How much ventilation do I need for a 1000W grow tent?

[chronicinjury]

How much ventilation (CFM) is necessary for a 1000W grow tent (4x4)?

I already have a 660 CFM fan but it is just too damn loud.

Can I get by OK with 142 CFM?

Seems that 200-300 would be ideal, but the can fans jump from 170ish straight up to 400.

 

[FreezerBoy]

Ventilation 101

 

[Seismic]

Hi chronic, I also have a 4x4 tent(Dr120) with a 1000w hps, and in order to keep it at 79.5F, which is 4 degrees above ambient room temperature, I am using a 6" elicent(309cfm) to cool the light through a cooltube. I also use a 4" vortex(175cfm) to scrub the tent's air by pulling through the carbon scrubber.

Using a duct muffler with the elicents intake makes the noise pretty manageable. I assume that using insulated ducting, and building sound proof boxes to enclose your fans in would further reduce noise.

Best of luck

 

[Mr. Bongjangles]

I run a can33 in my 5x5 tent, with a 6'' vortex at about half speed, little less. Prolly pulling 200cfm through the scrubber.

I also use a 6'' vortex on the 1000w light, likely overkill but that's how I roll.

This setup has also been used in a 4x4 tent.

In any event, I dunno if the 200cfm on the scrubber would be enough without air cooling the light as well.

Perhaps you could use the 660 cfm fan on a speed controller to a scrubber like a can 50, which can support up to 420 cfm in non-recirculating use. Drop the fan to like half speed, (more if you need it since the scrubber will have a little headroom,) and you could possibly be in business.

 

[chronicinjury]

Ventilation 101

sorry i can't tell what CFM that point on the graph corresponds to?

 

[FreezerBoy]

sorry i can't tell what CFM that point on the graph corresponds to?

What point are you talking about? You haven't picked one. The 1K line is clearly marked, pick a point, any point. From that point: look left to read CFM, look down to see temp difference.

142 CFM will keep you within 25º of room temp. 660 cfm within 5º.

 

[mliokv48]

So is it reasonable to expect 5 degree difference with 750 de hps and 2 ac lep with 950 cfm exhaust?

 

[FromHolland]

I would take a 1500m3 (=882cfm) fan. This might sound stupid but it really isnt, on hot days it will be easier to maintain a good climate in your growroom and the fan doesn't need to run on 100% so there is less noise.

I'm not a fan on inline fans (sounds like a joke LOL) it's better to use a snail fan in a wooden sound isolated box/softbox (or however they call them). I find them to be much powerfull compared to inline fans. You can build it even yourself.