# confused on grow room ventilation



## mslady_1983 (Jul 27, 2012)

hello everyone.  i am very confused on getting air into the room.  i have a room with no windows.  i am wondering if i can bring air in from the basement.  and or can i put a air conditioner in the room. i am really confused.  can some one help pleeeaaaassseeeee


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## pcduck (Jul 27, 2012)

You can bring air from basement


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## Hushpuppy (Jul 27, 2012)

The trick is to think of air just like water. you can pull it from anywhere but if you pull air out of a space then air has to come from somewhere else to replace it. If you have nice cool air in your basement then you can pull that air and use it for cooling the grow space and/or lights. However, that air that is going in and getting hot has to go back out again (ie. through an exaust to the outside of the house) so that more cool air can come in. 

If you pull air from your basement, is there a way for it to be replaced? Are you exausting the heated air out of the house or out into a room? If you are pulling the heated air out of the house and pulling cool air from the basement then air has to come into the house or basement to replace what is going out. If your basement has openings in it that lead to the outside (maybe through the crawlspace under the house where the basement isn't or some other ventilation setup that allows outside air to come in) then you can pull the cooled air from the basement. If not then you will not exaust air out of the grow-space very well.


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## ShOrTbUs (Jul 28, 2012)

i think i can better help you if provide some details of your setup

i'm going off the assumption that your growing in your own house.

where in the house is the grow space located? 
how big is it?
is your basement finished? what i mean by finished is, sheetrock/painted, ceiling instead of just floor joyces
is there no window because the space you chose has no exterior walls?

if i go off the assumption that your space is 4X4 ft, on the first floor of the house, all the surrounding walls are interior walls, and you have a unfinished basement. also assuming you have a HID light w/ hood, and inline fan. 

then i would say, in the corner of the growspace cut 2 holes right next to each other, in the floor the size of the duct you will be using on your reflective hood(4",6" or 8"). run your exaust duct from your light through one hole in the floor, and out a window in the basement. you can zip-tie the ductwork to the floor joyces along the way, so its not hanging all over the place. 

then buy a duct flange (hxxp://www.htgsupply.com/Category-Flanges.asp).

buy an air filter that is larger then your hole in the floor (hxxp://www.lowes.com/Heating-Cooling/Air-Filters/_/N-1z0znaz/pl?Ns=p_product_qty_sales_dollar|1). 

cover the hole with the filter, and screw the flange onto the floor, over the hole & filter. the filter is not for purifying the air that enters the room. its just to keep insects out, mostly. if done properly. when you turn on your inline fan. it will suck the hot air out of the room, through your duct, and safely out of your house. this will cause negative pressure to build up in the grow room. cool c02 enriched air will be suck from the basement through the hole with the filter over it. i believe they call this passive air exchange.

hope this helps, green mojo for your grow. 

SB


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## The Silver Bullet Special (Jul 28, 2012)

My room is in my closet hidden behind drywall (in a false wall type set up for stealth) I'm just pulling the cooler air through the wall via holes cut out with a louvered vent covering up the holes and pushing the exhaust into the attic where hot air doesnt mess with the inside home air.

To pull from the basement just cut a hole in your floor. If you want to keep the floor holes hidden just cut the hole in the floor under where the wall is standing (walls are hollow other than the studs in the wall) and then cut holes in your wall so it draws it up from the basement and through the wall.


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## The Hemp Goddess (Jul 28, 2012)

If you exhaust into the attic, make sure you have adequate ventilation up there.  Moist air in the attic without proper ventilation can create mold.

I have my fan located in the crawl space below my grow room, which is a closet in the master bedroom.  I pull cool air from the crawl space and the exhaust runs to outside under the deck.  I have several passive intake holes that I cover with screen to keep bugs and such out.


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## ShOrTbUs (Jul 28, 2012)

The Silver Bullet Special said:
			
		

> To pull from the basement just cut a hole in your floor. If you want to keep the floor holes hidden just cut the hole in the floor under where the wall is standing (walls are hollow other than the studs in the wall) and then cut holes in your wall so it draws it up from the basement and through the wall.


 
while yes, interior walls are hollow. exterior walls will most likely have insulation in them, which can cause issues. drilling a hole in the floor, inside your wall isn't something i would suggest doing. there is a 2x4 at the top and bottom holding the framework together for a reason. DO NOT DRILL THROUGH IT. especially with a hole the size of the one you need to properly exchange air passively. those 2x4's are there to protect you in the event of a fire. they keep the fire from spreading throughout the house quickly(inside your walls). thats why it is illegal to "balloon frame" houses anymore. its a very serious fire hazard.

while it may seem like one little hole isn't significant. it very well may save your life and the lives of your loved ones. my uncle has been a fireman for 30 years. he's seen old 2 story homes with balloon framing completely engulfed in flames in under 30 mins. from a small electrial fire that started in the basement of the house.


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## The Silver Bullet Special (Jul 28, 2012)

ShOrTbUs said:
			
		

> while yes, interior walls are hollow. exterior walls will most likely have insulation in them, which can cause issues. drilling a hole in the floor, inside your wall isn't something i would suggest doing. there is a 2x4 at the top and bottom holding the framework together for a reason. DO NOT DRILL THROUGH IT. especially with a hole the size of the one you need to properly exchange air passively. those 2x4's are there to protect you in the event of a fire. they keep the fire from spreading throughout the house quickly(inside your walls). thats why it is illegal to "balloon frame" houses anymore. its a very serious fire hazard.


 
Good point, Never gave that any thought! Yeah, disregard my advise on the drilling through the floor under the wall thing... also didnt take into consideration if it was a load bearing wall.. Just moving from a house that the previous owner took out a load bearing wall and had to replace it caused major problems with the roof as well.


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## The Hemp Goddess (Jul 29, 2012)

I am a plumber and we drill hold through the base plates and top plates all the time.  It is not a structural issue and will not harm the integrity of the wall whatsoever.  The 2 x 4s themselves do little to stop the spread of fire.  To insure against this, every single little tiny hole, every penetration, has to be fire caulked--and fire caulking does not just apply to holes within the walls (the stud bays), every single opening in the floors, ceilings, and drywall need to be fire caulked if you hope to stop fire from spreading.  I have never seen that done in the normal residential structure.  Mostly it is newer multi-resident apartment buildings and commercial buildings that require fire caulking.  It is an incredible PITA to do.  I think most people would be quite surprised if they could look inside their walls--I have seen some pretty strange things.

However, there are other problems trying to drill within the joist bays of finished homes.  First of all, there could be other things in that space--plumbing, hvac, wiring--we all use those spaces.  In addition, you most likely are going to need a hole that is more than 3-1/2" in diameter.  Virtually all interior walls are 3-1/2".  If you are on an exterior wall, these are usually 6 xs, but you run into other problems, like hitting the roof joists if you are going up or hitting the foundation if you are drilling down.  You also have to strip away a large amount of drywall to get a large drill (you would need a 1/2" drill like a Hole Hawg with a large hole saw) into a wall space.  All in all, cutting a hole in the floor or ceiling not inside the joist bays is your best solution.


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