Temp near 100F!

[InuYasha]

It's my first day running my air "cooled" 600W MH-Conversion lamp in my 2x4x7 tent and I'm getting temps approaching 100F (37.8 C) inside my tent:holysheep:.

I have 2 6" Inline Duct fans on the AIROFLOW reflector and 2 more for tent ventilation. Each fan claim 250 CFM Boosted, 160 CFM Free airflow. Each of the two lighting fans sit at the end of about 12' of flexable ducting.

I'm in FL and the highs are still in the upper 70's, so I'm running the AC at 76F. The bedroom temp where the tent is 86F.

How big of a problem is my temp for young seedlings? What should I do to drop the temp (more fans, bigger fans, aux. A/C, shorter ducting runs, reposistioning of the fans, etc)?

 

[pothead4life]

can you run the fans so you get fresh air form outside

 

[InuYasha]

I would draw the air from the outside, but it's FL and the outside temp is higher than what I have my A/C set at.

 

[Pothead420]

i would say you need a bigger exhaust fan. i use a dayton exhaust blower rated at 465 CFM with my 600w HPS cooltube i have those inline fans they dont pull much air at all. also if you have a basement pull cool air from it for air intake

 

[blancolighter]

Ok kinda hard to tell about your setup, but I think I kinda get it and might be able to help.

You said you have two inline fans hooked up to the light reflector via ducting. I asuume the ducting is on both sides of the light. Now this is where you went, well not wrong, but this is where change needs to happen. Remove one of the fans and tubing to the light. Have only one fan with tubing connected to the light, pulling air out of your tent. This way, you're not just pumping air past your light like you were, but with an open end on your reflector your bringing air past your light and cooling it, AS WELL AS pumping out the hot air in your tent.

Hope that makes sense. If it doesn't I can draw a picture, cause I dont explain things well.

 

[InuYasha]

Does anyone know if these types of fans are supposed to be run with ducting on both ends? I have them at the end of the duct runs with nothing attached to the other end. Maybe that's my problem?

 

[InuYasha]

Thanks blancolighter. I will trying disconnecting the light intake so that it takes air from the tent.

 

[InuYasha]

I disconected the lighting intake so that it draws warm air from inside the tent, passes this air over the bulb and exhausts to the outside room. It did not seem to have much of an impact. I'm still at about 98-99 in the grow tent.

I think I need to get a bigger fan (something like the 465CFM suggested by Pothead420).

I may also try to cut a hole in the celling to vent that warm air into the attic.

 

[daf]

try t0 hook up a vent from ur ac to the tent , thats ur best bet

 

[BUDISGUD]

try t0 hook up a vent from ur ac to the tent , thats ur best bet

ditto

let us know if it works :hubba:

 

[InuYasha]

Thanks for everyones' help.

I cut a 6" hole in the celling (apologies to the land lord) and I'm venting the heat from the light into the attic. It seems to have helped a great deal. I was stupidly blowing the 94F air into the room and I think that was a big problem. Upon blowing that air into the attic the temp in the tent dropped to 84 above the reflector and 90F in the "sun".

I would love to hook the A/C up to the tent, but I can't do too much work as it's not my house.

I think I'm going to get better ventilation to cool the light. I was looking at a Valueline 6 Inch Centrifugal Inline Fan that claims to move 435CFM.

What is the difference between a blower (such as suggested by PotHead420) and a centrifugal inline fan?

 

[ArtVandolay]

Hello from Florida! Watch out for mold in the attic, it will grow quickly and you will have a whole new set of problems. As long as you're venting into the attic, try to vent out the soffit/eaves.

Veg 18/6 and flower 12/12 during the coolest hours of the day if you're not already. I can't veg 24 at all because of the daytime temps.

 

[InuYasha]

Thanks Art Van Dolay. Are you the Art Van Dolay of Van Dolay Industries or Judge Van Dolay?

I don't have too much attic access unless I cut another hole large enough for my fat *** to squeeze through, so I really can't run the ducting further than a foot or to into the space. I've already punched too many holes in a house that is not mine.

My GF probably won't allow me to have the lights on during the cooler evening hours (she's a pain about light and fan noise when she's sleeping). I'm running them from 8am to 2am now, which sucks b/c I'm hitting the notorious 11am-4pm heat.

Even with venting into the attic, the temp in the room where the tent is was still at 82 in the middle of the day. It was 94 in then tent, under the light at seedling level.

After trying blancolighter's suggestion of letting the reflector suck air from inside the tent, I reconnected the air intake to the reflector and it dropped the room temp to 80 and the tent temp to 90. I think that the cooler air from outside the tent has more heat carrying capacity, plus it's moving at about 160CFM.

I've ordered a 435CFM centrifugal inline fan, so hopefully my girls will hang in there until that comes. If that doesn't help, I've tracked down a cheap aux. A/C unit. These babies made it from Holland, I'm not having them die in the FL heat!

I'm concerned about the mold. It's a new house, and the lighting vent system is (now) isolated from the tent ventilation, so hopefully that helps. How would I recognize a FL mold problem?

 

[ArtVandolay]

I'm Art the importer/exporter

Let's see...

- if you're having these heat problems with the relatively cool weather we're having now, you can be sure they will be twice as bad in the summer;

- I'm a 1st time microgrower, just so you know what you're dealing with ;

- I started with 400W HPS and was completely unable to cool it. I don't have access to A/C air, I'm growing in a plastic cabinet in the garage under CFLs so all I have is the coolest air of the day (18 or 12); you may find you can cool 2 of those $20 HPSs with the fans/venting you have and still be enough light?

- I know about the mold because the clothes dryer vent runs through the house ceiling and then out through a roof vent. While poking around looking in the attic (contemplating venting up there), I noticed the through-ceiling fitting was leaking air because of the green stuff growing on the 2x4s. Nothing a little duct tape couldn't fix but it was enough mold to get your attention;

- you didn't mention where your ballast is - it generates as much heat as the bulb, in my experience. Can/did you isolate it outside the grow space?

 

[InuYasha]

Thanks again Art.

I plan on moving to my own house in March / April, so I'll have access to my own A/C by the time the brutal FL summer rolls around.

I'll have to keep an eye in the attic and watch for mold around my vent. I'm going out today to get some hydroguard as a precautionary measure (a quart of prevention...).

I have the ballast outside the tent (still in the same room, about 1' away). It's a digital greenhouse ballast and so far runs cool to the touch (I knew heat would be an issue, so I went with the digital). I'm impressed with it so far (mind you, it's only been running 2 or 3 days).

I just found out my centrifugal fan gets here on Wednesday, so I just have to think cool thoughts until then.

 

[jdmnismo300]

im fearing the worst. i just installed a 4in inline duct fan to ducting to one side of my 400w hps reflector out into my attic florida resident aswell and im chekin my temps every five minutes and it keeps goin up its at 89 right now my closet is 2ft W x 2.5ft L x 8ft H

 

[daf]

u got a fan in there

 

[JBonez]

Luckily, young seedlings welcome higher temps and humidity.

but yeah, you need more air exchange bud, remember, its better to pull air out of the tent and exhaust it. You shouldnt exhaust into the attic (even tho im doing that right now, lol) but i havent gotten any mold in 4 months of venting, so yeah, but my humidity is only at 35%, im from florida and if i was still there i would run the indoor a/c as low as possible, im currently running my a/c at 68 degrees just to keep temps at 79 degrees.

 

[InuYasha]

It seems like it's been a hot winter in FL this year. The inline duct fans (like the ones pictured at the top of the thread) are nearly worthless (hence the reason they are $25). They hardly move any air. I finally went out and bought a centrifugal fan for $80 that actually moves air and my temps are decent now (mid 70's). I'd suggest getting one of these to suck out your hot air and exhaust it somewhere else (outside, another room, somewhere away from your grow space).

Here's the Valueline cent. inline fan that I am now using:

 

[_Sir Smokes Alot_]

eh y not just get a larger tent, first off that space is WAY too small for that light. Here's something that might help u out.