Cutting hole in ceiling for extraction. Also where to get air in from?

O

Orblight

Well-Known Member
Hey guys when you cut a hole in the ceiling for extraction duct to go, do you just cut a round hole the size of the duct and feed the duct through? Or is there a better way?

Also where do you get air in from? Windows is covered so not a option for me really. I can only think of 3 options.
From the bottom of a wall, but I don't know how that will work out.

From the ceiling also but that could be some pretty hot air at times also the exhaust will also going in there.

Or something I don't want to do but I could cut a hole in the floor boards and take it from the cavitie under the house ( I really don't want to do this)
 
coreywebster

coreywebster

Well-Known Member
I've done this and yes I just drew around the duct and got a drill and machine gunned it out or use a jigsaw. Go an inch smaller than the duct.
Edit. I only did this to tap into an existing hole in chimney in the attic.

You need to know there's no wires and you need to go between joists .
It's not a good idea to just vent straight into an attic due to mould. Unless there's lots of air exchange up there.
Depends on how big your set up is.

better if you have a disused chimney to tap into that.

Most rooms are not sealed and should breathe, air will come through gaps under skirting and around door. Again it depends on how much air your extracting as to if the room can breathe enough to keep up with extraction.
If you have old floor board you could just pull a board up.

Really I would cover the window in a way you can have it open but still block light.

Another concern with venting into a roof space is how that looks on a FLIR if you live in an area that uses them to actively bust growers?
 
O

Orblight

Well-Known Member
Thanks I'll try go a little smaller than the duct and see if I can still pull the duct through.
Still need to check for wires. I think there's abut of air exchange up there it's just a tile roof and I felt a small breeze when I stuck my head up there.
Your right there's a good chance it will breath enough by itself guess I'll find out once there a extraction in the room.

Good idea with the window if it doesn't breath enough, if not just a floor board.
 
bam0813

bam0813

Well-Known Member
Imo its better to use solid when the ducting isnt exposed. A short piece for the wall/ ceiling itself and a take off to attach the soft duct . You wont ever have to worry about a hole or tear you cant see
 
Friendly_Grower

Friendly_Grower

Well-Known Member
Orblight said:
Hey guys when you cut a hole in the ceiling for extraction duct to go, do you just cut a round hole the size of the duct and feed the duct through? Or is there a better way?

Also where do you get air in from? Windows is covered so not a option for me really. I can only think of 3 options.
From the bottom of a wall, but I don't know how that will work out.

From the ceiling also but that could be some pretty hot air at times also the exhaust will also going in there.

Or something I don't want to do but I could cut a hole in the floor boards and take it from the cavity under the house ( I really don't want to do this)
Click to expand...
There are also hole saws.
I own a 4 inch and a 6 inch and one that is specifically for 6 inch lighting and duct. Just the right size to accommodate ducting and or recessed lighting.

While putting a nail or screw in the center and using a string attached to a pencil so that you can outline the diameter neatly for drilling and then using a jigsaw or other type of saw is reasonable the clean cut of a hole saw is a step up in modifying your house. It looks better.

Please note that to start a hole with a hole saw that size run it in reverse first. This lessens the chance that it will deform as the teeth dig in. Once you have a neat cut started then you can switch directions.

Also and MOST important be absolutely sure there are no electric wires where you cut into. Repairing electric properly is more work and possibly deadly if you cut into power!

So whatever you decide turn off power if unsure. bore a a small hole with a wood space bit. Put your borescope in there and have a look around first.

Stay alive and do an excellent job. Personally I would try something else before cutting holes in ceiling or floor.
 
Last edited:
N

NewtoDWC

Active Member
Hey all, I’d like to piggyback of the topic and ask if you could use a Y connector to pull exhaust from two small grow tents using separate fans and filters just sharing the same exit. Would there be enough flow for both tents?
 
HydroKid239

HydroKid239

Well-Known Member
NewtoDWC said:
Hey all, I’d like to piggyback of the topic and ask if you could use a Y connector to pull exhaust from two small grow tents using separate fans and filters just sharing the same exit. Would there be enough flow for both tents?
Click to expand...
If using a fan to extract from each tent you should be ok. Filters inside the tent?
 
PadawanWarrior

PadawanWarrior

Well-Known Member
Orblight said:
Hey guys when you cut a hole in the ceiling for extraction duct to go, do you just cut a round hole the size of the duct and feed the duct through? Or is there a better way?

Also where do you get air in from? Windows is covered so not a option for me really. I can only think of 3 options.
From the bottom of a wall, but I don't know how that will work out.

From the ceiling also but that could be some pretty hot air at times also the exhaust will also going in there.

Or something I don't want to do but I could cut a hole in the floor boards and take it from the cavitie under the house ( I really don't want to do this)
Click to expand...
I hope you own this house.
 
jondamon

jondamon

Well-Known Member
NewtoDWC said:
Hey all, I’d like to piggyback of the topic and ask if you could use a Y connector to pull exhaust from two small grow tents using separate fans and filters just sharing the same exit. Would there be enough flow for both tents?
Click to expand...
I’m assuming the following.

fan and filter in each tent exhausting out to a Y splitter for the exhaust?

I would say enlarge the Y compared to the exhausts diameter to make sure you definitively have enough flow.

so for example.

If tents are 6” filter and fan use an adaptor and get an 8” Y to couple into.

that way there shouldn’t be an issue (doubtful there would be an issue with a 6” Y but this addresses it as a just incase).
 
N

NewtoDWC

Active Member
jondamon said:
I’m assuming the following.

fan and filter in each tent exhausting out to a Y splitter for the exhaust?

I would say enlarge the Y compared to the exhausts diameter to make sure you definitively have enough flow.

so for example.

If tents are 6” filter and fan use an adaptor and get an 8” Y to couple into.

that way there shouldn’t be an issue (doubtful there would be an issue with a 6” Y but this addresses it as a just incase).
Click to expand...
Thanks, I was thinking of adding a bigger outlet but wasn’t sure if they made adapters for ventilation. I’m in the pre build stage, just trying to get all my ducks in a row. Also trying to figure out how to fix issues before I run into them. I know you can’t prepare for everything in a grow, but It doesn’t hurt to try
 
You must log in or register to reply here.
Top