First HID closet grow setup - All suggestions and knowledge appreciated

[nugsinspace]

Hi,

I'm about to set up my first HID closet grow and I have a bunch of questions. If you have any input then please share. Sorry I have no pictures. I'm planning to do a sketch up model of it. If I do I'll post it.

Dimensions wdh: 2ft 6in x 1ft 9in x 6ft 4in or 765mm x 545mm x 1940 mm
Light: 1 x 250w magnetic ballast with MH and HPS for veg and bloom.
Ventilation: Air cooled sealed reflector, 2 x 280 cfm inline fans. One for reflector and one as exhaust. Both have fan controllers. No intake fan (as of yet). One 5in circulation fan.
Miscellaneous: 1 x 250 cfm coal filter, mylar covered walls, automatic fire extinguisher that activates at 174f or 79c.

Setup: My initial plan was to seal off about 1 foot at the top of the closet and store all the electronics there as in fans and ballast. That's also where the extinguisher will be located. Ventilation tubes will be running down to the grow area and out the back of the closet where there is about 4in of space before the wall. Ambient temperature outside the closet is anything between 68f to 82f or 20c to 28c.

Questions:

1. How close to any other electronics can a magnetic ballast be without causing problems?
2. How hot will a 250w magnetic ballast get? Do you need it to be in a ventilated space or can it be enclosed?
3. How much cfm do you need through an air cooled sealed reflector to cool a 250w bulb?

I could have the ballast outside of the closet. It just means I would have to do more complicated wiring for the timer et cetera.

Many thanks

 

[Croatsan]

Hi nugsinspace

Keep your ballast outside of the closet if you can. They can get quite hot.

I'm venting my dual cooltube 2x400W with a dedicated 107m3/h (63cfm) inline fan (pushing air, not pulling) and it's working well. But for the next run I'm gonna go with, at least, 180m3/h (106cfm).

Regards.

 

[nugsinspace]

Many thanks Croatsan,

I've found a way to have the ballast outside the closet and still control the electricity from within the closet. Actually my inline fans where 280 m3/h and not cfm.

It should mean I could lower the rpm and noise of my fan if I remove the exit plate on my reflector. It has a bunch of holes in i but absolutely kills the airflow.

Why push and not pull? Is it because of smell or?

/Nugsinspace

 

[Croatsan]

Why push and not pull? Is it because of smell or?

No, not because of the smell. I have a dedicated air line for the cool tube. It doesn't interact with the air in the grow tent. It's only blowing the air through the cool tube.

It's because of the heat. Two 400W HPS can get real hot and I don't want the hot air passing through the inline fan, which would happen if the fan was pulling air.

 

[nugsinspace]

Of course. Don't know why I didn't think of that. I just heard that pulling is more effective than pushing. Since my is one 250 MH or HPS perhaps I could use pull. Also Croatsan. If you have the time to look at my reflector. Just want a second opinion. I think I will have to remove the "exit plate" and "entry plate" where the ventilation holes are. They have perforated edges along the 125 mm tubing so I guess you're supposed to be able to do it anyways. Sure you loose some light but better air flow.

Many thanks.

 

[Major PITA]

Pulling air is more efficient than pushing it. That's how I do it with my cool tube. The difference in air temp is not enough to matter. The air passes through the tube so quickly, it doesn't heat up more than a couple degrees (75F going in / 78F coming out for a 600W bulb).

 

[Croatsan]

Pulling air is more efficient than pushing it.

Yeah, I keep hearing that everywhere I turn and I've read all the arguments for and against. I had it pulling at first, but after couple of hours the fan started making funny noises. I thought it was because of the heat. And I was right. Now it's pushing and it's quiet.

I still wonder, if pulling is more efficient than pushing, why don't we cool off our hot beverages by sucking the air in instead of blowing it

 

[Croatsan]

I think I will have to remove the "exit plate" and "entry plate" where the ventilation holes are. They have perforated edges along the 125 mm tubing so I guess you're supposed to be able to do it anyways. Sure you loose some light but better air flow.

I would leave everything in place as is. These things are constructed to work out of the box. For better airflow I'd always recommend a stronger fan.