firsttimer2065

A negative air pressure room, similiar to ones found in hospitals, sucks in air when a door is opened to that particular room as opposed to letting air out. This would in theory keep all of the odor in, and carbon filters, ozone, etc would not be needed. Im curious if anyone else on here is fimiliar with this concept and if it would be hard and/or xpensive to set up.

bluebloodletter

This is a common technique, but it can get a little tricky. The main problem is the smell has to go somewhere. For this reason, the most effective examples of this that I've seen have been with fans directing air to an attic, or out the roof, or something similar.

Xgone.

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Like a carbon filter

I use neg. air pressure in my cabinet, but obiously the stinky exhaust needs to go somewhere so I use carbon. It works something amazing.

RipPin420

I use the same technique. Works great. My to cabs exhaust into attic and pull about 350 out of room (10x10). You can easily fell the draft coming all around the room door, and if you crack the door open ,it will blow open about 6in. Major neg pressure.
I am now experimenting with a couple of ways to release some of this pressure so it doesn't effect the heating and cooling of the house
Since I have been doing this, cpl of places in the house stay cold and breezy.
I want to be able to leave the door shut and know that the room is getting plenty of air. Running a duct from other end of house to the room and leave it passive. Even things out a little. While doing this I will still need to maintain some neg pressure in the room for the door. So I'm trying a very small duct.
Always something to do or try.

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Leg Bud!

firsttimer2065

How is it set up exactly?

Xgone.

I have a 440cfm inline hooked up to my aircooled hood. I leave one flange open and that is the intake for my exhaust.

At the base of my cabinet I put a 265cfm squirrelcage blower.

That leaves a pretty good negative defecit between my intake and exhaust.

Xgone.

Damnit. doublepost.

panamajuice

Negative presure, It saved my grow room.

My grow area is inside my house, a bathroom. Without negative presure all the sweet ganja smell would fill my house in no time.

So this is what I did:

I set an inline fan inside a 8" tube that was directed to a hole in the window that is covered with a piece of wood. The other end of that tube goes into my reflector so I also keep my bulb as cool as posible. So is Relfector-inline fan-hole to the outside window.

Now once I turn that fan ON it is gonna create a negative pressure inside the room because basically the only air inlets are the cracks around the door that leads to my house where I don´t want the smell to go. I like to show my wife a little trick by which a hold a lighted joint and run it around the frame of the door and you can see clearly how the smoke from the joint goes right in thought the holes... nice, she says well then I guess it´s Ok.

Anyway, you wanna seal the window pretty good, use some silicon. Also you may wanna use some silicon around the door depending on just how big are them cracks, you see you don´t wanna make it an air tight door cause then you will force the fan too much and there woun´t be enough air circulation.

On more thing, I own a ozone generator that I have used inside the exhaust tube and this is the absulute best choice for security reasons cause the tube exhaust is a perfect place for the ozone to attach to the air molecule and making it odorless. And you don´t get any inside your growroom!. Unfortunately this didn´t work to well for me cause the ozone unit I have generates too much O3 and some of it was escaping the exhaust tube into the growroom, not good... I´m sure a bigger fan would do the trick!, or a smaller ozone generator.

My exhaust is place in the second floor of a house the is not to close to anything much so I don´t really care about not using the Ozone gen...


Hey, hope this helps....

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lootpimpin

during flower how do you go to the bathroom? lol :/

DontwanaGROWup

yep... but be careful if youve got plastic on the floor or mylar on the walls, as air pressure falls lower than normal the room becomes a vaccum chamber...the air sealed behind your mylar or plastic will expand causing your mylar/plastic to bubble and if the pressure is low enough it will even burst them like a ballon

the solution is to use a passive intake and slowly make it larger until there is only a very slight breeze coming around the crack of the door...mine was 16"x 16" with a 465 cfm blower...

then any air leaving the room should be leaving via the blower and passed through a carbon filter...

hope that helps