dumping hot air into wall, any problems?

[Norrath]

well i have set up a tent with 2 x 400watts vertically in cooltubes, but they are able to take the sealed 100sqft room from 72 to 81 in a matter of hours without dumping the hot air anywhere; goes without saying.

the system goes:

cool tube || cool tube || ducting || fan || ducting || can filter

it's a short run so the air moves fast, i was thinking about putting the filter in a big rubbermaid bin (with a sealed top) and drilling a 4" hole and running a booster fan from that into the wall.

i ran this predicament passed my friend he told me otherwise as it would cause more issues structurally INSIDE the wall due to condensation build up and whatnot from a cold wall and hot air.

with all the air movement mixing in the rubbermaid bin then positive pressure and a booster fan taking the air to the wall(which would be a foot or two) i doubt the air would be so hot it would cause problems inter-wall, but you all think he's right?


afterthought, if there is a cap on the top of the wall(who knows for 45 year apartment) i could drill a 2 inch hole on the direct opposite side of the wall and put in a unseeable grille that would let dumped air out of the wall(IF NEED BE)....idea....

lemme know folks, i need to DO THIS if it's doable. many thanks.

pics or shens! purdy nice eh? cant wait to copy the shit out of sunnydog with tropf blumats...

 

[FreezerBoy]

Sounds like black mold city. Your wall interior is not open to the attic, it's sealed. More over, there may well be cross beams just above and below your hole. You could be pumping air into a 1 cubic foot area or less. That's a lot of trapped moisture. Bad idea all around.

 

[Norrath]

by the by, i really appreciate the input FB, youre always there to help. you'is quite the shining beacon of information.

the interior of the wall seems to be super vacuous..

what do you think about the grille on the opposite drywall section to alleviate the pressure inside the wall AND more importantly not allowing the air to sit stale in teh wall; the movement should push air into the next room, hopefully not bringing smell with it(but the can filter should really suffice)

second thought:

i could even pump the air without a booster using positive pressure in the rubbermaid and run 2" ABS from the bin holding filter THRU the wall into the next room, right above the baseboard behind my tv stand..put a cap on the abs with a nice wall coloured grille and i could practically heat my living room with my grow i think this is a last resort though, id rather not run full tilt pressured air into the next room, 0dBs is better than 20-30 of air movement...

i say utilize this thru the wall technique because there is already a sizeable hole there from the previous tenants running coaxial into the bedroom... i could use my holesaw and make it a real hole, and i fix walls for money in this building, it's easy as picking apples for me to retrofix.

if only i had the available electricity for a nice air conditioner:/

 

[FreezerBoy]

If you're going to pump through the wall I'd make sure you pumped ALL the way through. Make sure the air never touches the inside of the walls.

Outside the verticals every 16 inches, until you remove the drywall altogether, you have no idea what horizontal braces are there. Just because a 4" hole doesn't contact a brace doesn't mean you have 8 feet of vertical space. It means you have 4 inches and that may be all.

Yes the following is an extreme extreme possibility but mold in the walls can make you dead. As in DEAD, muerte, sleeps with the fishes, food for worms. I seem to recall Ed McMahon lost his dog to this. And we're not talking slums, it was a multi million dollar mansion.

 

[bp420!]

I'm glad I found this post, i'll be setting up my closet in the next week or so and I was planning on venting into the wall. I live in a townhome and have no access to the attic, so i don't know how large my attic is, but, is it reasonably safe to vent into the attic?

 

[messn'n'gommin']

How about a wall stack? Two 3' sections attached to boot collars located one foot down on the grow side and one foot up from the exhaust room side will go a long way to solving that. lol...Maybe it is the cheapskate in me, but, unless there is just no other way, I couldn't see my way to vent my heat or a/c into an attic, that just seems like such a waste.

Namaste, mess

 

[FreezerBoy]

is it reasonably safe to vent into the attic?

I'm no contractor or city engineer but, every attic I've been in has a ventilation system. It may be entirely passive but, a designed ventilation system none the less.

While the wall wasn't hermetically sealed, it was designed to hold air in. That's the insulation in interior walls.

 

[SpasticGramps]

Like FB said. You don't want to pump into wall because you are pumping a lot of air into a relatively small space. This creates a positive pressure in that small space that's going to work against the fan pumping into that space. Going straight into a wall you are going to be pushing air against the opposite side wall sheetrock, plus all the studs in the wall and possible insulation. There is just nowhere for that air to escape to. It's going to push back against your fan and clog up your ventilation system like a big turd.

All attics have Whirly birds, electronic vents, or passive holes to allow for air to escape. With as much air as you are moving, I can't see an attic space not being able that much air outlet. A 4in hole ina decent size space would suffice IMHO. I'm still a newb too, so if someone has more experience, feel free to crush me on this. I'm pretty high too.

It's not the most efficient design because your pumping air out your house, but it should keep your temps down. You have to dump the air into a big enough space for the size of fans as to not f with their efficiency though. I don't think would advise into a wall.

 

[whatissixbynine]

.

 

[FreezerBoy]

I'm no contractor or city engineer. That's my story and I'm stickin' to it.

Run sealed metal ducting through anything you want as long as it exhausts in a spot designed to accommodate it. The interior of a wall is not such a place. Pumping warm moisture into walls can't be a good thing.

 

[SpasticGramps]

I'm no contractor or city engineer. That's my story and I'm stickin' to it.

Run sealed metal ducting through anything you want as long as it exhausts in a spot designed to accommodate it. The interior of a wall is not such a place. Pumping warm moisture into walls can't be a good thing.

Very wise advice IMO.

 

[Norrath]

but spastic gramps/fb, what if there was a hole on the other side of the sheetrock? wouldnt the space inside the wall for a 10 foot long section be just over 100sq feet? with the fan pumping into teh wall and a sizable hole on the other side, the newly created positive pressure in the wall should force the air out the other side into the next room...

if the fan is pushing good cfms one could imagine a quick change over of air out hte other side. Unless there are dead spots in the wall cavity where the air is gets trapped not going right through, and breeds nasty things.. hmm

perhaps right thru wont be noticeable..soundwise, though i have my doubts

i think im just about convinced(freezerboy!) that i should not pump into the wall

it will be really nice to get air moving out of the room, then i can crack the window a quarter inch and the negative pressure in the room will draw in cool air. simply brilliant, but need to deplete that air!

 

[PermaBuzz]

Your idea will work as long as the hot moist air doesnt make contact with insulation. An empty stud cavity oughta work. There will be some moisture that migrates into other parts of the wall but you can get away with it - for awhile. At some point, you'll have to give it a rest. Thats what warm summers are for. If its an old house, the chances are high that its drafty and uninsulated - which is better for this purpose.

 

[SpasticGramps]

but spastic gramps/fb, what if there was a hole on the other side of the sheetrock? wouldnt the space inside the wall for a 10 foot long section be just over 100sq feet? with the fan pumping into teh wall and a sizable hole on the other side, the newly created positive pressure in the wall should force the air out the other side into the next room...

if the fan is pushing good cfms one could imagine a quick change over of air out hte other side. Unless there are dead spots in the wall cavity where the air is gets trapped not going right through, and breeds nasty things.. hmm

perhaps right thru wont be noticeable..soundwise, though i have my doubts

i think im just about convinced(freezerboy!) that i should not pump into the wall

it will be really nice to get air moving out of the room, then i can crack the window a quarter inch and the negative pressure in the room will draw in cool air. simply brilliant, but need to deplete that air!

It may well work pumping into that cavity. Rig it up and see how it does would be the next step IMO.

 

[messn'n'gommin']

If you're going to pump through the wall I'd make sure you pumped ALL the way through. Make sure the air never touches the inside of the walls.

Outside the verticals every 16 inches, until you remove the drywall altogether, you have no idea what horizontal braces are there. Just because a 4" hole doesn't contact a brace doesn't mean you have 8 feet of vertical space. It means you have 4 inches and that may be all.

Yes the following is an extreme extreme possibility but mold in the walls can make you dead. As in DEAD, muerte, sleeps with the fishes, food for worms. I seem to recall Ed McMahon lost his dog to this. And we're not talking slums, it was a multi million dollar mansion.

That was my reason for suggesting the wall stack. They are designed to fit into the 3-1/2" X 14-1/2" wall space.


Most any interior wall, for the most part, is only designed to separate the living space into separate rooms with little consideration for insulation or even sound-damping properties. As for any horizontal bracing in interior walls, they are usually there to keep bowed studs 16" on center during construction, even exterior walls (read: extra cost in man/hours for custom fitting of drywall/sheathing and/or insulation). Removing one for the stack isn't going to compromise any adjoining studs into warping because of the screws/nails holding the existing drywall/sheathing in place. At 3-1/4" X 10", the wall stack gives 30.25 sq/in for a decent amount of area for exhaust flow. Even then, two wall stacks connected to a wye in the grow room and a larger grill in the living space your exhausting into, will double that. If redirecting the exhaust into another room, by the time it gets back to the intakes it is going to be, more or less, at interior ambient temps and gives a bit of additional control over the cab/tent/closet temps by adjusting the thermostat.

For most modern construction, since about the 60's/70's, standards in building construction has gotten much better (read: virtually airtight) and moisture is definitely something to consider, but, as long as it isn't a large grow, any good HVAC system is going to alleviate most of that and a dehumidifier will certainly take care of the rest. Still (without an attic fan), dumping heated or cooled interior air into a cold or hot attic, respectively, is going to create condensate in its own right. Even with a thermostatically controlled attic fan, exhausting warmer attic air into the cold outside winter air might be enough to draw unwanted attention.

Hope this helps to clear up any misunderstanding I may have caused.

Namaste, mess

 

[Norrath]

i DO run a dehumidifier in teh room as well, room runs about 30-40% max.

thanks for the help guys, 45 year old apartment, but still have to give special consideration to permanence of the set up.

im going to start tonight after lights out