Dual Exhaust Question

[MMJcali]

Hey all,

Designing a room for an ill friend, here's the rundown: 4.25' x 6', 7.5ft tall. Thinking of doing two 600watt HPS in cooltubes,

duct from adjacent room -> tube1 -> tube2 -> fan -> outdoors

and passive intake -> scrubber -> fan -> outdoors for the room.

cooling the lights separately should really keep the temps down, but I'm wondering what kind of fan and how many cfms I need for both of the cooltubes? I've read some who say a simple duct booster or axial fan is enough, others say a 4" inline should work, others say go all out and get a 6" inline.

For the room I figure 191cubic ft, Hurricane 6" 435cfm will do two changes per minute...

For the cooltubes, a hurricane 4" 171cfm inline? or is that overkill?

Thanks much!!

MMJC

 

[Photosynthesis]

Hey all,

Designing a room for an ill friend, here's the rundown: 4.25' x 6', 7.5ft tall. Thinking of doing two 600watt HPS in cooltubes,

duct from adjacent room -> tube1 -> tube2 -> fan -> outdoors

and passive intake -> scrubber -> fan -> outdoors for the room.

cooling the lights separately should really keep the temps down, but I'm wondering what kind of fan and how many cfms I need for both of the cooltubes? I've read some who say a simple duct booster or axial fan is enough, others say a 4" inline should work, others say go all out and get a 6" inline.

For the room I figure 191cubic ft, Hurricane 6" 435cfm will do two changes per minute...

For the cooltubes, a hurricane 4" 171cfm inline? or is that overkill?

Thanks much!!

MMJC

Do 2 6", and you will be happy. The 4" just are not worth your time.

 

[TheyCallMeJJay]

You've got it down pretty good.

IMO, I would go with 6 inch fans across the board. Everything will fit snugly and there wouldn't be any need for reducers that's involved with a "4.

I'm not sure what pricing you are looking at on the equipment, but I'd say it would be negligible considering the adapters. That said, if one of the fans fail, you can easily hook up all with ducting until you can get a new fan in and you won't miss a beat.

My previous set up was this

Scrubber-Fan-lights-out. I did all this through an 8 inch fan. And when I had only 2 lights (600's), I did it with a 6 inch fan and I didn't need AC.

Hope this helps.

 

[MMJcali]

thanks Photosynthesis, and JJay - makes sense.

I just read that pulling air through two cool tubes is a bad idea, since the heat from the first tube will warm up the second tube... is this an issue with separated exhaust, ie my 6" will ONLY be cooling the tubes and not the room?

Thx again!

 

[Photosynthesis]

You can pull through multiple fixtures without an issue. 2 - 6" fans will have things in perfect order.

 

[Granger2]

Axials and duct boosters will absolutely NOT do the job. One 4" won't either. You need at least 1 6", but 2 would be better. You can cool 2 with 1 fan if you use a plenim. Use a large straight metal duct pipe, with the fan on one end, pulling air thru both lamps. "T" to each lamp, and you won't have the heat from one trying to cool the 2nd lamp. You could also use one 8". You can never have too much air flowing thru the lamps. Good luck. -granger

 

[MMJcali]

second question - for the air cooled hoods 'circuit', is it better to intake outside air or air from the adjacent room? I'll be pulling from the adjacent room for the room fan, not sure if two 6" fans pulling from the same room will cause vacuum problems since the air is all being exhausted outside and no fresh air is coming in.

But I read about condensation problems from intaking through hoods. I'll be running at night when the temps get pretty cold in socal.

 

[raphenilweed]

For your little space one 6inch fan could be sufficient. Pulling air through hoods is always more efficient at cooling. Well you arent really cooling, more so moving hot air away from bulbs.

 

[Granger2]

Any amount of exhaust without intake will cause problems. If air is exhausted it has to be replaced from somewhere. Exhaust without intake is a total bust. -granger

 

[stoned-trout]

I used a 435 I think..well it was a 400+ anyhow ..both were on a speed switch...better to have it an not need it blah blah blah