Quote:

---

skullhuman said:
Alright, so here are a few different light setup ideas that could use your input.

1. Carbon Filter --> 400 W HPS Cool tube --> Duct --> Fan out
One exhaust in the entire cab which also serves to cool the light.  But the potential problem I see with this, is that perhaps particulate and such may be pulled from the filter and end up dirtying the light.  A hepa filter would handle this, but I don't really want to spend the bucks on that if unnecessary.

2. 400 W HPS Cool tube --> Duct --> Carbon Filter --> Fan out
As with prior setup, one single exhaust in the cab.  Duct and carbon filter are interchangeable in this sequence I suppose, but there are worries of pulling hot air through the filter.  What do you think?

3. Passive intake --> Duct --> 400 W HPS Cool tube --> Duct --> Fan out
The light would have its own ventilation separate from the rest of the cab.  Also, air coming from outside the cab may make for more efficient light cooling.  But this would require more fans, which translates to more bucks, because these things need to be quiet.  I'd even go so far as to say silent.  Also, an efficient fan is needed to cool the 400 W, so this method could get pricey.  Any suggestions on how to make this work with out spending $500?

So which of these would you prefer and why?

And some other questions..

Is it more sound proof to place the fan out before a duct in any of these sequences? How would this affect other aspects of the system? Would some air build up in the duct out and cause any possible problems?

Also, I understand these ducts should be coiled and what not, as not to allow light to escape through them.  Anything else one should know about light-proofing a vent?

And just how efficient of a fan is needed to cool a 400 W through a tube? How many CFM?

Aaaannnd.. a friend from Garden's Cure shared this experience about pushing air rather than pulling it to cool a fan:
"fans do seem have more suction than push force-- at room temp or lower--
but hot air propels itself and seems to need far more cfm and or ducting diameter to be adequately pulled than i currently have at least that's how i explain thinks to Self

like the heart, the primary force is in the contraction that pushes the heat thru wide open arteries --which then tugs harder at the chilled from the longer circuitry of more narrowly compressed veins"

Of course, the theory is just his own personal speculation, but what do others think of this? Any similar experiences? How many CFM's are needed to properly cool a 400 W by pulling air?

---

Quote:

---

DrGreenThumb said:
Try this: Carbon filter > Fan > CoolTube > Duct out.

1. You want to pull air into your filter (not push through).
2. You want the fan BEFORE the cooltube, pushing through it. This keeps hot air from being sucked over the internal components of your fan. It also makes the fan more efficient by sucking cooler air.
3. Exhaust from the other side of the tube out of your space.

This is the ideal setup.

---

Quote:

---

DrGreenThumb said:

Quote:

---

Buddy Guy said:
You guys are thinking to much. Quit sweating the small stuff...It is just a fan. Made by humans. It is not going to last forever. All I care about is spoiling my girls. 

---

You're right. You're absolutely right. I don't know what the fuck I was thinking.

I'm just going to hook it up whatever way seems easiest. Who gives a shit??? That's what a WARRANTY is for.

---

exactly 81. besides it's a hobby, were sposed to waste money and do things wrong right

no but really this is the applicable part:

Quote:

---

81renaissance said:
The heat from the light becomes negligible in its effect on the fan in my system because of effective air exchange (about 3 per minute), meaning that the air flowing across my fan is only 8-10 degrees warmer than the air outside the cab-well within the working parameters for the fan.

---