Which Filter should I get?

Track

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I have two choices:

1.) 720M3/h Filter + 700M3/h Fan
2.) 960M3/h Filter + 880M3/h Fan

Will the 880M3/h fan work fine with the 960M3/h filter or will it be too little?

Also, just to clarify, it's better to have a lower-output fan than a higher-output fan, compared to your filter, right?

Thanks.
 

Hushpuppy

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How big is the space you are using? I think having a filter with more CFM than the fan is best as it will still scrub the air efficiently with any size fan that is less CFM. What you don't want is a fan that pulls more than the filter can allow as that will cause the air to be pulled through too hard and not get scrubbed as well.
 

SmokinMom

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I have two choices:

1.) 720M3/h Filter + 700M3/h Fan
2.) 960M3/h Filter + 880M3/h Fan

Will the 880M3/h fan work fine with the 960M3/h filter or will it be too little?

Also, just to clarify, it's better to have a lower-output fan than a higher-output fan, compared to your filter, right?

Thanks.
a short fat one..... wait...... Or was it a long slim one ????? I forget now?
 

Track

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How big is the space you are using? I think having a filter with more CFM than the fan is best as it will still scrub the air efficiently with any size fan that is less CFM. What you don't want is a fan that pulls more than the filter can allow as that will cause the air to be pulled through too hard and not get scrubbed as well.
Yeah, I know. I'm just asking if it's okay to have a fan that is a lot less than the filter (960 vs. 880).

a short fat one..... wait...... Or was it a long slim one ????? I forget now?
Looks like this guy waited a little long after the amber trichomes appeared, LMFAO.
 

Hushpuppy

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The key to determining the size fan here is the size of your grow space. If you are pulling in air from outside and that air is rather warm and/or humid then you will want to be able to replace the air in your grow space 2-3 times a minute. If the air is cool and/or dry, then replace the air within the grow space once a minute or a little less. My fans replaced my air once every 90 seconds and I had no problems. That is why I asked you about the size off your grow space.

If your space is a 4'x8'x8'high and you get the 960 fan then you will be replacing your air 3.75x per minute. If you get the 880 fan you will be replacing your air 3.4375x per minute. A 4'x8' space is pretty big space, so the less expensive off those 2 choices would be better. If you space is smaller than 4'x8'x8' then you can go with a cheaper fan that will pull about 540cfm, if you can get that size. Or you can get the 880 iff that is all that is available to you and then use a speed controller to run it slower so that it actually runs quieter than when running at full speed. :)
 

Track

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The key to determining the size fan here is the size of your grow space. If you are pulling in air from outside and that air is rather warm and/or humid then you will want to be able to replace the air in your grow space 2-3 times a minute. If the air is cool and/or dry, then replace the air within the grow space once a minute or a little less. My fans replaced my air once every 90 seconds and I had no problems. That is why I asked you about the size off your grow space.

If your space is a 4'x8'x8'high and you get the 960 fan then you will be replacing your air 3.75x per minute. If you get the 880 fan you will be replacing your air 3.4375x per minute. A 4'x8' space is pretty big space, so the less expensive off those 2 choices would be better. If you space is smaller than 4'x8'x8' then you can go with a cheaper fan that will pull about 540cfm, if you can get that size. Or you can get the 880 iff that is all that is available to you and then use a speed controller to run it slower so that it actually runs quieter than when running at full speed. :)
3.75 times per minute? What? That's every 16 seconds.

As far as my calculations have taken me, I got that a 200M3/h filter will replace the air in a 10M3 space every 3 minutes, or every 180 seconds.
 

Hushpuppy

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I made a mistake in reading what you have there. I am used to working in ffeet but yours is listed in meters. If you have a 10cu/m space, that is equal to 353.15 cu/ft. In this case, the fans that I use that move 540cu/ft per minute will exchange your air about 1.5x per minute. The 880cu/h will exchange 14.66cu/m per minute, which will give you about 1.5x per minute exchange, which should be enough unless the outer air is warm and moist.
 

Track

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I don't know. I read that exchanging the air every 3 minutes is fine and 2 minutes is preferable.

With my space, I'd need a 960M3/h filter to exchange the air every 90 seconds, which is doable.
 
P

P Jammers

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If you are pulling in air from outside and that air is rather warm and/or humid then you will want to be able to replace the air in your grow space 2-3 times a minute.
:stoned:

This information is commonly given incorrectly here on MP. I have corrected it more times than I care to count.

A grow space should vent ONE time every 3 to 4 minutes, not 3 times per minute.

That would be a wind tunnel, not grow room specs.

For anyone interested in obtaining correct parameters for the grow space, rather than believe me, download a professional grow room app for your iPhone, as they are no longer supporting Android.

http://www.freshapps.com/cash-crop-hd/

The app also covers the correct amount of light per foot, CO2 parameters, and even has a section to figure out food.
 

Hushpuppy

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Thanks PJ :) I have always wondered about that but have always gone close to 1-2x per minute on my grow tents. I think having that much air flow in mine helped keep temps down in the summer. Plus I feel like you will never achieve the full amount off air flow due to the resistive factors that involve pulling the fresh air into the space. Plus the ffact that you always want to turn them down to reduce the fan noise. I almost always ran my fans at about 75% so that they would run quiet. I will definitely check out that app though. :)
 
P

P Jammers

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Was it called the same thing on Android? I would love to find the APK file on one of my Torrent sites.
Cash crop is an overseas nute company that created it, and it was like 3 bucks for the I systems.

I just did a quick search for the link when I posted and saw that it was cancelled on the Android system. Works on the ipad as well;)



Thanks PJ :) I have always wondered about that but have always gone close to 1-2x per minute on my grow tents. I think having that much air flow in mine helped keep temps down in the summer. Plus I feel like you will never achieve the full amount off air flow due to the resistive factors that involve pulling the fresh air into the space. Plus the ffact that you always want to turn them down to reduce the fan noise. I almost always ran my fans at about 75% so that they would run quiet. I will definitely check out that app though. :)
Yes I would venture to guess that most don't use two fans [one for cooling light, and one for exchanging air] but in a perfect world that would be the way to have it if you're running HID's. I'm sure lots pull through a filter, in to light, out of the area.

I feel it is also the reason people create that 3 times a minute number because it's needed the way it is hooked up.

That said, proper air exchange is still only 1 time per 3 to 5 minutes which in an air quality test is adequate for co2 levels to not be depleted which is what we are discussing when we talk "just" air exchange in the growing environment.

I sure would hate for someone about to set up a 1000SF place and think, wow I need a jet airplane to pull that amount of air.

*Exaggerated, to make point.
 

Track

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Was it called the same thing on Android? I would love to find the APK file on one of my Torrent sites.
It's called Cash Crop or Cash Crop HD, I believe.

Did you find it? I wasn't able to, even on my private torrent sites.
 
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