Got a heat problem

I have my closet completely set up and I am having some problems with heat. See attached photos.

Tent - Homebox GrowLab 2'7" x 4'11" x 6'7"

Light - 600W hps/mh light air cooled, digital dimmable ballast

Carbon Filter: 170 cfm

Ventilation - 170 cfm high velocity inline fan, 4" ducting. Air flows through carbon filter -> cool tube -> inline fan -> out, passive intake ventilation, 2 circulating fans, inline fan is plugged into temp/humidity controller.

I turned the system on to test and I can't get the temperature below 80 degrees. My thoughts are that I either need a more powerful fan, a less powerful light, add CO2 or add some kind of cooling to the tent. Im not adding cooling to the tent, so thats out. This is my first grow, so I am not sure I want to invest in a CO2 system, so that is also out. So which of the other two options do you recommend, replace the light, the fan or both?

I can turn the ballast down to 400W, would that work? I think I would need to buy 400W bulbs (right?) I am hoping I can make the set up work with the 600W light and not having to buy a different fan or light.

80 is fine, and you don't need another bulb

209 Cali closet grower said:

80 is fine, and you don't need another bulb

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It is only 80 if the fan is running non stop while the lights are on...is that normal? Will I be able to maintain any kind of humidity with all the air being sucked out constantly?

well whats your humidity at?

where you dumping you exhaust air?

209 Cali closet grower said:

well whats your humidity at?

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I don't know, I haven't bought a themometer that does humidity yet, but I don't have any plants either, so there is nothing in there to contribute to humidity yet.

Looks like you can make your ducting a bit more efficient, by reducing the number and severity of the bends. For example, you have 2 180 degree bends between your filter and cool tube.

If you reduce the amount of bends, and maybe shorten the ducting where possible so it is more stretched out, your will move more air.

If you turn the ballast down to 400w you still use the 600w bulb. If you put a 400 in there the starter will kill it when it turns on.

What do you have for air intake? Need twice the area of the fan for passive intake as a minimum.

My thoughts is a 170 cfm fan doesn't turn over the air quick enough in there. Though if it's only 80 I wouldn't worry about it as long as it doesn't get much hotter come summer

Nocturn3 said:

Looks like you can make your ducting a bit more efficient, by reducing the number and severity of the bends. For example, you have 2 180 degree bends between your filter and cool tube.

If you reduce the amount of bends, and maybe shorten the ducting where possible so it is more stretched out, your will move more air.

Click to expand...

The reason I did that was to accomidate being able to move the light up and down, not efficient, but I didn't think it was really a big deal.

Voidling said:

If you turn the ballast down to 400w you still use the 600w bulb. If you put a 400 in there the starter will kill it when it turns on.

What do you have for air intake? Need twice the area of the fan for passive intake as a minimum.

My thoughts is a 170 cfm fan doesn't turn over the air quick enough in there. Though if it's only 80 I wouldn't worry about it as long as it doesn't get much hotter come summer

Click to expand...

Right now the only air intake is from here View attachment 2078213 I didn't open the other two vents in the tent, but they are pressed up agaisnt the closet wall.

Every bend reduces your flow rate, and with a 170 cfm fan, there isn't much pressure left to play with after you add a filter.

You could flip your filter vertically , so that the duct attaches at the bottom. That will cut out one 180 degree bend. Also, you can definitely trim the ducting a bit, since the light will never have to reach as far as the floor.

It's generally a good idea to keep duct lengths as short as possible, so even if you don't shorten the ducting, you should gather it together and tie it up, rather than letting it just sag. This way, you could reduce the outlet side of the tube to a single 90 degree bend, rather than the loop that it is at the moment.

Thanks Nocturn.

So is it ok to have the fan running all the time?

Yes, most have the ventilation on all the time ur lights are on, unless your ambients are really low you really have to have them running all the time.

Yes, 24/7 venting is needed, otherwise the smell will not be filtered. Plus it's good for the plants, as humidity builds up during lights off, which can lead to all sorts of problems.

Allright, great. Can't wait to get started. Thanks for the help.

No problem. Good luck with the grow.

i only turn my inline fan on with my lights, they are both hooked up to the same timer.