Fans for light canopy

[DCFix]

What RPM, CFM and dB is ideal for a canopy with 2X250W 10,000K MH and 2X65W 10,000K PC?

I looked at data sheets for some fans. WHen they list the dB, those are actually negative values, correct? (Since a fan running at +30dB is ridiculous) In which case I should get a 40 over 25?

 

[comatose]

how big is the canopy LxWxH in inches there is a formula for it to figure how much CFM fan you'll need.

the lower the dbA the better and higher the CFM the better, the trick is getting a high CFM with a low dbA.
you also want to know if the fan is a sleeve or ball bearings inside. sleeve tend to be quieter at lower RPM but don't last as long as Ball bearing.

 

[DCFix]

The interior space will be 48X14, the height I need to double check first how high above the water the lights need to be.

Any recommendations for fans (brand/store)?

 

[comatose]

well if your 48x14 is about a foot high thats about 8064 cubic inches you need to cool down....you should turn over your air in the hood 3x so that comes to 25000 cubic inches of air each minute so you'll need at least 14 CFM fan. thats for power compacts, double that number for MH's or 28 CFM fan

 

[comatose]

any computer store has computer fans, you can also check radio shack.
just make sure you get the lowest dbA fans you can find, you'll thank yourself later.

 

[DCFix]

Thanks Comatose.

I found some Orion fans that more than meet that need running off 115V.

How high above the water do you recommend the MH and PCs should hang? Just in case I need to make a taller cabinet...

 

[comatose]

i wouldn't go any less than 5 inches

 

[scbadiver]

I'd recommend you check out the variable speed icecap 4" fans. They are pretty quiet at full speed but run slower unless you need it. I have 2 in a 8'x2'x1' hood with 3 250w mh and 4 110w VHO's and never have a heat problem. In the summer I only got about a 2 degree rise on very hot days.