New room build part 2 - need some input

[OZZ_]

What's up IC!

Awhile back I built a wall and put in a door on a cubby area that was in my garage in an attempt to design a grow room and also use it for storage.

AFTER building and installing the wall, putting in the door, dry walling, mudding and painting..... I realize the gas water heater which is vented - is a big problem! Shit.

So this is part two. After throwing in the towel and using it only for storage I'm determined to make the space work and I need YOUR help and ideas.

Here is a drawing of one idea I think might work and also will give you an idea of what I'm up against:

 

[OZZ_]

There's several problems to consider:

1) this room is in the garage, it is finished with drywall and an insulated garage door but still it gets hot in the summer and cold in the winter. It's a big 2 car garage.

2) the water heater! I must pull my intake from another area or else it will create negative pressure in the room, sucking air down the water heaters vent and blowing out the pilot light- this could be dangerous.

3) I'm not set on using the tents, but it's about all the space I need and with the need to pull my intakes from OUTSIDE the room it makes the most sense.

4) I do have the option of cutting an intake in either the kitchen pantry or the mud room. Either of these will allow me to intake air from my house which will be more stable temperature wise than the garage.

5) in winter I can add a space heater to the grow room to help keep things warm. If I had to I could add a window AC but this complicated things even more and I'm a personal grower.

6) the room is small, 10'x5'

I'm running a 600w HPS in the DR90 for veg/flower and I'll probably use a 2' t5 fixture in the dr60 for moms and clones. I would like to be able to grow year round, but it's easier to add a heater to the room rather than install an AC (although if I had to I could) so if I need to not grow during summer that's ok. Our summers are short and I'm a small medical grower for personal use. 6 plants in 3 gallons in the dr90 is plenty for me.

My first and most important question is this: when reviewing my drawing above, do you think my fan rated at 424 cfm will be enough to vent both tents efficiently? It's one fan, rated at 424cfm and it has to pull through a scrubber as well as some pretty lengthy duct work with quite a few bends. I do have another 424 cfm fan I could use and do have speed controllers

I know there's a way to rig this space up, but this is all I could come up with. HELP A BROTHER OUT lol

 

[Arthritis_sucks]

Whaaaaaaat!?! I've actually been waiting for full room nuggage shots. Figured you were so busy with the flow. Subbed. Get r going meng.

 

[OZZ_]

Arthritis! What's up chief!

Ya I got tired of beating my head against the wall and I had a ton of stash from my last grow so I said screw it and dropped it all together. I'm motivated to get this figured out though! I know there's a way- and probably a simpler way but I can't figure it out as of yet. Lol

 

[Arthritis_sucks]

I'll grab my graph book an draw up a suggestion when i get back from dropping off the wife. There's always a way my friend, an hope i can help.

 

[OZZ_]

Right on, appreciate it! Here's another option and I think I might like this one better.

Using both 424 cfm fans and two 8"x6"x6" duct splitters - one for intake on the flower tent and one to combine the exhausts of both the veg and the flower tent. The intake for the veg tent will just be leaving one flap open. Then I can use a space heater in there during winter. Summer I just won't grow.

 

[Arthritis_sucks]

I can't seem to upload from my phone so I'll try to explain best possible. Run 1 line to the smaller tent on the bottom, then in that tent install the fan inside blowing out and duct out the heat from the top to the bottom of the flower tent. In the flower tent have the light ducted on one side going to the roof an up into the attic where you will have the fan an filter. This is a push through filter setup so ya may wanna get some thick chicken wire an rig your prefilter inside, or just get another to put inside rigged up. Not needed but helps the filter. I have never ran push through situations but hear it works. Run rigid aluminum ducting to help the flow an the less bends the better.

 

[OZZ_]

I'm with ya.... So I'll have the small tent hooked up to the intake (that's pulling from the kitchen pantry so as not to create negative pressure in the room the tents and water heater reside) then I'll have one fan exhausting the hot air into ONE intake on the flower tents floor. Then run ducting from the hood, through the attic, where the second fan and filter sit in a push configuration.

A few questions:

1) What about the second intake in the flower tent? I don't think one intake pulling through the mom tent is gonna be enough airflow for the tent?

2) why not do it like that but have the filter and fan inside the tent pulling?

 

[r2k]

I think there may be a potential problem with your air flow.

1) The way I have it figured, you have an 8 inch duct. That's 50.26 square inches, or 0.35 square feet.

2) You have a fan that's 424 CFM.

3) Air must move through the the duct at a speed of 424 / 0.35 = 1213 feet per minute, or 20.24 feet per second. That works out to about 13.8 miles per hour.

I wonder if you might have some airflow noise. I also think you may lose some airflow to duct resistance, especially if you use flexiduct with the pleats. Going around those tight corners is also going to hit your airflow.

The 600 watt light is going to be the big problem for heat control (but you knew that). If you can actually move 424 CFM, the exhaust temperature should only go up about 4.5 degrees. Reduction in airflow will give you proportionately higher temperatures. Depending on where you live, winter air should be able to compensate for this. It would be better if you could pull air from the cold winter source instead of the pantry, but you gotta do what's needed to keep safe with that water heater.

I have heard of a trick to avoid some amount of separate heater during the winter. You can pull some air through the hood backwards and into the box. If that isn't your style, you can bypass some of the hot exhaust air back into the intake and circulate a portion of the warm air. This could make your ducting trickier than you really wanted.

If you do end up using flexiduct, follow the usual rules of trying to turn corners as gradually as possible. Right angle bends with zero radius are not good on airflow, much better to go through a larger radius.

If you have more than a foot of straight line for the flexiduct, there is a pictoral in my gallery that shows how to make stiffeners for flexiduct to pull it tight and remove the pleats. It's a bit unconventional but it really cuts the resistance to airflow.

Of course, I gave no consideration to visual security. All this ducting and fans are going to look like crap and be suspicious as hell. I assume you have that part worked out.

It might be a bit strange, but have you thought about setting the water heater so it pulls air from outside instead of the garage? Your problems with box venting might go away if you could pull air from another source for the burner. A direct inlet to outside air may also make you sensitive to the pilot light being blown out frequently when the wind picks up. This might not be possible, I'm just thinking outside the box.

-r2k

 

[Arthritis_sucks]

I'm with ya.... So I'll have the small tent hooked up to the intake (that's pulling from the kitchen pantry so as not to create negative pressure in the room the tents and water heater reside) then I'll have one fan exhausting the hot air into ONE intake on the flower tents floor. Then run ducting from the hood, through the attic, where the second fan and filter sit in a push configuration.

A few questions:

1) What about the second intake in the flower tent? I don't think one intake pulling through the mom tent is gonna be enough airflow for the tent?

2) why not do it like that but have the filter and fan inside the tent pulling?

Ya gonna have to double the intakes to get proper flow without creating to much neg pressure. So maybe 2 intakes to the veg and tap into the mudroom for the second intake from the flower tent. Might just do it.

you could do it with the filter inside the tent that way too.

 

[OZZ_]

Gracias Hombres! I think I have it worked out (see attached diagram). I'm using 6" ducting though not 8". Only the duct Y will have an 8" inlet to increase flow (6"x6"x8").

I think I'd rather work with installing intake and exhaust ports into the walls of the room rather than trying to box the water heater in and all that jazz. Just seems like to much hassle.

I am concerned about noise, but not appearance necessarily as all this will be behind close doors.

Please see attached diagram- this is what I'm gonna do. I'm gonna use the mudroom as my intake and run one intake from the flower room directly to the y adapter pulling from the mudroom. Then the other intake from that y will run into the mom tent. I'll use a 170 cfm inline fan to boost airflow out of the mom tent and into the other flower tent intake and use the 424 cfm vortex to pull through the scrubber and exhaust the whole shebang into the attic or into the garage (see below). I do have a few other problems to get worked out.

1) if I can't grow year round because the garage gets to hot in the summer (this isn't the end of the world our summers are short) the that means I'll be growing in winter primarily. Exhausting all that hot air to waste (into the attic) then warming the space with a heater seems counterproductive. So I think I'm going to run two exhaust outlets - one exhausting into the attic for spring and fall when the weather starts warming up and another exhausting INTO the garage itself. I'll switch them as necessary with a short piece of flexi duct. I brew beer too and have temperature controlled fermenters in the garage. Plus it's my man cave. This will help keep the garage comfy all winter long and while it isn't heating the grow room itself it will raise the temp of the surrounding garage so that will help and is certainly better than wasting it.

2) the noise! As mentioned I brew and my "taproom" is in that very same garage. This is a legal medical grow but I don't want people knowing regardless. I do have "cover" for some noise such as multiple refrigerators, kegerator, etc, etc but the thing sounds like a jet engine when it's running lol. I am ALL EARS on how I can reduce noise.

I'm going to start by insulating the room, while I'm there ill repaint and seal the bottom of the door as much as possible. Also I was thinking about using straight pvc pipe or metal ducting in a few of the longer runs so as to minimize airflow resistance as mentioned by R2k above.

Would insulated ducting be better than straight pipe? I'm unsure as to what is best to use. Up until now I've just used the flexible pleated ducting.

Appreciate the help guys!

 

[OZZ_]

For noise reduction... Would straight pvc pipe be better than insulated ducting or would insulated ducting be the way to go?

 

[Granger2]

I would use straight metal duct everywhere possible, and insulate it. You'd be better off using both 6" fans for exhaust with passive intake-twice the sq inches of exhaust sq inches. Good luck. -granger

 

[r2k]

If you can get PVC pipe with a large enough diameter, I would say it is much better than flexiduct. Finding large enough diameter will be the trick. You don't need thick walls, you need a fat pipe. ABS pipe would also be a possibility and it might be cheaper.

The best way to reduce noise is to slow down the air. Slowing down the air means using bigger diameter ducts and/or adding more ducts in parallel. This also reduces your air resistance and allows more pounds of air per minute to move through the system.

In the latest drawing, you have a U-turn at the bottom of the DR-90 tent. I would suggest you think about straightening that if possible, it just wastes air pressure and reduces air flow.

Are those hoods fully enclosed? That's a good way to trap heat from the bulb. You lose a bit of light through the front glass but it allows you to pull out lots of heat.

It looks like you have the 424 CFM fan blowing into the hood and then out the exhaust. This works but it will put positive pressure in the outlet duct going up through the top. Any little holes or unsealed joints will leak stinky air back into your man cave (or wherever the hole is). Make sure you seal anything that needs it.

-r2k

 

[OZZ_]

Thanks guys .... I've been slaving away. Came up with a good plan that will allow me to divert the heat into the main garage in winter and in summer send it to the attic.

Got the walls insulated, two of the exhaust holes cut and fitted, and the entry door light proofed as well as got all the ducting assembled and ready to go. I went with straight metal ducting. I'm gonna HAVE to use 90 degree bends though in order to keep the light from bouncing through the ducting and into the flower tent (been there, done that). I'll probably still need to assemble some light traps or something in order to keep it dark in the flower tent. I'll assess that once things are up and running.

I've got a bday party out of town tomorrow and ten gallons of home brew ready so I'll have to get back at it on Sunday.

Thanks again guys!

 

[OZZ_]

And away we go.... Snapped a few pics of the progress last night. I got the walls insulated, ran a new 60 amp breaker (2x30 amp outlets), got the intake and exhaust holes cut (which was a pain in the ass trying to avoid gas and plumbing lines) and got most of the straight ducting mounted. I'll be insulating it tonight and putting in the mom tent as well as caulking the door jams for light proofing and installing the scrubbers and lights.

I'll also drop some beans tonight. Gonna pop ten hazemans "the madness" (bubba x 88 g13/hp). I'll start another thread for the grow log.

Hmmm .... New iPhone and for some reason it will only let me upload one pic at a time? Weird

 

[OZZ_]

Ducting

 

[OZZ_]

Cont'd

 

[OZZ_]

Pic

 

[OZZ_]

Pics