question about upgrading my inline fan

[MarthaStewart]

Hey everyone...a few months ago I started planning a new grow room for myself. I had an old 4 inch 127cfm inline fan from an older grow so I decided to use it. The weather is starting to warm up and I'm worried that the 4 inch fan is not going to cool my tent enough when it starts getting warmer.

My setup is a tent I have inside of a closet. The room the closet is in has an ambient temp of around 65-69 def Fahrenheit and inside the tent its been getting as high as 79 deg F with my 900 watt led light on. The way I set up the ducting is there is ducting going from inside my tent into the 4 inch inline fan thats in the closet. Then I have 4 inch ducting going from the fan Into the ceiling and through a vent in my attic.

I was wondering If I install a higher cfm 6 inch fan would I still be able to use the 4 inch ducting. its a lot of ducting I bought and it would really be a hassle to re-drill for 6 inch holes and running all that new ducting...etc. I saw they sell 4 to 6 inch adapters I would be able to attach to each end of the new fan....making it look like it has two 4 inch ends instead of 6.

What I want to know is if I get a good fan like the hyperfan has 315cfm will this cool the tent more for when the temperatures in the closet start to increase?

 

[queequeg152]

yea it will.

you could push 2,000 cfm through a 1" pipe if you wanted too. the air would have to be going like the speed of sound though. and you would need like a 200amp 3 phase compressor....

the key to maximizing the efficiency of a blower is to give it the lowest possible resistance to air flow.. this means no flex duct, only long radius elbows, and no reductions etc.

your 315 cfm blower is probably rated as such at 0" inches of water. with your 4" flex duct it will be significantly less.

 

[Granger2]

Re-drill, and while you're at it go with 8". Replace any flex duct with straight metal duct. You can still use a 6" fan if you don't think you need an 8". Good luck. -granger

 

[MarthaStewart]

well now I have some stuff to think about....8" or 6"...Also I'm using all flex duct right now :X.. I guess its good I didn't buy a carbon filter yet. I have to budget this because I dont have the extra money now. I guess in a few weeks Ill be taking a trip to the hardware store.

 

[MarthaStewart]

Ok as a temporary fix I straightened out all the flex ducting as best I can. I dont have any elbows or anything so I made the 2 turns as wide and clean as I can kind of mimicking an elbow. Also, I took out the ducting that went from the ceiling into the attic vent and I just have ducting from my tent going into the ceiling and thats it. It actually reduced a bunch of drag and I have a lot more pull coming from the fan right now.

I think once I get a carbon filter I will be back to square one though...I'm prob going to go with a 6 inch fan with straight ducting and long radius elbows since my tent is on the smaller side...Just have to wait a few weeks once I have the money to spend on that.

Thank you for the suggestions guys!

 

[queequeg152]

Ok as a temporary fix I straightened out all the flex ducting as best I can. I dont have any elbows or anything so I made the 2 turns as wide and clean as I can kind of mimicking an elbow. Also, I took out the ducting that went from the ceiling into the attic vent and I just have ducting from my tent going into the ceiling and thats it. It actually reduced a bunch of drag and I have a lot more pull coming from the fan right now.

I think once I get a carbon filter I will be back to square one though...I'm prob going to go with a 6 inch fan with straight ducting and long radius elbows since my tent is on the smaller side...Just have to wait a few weeks once I have the money to spend on that.

Thank you for the suggestions guys!

yea i was not going to suggest you go out and buy all new duct. straighten it out as best as you can. id suggest buying some 2" duct strapping though. you should remove all sags, and reinforce each end of a bend transition, making it as smooth and long as possible.

in the future consider buying smooth metal duct for new construction. you can buy it in sheets, or prerolled into tubes. you simply apply mastic to seal it, and screw segments together.

you are probably right about the carbon filter reducing the flow of your fan substantially.... you could buy a very large filter, much larger than you would other wise need, and simply use a reducing fitting.
this would help greatly.

 

[stoned-trout]

you cant cheat physics..upgrade the right way and you wont regret it...start drilling...using reducers adds backpressure to fan too..let the fan do its job properly..i even recommend oversized fans and speed controls... I never recommend 4 inch for anything after 400 watts...yeehaw good luck

 

[queequeg152]

while im inclined to agree... that upgrading would be best.

nothing he is proposing is cheating physics... hes simply trading down efficiency for simplicity of operation.

 

[MarthaStewart]

I cant go with bigger ducting then 6 inch because my tent only has 6 inch ports on each side. My tent is only a 3x2' and around 6' tall. But I think once I get a better fan I will be ok. I was a bit greedy when I went to buy my light...I wanted the 700 watt mars hydro led, but I went on ebay and saw an auction for the 900 that was ending in 10 min for super cheap. I ended up paying less then what the 700 watt one costs on their website. The 900 watt actually puts out 400 watts according to their site so I'm not actually using 900 watts.

If worse comes to worst I have a window ac unit that I can set up in the room my tent is in...but I really don't want to set that up till its really needed. Also I wont be growing when its peak summer here. I'm switching to veg in a few weeks and once they are done flowering I wont be starting another grow until around September when it gets a lot cooler.

 

[r2k]

I agree what they said about going big on ducting. Cut the holes, you will be glad you did.

As for the flexi-ducting, I would have to agree that solid duct is the ultimate best, but you can do pretty darn good with a little thing I call "Duct Viagra". It puts the stiffy in your flexi-duct. I have played around with it a bit and I would post pictures but I'm still a newbie and can't post yet.

To make it, you get some stiff steel wire, the longer the better. I got 24 inch insulation support wires at Home DePot, but it is better if you can get longer. It is about 8 or 10 gauge diameter so it's pretty stiff but still springy. Be really careful of the ends, they are super sharp and you are going to be bending these a bit.

The idea is that you bend each end into an S shape. Try to keep the S shape as small as possible, it consumes length. If you put an S onto each and and then flex the wire a bit, you will find it springs back. This will put the stiff into your flexi duct but it will still flex. You poke one end of the Viagra wire into the flexi-duct right next to the spiral wire inside. The S shape hooks under the spiral wire and you only have one small puncture through the flexi-duct. You can patch the flexiduct with a square metal tape (also available from Home DePot). Once you get one end anchored, flex the wire a bit to create tension and gouge it under another spiral wire further up the duct. The wire tries straighten and puts the flexiduct under tension. It will take you about two wires to figure out the process. I put one stiffener along the outside of the duct on opposite sides, but I think you might be able to do it with one stiffener for most of it if you play around with the technique.

Once the flexiduct is under tension, it pulls out smooth like solid ducting. It's really cool how smooth it is. I think this method is even better than solid ducting because it is cheaper, just as good, and it is still a bit flexible to guide around slight bends.

I have not tried, but I think you could probably put the stiffener wires inside the flexiduct. This would give a nice looking system and no external wires to catch on other things. If you get to a corner and need a sharper bend, just don't put stiffeners there and bend away. It's still flexiduct, so corners are what it does.

As an experiment, I made a section of this back in 2005 or 2006. I wanted to see if the aluminum foil on the flexiduct will tear if it is under continuous tension. It's now 2015 and it wasn't torn last time I checked. I think it works.

So the big problem with this is the steel wire. It's a bitch to bend. I ended up using a bench vise and a hammer, plus some large channelLocks. I think it would work well with an industrial box and pan break to do the bending.

I'll try to post some pictures of the wires and my 8 year experiment when I get the privilege on icmag. I think I only need to make about 8 more posts to get there.

-r2k

 

[noyd666]

often wondered how much crud get's trapped in flex ducting even when pulled tight, bit like a gold dredge riffle, started to replace mine with single pipe runs and u-bends, 8'' hypher fans & speed controls. but have used the flex for years.

 

[Granger2]

It's much better to get the bends out, and stretch flex duct out as much as possible. Even with that the ribs still offer static pressure that straight metal duct doesn't have. Metal duct isn't very expensive. You can order it online and pick up at store. Good luck. -granger

 

[MarthaStewart]

I agree what they said about going big on ducting. Cut the holes, you will be glad you did.

As for the flexi-ducting, I would have to agree that solid duct is the ultimate best, but you can do pretty darn good with a little thing I call "Duct Viagra". It puts the stiffy in your flexi-duct. I have played around with it a bit and I would post pictures but I'm still a newbie and can't post yet.

To make it, you get some stiff steel wire, the longer the better. I got 24 inch insulation support wires at Home DePot, but it is better if you can get longer. It is about 8 or 10 gauge diameter so it's pretty stiff but still springy. Be really careful of the ends, they are super sharp and you are going to be bending these a bit.

The idea is that you bend each end into an S shape. Try to keep the S shape as small as possible, it consumes length. If you put an S onto each and and then flex the wire a bit, you will find it springs back. This will put the stiff into your flexi duct but it will still flex. You poke one end of the Viagra wire into the flexi-duct right next to the spiral wire inside. The S shape hooks under the spiral wire and you only have one small puncture through the flexi-duct. You can patch the flexiduct with a square metal tape (also available from Home DePot). Once you get one end anchored, flex the wire a bit to create tension and gouge it under another spiral wire further up the duct. The wire tries straighten and puts the flexiduct under tension. It will take you about two wires to figure out the process. I put one stiffener along the outside of the duct on opposite sides, but I think you might be able to do it with one stiffener for most of it if you play around with the technique.

Once the flexiduct is under tension, it pulls out smooth like solid ducting. It's really cool how smooth it is. I think this method is even better than solid ducting because it is cheaper, just as good, and it is still a bit flexible to guide around slight bends.

I have not tried, but I think you could probably put the stiffener wires inside the flexiduct. This would give a nice looking system and no external wires to catch on other things. If you get to a corner and need a sharper bend, just don't put stiffeners there and bend away. It's still flexiduct, so corners are what it does.

As an experiment, I made a section of this back in 2005 or 2006. I wanted to see if the aluminum foil on the flexiduct will tear if it is under continuous tension. It's now 2015 and it wasn't torn last time I checked. I think it works.

So the big problem with this is the steel wire. It's a bitch to bend. I ended up using a bench vise and a hammer, plus some large channelLocks. I think it would work well with an industrial box and pan break to do the bending.

I'll try to post some pictures of the wires and my 8 year experiment when I get the privilege on icmag. I think I only need to make about 8 more posts to get there.

-r2k

Dude the first time I read this I didnt really understand what the fuck you were talking about. But I re read it and got the gist of it. I just did your duct viagra on the two pieces of duct I have and it really works! I essentially pulled the flex duct so tight its pretty much like straight duct...only difference being its really flimsy and you can easily poke a hole into it. I also made my own wide angle turns with reinforced wires on the outside to keep it the shape I want. It lowered my temps around 5 degrees.

I commend you sir, you crafty bastard.

 

[MarthaStewart]

often wondered how much crud get's trapped in flex ducting even when pulled tight, bit like a gold dredge riffle, started to replace mine with single pipe runs and u-bends, 8'' hypher fans & speed controls. but have used the flex for years.

funny story but I was just reworking my ducting and had one piece pulled tight using the other guys viagra method and I turned on the fan with the other side of the ducting towards me to see if I got a change in pressure...well it blew out a bunch of crap all over my face.

 

[queequeg152]

http://www.amazon.com/HVAC-Duct-Elb...id=1427153169&sr=8-1&keywords=flex+duct+elbow

is that what you mean by duct viagra? im confused.

these things are fairly common, but a good long radius stamped metal elbow is still better.

 

[MarthaStewart]

http://www.amazon.com/HVAC-Duct-Elb...id=1427153169&sr=8-1&keywords=flex+duct+elbow

is that what you mean by duct viagra? im confused.

these things are fairly common, but a good long radius stamped metal elbow is still better.

What I did was I had a big spool of thick gauge electrical wire I pierced one end of the duct with it and looped it around then pulled it through the duct then pulled the duct as tight as it would get and cut the wire to where the duct ended then pierced the other side of the end of the duct and tied it off. I did 2 wires per duct and it stays pulled tight now. Also moved my inline to a better location where there the angle the ducting it hooks up to is not as sharp.

I believe you guys that straight ducting and long radius elbows are better and will be going with that if need be but for now my tent is only 2 degrees then the ambient temp of the room its in.

 

[MarthaStewart]

How do I edit a post here? Anyhoo I think thats what he meant by duct viagra? My ducting is now long and hard when it was just floppy before lol.

 

[noyd666]

I agree what they said about going big on ducting. Cut the holes, you will be glad you did.

As for the flexi-ducting, I would have to agree that solid duct is the ultimate best, but you can do pretty darn good with a little thing I call "Duct Viagra". It puts the stiffy in your flexi-duct. I have played around with it a bit and I would post pictures but I'm still a newbie and can't post yet.

To make it, you get some stiff steel wire, the longer the better. I got 24 inch insulation support wires at Home DePot, but it is better if you can get longer. It is about 8 or 10 gauge diameter so it's pretty stiff but still springy. Be really careful of the ends, they are super sharp and you are going to be bending these a bit.

The idea is that you bend each end into an S shape. Try to keep the S shape as small as possible, it consumes length. If you put an S onto each and and then flex the wire a bit, you will find it springs back. This will put the stiff into your flexi duct but it will still flex. You poke one end of the Viagra wire into the flexi-duct right next to the spiral wire inside. The S shape hooks under the spiral wire and you only have one small puncture through the flexi-duct. You can patch the flexiduct with a square metal tape (also available from Home DePot). Once you get one end anchored, flex the wire a bit to create tension and gouge it under another spiral wire further up the duct. The wire tries straighten and puts the flexiduct under tension. It will take you about two wires to figure out the process. I put one stiffener along the outside of the duct on opposite sides, but I think you might be able to do it with one stiffener for most of it if you play around with the technique.

Once the flexiduct is under tension, it pulls out smooth like solid ducting. It's really cool how smooth it is. I think this method is even better than solid ducting because it is cheaper, just as good, and it is still a bit flexible to guide around slight bends.

I have not tried, but I think you could probably put the stiffener wires inside the flexiduct. This would give a nice looking system and no external wires to catch on other things. If you get to a corner and need a sharper bend, just don't put stiffeners there and bend away. It's still flexiduct, so corners are what it does.

As an experiment, I made a section of this back in 2005 or 2006. I wanted to see if the aluminum foil on the flexiduct will tear if it is under continuous tension. It's now 2015 and it wasn't torn last time I checked. I think it works.

So the big problem with this is the steel wire. It's a bitch to bend. I ended up using a bench vise and a hammer, plus some large channelLocks. I think it would work well with an industrial box and pan break to do the bending.

I'll try to post some pictures of the wires and my 8 year experiment when I get the privilege on icmag. I think I only need to make about 8 more posts to get there.

-r2k

LENGTHS OF OXY WELDING WIRE, SOFT GOOD FOR MAKING TEMPLATES ETC.

 

[noyd666]

funny story but I was just reworking my ducting and had one piece pulled tight using the other guys viagra method and I turned on the fan with the other side of the ducting towards me to see if I got a change in pressure...well it blew out a bunch of crap all over my face.

 

[r2k]

Dude the first time I read this I didnt really understand what the fuck you were talking about. But I re read it and got the gist of it. I just did your duct viagra on the two pieces of duct I have and it really works! I essentially pulled the flex duct so tight its pretty much like straight duct...only difference being its really flimsy and you can easily poke a hole into it. I also made my own wide angle turns with reinforced wires on the outside to keep it the shape I want. It lowered my temps around 5 degrees.

I commend you sir, you crafty bastard.

Yes, exactly. I would like to see pictures of your work. I'll show you what I have when I can post pictures. The skin gets pulled tight and puts a stiffy in your flexi. It's a really cheap fix and seems kinda lame, but you can't argue with a 5 degree drop for a couple pieces of wire. Sorry about the duct fluff in your face, I couldn't think of everything.

noyd666 mentions using welding wire. That would probably work. Anything that is stiff and has some springiness to it will work.


-r2k