Help me cool my closet - It is 85 degrees!

[Major PITA]

IMO you need a bigger fan - end of story.
Its location could be better, but more air extraction should be your primary goal.
Also, what is the temperature of the air you are pulling in? If you pull heated air into the cabinet, it takes a lot of it to do much cooling. If your room is heated to 75 F, you need a lot more air to pull down the temperature than if you were pulling in outside air at 50 F.

 

[Mello136]

Also, the exhaust should be a tad higher. All your heat is going to the top of your cab and being absorbed.

 

[OlderGrower]

You're typing slow again.

I have to start typing today so I can post tomorrow I am that slow

 

[OlderGrower]

IMO you need a bigger fan - end of story.
Its location could be better, but more air extraction should be your primary goal.
Also, what is the temperature of the air you are pulling in? If you pull heated air into the cabinet, it takes a lot of it to do much cooling. If your room is heated to 75 F, you need a lot more air to pull down the temperature than if you were pulling in outside air at 50 F.

Most of the time I agree with you, but this time I am not so sure. He has a total of 23.296 cubic feet of grow space being exhausted by a 60 cubic feet per minute fan. Even if you take into account that the fan may bot be capable of actually pulling 60 cfm say it only was running at 50% because it was an old used fan, that still would be more then enough air transfer to eliminate the heat. A easy to follow analogy is a beer bong. If you take a beer and try to guzzle it, the beer can only come out of the can as fast as the area of the can is replaced with air. Now open a big hole in the bottom of the can and it flows out supper fast. 7 little drilled holes is not enough of an intake to allow that fan to pull air out. Bigger fan just means while it will pull a little more air in, it will still struggle to pull enough.
That is just my 2 cents

 

[Mello136]

How is your humidity? High humidity will also increase your heat....

 

[zBRiCKz]

actually the wall on the right is quite hot, I didn't use reflective material inside the warddrobe because it was plain white.

here is a photo

I would try maybe adding a layer of Mylar or blackwhite plastic. That should eliminate heat buildup on walls. Then a fan blowing directly on your light will help a lot

 

[Spitz]

What is the ambient room temperature ? Your probably going to only get a delta temp of 10*F with any normal sized fan. If the room is already 75*, you'll just have to fight it (or buy a cool tube). Good luck!

If your plant is showing signs of heat stress, you could always ditch 90% of that energy by putting her under a single 23 W cfl while figuring out your temp issues.

 

[OlderGrower]

If your plant is showing signs of heat stress, you could always ditch 90% of that energy by putting her under a single 23 W cfl while figuring out your temp issues.

DOH, why didn't I think of that Marg? in my best Homer Simpson impersonation.

excellent temporary solution to the problem.
Splitz your my new hero

 

[Major PITA]

Most of the time I agree with you, but this time I am not so sure. He has a total of 23.296 cubic feet of grow space being exhausted by a 60 cubic feet per minute fan. Even if you take into account that the fan may bot be capable of actually pulling 60 cfm say it only was running at 50% because it was an old used fan, that still would be more then enough air transfer to eliminate the heat. A easy to follow analogy is a beer bong. If you take a beer and try to guzzle it, the beer can only come out of the can as fast as the area of the can is replaced with air. Now open a big hole in the bottom of the can and it flows out supper fast. 7 little drilled holes is not enough of an intake to allow that fan to pull air out. Bigger fan just means while it will pull a little more air in, it will still struggle to pull enough.
That is just my 2 cents

I agree, his volume is about 23 cu-ft, but I'm very skeptical he is able to exhaust 30 CFM with that fan. I am probably wrong, but the fans I've seen that are rated below 100 CFM are sort of toy fans. The reality is they do little. I'm playing with a Suncourt fan right now rated the same as his and it doesn't do much even in free air. With minimal restriction to air flow, you basically end up with an electric whirligig in your tent. Definitely, the air intake should be addressed as well as the exhaust placement.

Since I don't know his fan, I should not have made that blanket statement. There must be good quality centrifugal fans that are 60 CFM.

 

[Mello136]

Actually, let me rephrase myself. If your heat is high, low humidity would counteract it. It would be fine as long as you mist your early veg plant but when she grows you'll have to get a handle on the heat.

 

[OlderGrower]

I kind of figured thats where you were going with that. Old eyes ta know. The exhaust fan looks to me to be located on the right wall up about 3 maybe 4 inches above the top of the reflector, but it is very hard to make it out from this angle. All exhaust needs to be pulled from the highest point since heat rises. Think everyone is on agreement on that. What it boils down to is the fan really a 60CFM or is just another case of "truth in advertising" where the manufacture just picks random numbers to make themselves look good. (Not like that does not happen in every product imaginable) I am going on the assumption, and we all know what happens to me when I do, that he is using that exhaust fan because it is what he has available. Best case situation, bigger fan better intake. but if he is tapped for cash for a bit he could try propping the door to the cabinet open a little to allow more air in, not best case since ideally he wants his intake to come from the lowest point but better then nothing and see if that allows the fan to move more air. Till he gets it figured out I really liked Spitz advice of turning that light off for now and running a CFL till he gets the exhausting issue resolved.

 

[Major PITA]

I had to shake my head in disbelief when I was looking at small fans and their ratings. Many are sold as "booster fans". That means they only reach their published rated spec's when air is already moving. The Suncourt DB206 series of 6" fans are marketed as being 250 CFM. But when you read about them, they only move 160 CFM in free air. When you add a little air restriction, they drop a lot more. That 160 CFM quickly drops to 125 or less. So your 50% of the rated amount is probably a pretty good guess.

 

[OlderGrower]

I think it is more of a perspective kind of thing. All fans are hindered by the same influences, not just small ones. Number of bends in the airway, size of the intake, size of duct, age of the fan (all things wear out) it is just way more noticeable with smaller fans because 50% of a 480 cfm fan is still 240 cfm but 50% of a 60 cfm is only 30 cfm which isn't much.

As for probably a pretty good guess
You nailed that. It is just a guess, without being actually able to measure the fan or at least be there to see it in action, it is all mostly just a guess.

 

[Major PITA]

I've got no problem with restrictions lowering the CFM. My gripe is rating a 60 CFM free-air fan as being an 85 CFM fan. It's like publishing a car's top speed as 150 MPH, but only down hill.

 

[OlderGrower]

I've got no problem with restrictions lowering the CFM. My gripe is rating a 60 CFM free-air fan as being an 85 CFM fan. It's like publishing a car's top speed as 150 MPH, but only down hill.

Next thing I am guessing is you would like a little truth in advertising. Now wouldn't that be nice