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

jswett1100 said:

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?

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Us a 6 in 400 cfm fan with filter attached.
Use window ac for cooling as it does not play into pressure at all.
Have your regular fans going for circulation.
Seal tent with duct tape on all zippers and holes not used a long with the edges of the exhaust ducting. Make sure this exhaust hole is at the top of tent. Same concept work with larger spaces like rooms. Just have to make sure your seal is good.
Now brig fresh air in the room at a rate of half the exhaust is running. So if exhaust is 400 cfm 6 inch.. Then intake should be 4 inch 190 to 200 cfm.
That way intake is slower exhaust is faster. Creating negative pressure because more is trying to leave than is coming in.
Now your scrubbing the exhaust 2x faster than air can come in the room. This ensures all smell is scrubbed before leaving the room.
If smell still is a problem. Add another 4 or 6 in fan sucking through a carbon filter. Never blow through the filter all ways set it up to suck through the filter. Don't vent this filter mount it where the filter sits on the floor and the fan sits on top of the filter sucking air through the filter and set it in the corner. If you match your scrubber to your exhaust cfm.

This will result in half the air being scrubbed before it is exhausted essentially scrubbing 50 of the air twice to ensure no smell. I may be wrong with number here but I am to tired to double check. Been a while since I needed the info. Happy Growing!!

ALong14U said:

Us a 6 in 400 cfm fan with filter attached.
Use window ac for cooling as it does not play into pressure at all.
Have your regular fans going for circulation.
Seal tent with duct tape on all zippers and holes not used a long with the edges of the exhaust ducting. Make sure this exhaust hole is at the top of tent. Same concept work with larger spaces like rooms. Just have to make sure your seal is good.
Now brig fresh air in the room at a rate of half the exhaust is running. So if exhaust is 400 cfm 6 inch.. Then intake should be 4 inch 190 to 200 cfm.
That way intake is slower exhaust is faster. Creating negative pressure because more is trying to leave than is coming in.
Now your scrubbing the exhaust 2x faster than air can come in the room. This ensures all smell is scrubbed before leaving the room.
If smell still is a problem. Add another 4 or 6 in fan sucking through a carbon filter. Never blow through the filter all ways set it up to suck through the filter. Don't vent this filter mount it where the filter sits on the floor and the fan sits on top of the filter sucking air through the filter and set it in the corner. If you match your scrubber to your exhaust cfm.

This will result in half the air being scrubbed before it is exhausted essentially scrubbing 50 of the air twice to ensure no smell. I may be wrong with number here but I am to tired to double check. Been a while since I needed the info. Happy Growing!!

Click to expand...

Exactly, an air scrubber in the room as well and you will have zero smell. I think your cfm and volume is a bit overkill you could get away with less, but too much is a good problem to have as how effective carbon is changes with humidity.

Also where you have such a difference in the cfms you have a very large negative pressure, in that kind of situation the seal and airtight of your tent is way less important. If your pressure difference was lower the seal would be more important.

In the end the numbers arent that important just error on the side of too much and you can always lower your fan speed if you want to.

This is way more than anyone would need if you dont care about the grow space itself smelling. Most growers just go with a solid negative air and as long as people arent going into that room they will never smell it.

ALong14U said:

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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A more effective way if you were looking to have that room be completely odor free would be to have an air scrubber in the room vs making your negative air even higher cfm.

By that i mean right now your 200cfm exhaust neg air is scrubbing 100% of the smell as you cannot smell anything from the exhaust and its creating a good negative pressure in your room. As your negative pressure is a larger difference it becomes more and more difficult for your fan to pull the air in so you need to have less of a sealed room. You would be better off having a standalone air scrubber in that room of 100 cfm than to increase the cfm of your negative are to 300.

I hope i explained that okay, but basically a neg air is most effective to ensure your exhaust will be odor free. Once your exhaust is odor free if you want to room itself to not smell its exponentially more effective to have the air in the room to be seperately scrubbed than to just make the airflow of the neg air higher. The main goal of neg air is to ensure particicles have zero chance of escaping except thru the filter, it sucks at keeping the contaminated room itself clean and once the air pressure reaches a certain point you will see diminishing returns on making your cfm higher.

I suck at putting what im trying to explain into words but i think you will get it.

jswett1100 said:

a

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

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Yea. Ineffective as hell. When you turn on the ac at your house do you leave all the windows and doors open? Nope. Your essientially sucking money right out the house using both.

haze010 said:

A more effective way if you were looking to have that room be completely odor free would be to have an air scrubber in the room vs making your negative air even higher cfm.

By that i mean right now your 200cfm exhaust neg air is scrubbing 100% of the smell as you cannot smell anything from the exhaust and its creating a good negative pressure in your room. As your negative pressure is a larger difference it becomes more and more difficult for your fan to pull the air in so you need to have less of a sealed room. You would be better off having a standalone air scrubber in that room of 100 cfm than to increase the cfm of your negative are to 300.

I hope i explained that okay, but basically a neg air is most effective to ensure your exhaust will be odor free. Once your exhaust is odor free if you want to room itself to not smell its exponentially more effective to have the air in the room to be seperately scrubbed than to just make the airflow of the neg air higher. The main goal of neg air is to ensure particicles have zero chance of escaping except thru the filter, it sucks at keeping the contaminated room itself clean and once the air pressure reaches a certain point you will see diminishing returns on making your cfm higher.

I suck at putting what im trying to explain into words but i think you will get it.

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That's exactly what I meant. Add a scrubber to 100 cfm of negative pressure.

You are right my friend. It works wonders for me.
Other caregivers come over and are blown away. There whole block smells from their grow and you can't smell mine in the living room 5 feet from my door.

Carolina Dream'n said:

Yea. Ineffective as hell. When Zee you turn on the ac at your house do you leave all the windows and doors open? Nope. Your essientially sucking money right out the house using both.

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I have 2 5000 btu ACS. They are on one side of the room. The exhaust is in the opposite corner. Wall mount acs do not bring in fresh air. They cool hot air from the room. By separating the 2 as far away as possible it gives the cold a it a chance to cool the room before being exhausted. My room stays at 75 to 77 lights on and 70 lights off. 100 cfm negative pressure .
Happy Growing

haze010 said:

Exactly, an air scrubber in the room as well and you will have zero smell. I think your cfm and volume is a bit overkill you could get away with less, but too much is a good problem to have as how effective carbon is changes with humidity.

Also where you have such a difference in the cfms you have a very large negative pressure, in that kind of situation the seal and airtight of your tent is way less important. If your pressure difference was lower the seal would be more important.

In the end the numbers arent that important just error on the side of too much and you can always lower your fan speed if you want to.

This is way more than anyone would need if you dont care about the grow space itself smelling. Most growers just go with a solid negative air and as long as people arent going into that room they will never smell it.

Click to expand...

Your right for sure. I grow in what is technically a master bedroom with linoleum floors and an attached bathroom. Fresh air comes in from a hole cut in the floor that is charcoal scrubbed before entry. Easiest way I figured for no bugs mold and what not.

The door leading the flower room to the rest of the house has a large gap on the bottom. When lights are off door is sealed and I have a large piece of rubber I slide under the crack and then add a blanket rolled up to extra cover the gap for light.

With no blockage on the bottom door. When it's closed and you stand in front of it in bare feet. Like I do cause I can't stand shoes lol.

You can feel the negative pressure. There is a steady 150 to 200 cfm I think. Like stated numbers are not super important. The air blows over your feet and toes at a constant steady breeze.

Essentially with my exhaust routed into the heating vents to recycle any heat. Works great in the winter. I'm scrubbing my scrubbed exhaust air. You can walk up to my front door be 4 feet from 30 to 40 plants and have no clue. Only thing you see is an account mounted in the window. That probably isn't running as I have 2. The other is mounted in a closet wall attached to 1 wall of the flower room. So I run that when temps are colder outside. Open the closet door which is in the entry way leading to the living room. It heats it nicely working with the exhaust.

When temps rise I have to run both as. I flower at night so who cares nobody around acs are normal. I close the closet door and exhaust heat out of the curling via a small 4 in 120? Cfm fan through the roof attached to a vent so all looks normal.

Pretty medicated sorry to ramble. Your correct. We agree 100.

Happy Growing

ALong14U said:

Your right for sure. I grow in what is technically a master bedroom with linoleum floors and an attached bathroom. Fresh air comes in from a hole cut in the floor that is charcoal scrubbed before entry. Easiest way I figured for no bugs mold and what not.

The door leading the flower room to the rest of the house has a large gap on the bottom. When lights are off door is sealed and I have a large piece of rubber I slide under the crack and then add a blanket rolled up to extra cover the gap for light.

With no blockage on the bottom door. When it's closed and you stand in front of it in bare feet. Like I do cause I can't stand shoes lol.

You can feel the negative pressure. There is a steady 150 to 200 cfm I think. Like stated numbers are not super important. The air blows over your feet and toes at a constant steady breeze.

Essentially with my exhaust routed into the heating vents to recycle any heat. Works great in the winter. I'm scrubbing my scrubbed exhaust air. You can walk up to my front door be 4 feet from 30 to 40 plants and have no clue. Only thing you see is an account mounted in the window. That probably isn't running as I have 2. The other is mounted in a closet wall attached to 1 wall of the flower room. So I run that when temps are colder outside. Open the closet door which is in the entry way leading to the living room. It heats it nicely working with the exhaust.

When temps rise I have to run both as. I flower at night so who cares nobody around acs are normal. I close the closet door and exhaust heat out of the curling via a small 4 in 120? Cfm fan through the roof attached to a vent so all looks normal.

Pretty medicated sorry to ramble. Your correct. We agree 100.

Happy Growing

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Just an after thought as well. With the gap in the floor or the door open toy grow room. I have a 2500 cfm swamp cooler in the living room. If I turn it on high it creates positive pressure on the house of all other doors are closed. It will literally blow the front or back door open and keep it open lol. So at that point the only escape with outer doors closed is my filters.
I think this is correct but who knows. I learned all this setting up grow rooms in trailers in the late 90s super effective at chillen in a subdivision in a 3 bedroom pumping out 3 to 5 lbs a week with nobody the wiser.