Vertical Heat

[Trewarin]

Hi Guys,

I've got another thread up with my grow but I thought I'd chuck up a throw-away thread to see if anyone can help out with a temperature problem.

I have a 2ftx3ft "fridge" that is 5ft tall.

I'm currently running a ~400cfm AXIAL fan with fairly poor ability for negative pressure and a 600w HPS from a magnetic ballast (cheap shit!)

The ambient temps are currently sitting around 15-20C at night when I run it and the cabinet gets up to 27-32 with lights on.

As I see it there are a few options that COULD lower temps

1) buy another $40 axial fan and either mount it on-top of the cabinet with the other one, or place it in the base to force air into the cabinet instead. (two out, or one in one out)

2) spend ~$120-150 on a 6inch 440cfm centrifugal fan, possible using the old axial as intake... or make it passive.

3) DIY/BUY a cool-tube ~$70 and install muffin fans for air intake to the cabinet, with the axial fan drawing the cool-tube

4) Buy a 400w dimmable digi ballast and bulb for ~$180
Apparently someone elsewhere on the net ran a 600w magnetic @ 32C
600w digital did...

@ 50% 22c
@ 75% =450w 24c
@ 100% 600watt 26c
@ super lum 6 = 28c

Has anyone noticed similar things with digital ballasts? if that IS true it seems like the best route... I hope someone can chip in.

Thanks in advance to anyone who stops to chat here.

 

[Bennyweed1]

go on ebay and get a centrifugal fan. I just bought a 530CFM 6" for $89.99.

 

[Trewarin]

go on ebay and get a centrifugal fan. I just bought a 530CFM 6" for $89.99.

So you think just a fan can make the difference in the box temperature wise?

 

[Grizz]

plug in the fridge, burrrr

 

[Trewarin]

plug in the fridge, burrrr

haha, I say "fridge" because what it really is is hard to explain.




It's an old clothes dryer... fan mounted in the bottom with heating coils and a space for air to exit at the top back.

It's been modified to my specs... but this thing is made for growing, it's made of aluminium for one!
I do have a mini-fridge for popping seeds/cloning though.

 

[Grizz]

i take it your not running anykind of cooling, ac , small swamp cooler ??? i would force feed some cool air into that bottom intake and a good 6in or 8in exaust fan on top.

 

[Trewarin]

i take it your not running anykind of cooling, ac , small swamp cooler ??? i would force feed some cool air into that bottom intake and a good 6in or 8in exaust fan on top.

Hey!

Yeah, no cooling... hopefully I can get it cool WITHOUT aircon, as it's still winter/spring where I am.
I intend on chucking aircon into the room for summer, as it's my workshop but the ambient temps are really low already at the mo'

 

[Trewarin]

The left is the current set-up... some sized intake as exhaust.
Should I widen that up to twice it's current size, or go the route I've detailed on the left?

Sorry about the MS Paint... I'll get back into sketchup soon.

something to show scale:

 

[Trewarin]

I'll learn soon how to make my threads more interesting for you guys... lots of people look, not many post

*sadface*

 

[Hydroformer]

Re: Op

It sounds like your not getting enough air movement through your tent, do the sides of your tent bow in under negative pressure? If so you need larger passive air inlets to equal out the pressure.
Once you get enough air flowing up and out of your tent and away from your grow/lung room you'll find you don't need a cool tube.


Re: Dimmable ballasts, Under powering a bulb lessens it's life span, It's recommended to have a bulb for each wattage output

 

[Bush Dr]

You need positive intake pressure and for a 600 W a 300m3/hr extraction set up. you're looking for at least 2 air changes per minute

Put the extraction vent directly above the lamp and put a fan under the lamp .... cool tubes are more trouble than they're worth IMHO