Ducting opinions!

ZuuTeD614

Well-Known Member
I have a 4" AC Infinity exhaust fan in my grow tent. To vent it out will 30ft duct work or the shorter thr better or does it matter how long your ducting is?
 

OldMedUser

Well-Known Member
Shorter and straighter is best. A 4" doesn't move much air as it is and if you have a carbon filter and 10ft ducting it'll be down to half or less of it's rated output. A whole 30' of flex ducting will create a lot of turbulence and cut it down to half on it's own. A straight run of plastic tubing would offer the least resistance to airflow.

:peace:
 

ZuuTeD614

Well-Known Member
I just moved my tent indoors so I am down to I think 8 ft now or less. I thought so because when my lights are on humidity is 38-45 and when lights go out it jumps to 57, humidity in my house is 40-50. Fan has a hard time to keep it down, so I will take some ducting off when I get home.
 

ZuuTeD614

Well-Known Member
Cool that what I was doing thabks everyone. So if I can't get humidity past 55 with lights off if I have good circulation I shouldn't have any bud rot?
 

B|uDreamer

Well-Known Member
Lower humidity helps but there are other factors in play as well. The density and size of the colas can create the right conditions for it even with low RH in the air. In my experience the best way to prevent bud rot is to focus on keeping your plants healthy all the way through to harvest.
 

OldMedUser

Well-Known Member
I just moved my tent indoors so I am down to I think 8 ft now or less. I thought so because when my lights are on humidity is 38-45 and when lights go out it jumps to 57, humidity in my house is 40-50. Fan has a hard time to keep it down, so I will take some ducting off when I get home.
The R in RH is for Relative Humidity. That is the percentage of moisture that the air can hold relative to air temp. When the lights go out the temp generally drops so the percentage rises even tho there is no more moisture in the air than there was at the higher temp. Without exhaust the actual amount of moisture in the air will rise as the plants transpire more moisture into the space.

Like pH there is a lot more to it than a couple of numbers and can take some study to wrap your head around it and really grok what it all means.

When you have warm, humid days but it gets cool at night there is dew on the grass in the morning. That's because as the temp went down the RH went over 100% and the extra moisture exceeded the dew point and the excess moisture falls out of the air and creates dew.

And if I turn my clip fans off when my lights go off will that rise or lower humidity?
If you want to help keep your colas mould free keep the circulation fans going and blowing across the colas 24/7. Moisture will settle into them and promote mould growth in still air.

Hope that helps.

:peace:
 

ZuuTeD614

Well-Known Member
The R in RH is for Relative Humidity. That is the percentage of moisture that the air can hold relative to air temp. When the lights go out the temp generally drops so the percentage rises even tho there is no more moisture in the air than there was at the higher temp. Without exhaust the actual amount of moisture in the air will rise as the plants transpire more moisture into the space.

Like pH there is a lot more to it than a couple of numbers and can take some study to wrap your head around it and really grok what it all means.

When you have warm, humid days but it gets cool at night there is dew on the grass in the morning. That's because as the temp went down the RH went over 100% and the extra moisture exceeded the dew point and the excess moisture falls out of the air and creates dew.



If you want to help keep your colas mould free keep the circulation fans going and blowing across the colas 24/7. Moisture will settle into them and promote mould growth in still air.

Hope that helps.

:peace:
Thanks man got home Temps in tent was 86 with lights on got into attic and un connected the 25ft ducting, so now I just exhaust into my attic and it dropped it all the way to 82. That's crazy I have been making my inline fan struggle. Thanks guys!!! Hops someone else stumbles across this post and helps them!
 

B|uDreamer

Well-Known Member
Thanks man got home Temps in tent was 86 with lights on got into attic and un connected the 25ft ducting, so now I just exhaust into my attic and it dropped it all the way to 82. That's crazy I have been making my inline fan struggle. Thanks guys!!! Hops someone else stumbles across this post and helps them!
I'd advise against exhausting into your attic. It can cause mold problems, in your house not your tent, that can become pretty severe depending on your climate and how the attic is vented. Upsizing the exhaust once you're in the attic will make the additional length much less restrictive.

Edit: If you're attic is finished and is conditioned(has heating/cooling) then it's not an issue.
 

V256.420

Well-Known Member
Look for a static pressure chart for your fan. Some websites have them. You can see how weak your fan gets over distance. AC Infinity does not have them. But I found a website that does. Soler and Palau. AC copied their fans and gave them a different color. Here is a good static pressure chart for those fans: https://solerpalau-usa.com/documents/Brochure/inline-fan-options.pdf

Look on page 7. Gives you a good reference on what each fan is capable at pushing/pulling @ a certain distance. The fans are basically the same so it's a great reference to look at for most fans made like this.
 

ZuuTeD614

Well-Known Member
I'd advise against exhausting into your attic. It can cause mold problems, in your house not your tent, that can become pretty severe depending on your climate and how the attic is vented. Upsizing the exhaust once you're in the attic will make the additional length much less restrictive.

Edit: If you're attic is finished and is conditioned(has heating/cooling) then it's not an issue.
My attic, just put a brand new roof and plenty of ventilation. And also we'll installated. It shouldn't be a problem.
 

Star Dog

Well-Known Member
Look for a static pressure chart for your fan. Some websites have them. You can see how weak your fan gets over distance. AC Infinity does not have them. But I found a website that does. Soler and Palau. AC copied their fans and gave them a different color. Here is a good static pressure chart for those fans: https://solerpalau-usa.com/documents/Brochure/inline-fan-options.pdf

Look on page 7. Gives you a good reference on what each fan is capable at pushing/pulling @ a certain distance. The fans are basically the same so it's a great reference to look at for most fans made like this.
I'm baffled why you think it's a good reference?
The S&P Td silent is in a different league from the fan in question and lots of others.

It's sort of like using a ferrari as a reference to a ford.
 

V256.420

Well-Known Member
I'm baffled why you think it's a good reference?
The S&P Td silent is in a different league from the fan in question and lots of others.

It's sort of like using a ferrari as a reference to a ford.
I'm baffled why you would be baffled. The fans are made the exact same way with almost the exact same parts. The silent series have extra material on the outside. You missed the results for the Silent series was on page 13. I gave page 7 as the correct page for the Mixvent series which matches the AC Infinity line.

The AC Infinity fans are made and copied from S&P. The charts should be similar as far as static pressure is concerned. Nothing baffling about it.

I'm baffled by which fan you think is a Ferrari and which is a Ford. Also, I never pointed out the Silent series..................you did.
 
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ZuuTeD614

Well-Known Member
Just keep an eye on it if your in an area that gets cold winters. A cold attic plus humid exhaust creates a lot of condensation and by the time it hits the drywall it's created quite a few problems.
Thabks for the advice yes I do get winters here, when that time comes I will go in the attic and check it out.
 

OldMedUser

Well-Known Member
I'd advise against exhausting into your attic. It can cause mold problems, in your house not your tent, that can become pretty severe depending on your climate and how the attic is vented. Upsizing the exhaust once you're in the attic will make the additional length much less restrictive.

Edit: If you're attic is finished and is conditioned(has heating/cooling) then it's not an issue.
Ditto that! I was exhausting into the attic of my garage all winter when I lived in town and come spring it was raining indoors there. All that moist air froze up there and it was a f'n winter wonderland when I climbed up to have a look. Poor ventilation let all that warm moist air turned into frost and snow. What a freakin' mess. lol

:peace:
 

Star Dog

Well-Known Member
I'm baffled why you would be baffled. The fans are made the exact same way with almost the exact same parts. The silent series have extra material on the outside. You missed the results for the Silent series was on page 13. I gave page 7 as the correct page for the Mixvent series which matches the AC Infinity line.

The AC Infinity fans are made and copied from S&P. The charts should be similar as far as static pressure is concerned. Nothing baffling about it.

I'm baffled by which fan you think is a Ferrari and which is a Ford. Also, I never pointed out the Silent series..................you did.
I have the 6" S&P and a 6" AC infinity, the AC is a good fan but the S&P is a cut above it for shifting air through static pressure.
 
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