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Strider
28-05-11, 12:12 PM
Hey guys, could use a bit of help here if folk have the time,

Basically my extraction rig seems to suck, can't get temps below 30d so i think i've made a big design flaw somewhere,

Area is a 2.4m x 1.2 x 2m tent with 2 600w HPS's in 125mm aircooled reflectors, fan is a dual speed PrimaKlima (230/360m3/hour) linked to a standard 125mm budget filter

Carbon filter in far corner, fan, ducting bend, through both lights inline then through another 2.5m odd of bendy ducting

http://img585.imageshack.us/img585/9453/vents.jpg

I already know the system isn't really right, i don't think your really supposed to run air cooled lights and a filter off the one fan, i can only assume due to the length of ducting needed and possible particle damage to the bulbs *shrug* but another inline is a bit out of my budget right now, plus the tent doesn't have 3 large vents for me to run the filter/fan plus an in/out for the lights

I also have a hunch the length of ducting im using and the amount of bends isn't really practical, theres obv a big loop after the fan and first light to allow the lights to raise and lower, 2m straight through the lights, then a similar loop at the other end, then it goes out the tent roof and down round the side and through a vent in a door which is another 2.5m odd, but with the current setup thats basically as short as it can be, but at the end you only get a faint gust of warm air, as opposed to a powerful blast off the 100mm ruck i tested the other day with just a filter and 1m of ducting

Bit of a ramble but I hope you followed, in summary, am i just being unrealistic expecting this one fan to push air through all this? its starting to look more and more stupid the more i type it out in black and white, i only upgraded to aircooleds recently and so far if anything they've made things worse, i can only assume due to this problem, the glass and the space under it do heat up a fair bit, if anything its radiating near the same as a naked bulb, is this simply because its not getting air pushed over it fast enough?

As far as i know i have access to a spare 200m fan, which of course doesn't fit the filter, ducting or lights...at all, a 100m toty inline from B&Q i planned to use as an active intake (didn't even dent it) and a somewhat dodgy 150mm cheap ruckclone, was thinking that bunging the 100m inline somewhere in the system might give it a bit more pull?

I'd obv prefer not to have to dismantle the entire system, but its looking more and more likely, any help or suggestions would be much appreciated, as i cant really commit plants to this area till its fixed :)

TheGreenMachine
28-05-11, 12:20 PM
I run a pair of cool tubes off one 150mm fan with matching filter and my temps are steady.
My only guess is like you say, the length of ducting and bends slowing down the flow.

What I do is shorten my lengths by using clips to compress the ducting like collapsing a bendy straw that way the ducting is only as long as I need it untill I need to lengthen it.
I use those keyring clips.. Can't think of the name of them but they look like question marks and are for clipping keys to belts...
They work perfectly for holding the ducting compressed if you clip them over the metal ducting loops....

May help the flow and also it stops the ducting expanding and shoving the lights over to one side!

Nice set up by the way!!!

TheGreenMachine
28-05-11, 12:29 PM
Like this...
Excuse the swiftly made explanitory pic lol...
https://www.thctalk.com/gallery/data/903/compress_duct.png

Strider
28-05-11, 02:34 PM
I'd tried doing that when i first set it up a while ago, thats the black strip on the loop, trouble is during veg when temps are at highest, the lights tend to be lower down so the ducting is fully extended, they're only that slack just now because i've been in doing work,

Hmm, the tent itself sits in its own room, with a 2m odd duct leading to the door and into the living room, would scrapping the 2m duct and just have it venting out the top of the tent help?

Anthrax
07-06-11, 11:53 AM
Maybe your carbon filter is reducing the airflow too much, you could buy a Y piece buy another carbon filter and put 2 carbon filters on the Y piece, you would get more airflow which could reduce your temps.

Strider
07-06-11, 03:52 PM
it is possible, it is a relatively old budget one, and the sleeve was pretty clogged, but i went over most of it with a wirebrush to hopefully clear it out, but as you say it just might not be allowing enough airflow, buying another filter is sadly out my range for just now though :(

Im obv still having an issue with this, theres 5 fucking fans now, windows open, tent partly open, and it still wont come below 30dc, i rigged a second beat up 150mm inline into th end of the extraction feed to try and draw the air through better, but it doesnt seem to have made a bit of difference

starting to wonder if this aircooled bollocks is worth the hassle, i've spent too much money on it for near fuck all effect

Goodbuddy
07-06-11, 04:49 PM
You need to shorten it and reduce those ducting bends in my humble.

Try CF->CT->CT->Fan. Hook up the CF directly to the furthest cooltube and the fan directly to the end of the nearest cooltube, that'll shorten ducting and straighten everything before the fan. Then duct out with as short a ducting length as possible and try to keep the bends less than 90deg if possible. That way you are only constrained by the ducting on the way out, just about everything is being sucked rather than sucked and pushed.

Obviously it depends on space, vent holes etc,. but would increase the performance of your current setup without resorting to extra fans :)

peace:p

Anthrax
07-06-11, 05:20 PM
Try taking your carbon filter out of line for 30 mins and see if the temp comes down, because if the outer sleeve was that bad then theres your problem.
Plus you are venting outdide of the room, away from the intake I hope, because if your not then theres another problem.

Hope you get it sorted m8.

Strider
17-06-11, 12:53 PM
I seem to have 'fixed' this, but i've admittedly no idea how :S

I did take up about a meter of slack from the ducting though and jimmied the intakes a bit, temps holding at 27dc now which is acceptable,

And yep, the in and out vents are in different areas, sucks in air from the window and vents it out the door into the living room

franky118
19-06-11, 10:55 AM
you should put the in-line fan at the end off the lights rather than push air through them cos that creates positive pressure in the lights which pushes air out little holes on the reflectors (i have the same ones) but if u suck air through them that creates negative pressure and removes a little more heat

Strider
21-06-11, 05:04 PM
That makes good sense actually, i didn't think of that

Its holding for now, and as its mid grow im not really wanting to rip the thing to bits just now, its got a second inline added after the lights now though, which is likely helping, even if only a wee bit

habiszti
26-06-11, 11:07 AM
like:)gg,grat

stone14
28-06-11, 12:30 PM
Maybe your carbon filter is reducing the airflow too much, you could buy a Y piece buy another carbon filter and put 2 carbon filters on the Y piece, you would get more airflow which could reduce your temps.

realy? i think my prob is mt cheap cf restricting my air flow, i have another fan which has the same air flow max, can i put both on and will this allow more air flow? sorry to hyjack ...............

Strider
02-10-11, 01:42 PM
Im still having loads of trouble with this setup, and a lot of seemingly conflicting advice :S

Since the pic in the OP i'e replaced the 125mm short CF with the 125mm long one, the fan has been taken out of line and moved to after the two lights, so the flow now starts and progresses as

Carbon filter > ducting loop (to allow lights to move up and down in relation to CF) > 125mm reflector > short ducting length > 125mm reflector > ducting loop > 360m/h 125mm fan > ducting loop out top of tent and down to the room door, maybe 1.5m, widening to a 150mm duct and ending with a beat up 150mm inline fan that id hoped to use to counter the loss of pressure due to the long ducts, still getting temp problems with it, and the output at the end is pitiful, don;t think its moving air anywhere near quick enough :S

any suggestions? am i better taking the main fan and putting it back where it was? blowing over the lights as opposed to sucking air away from them?

ChuChu
02-10-11, 02:10 PM
Try and get some colder air in or a bigger fan.
Can you seal off the window and put your intake into it or get it from the loft hatch to keep the hot & cold seperate.?
I had a set up exactly like you have it now but had a 6 inch 150mm fan on the outlet and a 4 on the inlet.
CF (duct) CT (duct) CT (duct) 150mm fan (duct) out of tent
Also have your inlet going in from the opposite side of the tent from your filter and a circ fan blowing the same way towards your filter to get good flow from one side to the other.

Hope this hepls.
ChuChu.

Anonymiss
02-10-11, 02:15 PM
First up, blow through the cool tubes, don't suck. Ideally,connect the fan directly to the tube, with no ducting.

Second, as others have said, reduce the amount of ducting.

Third, make sure that the bends in the duct are as efficient as possible. The radius 'r' (along the centre line) should be 1.5 times the duct diameter 'd':
http://i51.tinypic.com/30trsyw.png

Also, make sure that the duct is straight and fully-extended (taut). Anything else and the losses will be much greater.

If your ducting is properly air tight then also blow through the filter, which can then be outside the space.

Fans (almost) always blow more efficiently than they suck.

Finally, with an air flow of 360 m³/hour and 1,200 Watts of equipment you're only ever going to achieve 10°C above ambient. But, with ducting and a filter you won't be getting anywhere near the fan's rated 360 m³/hour. That figure will be in free-air conditions and will derate considerably as soon as it's connected to anything at all.

Anonymiss
02-10-11, 02:25 PM
Another thought:

Try using larger ducting, with tapered reducers to fit the fan, etc. Generally, using over-size ducting will result in better performance, and also reduce the noise level.