How to setup my 168 cubic foot grow room

Hey people, I've already got an idea in my head how I want to do this but I just wanted to check with everyone to see if it makes sense.

What I have is a 168 cubic foot room, Inside I will have 4 large plants and 2 1000 watt bulbs burning inside cooltubes. I will buy 1 oversized carbon filter to minimize air restriction. I have 1 4" fan that is rated at 175cfm.

What I would like to do is pull air through the filter, then through the fan, then through one cool tube with 1000HID and then another cool tube with another 1000HID, Then pump that out of the room. I was thinking I could create a point in the vent tubing where I fashion it with a DIY valve to give me complete control of airflow without neccessitating a Variable Frequency Drive. The intake will come from a hole that brings cool air(50-60F) from the rest of the basement. Do I need a bigger fan to make this work?

need some dimensions on the room you say 168 cu ft

You're going to "pump that out of the room"? What exactly do you mean? You need to pump it out of the house, either into an attic or some other area that will FORCE fresh air to be drawn in from outdoors.

Trying to restrict the duct is bad. Get a good speed controller (preferably one thats temp-sensitive). Buy your equipment big enough to deal with a worst case environment because 1000w light will make a lot of heat and humididty you'll have to deal with.

the room is roughly 4x6x7. so 168 cubic feet roughly.

What I mean by pump that out of the room is to vent it into the rest of the basement and have cooler air from the basement be sucked back in at the bottom through a hole. The uninsulated basement cools the hot air that is vented out and by the time it comes back to the bottom vent it is cool air(50-60F)

Right now I have plants growing in the room and am not running any fans other than a small oscillating fan. There is a hole near the top of the room and a hole at the bottom and this has been good enough to control temperature and humidity. The plants are still small however only about 9 inches tall. Im only using 1000 watts right now, but I will be putting another 1000 watts. I have a CO2 burner that has a controller that keeps the entire basement at 1500ppm. No air goes into or out of the basement except for when I open the door. I have a dehumidifier I can run in the basement if humidity rises but so far its not a problem. I don't want to vent out the windows because I have people living 2 floors above me in the same building so having a vent run 12 hours a day will seem odd when they walk by that vent every day. and if my CO2 filter happened to be not working 100% then my cover would be blown for sure.

Thanks for helping, it sounds like Im going to need to rethink my plans a bit before Im ready for flower, any suggestions given the this info?

You must be living somewhere aweful cold if you can keep 2x1000w light cool using a 4" 175cfm fan. That's ridiculously small for this application, but if you live in michigan in the winter I suppose it would work.

I live right next to michigan in Ontario, actually its been really warm lately for winter, all the snow is melting.

I wasnt planning to run cold air through the cool tubes either unless this is the only way to go. I was planning to run the air in the room through a filter then through the cool tubes and then out the room. Sounds like I dont have a big enough fan to do this. Im not trying to make my cooltubes totally cool just minimize the heat somewhat. Afterall I dont want to have to run a heater in there during lights on just to keep things warm. Right now I am using 1000watts of light and this is keeping my temperature perfect through the day with only small vent holes and no fans to exhaust or bring in cold air. Maybe part of the reason Im able to burn 1000watts and have no temperature problem is that 2 of the walls in this 4x6x7 room are made of concrete foundation.

One big concern is that I dont want to have the sound of a jet engine coming from the basement for 12 hours a day. The 175cfm fan makes a bit of noise but is just below my threshold of what I will consider too much noise. This is with the fan being connected to nothing but 6 feet of ducting. I imagine with a larger fan noise is going to be a problem. any suggestions? How big should my fan be to pull air through a carbon filter then push through 2 cooltubes? Thanks for helping me solve guys

The bigger the fan, the queiter it will run. You'll need to get a speed controller, but it'll be queiter. For instance a 6" 360cfm fan will be noisier than an 8" 600+cfm fan running at 360cfm. If you can swing it, for sure go for it. Ontario is even colder than Michigan, lol. I sure envy you guys.

Also Id like to point out that Im not trying to cheap out, I will buy a bigger fan, just wondering how big I should go? After the fan is connected to a filter on one side and the two cool tubes on the other, I am hoping that it will be muffled and not make more noise than Im willing to allow. Will the fan I need for this setup be as quiet as my 175cfm fan? I sure hope so. With the larger fan should I use my 175cfm fan to pull air in at the intake?

Ok thats good to hear, I imagine it must be extremely loud when you crank it to full though lol

So maybe I will go for a 6 inch fan with a high CFM rating.

Whats this about speed controllers? Ive been reading about these and what Im reading is these shouldnt be used with certain fans, unless the fan is specifically designed to work with one. What Ive seen recommended is to buy a variable frequency drive if you want to change the speed of your fan. The variable frequency drive changes the Hertz, not the voltage or watts, apparently changing the watts or volts can burn up your fan fast and even cause a fire. Unfortunately those VFD's cost alot of money. Maybe there is a 6" fan that has speed controls built right into it?

Why not vent the warm air back in to the house and use the cool basement as an cool intake. As for you running co2 in the basement you are wasting a ton of co2 due to the size of the basement compared to the size of your grow area. co2 falls to the lowest point so you would have to suck up the co2 from the floor of the basement if you install your co2 generator high in the grow area it will fall across the plants evenly as your temp rises the exhaust should be on a thermostat to engage as the temp rises, so you are not wasting co2 there are timmers and co2 controllers that can snyc all of this u save cash and heat your house especially with 2 1k lights

stainedtrichromes said:

Why not vent the warm air back in to the house and use the cool basement as an cool intake. As for you running co2 in the basement you are wasting a ton of co2 due to the size of the basement compared to the size of your grow area. co2 falls to the lowest point so you would have to suck up the co2 from the floor of the basement if you install your co2 generator high in the grow area it will fall across the plants evenly as your temp rises the exhaust should be on a thermostat to engage as the temp rises, so you are not wasting co2 there are timmers and co2 controllers that can snyc all of this u save cash and heat your house especially with 2 1k lights

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I think your misunderstanding what Ive described, which is common because what I am planning to do is not the same as what most people do. Ill clarify the important parts:
I wont be exhausting any air from the basement, the hot air from the grow room will be exhausted directly into the basement after being filtered and run through 2 cool tubes. I will definately have to invest in a good quality air filter or I will stink up the whole house. I run a dehumidifier to keep the basement from becoming extremely humid. The cool walls of the unfinished basement keep the basement from becoming warm so even with the hot air being expelled into the basement the ambient temperature doesnt rise about 65F. Because nothing is expelled to the outdoors the air simply recirculates throughout the basement, if I put it at 1500ppm it will stay at 1500 ppm fairly easily because the only CO2 lost is either through small air leaks in the ceiling to the floor above and to the plants absorbing small amounts of CO2. This should save me money on CO2 because I wont be expelling perfectly good CO2 enriches air to the outdoors every 15 minutes or so. This all makes good sense to me however I havent seen anyone attempting such a setup, everyone seems to expell the air to the outdoors with their CO2 unit and fan set on a thermostat/CO2 controller or a CO2 timer/fan controller.

As long as I get myself a 450cfm or larger with a speed controller is this going to work? I there anything clearly wrong with this plan?

Your only problem is going to be heat. It's an awful big assumption that the temp will not reach above 65 degrees. What if it does? How will you cool the room if it gets warm? The 450cfm fan will effectively scrub the smell. You'll be soaking the entire basement at 1500 ppm (expensive).

I have two 4x8 tents running as a closed loop system (no exhaust) so I do know a little about the type of setup you're planning.

If things do get hot, you should first get a seperate inline fan for the cool-tubes. You'll need a lot of ducting though because you'll have to bring in fresh air on one end and expell to fresh air on the other end. No need for a filter on this line because it's completely seperated from your smelly, Co2 enriched room at all times. All it does is cool your lights without exhausting the smell or the C02.

smokingrubber said:

Your only problem is going to be heat. It's an awful big assumption that the temp will not reach above 65 degrees. What if it does? How will you cool the room if it gets warm? The 450cfm fan will effectively scrub the smell. You'll be soaking the entire basement at 1500 ppm (expensive).

I have two 4x8 tents running as a closed loop system (no exhaust) so I do know a little about the type of setup you're planning.

If things do get hot, you should first get a seperate inline fan for the cool-tubes. You'll need a lot of ducting though because you'll have to bring in fresh air on one end and expell to fresh air on the other end. No need for a filter on this line because it's completely seperated from your smelly, Co2 enriched room at all times. All it does is cool your lights without exhausting the smell or the C02.

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would you say I should put the bigger fan on the lights and the smaller fan on the filter/exhaust? that was mentioned earlier, seems weird to me i would have thought the lights didnt need much but the room needed more.

Soaking the whole basement with CO2 shouldnt be that expensive, it takes 20 minutes to initially fill the basement to 1500ppm and then because none of the air from the basement is being exhausted anywhere the burner only has to kick on for a few minutes a day to compensate for what the plants have used or what has escaped from small leaks in the windows ceiling or when I open the door to go downstairs. I get 30 hours on a propane tank so its not bad at all

Your right though I should be prepared in case the basement gets warmer, I just moved in so I don't know what to expect during the summer. though the concrete walls ought to help out quite a bit

Since you're not really doing much with the exhaust but cleaning a little air, yes I would put the small fan on exhaust duty and use the big one to cool the lights.