thermoelectric cooling for small box grows(safisticated ones!)

[medgt]

with this thermoelectric controller, a tec and temp sensor i reckon i could keep my small drawer grow box at optimum temps.

using two pc heat sinks(fan cooling) for each side of the tec. but with the heatsinks on either side of the back wall of the box.

the controller and sensor will do the rest.
its basicaly how small tec fridges work.

[Don Piano]

http://www.allelectronics.com/cgi-bi...C_DEVICE_.html

These may be cheaper and come with the heatsinks. No need for the connected potentiometer on the unit you showed if you plan on using a temp sensor. You should dig around on that website if you like the electrical gear.

[medgt]

i like it!
cheers don.
nice low profile too maybe a fan to help move the cool air.

need to see if my bigger diy hood will keep the temps down during the summer heat.
but i like the the control this would give.
easy to do i think.

do you know of this being done already?

[medgt]

i read your closed attic thing last night too.
nice work bud. good planning and craftmanship right there.

i have one hang up man. why didnt you keep the box roof the same as the real roof?
you know? like a triangle shape?

[Don Piano]

Thank you. To answer your questions;
Tooo much extra work, and more wood to haul into the house, while nosey neighbors just wait for the chance to call the city inspector to see what I am doing and why I don't have a permit.
Also, No need for the extra height. Its going to flower clones in a sea of green. They wont get too tall, they will be going into flower as soon as they root. The box is 4ft tall and the light is cooled so the light can stay close.
I also needed room on top of the cab for various things such as my fan for the light, and my 20lb CO2 tank.
I also wanted to make sure that the airflow in the attic was not blocked off, so I can properly vent the attic heat.
Good questions though for sure.

I am not sure if it is being done (the TEC) but if the grow is small enough, it should be great with a fan.
Probably want a fan taking air off of the hot side (outside the box) as well, to further the effect , though it would have to investigated, I am not for sure on that.

[medgt]

well don this is the size of it..
http://forum.grasscity.com/grow-room...-lumens-2.html

just ignore the poor plants, i was testing differing sizes of clones going straight to flower and i trimmed to see what size colas they would produce.

cheers for your input bud.
total respect for your growing and the way you go about it.

[Don Piano]

Thanks for the kind words.

That looks like a nice little cab. Nice colas, and way to keep the mom to size.
You may want to use 2 of those TECs for that size. I realize it's only 70watts, but if you can make the TECs cool faster with 2, then I am all for it.
Are you going to seal the rooms and add co2?
Is your light air cooled? If it is, and those TECs keep temps in check, you would be a prime canidate for sealed growing with co2.

[medgt]

thanks man
the mother plant is wierd

it is an air cooled hood. but just like the whole box its kind of a prototype.
the next one will be built in one go. this one has been ongoing for a year now.

i like the sound of a closed box with co2 feeding but dont think i have the room for tanks and control gear.
i could do it, i think, if it was kept external to the box but im realy keen on keeping it all enclosed. stealth being my main focus.

is co2 feeding a big enough difference to consider?
what about the other components of air the plants need? ie oxygen?

[Don Piano]

Plants need the co2, and produce oxygen. CO2 is the primary concern when it comes to bringing fresh air in, plants need it live. The normal air pulled into the chamber is going to contain 300ppm give or take of co2. Putting it to 1500ppm makes a huge difference in yield time, density, and bud size. Plants have a maximum potential that they can not exceed, but to get there, all requirements must be met.

Sealing that grow and using co2 would not be hard. You can use a smaller tank than most (5lb) and release it on a timer if your box is sealed (no controller needed, just some math) and a 5lb tank could be concealed pretty easily in a speaker or something small like that. You would need a regulator with solenoid though.

Very nice work though with your box. I give you plus rep for building it.

[FullMetalJacket]

I found some aluminum heat sinks on ebay.. A ton actually and one guy will even cut them to the size you need. I really like the idea of TEC and think it will resolve my issues. The key is keeping the hot side cool as possible to lower the cold side temps even further. I was think though you could build a unit that did both act as an a AC and dehumidifier. So if you had like 4 of those units Don saw have three cold sides in the cab and 1 hot side in the cab. When you wanted dehumidifier send power to the one that gets hot as well as the cold ones to offset the temp. When you wanted to cool simple just send power to the cold ones. I think these are great just wish someone had them working in a cab already...
he
I was thinking about adding a third cab for AC and dehumidifier, but even the smallest ones i could find would be overkill. These would be smaller and quieter, possibley cheaper too. Definitely ahve the cool factor. Thanks for starting this thread and as always Don , your input.

[FullMetalJacket]

I bought a small dehumidifier that uses this technology for like 30 bones about a month ago. It is 26 watt (including the fan) and the cold heat sink is 2 inches square. It removes 10-16 oz of humidity a day. That will probably not be enough right? That is why i was thinking of making one... This would also allow me to keep the hot end on the ouside of the flower area in my util area with ventatlition out...

[medgt]

don buddy, im totaly convinced!

im willing to invest in working ideas so i reckon one of these will save me some hassle...
http://www.tradehydro.com/products/u...ontroller.html
what do you think?
run it on the 1 cubic meter room size.

there is a welding supplier with 5lb bottles down the road from me so im sorted for them.
wonder how long a bottle would last?

im gonna need to wait a month or so to afford it but my mind is made.
the tec thing will have to follow pretty quicky after.
my temps hit 32c with no air replacement but after reading up on co2 growing today it would seem you can get away with that but i dont want to push it.

any of your thoughts would be appreciated bud.

hey fullmetal its a good solution it would seem. cheers for the heads up on heatsinks.
i have loads of pc heatsinks that i want to utilize tho. i even run all my fans currently of a pc power supply.
there are loads of pc parts that could be used for small grow boxes.

the best part about it all is how creative you can be in doing it.
just check out the dons grow!( no pc parts, just brilliant )
who said stoners were useless?

[FullMetalJacket]

Thats a cool co2 controller, i wonder what exactly that micrprocessor does. I went with the Sentenial CHHC-1 though for PPM measurements and integration with my dehumidfier and cooling.

Dons shit is definitly impressive. He knows his stuff and has helped me a great bit.

Humidity will go up faster than your temps with the sealed enviroment. With that small of an area though it wont be too bad if you have to vent often becasue you would waste little co2 in the process.

If you google 'CO2 calculators' you can see how long a Co2 tank will last you. I can get 84 days if i clear my air every 15 minutes(I dont want to clear this often though). But at least it gives me an idea.

--
example-
Grow room area: 36 cubic feet
Amount of CO2 required: 0.0432 cubic feet
On time: 0.65 minutes
At this flow rate:
If you are using a 20 pound CO2 bottle with a regulator, it will last 43.7 hours.
flow setting 4

4 times an hour
12 hours on

48 cO2 cycles at .65 min
48 * .65 = 31.2 min a day

C02 tank will last 43.7 hours or 2622 min
using 31.2 min a day

2622/31.22 = 84
20 lb Co2 tank will last 84 days of usage if I recycle my air every 15 min (this is worst case scenerio)

[FullMetalJacket]

Don the thermoelectic devices. How large of one in watts/heat sinks do you think i would need on 36 cubic feet for reducing temps 5 degrees at 92 and keeping my humidity < 50? Its hard for me to find alot of info on their "rate of recooling per watt" when x amount of heat is removed.

I know it is highly dependent on the heat you can remove from the hot side, but i will overkill that for sure.

I was thinking like something like 3 maybe of the device you posted? What are your thoughts bro?

[medgt]

i just checked out your grow fullmetal..........
now thats what im talking about!

seriously good work man. first class.
you set the standard for what i want to achieve.
reps to you both