100%) and then add a box to it.

(and probably cheaper after time spent and extra materials bought)

 

[FullMetalJacket]

Beaster - google "C02 calulator" and punch in your numbers and it will give you results.

Here are mine for an example:

Grow room area: 36 cubic feet
Amount of CO2 required: 0.0432 cubic feet
On time: 0.65 minutes
At this flow rate:
If you are using a 20 pound CO2 bottle with a regulator, it will last 43.7 hours.
flow setting 4

4 times an hour
12 hours on

48 cO2 cycles at .65 min
48 * .65 = 31.2 min a day

C02 tank will last 43.7 hours or 2622 min
using 31.2 min a day

2622/31.22 = 84
20 lb Co2 tank will last 84 days of usage if I recycle my air every 15 min (this is worst case scenerio)


Green tea - I am not sure. I just know that my dual hose portable AC definitely mixes air. I havent opened it up as it was like 600 bucks. Right now im just using it to cool the room my cab is in, since the heat exhaust heats up the room and im unwilling to run duct to the window or sealing. Maybe i will try to open it though but it may be diificult to mod if there isnt at least a partial wall between the hot and cold side coils.

My window AC for my sealed grow was only like $200 and didnt need any mods other than a box on the back and a 295 cfm fan to exhause the box...


Found some info -

Q: What is the difference between a single hose design and a dual hose design?

A: Some portable air conditioners offer one air exhaust hose while some offer two, one for air intake and the other one for air exhaust. A single hose takes the air in, cools it and returns the same air back into the room. A small portion of this air will be blown out of the air conditioner’s exhaust host. A dual hose unit works by taking in air from the outside though one of the hose pipes cooling the air and releasing it while releasing the hot air through the exhaust pipe. As of now, there is no conclusive proof as to which unit produces more efficient cooling and conserves energy at the same time.

 

[green_tea]

yeah true, the portable ACs are usually like 2x-3x the price of an equal BTU window mounted AC.

Maybe I'll just take apart a window AC and make sure its 100% sealed at all times.

 

[Beaster]

whoa, thats some math right there....let me try

Grow room area: 672 cubic feet
Amount of CO2 required: 0.8064 cubic feet
On time: 12.1 minutes
At this flow rate:
If you are using a 20 pound CO2 bottle with a regulator, it will last 43.7 hours.
flow setting 4

4 times an hour
12 hours on

48 cO2 cycles at 12.1 min
48 * 12.1 = 580.8 min a day

C02 tank will last 43.7 hours or 2622 min
using 580.8 min a day

2622/580.8 = 4.5
20 lb Co2 tank will last 4.5 days of usage if I recycle my air every 15 min (this is worst case scenerio)

lol...i hope my math is wrong i set the "flow" to 4 and ppm 1200....at that rate i will need a lot of tanks!

 

[Delta Force]

My vote is for sealed after reading into it some more and seeing some other posts. This Calyxlover guy sounds like a handsome stunning man with vast growing expertise.......am I right?

 

[Beaster]

werd up....i edited my OP

 

[FullMetalJacket]

Beaster-

with a truely sealed room you definitely wont be exchanging the air every 15 minutes. I would figure 6 hours at most but you should never need to exchange it if you set the room up right. Or if you do exchange it do it at night when your not using CO2. Due to the size of my cabinet, im not sure i want to add an AC and Dehumidifier for stealth reasons. So i will be using the exhaust to mostly control humidity and some temp. When I had a sealed 7 x 4 x 8 closet grow with an real AC and a dehumidifier I only exhausted once a day right before by "night period" to just to freshen up the air.

I use a sentinial chhc-1 co2 controller and it has plug for you heat, ac, dehumidifier, and co2. You can set it up to not run C02 with exhaust. In your case it will just kick off your ac and dehumidifier when you set thresholds are met. They run 500 but are really easy to work with.

You should be able to do 1 grow (50-60 days C02) off a 20 lb tank. If it doesnt last that long just go get it filled, no rush its not going to hurt.

Also i prefer my temps at 95 with CO2, but some people call me crazy. That is just where i see the best results. I dont run the CO2 the last 2-3 weeks before harvest. During those last 2-3 weeks i vent constantly and drop my temps back down below 80 and humidity as low as i can get it...usually around 22-25%.

 

[Beaster]

oh ok, that sounds a lot better lol...great post, that helps a lot....i will look into that controller, it sounds like it is just what i need