Concrete walled garage intake/extraction

[Cajafiesta]

RE extraction volume and frequency.  

 

Simple enough.  I forget the correct time/volume but someone somewhere has already worked out how frequently air should be exchanged.  It's volume-per-time. Figure out what it should be, ideally, and then size your extraction so that you can move X volume of air in Y amount of time.  That's the answer. 

 

 

I'm assuming that, because this is the garage, the foundation is a concrete slab? If you wanna get REAL 007 with it, you could always cut the slab, dig a trench, put in 4-6" PVC that goes from the garage floor, under the load baring wall, and out up into the yard.  put a rain cap on the vent.  Boom.  you now have a "sewer cleanout," or a "drain vent" if that's a thing that's done in the UK. Very common in the states.   Bury the pvc pipe, pour concrete and finish to cover the trench in the floor, hook up extraction that PUSHES out of that pipe into the back yard.   That's a lot of effort, but is probably the least suspicious thing you can do.  Hope you don't mind a lot of sledge hammer and shovel work 

[Gaijin]

26 minutes ago, porky said:

Chances are its got steel rebar or mesh so pick your spot carefully.

 

Very good point. It's quite possible. The panels have thick ridges where they are bolted together and "appear" to be quite thin in the middle. Might be some reinforcement in the thicker sections. Maybe they left the centre of each panel alone. Virgin 'crete  

[RUFUS HOUND]

do you have a photo of the roof inside, towards the door, sounds like my concrete sectional garage that has the old looks like asbestos corrugated roof but actually cement based - I may have a solution for you if it is

 

but I also like the catflap idea - genius

Edited August 4, 2022 by RUFUS HOUND

[RUFUS HOUND]

36 minutes ago, Cajafiesta said:

RE extraction volume and frequency.  

 

Simple enough.  I forget the correct time/volume but someone somewhere has already worked out how frequently air should be exchanged.  It's volume-per-time. Figure out what it should be, ideally, and then size your extraction so that you can move X volume of air in Y amount of time.  That's the answer. 

 

found this for ya 

How often does the air need to be changed in a grow tent?

 

 

Air in your grow area should be exchanged at least every 5 minutes. If you are using a grow tent that is 5' x 5' x 6' this is 150 sq/ft of air. For optimal airflow, you need a filter and fan that can move between 30 and 60 cubic feet per minute (CFM). 

[Gaijin]

@RUFUS HOUND I just removed a sheet of drywall and the insulation and found compressed board. Particle board? Whatever that board's called  And the sheet appears to be sitting on top of the upper edge of the vertical wall panels. I'll have to check, somewhat carefully, but it appears I have a wooden roof? 

 

@Cajafiesta interesting idea, that. I'd hire some suitable heavy equipment if I went that route   I've worked out the correct size fans for extraction; what I'm missing is what size passive intake vents/ports/holes I would need in to account for the extraction. is there a formula of some sort of work out what size hole I would need for intake?

[MindSoup]

Even a well built house has a fair amount of air leaks all over the place, I'd be amazed if you got much of a restriction even with no vent hole whatsoever in an old garage, for example if you smoke a joint in there I bet the wife can smell it from outside. Even just the gaps around a door will let in a lot of air. If you do go for a vent hole put it low down and sit a bench or a bird bath or something in front of it. 

Edited August 4, 2022 by MindSoup

[Bobcharlieeeee]

@Gaijin Diamond core should get through that bar, the bar will only be a few mm in diameter 

[Gaijin]

45 minutes ago, MindSoup said:

Even a well built house has a fair amount of air leaks all over the place, I'd be amazed if you got much of a restriction even with no vent hole whatsoever in an old garage, for example if you smoke a joint in there I bet the wife can smell it from outside. Even just the gaps around a door will let in a lot of air. If you do go for a vent hole put it low down and sit a bench or a bird bath or something in front of it. 

 

You could well be right, mate. I guess the best thing to do would be get the tent and fan set up, bore the extraction holes out and hook it all up. Then turn it on, say 75% and see if the garage walls bow in  Well, just see what if any airflow issues or noises I can hear. I hear that the gaps around the door will let in a bunch of air; I just want to eliminate possible noise 

[twigs]

ooh it’s made me remember that video of the dude kicking the prefab fence or shed panel through and the one above slides and lands on his leg  

[MindSoup]

8 minutes ago, Gaijin said:

 I just want to eliminate possible noise 

 

I'd be more worried about the fans and stuff inside tbh, easy fix, outdoor water feature with a nice little fountain, lovely sound to watch clouds to 

[MindSoup]

@twigs oh god I remember that, poor little wally. Must have been there a while waiting for them to get that leg free. 

[Gaijin]

9 minutes ago, MindSoup said:

@twigs oh god I remember that, poor little wally. Must have been there a while waiting for them to get that leg free. 

 

19 minutes ago, twigs said:

ooh it’s made me remember that video of the dude kicking the prefab fence or shed panel through and the one above slides and lands on his leg  

 

 

 I bet he didn't do that again, silly lad. My shin is actually cringing, somehow, as I type this  

[MindSoup]

9 minutes ago, Gaijin said:

My shin is actually cringing, somehow, as I type this  

Yeah I know what you mean, its like hearing fingernails on a blackboard..

[geogeo]

@Gaijin sorry mate , got a few old core bits in workshop , 117mm an 150mm if you was nearer i would core for you no bother! have a look at

BES , birmingham , or toolstation for vents ,  geogeo  / ooo the concrete garages that bolt together  70mm thick at parts some with galv/ mesh 

Edited August 4, 2022 by geogeo
forgot to add text

[RUFUS HOUND]

2 hours ago, twigs said:

ooh it’s made me remember that video of the dude kicking the prefab fence or shed panel through and the one above slides and lands on his leg  

 yea, little shit probably lost his leg - that will learn him 

 

I believe (dont quote me ) but your intake needs to be slightly less than your extract to create a neg press and keep smells in tent /enclosure.