Air Cooled hoods.... air flow problem?? Please help!

[Ozymandias15]

I'm a little stuck on this one guys and any help would be hugely appreciated...

I've just set-up 4 air cooled lamps in a straight line, they have 150mm spigots and i have attached them to a 200mm fan via a reducer. There are a couple of bends and the fan is approx 50cm lower than the hoods (at the moment). When i switched the fan on no air came out of the end (the fan is on the correct way and should suck air through the lamps). I'm going to chop some bits out of the hoods to increase the air flow but i'm not sure it is going to be enough... i'm also going to add another 4 hoods on a T-Piece.

I have a spare 200mm fan which end should I put it on? The same end that the fan is already on so that more air is sucked through or should i place it on the other end so that air is blown through?

Any help from someone in the know would be a real help, thanks guys

 

[Guest]

With 4 lights you need at least 750 cfm pullin on it. them more pul the cooler the lights will run. Can you feel air pullin at the end of the hoods ? If not you need more cfms pullin!!

 

[clowntown]

Also, the type of fan plays a large role. Some types of fans just plain suck when it comes to static pressure. Other things that play a role are obviously the aerodynamics in the layout of the ducting (the bends you mentioned), and in the turbulence generated within the reflectors (design of the reflector) as well as within the ducting (smooth bore vs. "flexible dryer hose").

 

[Mr Celsius]

Also, the type of fan plays a large role. Some types of fans just plain suck when it comes to static pressure. Other things that play a role are obviously the aerodynamics in the layout of the ducting (the bends you mentioned), and in the turbulence generated within the reflectors (design of the reflector) as well as within the ducting (smooth bore vs. "flexible dryer hose").

Clown you know your stuff when it comes to hoods and lights, had a question for ya. Whats your thoughts on this fan cooling 3 1000w hps's?

BTW, sorry to the thread starter, but if this fan works, then maybe its a viable option for ya.

edit: Hoods are normal 8" AC hoods.

 

[clowntown]

Avoid it. Those SunCourt duct booster fans are a perfect example of the types of fans that won't work well in pushing air through ducting. You want an inline centrifugal fan, like a Vortex or Elicent. I hear Can-Fans are noticably louder than their Vortex or Elicent counterparts for the same size / similar CFM rating. Avoid EcoPlus; they're definitely louder for sure, and not much cheaper.

 

[Guest]

running light cooling ducts inline passes heat from one light to the next so a big fan is needed when doing this. blowin the heat of 2 or 3 lights on to the next one is not very effiicient. it takes much less cfm to cool the lights when running an individual cool air duct to each light. you can do this using a plenum and a single fan- much smaller than you'd need in an inline set up.

my 10" can fan is quieter than my 6" vortex.

 

[Mr Celsius]

running light cooling ducts inline passes heat from one light to the next so a big fan is needed when doing this. blowin the heat of 2 or 3 lights on to the next one is not very effiicient. it takes much less cfm to cool the lights when running an individual cool air duct to each light. you can do this using a plenum and a single fan- much smaller than you'd need in an inline set up.

my 10" can fan is quieter than my 6" vortex.

I agree with you, but when you have 6 different hoods in a room, that would require 6 different intakes as well, not to mention, how would you put them in a line order?

Typical light arrays are linear, so yes, heat builds up, so you use a larger fan.

Its unfortunate that those Suncourts wont work, as they are so affordable and high cfm... o well. Looks like 4 Can fan RS8L.

 

[Ozymandias15]

Thanks for all the help guys. Looks like i'm going to have to try putting fans at each end of this set-up and see which is best... if that doesn't work then i'm going to find the biggest damn fan out there 'cos this set-up has to be this way due to limitations with the room... particularly with space 'cos their ain't none, so i can't have more ducting or intakes or... well... anything really. The hoods have something like a 2 inch gap between them!

 

[clowntown]

You must have a bad Vortex. I've never heard a 10" Can-Fan, but I've heard 8"s and I own a 6" Vortex. My 6" Vortex is super quiet. The 8" sounded like a jet engine.

 

[Ozymandias15]

i've just put a 250mm inline centrifugal pushing air into the system with only minimal impact... my tank heater has bitten the dust and both of my ph meters have broken in the past 2 days! I've had enough.

I think that i've got at least 1500m3 per hour on these two fans but nothing much is happening and i've GOT to put another 4 hoods on this set-up somehow.

So should i go for a 315mm Turbo fan that is 1800m3 and use that to blow air in (leaving the 200mm to suck air out) or am i going to need to get something more substantial... something outside of the hydro market. I'm trying to find suppliers of the next systemair inline range that go uptp 8000m3 out of a 315mm fan but i've no idea how much these babies are going to cost

AAAAAAARGH!

 

[Guest]

I agree with you, but when you have 6 different hoods in a room, that would require 6 different intakes as well, not to mention, how would you put them in a line order?

you can run one intake and one exhaust in the room as you would when running them inline. run the cool air plenum/duct along one side of the lights and the exhaust along the other side and give each hood it's own duct between the 2.



this set up has 3 1k hps cooled with a single 6" fan and works great. the hood flanges are 4" and flow plenty when done like this. it does take some extra duct work but its worth it.

 

[Mr Celsius]

forty I'm impressed. I've never seen anything like that before.

My only concern is the bends in the air lines reducing flow.... I bet I could think of something...

Also, I found these 10" "cool tubes" Max Air shades. Imagine a nice 10" fan hooked up to a series of these.

 

[Guest]

What`s up Forty Grit?.....I posted in another thread recently how clean and damn near perfect your rooms always look.......Smaller more controllable areas that do their thang rock in my book....The plenum trunkline is absolutely ingenious.......Cooling 3-1000`s with a 6 inch inline fan rules my buddy.......Works sorta like my big ceiling box thingy heat and smell scrubber out the top of the room when I was doin krusty buckets but your`s goes out the side by itself and with separate light cooling as well........Have yas got the scrubber/fan combo on a thermostat or a timer?....Major props for the pics and explanations.......Now Mr. Celsius.......If you have rectangular reflectors like FG you could turn em around feeding directly into the plenum trunkline and spread em for the proper footprint you`re looking for as far as sq. ftg. since you`re concerned with the kink in the flex pipe insulation for flow but if Forty`s handlin 3 -1000`s with a kink in the hose I say go for it with inline footprint......He knows his shit.....But 10 inch coolshades sounds awesome as well.......I`m too much of an `ol head to use anything but my vertical bare bulbs but that`s just me.......Lumen loss don`t help my bitches but I have no probs with temps with fans below each light blowin straight up at my scrubber wired to a fan speed controller and thermostat with a wall fan at the tops of the plants and another one on the opposite wall blowin down underneath for circulation ....I also have a portable a/c on thermostat with a dehuey for a safety valve in late flower........Basically, it`s either adapt or perish in the growroom scene so as much environmental control that you have hold of makes yas happy in the end .......Good luck......Peace......DHF.......

 

[clowntown]

Nice setup, forty.

sonoma has a very good guide, I think in his 5400w medical growroom build thread, on how to build a manifold system similar to that.

However, you won't be able to have near the efficiency as running an "inline" configuration simply due to the fact that you're dealing with physics. Each turn and bend, especially those 90-degree bends, greatly reduces the air moving capacity and velocity of that system.

 

[Guest]

running light cooling ducts inline passes heat from one light to the next so a big fan is needed when doing this. blowin the heat of 2 or 3 lights on to the next one is not very effiicient. it takes much less cfm to cool the lights when running an individual cool air duct to each light. you can do this using a plenum and a single fan- much smaller than you'd need in an inline set up.

my 10" can fan is quieter than my 6" vortex.

I like the avitar forty drit!!!!!!!!!!!!!!

 

[Guest]

I bgot a 12 inch running right now that I can bearly hear!!!!!!!!!!!!!

 

[Ozymandias15]

Thanks for all the replies guys. The main problem i'm facing i that i have a sealed room and i want the air to come from an seperate room and go through the chimney that no air is removed from the room...

so i'm going to get two 1800m3 rvk fans and stick one on each end. I know it will reduce the life of the fan having all of that hot air going through one of the fans but i don't think i have any choice.

Silly or might just be enough?

 

[Mr Celsius]

I think what forty just showed us would be awesome, should think about doing something like that and you probably wouldn't need to buy anything.

 

[Ozymandias15]

Unfortunately i don't have space for anything live forties set-up, i also like sealed rooms so the air has to start and finish outside the rooms if it's being used to cool the lamps.

What do you guys reckon to coolshades instead? My supplier can only get me 6" ones but i've seen them before and they seem to have much less restriction/turbulence to the airflow...

any thoughts?

 

[Guest]

I think that i've got at least 1500m3 per hour on these two fans but nothing much is happening and i've GOT to put another 4 hoods on this set-up somehow.

So should i go for a 315mm Turbo fan that is 1800m3 and use that to blow air in (leaving the 200mm to suck air out) or am i going to need to get something more substantial... something outside of the hydro market. I'm trying to find suppliers of the next systemair inline range that go uptp 8000m3 out of a 315mm fan but i've no idea how much these babies are going to cost

AAAAAAARGH!

if you're not up to building a plenum to feed each hood individually you can use a "Y" adapter at the fan't output then run a reducer on each leg and supply 2 light hoods with each leg. running a reducer right off the fan, then trying to cool 4 lights in a row seems like it wouldn't let the fan run as well as it could.

in a push-pull set up with a fan on each side i'd think the fans should be the same size/flow to avoid any pressure differences and possibly a leak somwhere as a result. hope you get it sorted.

DEDHEDFRED.. what's up bro? that's not my room but i did do all the duct work there. there's 6 lights, 3 on the other side of the room. the scrubber is on the same timer as the light cooling fan so it runs during lights on only and the room stays sealed w/co2 flowin. at lights out the room is vented and exhasts through a separate carbon filter so no need to run the scrubber then. i didn't come up with the idea of the individual light cooling so can't take credit for that. these ****en hoods are very, very good stuff imo and made smart. they reccomend the individual cooling and that's one reason why they only have a 4" duct. they happen to know that minimal cfm is needed to cool em this way. the other reason is the bigger the flange hole the less reflective surface you have in the hood. i am very impressed with how much went into makin these hoods but i guess the engineers got it wrong according to this clowntown fella eh?

anyway they are made by bell lighting tech
http://www.belllighting.com/product/lr-mv-main.htm
by clickin on the photometrics thingy there you can see how much testing they put into makin a good reflector. i know you're a vertical light guy but you might need a reflector some day. oh yeah, that pic i posted makes it look like a kink in the flex duct but there aint one... it makes a nice wide curve...smooth flow 101

you won't be able to have near the efficiency as running an "inline" configuration simply due to the fact that you're dealing with physics. Each turn and bend, especially those 90-degree bends, greatly reduces the air moving capacity and velocity of that system.

a reduced velocity/less cfm is the whole point- you don't need it...lol thought that was obvious. the engineers designed the hoods to be cooled this way and i'm not surprised one bit that it works as designed. i've been there and know that the set up works beautifully ...but you know better sitting behind your computer and reiterating what you've read does not make up for lack of real experience just so ya know.