Mill's pride/wardrobe growers - i'm in desperate need of help regarding temp issues

[sophanox]

Hey guys,

I have a 3x1.75x6 compartment (wxdxh (feet)) of a two compartment wardrobe that I have been trying very unsuccessfully to convert into a growdrobe, mill's pride style. (the other compartment is just used for storage). I have spent a lot of time and a lot of money trying to get this setup working, involving upgrading fans, switching from an air cooled hood to a cooltube, moving the whole wardrobe do a different part of the flat (thought lack of air circulation in a small room might have been why), but still my temps are up in the 90's - 100s+.

I have a 400w hps in a 6inch cooltube, which has air sucked over it by a 495 cfm inline fan. For passive intake i had 3 4inch holes at the bottom of the wardrobe. Thinking that these might not be large enough I also added 2 5inch holes a bit above them.

To add insult to injury, I also installed a 275cfm inline fan at the top, purely to help remove the hot air. This has had little to no effect =S.

I bought the fans off the same supplier from ebay, so naturally I presumed they might be cheap replicas. However, they do seem to move a lot of air, and the company seems legit - see here: http://cgi.ebay.co.uk/RVK-ALTERNATI...s_JN?hash=item5acf838253&_trksid=p3286.c0.m14

I'm in a cool country and ambient air temps are in the low 70s high 60s.

Below are pictures to help, please excuse the light leaks and messy state, i have just been trying to get this sorted before perfecting the setup any further.










These temp readings are taken on the top of the dwc rez, where the plants would be. Please also bear in mind the air pump is off so in reality the temp will be even higher.

If you need anymore info/pics please let me know - any and all help is greatly appreciated.

Thanks

 

[fatigues]

I'm working on my own implementation of this ventilation issue right now, albeit with a larger diameter cool tube (8").

This should not be a problem to fix, especially as you have already added the second exhaust fan. You just need to change up your ventilation a bit to make those two fans work better to cool your cab.

Now that you have two fans, your fans should be set up as follows:

1 - COOL Tube Fan: outside>intake vent>duct>cooltube>duct>FAN>exhaust vent>outside

This will require you to add a duct to the other side of your cool tube. If you don't have the room to orient the tube side to side in your cab, you'll need to position the cool tube / grow light corner-to-corner over your grow. Looks to me like you have the room to make it fit.

Having a sealed cooltube which draws in air from outside to cool it should fix your problem ... for at least 8 to 9 months of the year. If you have sweltering heat in the summer, you will probably want to draw cooler air from inside the home during those months to cool your cool tube and then vent that hotter air outside.

2 - Scrubber Fan: Carbon scrubber> FAN>duct>exhaust vent>outside

This setup should drastically reduce your air temps in your cab. Moreover, as the air temperature decreases outside, your cooltube temperatures will plummet, permitting you to lower your lights even closer to your plants.

The cooler it gets outside, the cooler your cool tube will be.

Please be sure to set up a filter directly behind your intake vent for the cool tube fan. You don't want to be drawing in bugs, dirt or snow directly over your grow light!

Your passive intakes should be twice as large in volume as your exhaust on the fan that should be hooked up to the scrubber. Not sure what you have right now, but try this new configuration first before you decide to open up more intake holes or block off existing ones. With 3 4" holes and 2 5" holes, you should have plenty of intake for your scrubber fan. If anything, you might be closing one of those passive intakes. But...try what you got first.

You can also experiment with switching to see which of your fans you want cooling your cooltube once you have it drawing air from outside to cool it. May well be that you will want your stronger fan on your scrubber and not need it on your cooltube.

Lastly - can you take a pic and show us how you have mounted your mogul socket in your cool tube? Just want to make sure you have adequate air flow in your cooltube duct... because 110 degrees in your cab is damned hot given that your tube is hooked up to a 475CFM vent fan right now.

Q: do you have fan speed controllers hooked up to either of your vent fans?

 

[fatigues]

I have a 400w hps in a 6inch cooltube, which has air sucked over it by a 495 cfm inline fan.

No. You don't. The strength on that fan is not expressed in cubic feet per minute, it is expressed in cubic meters per hour. That is a fan of significantly less power.

In CFM, it's a lot less than that. It's actually 285cfm or so, at max draw with zero static pressure resistance. Assuming the seller is not lying about it's performance - and I am beginning to think that they are.

Assuming you made the same error on the other fan you purchased, a 275m^3/h fan is, when expressed in CFM:

(275x35.31) / 60 = 160 cfm, again, assuming zero static pressure resistance. 160 CFM is not very powerful at all (though if it actually works at that speed, you should still be able to cool your cab to about 7 degrees above ambient using a 400w HID)

That said, the 285CFM fan should be enough to cool your cab to about 5 degrees above ambient room temp when running at max (again - assuming zero static pressure - and with a mogul base in the way - it's definitely NOT zero static pressure).

The fact that your fan is barely working at all makes me wonder whether it is working at even close to the advertised air flow.

Something wrong here... Still, hopefully, after using outside air to cool your tube you should be able to get this thing down to sane temps. If you cannot, it's time to get a S&P or Vortex fan and stop going for the cheap hardware.

 

[sophanox]

Fatigue man those are two great posts, thanks so much mate.

I must have misread the product information for the fan...for both of them - what an idiot I am lol.

In any case I put the cooltube in a closed ventilation circuit and used the smaller fan to extract grow room air and that has helped dramatically.It also appears I have been misinterpreting the readouts off my thermometers, as they were placed directly beneath the light, thus absorbing radiant heat. When I placed a thermometer in the shade, the difference was considerable.

Temps are now at about 80F (with the thermometer probe in the shade) which is good good news! The only problem now is both the fans running together are pretty noisy. I think I may just buy the real deal this time (what I should have done in the first place tbh) and invest in a 400cfm ruck fan which hopefully will be powerful enough to extract from the grow room and cool the light, whilst being relatively quiet helped by acoustic ducting and a silencer.

I'm not using a fan speed controller atm, though I may get a temperature controlled one.

Here is the mogul socket in the cooltube, in case that is also having an effect



Thanks again mate you've been a great help!

 

[fatigues]

Yeah those fans will be loud. On the plus side, if they worked as well as a Vortex, it would sound like a Harrier Jump Jet in your cab - so - hey it could be worse If you hook those fans up to two fan speed controllers, you cna dial down the speed/noise from max to the happy point where you can live with the cooling/resultant noise.

There really are no quiet fans out there though. The two that come closest to quiet are the Panasoni Whisper Fan and the S&P Mixed vent line. (I've gone with S&P as they are easier to hook up to a scrubber - and cheaper, too.)

If you want something more quiet - look for a S&P mixed vent fan. You can get them at Hvacquick.com here - who evidently will ship to the UK. There may be other sources closer to where you are that you might prefer.

As for the temps - 80f? Awesome! You're on the money there.

I assume, given that you are living in a flat that you are going to soon care a great deal about being able to scrub your cab exhaust. Please be sure to get your scrubber hooked up now to your cab exhaust fan and test it with a few incense sticks. If you smell anything out of the exhaust - make adjustments to your cab and ducting (might need to block off an intake or two) and check for any air holes around your duct work. You'll have to order a new scrubber or new fan (or both) if the adjustments don't fix it.

You don't want to be in a position where your grow is skunking up the place while you are waiting for a delivery of a new fan / scrubber. That would be most definitely not cool. Best to deal with it asap while you got the time - as soon enough - you won't.