How can I lower my temps in my closet?

[gazcat]

My temps right now have been getting up to about 85 during the day, (its real hot here), and I don't know what to do...

I have an intake that is 120cfm and an exhaust that is 250cfm.

Lights are about 200w of CFLs. Temps inside the room drawing air are around 75 I would guess. Pretty chilly in here, AC is on all day.

Should I increase intake? Or exhaust?

 

[chubbynugs]

Umm i would wanna say if your temps are 75 you are a lucky man. Try growing in the low hundreds. If i am reading what you said wrong and your grow room is eighty five then i would say increase the cold intake. 85 is still not too dangerous. If you can increase co2 intake it shouldnt really matter what the heat is. Are your plants showing heat stress?

 

[gazcat]

No, not at all, not stress shown. And the 75 is from a window AC pumping into the sealed room with the closet. Outside the temps are well into the 100s at times.

Should I upgrade to a 250cfm intake and a 500cfm exhaust?

 

[FreezerBoy]

I'm cooling a 250 CMH with a 76 CFM axial fan. I can't imagine why you'd need a 500 CFM exhaust. Are you exhausting into the closet or into the room?

 

[george j warner]

you can get a air cooler , upgarde the fans to a higher diameter(and have them on more) and/or get co2 injection so the temps are acceptable ...

linning the growroom with ADF mylar(Anti Thermal Detection Film) will also help as it will protect the heat outside of getting in other than the fans ... ADF is normally used to stop the thermal imprint from helicopters (ie. red heat spike box at the top of your house)

but if your outside is hotter than the growroom the same principle will still apply. then running air con or air coolers in the grow space will have more effect

 

[ARTofMAKINGfire]

you can get a air cooler , upgarde the fans to a higher diameter(and have them on more) and/or get co2 injection so the temps are acceptable ...

linning the growroom with ADF mylar(Anti Thermal Detection Film) will also help as it will protect the heat outside of getting in other than the fans ... ADF is normally used to stop the thermal imprint from helicopters (ie. red heat spike box at the top of your house)

but if your outside is hotter than the growroom the same principle will still apply. then running air con or air coolers in the grow space will have more effect

I believe that he's saying he's ambient temperature in the room where the cabinet is, is 75F. And inside is cab is 85F.

So why would he go spend all that money to put up ADF? (whose effectiveness is questionable by some)

Infrared can only read SURFACE TEMPERATURES. So with 75F ambient air in his room, it looks like a normal air conditioned room. To anyone that is probably not looking.

This is a cabinet grow. And if he has followed protocol. ie. Tell no one. No light/odor leaks. Keep mouth shut. etc...

There is NO REASON for a chopper above. Of course I don't know the area, but no, not a chopper scanning low, and even so, it's a cabinet grow, and the temps won't show. Yes that flowed, it wasn't supposed to though...

And also how do you suggest he add C02 in this application? Yes, you are correct the addition of C02 would make those temps acceptable. With the air changing so often in the box, is this really a reasonable option?

This just stood out to me. Not trying to bust chops.

But this guy is obviously just starting out and could VERY well attempt to follow this advice. Resulting in a loss of funds.

gazcat - IMHO, you should exhaust that cabinet only, sealing it up well, and allowing negative pressure to build up. Basically air will flow ideally from the bottom of your cab through intake holes you make, then at the top exhaust with one or both of those fans. (if the bigger alone doesn't fix things) And with 75F going in and cooling CFL's you should be good. Possibly lower the outside the box ambient temp to 74, 73, 72, see what works perfect and you can probably dial you desired temp in.

You should think about getting a bigger light.

But wait. How big is your cabinet? Also, what's the diameter of the fans you have? You want to triple the diameter of your intakes...

Pictures would also help more. The more information you give us, the more we can tell you.

Good luck.

 

[ARTofMAKINGfire]

Basically, that's the plan. Keeping your mouth shut the whole time...

 

[gazcat]

Right now I have for intake is 2 2" pvc pipes with 60 CFM computer fans attached to them for a total of 120 CFM on the intake. My exhaust is a 6" can fan at 250CFM...

Another problem though with big holes is more exposed light from the closet. So I would like to keep intake (from inside my room to the closet) as big as 6" MAX. Just so theres not a bunch of light leaks.

The closet is a good size. 4.5x4.5 with 8' ceilings. I would like to get a 600 watt right now but I feel if I can't keep my temps down with CFLs then I gotta wait till it gets colder around here in fall (flower time for me).

What do you think?

 

[FreezerBoy]

Now we're getting somewhere. You're choking the cab. A 6" hole has an area of 113 sq inches. This means you want 226 sq inches of intake. You have 25. You need sixteen more 2" holes. Or two 6" holes.

 

[devilgoob]

make one of those light traps. with cardboard.

try just taking out those intake fans. I have no idea, but since they are lower-flowing and the 250CFM fan is pulling on them because theyre not delivering the pressure, then itll slow the whole loop down. try it though, im pretty sure it works in computers, so in here CFM means the same.

try to make your exhaust at the top, hot air rises.

 

[gazcat]

Ok, saying if I only could use one 6" intake. What would you do? thats really all the holes I want to cut...

 

[FreezerBoy]

Throw out half your CFLs.

 

[ARTofMAKINGfire]

Throw out half your CFLs.

Exactly.

You shouldn't be so fast to decide you only want to cut certain amounts of intake because of light leaking out. That is another issue in itself, and needs to be dealt with. It's part of growing. That attitude won't get you far...

 

[Kalifornia]

If it's not too silly of a suggestion,. I've seen some nice lights with cooling around the light bulb housing itself,.
or- doubling your exhaust and drawing in as much cool air at the lowest point possible - would be my suggestion,.

 

[alamony2005]

You have a pipe connecting the top of your reflector to the top of the cab? I cant see one... but that would help a large ammount... specifically if you put a fan to pull the heat out...

 

[FreezerBoy]

doubling your exhaust...

... won't do any good. You can't exhaust more than you intake. Too much heat with too little intake is the problem. Increase intake or decrease heat.

 

[devilgoob]

f it's not too silly of a suggestion,. I've seen some nice lights with cooling around the light bulb housing itself,

yup, do this, make cool tube thingies. take the heat right off the lights and dont give it time to circulate. therefore you dont have to empty the volume of the whole grow area, just the area around the bulbs.

 

[FreezerBoy]

Cool tubes are for single/double lamps, not multiple CFLs. He could seal off the light chamber with glass but, that would require an extra fan and a whole new set of holes.

 

[cdd]

should'nt the intake fan be double the size/power of the exhaust? or is is the other way around

 

[FreezerBoy]

In a passive system, intake area is two to three times larger than exhaust area with fan on the exhaust and nothing on the intakes other than filter material for bug control.

Check out the formulas that NanoScroger posted in the "passive intake, math of many small holes?" thread

i think 3x the exhaust port is generally accepted for passive intake...
passive intake calculator