How to run a/c while venting air outside? or pulling inside?

jswett1100

Well-Known Member
How would i go about using a window a/c in my grow room while pulling air from the inside? or putting it outside if need be?
 

TacoMac

Well-Known Member
All window AC's draw air from the inside. That's why there's a filter in the front you have to clean.

SOME (very few these days) have a vent you can open that will help suck air in from the outside.

In order to get the air out, you're going to have to rig something up. The easiest thing I can think of would be to secure a piece of venting to one side of the vent and just u-turn it right through the opening the window AC sits in and insulate around it. That way, a small portion of the cold air is blown outside continuously.

The only other way to do it is a stand alone fan aimed outside through that same opening. You can then just turn on the fan any time you need to vent the air.
 

jswett1100

Well-Known Member
All window AC's draw air from the inside. That's why there's a filter in the front you have to clean.

SOME (very few these days) have a vent you can open that will help suck air in from the outside.

In order to get the air out, you're going to have to rig something up. The easiest thing I can think of would be to secure a piece of venting to one side of the vent and just u-turn it right through the opening the window AC sits in and insulate around it. That way, a small portion of the cold air is blown outside continuously.

The only other way to do it is a stand alone fan aimed outside through that same opening. You can then just turn on the fan any time you need to vent the air.
So the a/c will take out hot air and put cold in the room, but how to I use the carbon filter? since its gonna blow the air the ac makes outside? what should i do for that so i can keep the smell down.
 

TacoMac

Well-Known Member
im growing in a whole room.
Ahhhhh...that explains the confusion.

Now, if you're growing in a whole room, there's really no way to keep that room from smelling. The task at hand is to prevent that smell from reaching the rest of the house. Whatever area your plants are in is going to smell, no matter what.

Now, if you're looking to keep the room you're growing in from smelling, you'll have to get a tent.

Think of controlling odor like Tupperware: The fish sitting on your counter in the kitchen is going to smell. If you put it inside the Tupperware, the inside of the Tupperware will smell, but the kitchen will no longer smell. If you vented the air that smells inside the Tupperware out into the kitchen through a carbon filter, then it wouldn't smell either.

But the inside of the Tupperware will ALWAYS smell.

So what I would do if I were you is use a fan to push the air in the room through the carbon filter and out the window. (You can cut out one of the expandable panels on the sides of the AC unit to fit the vent through.)

What that will do is suck air in the room that smells, pass it through the carbon filter out the window and that air will have little to no smell to it at all.

What that will also do is slowly suck air from under the door to replace the air you're pumping out the window. That will keep the smell from going under door into the rest of the house.

That's how I'd run it.
 

haze010

Well-Known Member
Ahhhhh...that explains the confusion.

Now, if you're growing in a whole room, there's really no way to keep that room from smelling. The task at hand is to prevent that smell from reaching the rest of the house. Whatever area your plants are in is going to smell, no matter what.

Now, if you're looking to keep the room you're growing in from smelling, you'll have to get a tent.

Think of controlling odor like Tupperware: The fish sitting on your counter in the kitchen is going to smell. If you put it inside the Tupperware, the inside of the Tupperware will smell, but the kitchen will no longer smell. If you vented the air that smells inside the Tupperware out into the kitchen through a carbon filter, then it wouldn't smell either.

But the inside of the Tupperware will ALWAYS smell.

So what I would do if I were you is use a fan to push the air in the room through the carbon filter and out the window. (You can cut out one of the expandable panels on the sides of the AC unit to fit the vent through.)

What that will do is suck air in the room that smells, pass it through the carbon filter out the window and that air will have little to no smell to it at all.

What that will also do is slowly suck air from under the door to replace the air you're pumping out the window. That will keep the smell from going under door into the rest of the house.

That's how I'd run it.
No offense here, but you're just incorrect with much of what you are saying. Your tupperware analogy is somewhat correct but the idea that the container is going to smell no matter what is just wrong. Many ppl run portable air scrubber setups that vent nowhere and their rooms are fine.

I do agree with you on that the best setup is whats called a negative air setup and thats what youre describing. An air scrubber setup works great too though, it just requires a much stronger fan and higher cfm filtering for the same volume of growing space.

I'll link professional hazmat and remediation documentation again here, its in the big giant odor control thread too and a few other places. Portable air scrubbers are effective enough so you can literally be 20 feet away from knee deep raw sewage and not smell it, it just requires a much more powerful setup compared to negative air which is what you described.

Anyway, industry professional documentation on air scrubbing. Keep in mind tho when you are reading about hepa in this thats talking about particulate in the air, which has zero to do with smell. All that really matters is the carbon filtering.

Professionals guide to air scrubbing.
https://www.drieaz.com/uploads/deca/gtas.pdf

Ive actually used a pancake style vacuum cleaner as a negative air machine before. Was on a jobsite and two negative air machines died at once, we used vacuum cleaners till the next day when we could replace them. Air filtration is way easier than some people make it out to be, anything that will move air through carbon will filter smell, anything that will move air through a hepa will filter particulate.
 
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jswett1100

Well-Known Member
a
Ahhhhh...that explains the confusion.

Now, if you're growing in a whole room, there's really no way to keep that room from smelling. The task at hand is to prevent that smell from reaching the rest of the house. Whatever area your plants are in is going to smell, no matter what.

Now, if you're looking to keep the room you're growing in from smelling, you'll have to get a tent.

Think of controlling odor like Tupperware: The fish sitting on your counter in the kitchen is going to smell. If you put it inside the Tupperware, the inside of the Tupperware will smell, but the kitchen will no longer smell. If you vented the air that smells inside the Tupperware out into the kitchen through a carbon filter, then it wouldn't smell either.

But the inside of the Tupperware will ALWAYS smell.

So what I would do if I were you is use a fan to push the air in the room through the carbon filter and out the window. (You can cut out one of the expandable panels on the sides of the AC unit to fit the vent through.)

What that will do is suck air in the room that smells, pass it through the carbon filter out the window and that air will have little to no smell to it at all.

What that will also do is slowly suck air from under the door to replace the air you're pumping out the window. That will keep the smell from going under door into the rest of the house.

That's how I'd run it.
I get what your saying,but would sucking the air out be inefficient since im using an a/c?
 

haze010

Well-Known Member
a

I get what your saying,but would sucking the air out be inefficient since im using an a/c?

It just depends how you do it. When people run a 100% sealed room they usually have ac that just vents in the same room and CO2 is provided. Smell in that setup is dealt with by an air scrubber.

If you mean one of the AC's that hangs in a window then you may be confused on how they actually work as most people are. A window hanging AC doesnt let outside air inside, and it doesnt allow inside air out. Its completely irrelevant, the inside air is cooled on a condenser and blown back into the room cooled. The exhaust end of one of those window ac's it sucks air from outside into a seperate chamber and tthe heat from the condensor heats that air and then blows it back out.

I probably explained that horribly but heres a picture that should make what i said understandable.

https://www.google.ca/imgres?imgurl=http://img.bhs4.com/3B/3/3B3B10F687C812FC6A880C90DEE13ED19CB8679C_large.jpg&imgrefurl=http://www.brighthubengineering.com/hvac/55241-how-the-window-air-conditioner-works/&h=600&w=600&tbnid=la8sZkPddPeP4M:&tbnh=160&tbnw=160&usg=__LEoyZm4fsTngDDsR313yWEU1uKg=&vet=10ahUKEwj__aaL1_zTAhXkylQKHWLdAd4Q9QEIKzAA..i&docid=AzQQbnz3og7MoM&sa=X&ved=0ahUKEwj__aaL1_zTAhXkylQKHWLdAd4Q9QEIKzAA
 

TacoMac

Well-Known Member
Which is exactly why I told him to run a separate fan through his carbon filter out the window via the side panel of the AC to suck air in under the door.
 

haze010

Well-Known Member
Yup taco im not disagreeing with you i was just trying to explain to him how AC works because it seems like he thought that would be an airleak to his room. The disagreement i have on what you said is when you said his room itself will always smell no matter what. Thats just incorrect.

Feel free to read the dri-eze link i posted above, its a 10+ page document on air scrubbing for professional remediation workers. If you do read it you will get what im saying about an air scrubber can easily keep his grow room odor free.
 
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TacoMac

Well-Known Member
I've never, ever walked into a room or opened a tent with a grow in it that I couldn't smell with ease.

Ever.
 

haze010

Well-Known Member
Yup and how many of those grows had an air scrubber in the room? When you use nagative air the clean air is vented outside so the only air in the room is contaminated air, the grow area in neg air will always smell. The benefit of neg air is its much easier to guarentee that nothing except that room will smell. In an air scrubber the cleaned air remains in the room, it requires a much higher cfm and circulation but when done properly the grow room itself will be odor free. You would have to stick your face to a plant to smell it.

You dont have to believe my opinion, just read the professional documentation i've linked.

https://www.drieaz.com/uploads/deca/gtas.pdf

Its my job to know things like this.
 

jswett1100

Well-Known Member
Which is exactly why I told him to run a separate fan through his carbon filter out the window via the side panel of the AC to suck air in under the door.
So your saying i should vent my carbon filter out the side of the a/c through the plastic like extending side panel thing right?
 

ALong14U

Well-Known Member
Yup and how many of those grows had an air scrubber in the room? When you use nagative air the clean air is vented outside so the only air in the room is contaminated air, the grow area in neg air will always smell. The benefit of neg air is its much easier to guarentee that nothing except that room will smell. In an air scrubber the cleaned air remains in the room, it requires a much higher cfm and circulation but when done properly the grow room itself will be odor free. You would have to stick your face to a plant to smell it.

You dont have to believe my opinion, just read the professional documentation i've linked.

https://www.drieaz.com/uploads/deca/gtas.pdf

Its my job to know things like this.
I only is about 200 cfm of negative pressure and it works great. 200 cfm leaving the room into the heat vent recycled to the house. 2 window acs. Sealed room so no matter what all air leaving is pushed through a carbon filter. Intake is only 100cfm give it take depending on barometric pressure. Of course it's scrubbed coming in as well. Just in case. Only 4 in intake. Room has a little smell could use a little more cfm out. But you have to rub the plants or stick your nose on top of a bud to smell it. Have people over all the time and nobody knows I'm growing.
 

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