Reflector question

[lampost]

Hi,
I'm getting ready for my first grow. It will be in a 4'x4'x6.5'H grow tent with a 600W HPS. I'd like to get a nice sunsoaker reflector or something, but I know with this set up I'm going to need some sort of air-cooling. I notice the cool-tube reflector, but the actual reflector kinda looks crappy. There's a similar one at HTG Supply that looks to have the same ventilation holes and has a bit better of a reflector. I think that's what I'll be going with.

So, anyway, on to my question. I plan on just running one tube off of the light/reflector with a fan blowing outside the grow tent. So, it will be pulling air into the reflector and exhaust it out of the grow tent. Do you think this would be adequate cooling? I'll also have another exhaust fan in the tent that will be exhausting the tent air... there will be one passive inlet in the tent. Also, I'll probably have a small fan in the tent to circulate air. Do you think this will be adequate ventilation?

I hope it is because my tent will only have 3 x 4-inch vent holes, so I can't really dedicate 2 of them to cooling the lamp and still have adequate ventilation in the main grow chamber. Also, I'll have to find a 6-inch to 4-inch vent reducer, but I'm sure those are easy to find.

Also, I'm curious about putting a HEPA filter or some type of filter in the inlet since it's going to be in a grungy basement. Do you know where I can find those as well as the exhaust fans (4").

Any advice would be much appreciated. Thanks!

lampost Reviewed by lampost on 11-17-2009. Reflector question Hi, I'm getting ready for my first grow. It will be in a 4'x4'x6.5'H grow tent with a 600W HPS. I'd like to get a nice sunsoaker reflector or something, but I know with this set up I'm going to need some sort of air-cooling. I notice the cool-tube reflector, but the actual reflector kinda looks crappy. There's a similar one at HTG Supply that looks to have the same ventilation holes and has a bit better of a reflector. I think that's what I'll be going with. So, anyway, on to my Rating: 5

[EvilCartman]

Hi, I'm getting ready for my first grow. It will be in a 4'x4'x6.5'H grow tent with a 600W HPS.

So, anyway, on to my question. I plan on just running one tube off of the light/reflector with a fan blowing outside the grow tent. So, it will be pulling air into the reflector and exhaust it out of the grow tent. Do you think this would be adequate cooling?

Yep.

Balancing 2 fans in a small, tight space like a tent can get tricky, a speed controller is handy. I've seen cases where a strong fan exhausting a tent over-powered a duct booster cooling the lamp. The air was pulled backward through the puny ductbooster, dumping the lamps heat inside! Make sure your intake is adequate for the flow, if using two fans!

I'll also have another exhaust fan in the tent that will be exhausting the tent air... there will be one passive inlet in the tent.

Sounds good. :thumbsup:

Also, I'll probably have a small fan in the tent to circulate air.

That's not a probably thing, you *will* have a circulation fan.

Do you think this will be adequate ventilation?

Yep, plenty. Just use decent fans, adequate intake area, and you're good. :thumbsup:

Also, I'm curious about putting a HEPA filter or some type of filter in the inlet since it's going to be in a grungy basement.

Which tent are you using? Just wondering, most have a decent screen covering the intakes. A furnace filter, covering the port, will work well for intake filtering.

HTH

[lampost]

^ Hey, man, really appreciate the advice!!

I was looking at this BudBox tent it's 4' x 4' x 6'6". I wish it had 4 inlets, but it's only got 3. What would you suggest for venting? Obviously, one vent will be used to pull air over the light through the hood and exhaust. So, that leaves 2 openings. I don't really want to mess with controllers and stuff for 2 fans, so I'm tempted to just have 2 inputs and then try to get the strongest fan possible to pull all the exhaust through the light. Do you think that would be good? I mean the tent is only 104 cubic feet, so if I can get anything over 105 CFM, I should be exchanging all the air in the grow tent in less than a minute!! Wouldn't that be plenty?
What kind of flow capacities can you find in these 4-inch duct fans?? If I could get like 200 CFM that would be awesome...

Please, if anyone has feedback good/bad, let me know. I'm just getting setup and obviously this is a very important aspect.

[EvilCartman]

What you mention above is what I do. One fan pulling through a carbon filter,through lamp then out.

The tent you reference appears to have 3 passive intakes down low, in addition to the 3 pucker-string ports up high. I don't see any dedicated port for cabling, though. If that's the case, I'm guessing that one of the pucker-string ports needs to be used for that purpose. I'm not familiar with that tent, so I'm just going by some pics from the 'net.

I haven't experienced any ventilation/temperature issues in my (smaller) tent using one fan to exhaust the space/lamp. In my case, I only use one of three (4") ports, the others are closed. The tent I'm using also has 3 bottom, passive intakes. (of which I am currently using 1)

I hesitate to assure you that the 4" exhaust fan would be sufficient, the ones I've seen run right about 200 cfm. Being in the basement helps, the lower your ambient temp, the less air you'll need to move.

FWIW, I run a 6" 400cfm fan throttled down to about 60% to control the temp in my (50cf) tent. My setup is in an area with temps about 68-70F so I need to move a good volume of air to keep temps in the area of 75F.

Before buying the fan, I would toss a thermometer in the basement location you are planning to use, to get an idea of the ambient temp. That will help in determining what you can/can't get away with, regarding your fan selection.

Hope this is of some help.

[lampost]

^Thanks again! Looks like I'll explore more options. I though 1.5 complete air changes per minute would be plenty to provide fresh air and keep temps cool.

Huh, so you have a 6-inch fan exhausting through a 4-inch port? So you have a reducer and such?

I didn't realize the rectangular areas at the bottom were ports. Can you typically leave those open without light intruding? How do they pull that off? If that's the case then I'm set. I'll just get a couple 4-inchers and leave one of the bottom intakes open.

Well, I'm finally going to make it to the hydro store Saturday so that should answer a lot of my remaining questions. One thing though... where/how do you attach the fans? I'm not experienced with HVAC stuff, so I'm just curious how you mount them. Edge of reflector? Edge of grow tent? Middle of duct?

Peace, LP

[EvilCartman]

Huh, so you have a 6-inch fan exhausting through a 4-inch port? So you have a reducer and such?

Yes. Using a plastic pipe reducer, fits nicely to the fan itself.

I didn't realize the rectangular areas at the bottom were ports. Can you typically leave those open without light intruding? How do they pull that off?

No such luck. Mine are just a simple screen with the velcro around to seal the cover. You'll need to fabricate some sort of shield/baffle to exclude light, if you'll be doing this in a well-lit room.

Well, I'm finally going to make it to the hydro store Saturday so that should answer a lot of my remaining questions. One thing though... where/how do you attach the fans? I'm not experienced with HVAC stuff, so I'm just curious how you mount them. Edge of reflector? Edge of grow tent? Middle of duct?

Edge of reflector works well.
I've got mine hung in the back corner, right @ the exhaust port. everything's hanging from the cross-members in the tent. (pic)

The tent came with a couple velcro straps. I didn't know what they were for, at the time, but I reckon they're for hangin' stuff. :i feel stupid:

The hydro store will probably have a couple different set ups to look at when you go. I hate going to the hydro shop. I always end up spending 10X what I'm planning.

Good luck.