Experimenting with MISTING cooling...and defying death...(born2killspam, dont look!)

[UptheDownstair]

Aloha,

I posted a thread earlier in the week about the problems I was having with my skyrocketing So Cal temperatures and am happy to say that I have now reached a safe and steady level...both temp and humidity. I would like to explain how and perhaps help another grower cool his or her small cabinet.

Sorry, its a bit of a read.

!!!WARNING!!! First, this is HIGHLY dangerous and I am only doing this because I have no regard or respect for the dangers of electricity. I laugh at the face of death and if I electrocuted myself from this dangerous experiment, at least I would go knowing I was doing it for something I love...growing my favorite herb.

Seriously, Im not putting down born for his legitimate, yet hostile concern in Doobieus' thread. What Im doing is seriously potentially unsafe (as is basically EVERYTHING related to growing weed indoors) UNLESS you have common sense and are careful.

So, if you decide to attempt this method of cooling down your grow room, have common sense and be careful, thats all Im saying.

So now that Ive said that, there's no reason to mention that what Im doing is potentially unsafe and can kill me...yada yada.

What I have going is 5 misting nozzles connected with 1/4" PE tubing and T fittings to whats called a diaphragm pump used in RVs for pumping water to the faucets and toilet ect. It's basically a high-pressure DC supplied water pump. You can get them on eBay for around 40 bucks shipped. If anyones interested I can tell you more about the one I have so you can find one for yourself.

Anyway, this pump is hooked up to a 12VDC transformer to power it. Here's the key to the temperature control...

In between the -12V power supply cord and the -12V pump cord is a 120VAC DPDT Relay. This relay turns the misting pump on and off only when the temp rises above the point set on the thermostat I have in place.

See, normally a thermostat is meant to turn on a HEATING device when the temperature DROPS below the desired level. Like in a reptile cage, when the temp on your lizzards rock drops below 90F, the thermostat turns on a heat lamp untill it's nice and warm again.

But for us MJ growers, we are dealing with wanting to COOL temps that are RISING, therefore we have to reverse the process of the thermostat.

That's what the relay is for.

A thermostat has a temperature control, a sensor, and a set of outlets to connect whatever heating devices you want to use. When the temp drops, the thermostat switches on and applies power to the outlets and to the heating devices.

So for us, instead of connecting heating devices, we connect a relay.

This relay has connections for a COIL (the electromagnet that throws the switch), COM (the common connection; for the power supply line of your cooling device), NO (Normally Open; we wont use that one) and NC (Normally Closed; connect the line from your cooling device, with its polarity corresponding to the polarity of the power line we connected to the COM connection i.e. negative power to negative line on the pump).

Just to be as safe as possible, we'll use the negative line. Therefore, we would have both COIL connections of the relay connected to leads from an outlet on the thermostat. We would have the Negative lead from the 12VDC power supply connected to the COM connection on the relay. And finally we would have the Negative lead from the misting pump connected to the NC connection on the relay.

Now we hook up the misting nozzles and water reservoir. I used 5 nozzles for my setup, which seems just about right. I have the pump drawing purified Reverse Osmosis water from a 5 gallon water jug (filtered or distilled water is a MUST here because misting nozzles get clogged quickly and easily with hard, unfiltered water).

When arranging the nozzles I tried to point them away from the plants so the leaves wouldnt be getting soaked every time.

Some of the water gets sprayed on the 120VAC leads connecting the CFL sockets. This is where there could be a safety issue I suppose. Oh well, it works amazingly well so Ill risk it I guess. I could also adjust the nozzeles to avoid hitting the sockets.

For now, this is the point of this thread:

I have brought my temp/humidity levels from 95F/28% to 79F/75%-85F/50%. The misting is automatic and the pump runs for about 20 seconds at a time, about 1-3 times an hour depending on the ambient temperature of the house.

A couple importiant points...

1) the thermostat sensor should be placed directly in the path of one of the misting nozzles. This will ensure the sensor is cooled quickly and the pump turns off as soon as possible (only a little mist is needed to lower the temp and raise the humidty)

2) air flow is critical! Air flow is what evaporates the mist and cools the cabinet. Also, if you dont have enough air to dissipate the high humidty and circulate stale, moist air, the plants will become weak to mold and fungus. in my cabinet, everything is DRY again in a matter of minutes after a misting.

3) dont direct the misting nozzles onto your lights or they could explode from rapid cooling (opposite of pouring boiling water into a chilled glass mug)

Here are a few pics. Let me know if you want more info or pics. Good luck and stay cool.

Peace.

 

[sirsmoksalot]

Like you said totally dangerous but a great idea if you can stop the moisture from attacking the sockets.

 

[orangejuice857]

I must say, I love your idea, besides being dangerous. The only thing I would do is enclose my lights somehow that way they dont get wet, but without losing any of their function.

Not to sure if clear
vinyl/ plexi glass / glass would defer the rays from the plants or turn it into a giant magnifying lense.

 

[UptheDownstair]

Thanks guys. Ive been thinking of ways I could make it safer. To stop the moisture from getting on the sockets I thought of some sort of rubber cap with a hole in it (for the cord) to fit over each socket. But I dont know if they make anything like that, and there's no way I could make one myself that I can think of.

And as for enclosing the lights, I thought of that too, but it really sounds like a pain in the ass.

The best thing I could do is reposition the nozzles so they dont spray on the sockets or fixtures at all. Actually the setup would probably work just as well with just 1 or 2 nozzles maybe Ill try that. I sort of threw this together quickly because I was so worried about the heat stunting my plants. Now that its under control I can do it a bit more carefully, take my time and think it through.

Im going to work this out and Ill update when im done.

 

[Atomizer]

Use 10 misting cycles of 2 seconds instead of one at 20 seconds over the same time period.
It`ll evaporate long before it hits the sockets and deliver the same amount of water.

 

[UptheDownstair]

Use 10 misting cycles of 2 seconds instead of one at 20 seconds over the same time period.
It`ll evaporate long before it hits the sockets and deliver the same amount of water.

That was actually my original idea; to use a timer. Although I dont have one that allows you to set that many cycles and Im not aware of one where you can set a cycle any shorter than 1 minute.

Besides I realized after doing it this way how much I love having it controled by the thermostat. I dont have to worry about the cabinet being over or under-sprayed depending on the ambient temp of the house. Its all automatic and amazingly accurite.

My temps all day have never gone above 86F or below 79F. And it was 95 in the shade today!

Also I have now changed where the misters spray and they no longer get the sockets or fixtures wet. And it still works just as well.

 

[Dankster4Life]

Glad to see you have some what fixed your fire hazard.What will you do when the mold grows though???Bound to happen don't ya think?

 

[born2killspam]

Ironically I don't see this as being that dangerous.. You're using DC , so as long as your transformer isn't on the floor where it could be flooded you're isolated from mains..
As for the light sockets, your biggest risk is blowing a fuse/breaker.. They are mains connected, but separated from you.. Still though, a little hot-glue etc gobbed over those leads may add peace of mind..

 

[UptheDownstair]

Glad to see you have some what fixed your fire hazard.What will you do when the mold grows though???Bound to happen don't ya think?

Im not too worried about mold growing. Ive got plenty of ventilation and with that, coupled with the excess heat, all the water evaporates within minutes. I will keep my eyes open though and if any starts to grow I will figure something out.

Ironically I don't see this as being that dangerous.. You're using DC , so as long as your transformer isn't on the floor where it could be flooded you're isolated from mains..
As for the light sockets, your biggest risk is blowing a fuse/breaker.. They are mains connected, but separated from you.. Still though, a little hot-glue etc gobbed over those leads may add peace of mind..

Yeah, I didnt think it was too dangerous either and now that Ive redirected the misting nozzles its that much safer. And the transformer isnt on the floor. Thanks for the tip with the hot-glue, that's a great idea! I will do it for sure.

And just out of curiosity, what makes something mains-connected or not? I thought every outlet/power source in a house was connected to the breaker-box, therefore any device that shorts would simply blow a fuse/breaker.

 

[born2killspam]

A transformer is two coils that are magnetically coupled, there is no direct wire connection between the two.. This separates the high from low voltage and limits the amount of current that can travel between the output leads in situations where the output voltage is dangerous..
So when I say mains connected, I mean there is no magnetic coupling in the middle, its just wire all the way from load to socket.. An isolated short will only blow a fuse if the transformer is big enough to draw 15A+ from the wall..
Fuses don't blow fast enough to keep you alive if you're in the middle (if they blow at all since 15A is way more than enough to kill).. They're there to stop fires from starting..

 

[UptheDownstair]

Thanks for the reply, born2kill. That makes sense, and thats pretty much what I thought transformers did. I also understand now why I was safe from the sockets. Even though I admit I didnt get it until the moment I was writing this post and reviewed your first reply.

As you said, they are (were, since I changed my entire setup yet again) seperated from me: they were suspended in midair and the cord ran straight to the outlet. Makes perfect sense and I thank you for clarifying the difference. It may very-well save my life down the line!

Yes, I have changed the configuration again. I ditched the CFLs and installed a 150Watt HQI 6400K Metal Halide fixture. Ive had it for a while, I just never thought of a way I could install it in the cabinet. It was one of the fixtures intended for use in aquarium applications: in a gigantic housing way to obtrusive for use in my tiny grow-space. I gutted the thing and was left with nothing but the reflector and double-ended socket assembly. And that was all I needed.

I also bought one of those Pyrex Bake-A-Rounds and when I get it I will use it to make a cool-tube. When I start flowering I will switch the MH for a HPS. Got a few weeks, at least, till then.

Fuck, I may just save the cool-tube idea till I get the HPS, because the misting is working GREAT to keep the heat down. Here's some updated pics of how I have it setup now.

Also, some current temp records:

(granted, this is at night when it's the coolest: current house temp @1:59AM 83.3/58%)

First reading is from sensor mounted at just a few inches above plant leaf-level.

Second reading is from sensor mounted just a few inches below light (near hottest point AWAY from misters)

First spraying at 1:09 AM; 88.3/53% & 90.5/49%
Next reading at 1:13 AM; 80.6/68% & 90.3/52%
Next at 1:17 AM; 82.2/64% & 90.1/50%
Next at 1:22 AM; 84/61% & 90.6/49%
Next at 1:27 AM; 86.3/56% & 90.6/49%
Next at 1:32 AM; 87.8/63% & 91.4/47%

Sprayed automatically at 1:32 AM when temps were 87.8/63% & 91.4/47%

Cycles have continued steadily since then.

Im happy to see the temps staying on the low-end of the 90s even at the hottest area of the cabinet. Thanks everyone for your continued interest and let me know if you have any other questions. Ill keep you all updated on the progress of this experiment.

Peace.