Very Interesting High Temps Solution.

[faithlessxxx]

So now that summer is here, both my fellow farmer and I have seen our temps go through the roof. We shouldn't be even trying during the summer, but we both thought, wtf, lets try anyway.

So our temps shot up to about 35C. We've both got massive fans etc, he has a cooltube, I chopped off the room halfway up with a sheet of polythylene, but we realized that the problem is that if the air going in is warm already, you're screwed.

We started philosophizing about different ways to cool things. Computer processors, motorbike motors, lots of other things are cooled by having a fan blow over cold metal.
We thought that if we could think of a construction whereby the intake has to pass over a fair sized amount of metal, it should cool it.

Then I went home. Sat there thinking that glass should be just as bad a conductor of heat as metal, so I fitted an old stormlight cooltube that I had lying around to the intake, shut the door, left it alone for 20 mins, then checked again. The temps dropped 3c.

I was really surprised at the difference it made. This idea could be developed further, I'm sure.

Thoughts?

[khronik]

heat sinks only work to dissipate heat into a cooler environment. If the environment is the same temperature as the metal, nothing changes temperature.

You're pretty much stuck with either air conditioning, or if the air in your area is very dry, you might be able to cool it by evaporating water somehow.

[Al B. Fuct]

khronik is spot on, well said.

Be careful about the difference between a human feeling cooler and actually reducing air temperature. People feel cooler in the breeze from a fan because there's water evaporating from the skin- not because the air is any cooler due to the air motion. Fans actually add heat to air by way of their motors.

Same for heatsinks or other chunks of metal. Your skin surface is about ~80-85F. When you touch something which has good heat conductivity and the ambient air temp is cooler than your skin, what you're touching feels cool- to you- but it is actually no cooler than the ambient air temp.

[Tomthehippie]

yea great bit of info there both well said! :) my temps are also way to high! And i donâ??t want to invest in a air-con unit just yet.

You can buy air cooling units that u can fill up with ice every few hours that then blow ice cooled air in to your room.

I had an idea of maybe some kind of water cooled system but i havenâ??t got much further with its design than just thinking about it. :)

[Al B. Fuct]

Tom, I've seen those ice-cooled heat exchanger units. A grow op of any decent size would eat a 5kg (10lb) bag of ice in very short order and the temperature isn't at all controllable.

These ice devices are only slightly better than evaporative or "swamp" coolers, which are of little to no use in a grow op as they dump lots of humidity into the air and lower temps only a few degrees.

Consideration #1 in a grow op is the ability to ventilate the space to get rid of waste heat from lighting, humidity transpired from the plants and to draw in fresh CO2 laden air.

If you can't ventilate a space adequately, you will always be dissatisfied with the quality and quantity of buds you pull out of it.

[4x5]

how about an old heater core and an old magnet pump filled with glycol alcohol, don't forget the squirrel cage fan.

[Al B. Fuct]

4x5, good onya for thinking about the problem, but a liquid cooling system won't make things any cooler than the ambient air.

The only common device which will remove heat from air is a typical air conditioner unit, though Peltier-effect (PE) cooling devices (http://en.wikipedia.org/wiki/Thermoelectric_effect) are kinda interesting. Very expensive, but mechanically mucho simpler than gas compression and evaporation air conditioning, not to mention just plain interesting. PE devices work like turbocharged heatsinks, but still require a place to dump their heat.

[Tomthehippie]

Arse. iv decided to have my lights on at night un till i get aircon. :)

[Markass]

what about window units? I've seen some of the smaller ones for under $100..I'm actually considering getting one for future grows to aid in cooling and dehumidification

[stinkyattic]

A bit about heat... it is moved in 3 ways: Radiation, convection, conduction. Radiation is what causes the heat burns on your leaves. Convection is why it is warmer near the top of your room... and why you should put the active exhaust up there to take advantage of that. The last is what you are thinking of utilizing... sorta...



but we realized that the problem is that if the air going in is warm already, you're screwed.

Right, which is the reason to use an ACTIVE intake and draw pre-cooled air from a cold place such as a basement of a room with ac.


Computer processors, motorbike motors, lots of other things are cooled by having a fan blow over cold metal.

Actually this is not how it works... the fan blows over HOT metal. The heat sink thing is securely fastened to the item to be cooled (heat is conducted into it) and the many small flanges on it create a greater surface area to be air-cooled, helped along by a fan.


We thought that if we could think of a construction whereby the intake has to pass over a fair sized amount of metal, it should cool it.

This will simply heat the metal. If you are passing air over very CHILLED metal, the heat will come out of the air and warm up the metal, making the air a bit cooler... but this isn't a practical way to cool a room!


Then I went home. Sat there thinking that glass should be just as bad a conductor of heat as metal,


No, metal is a fabulous conductor of heat. Glass, not nearly so much. Glass is actually a pretty decent insulator. When you are running an air cooled hood, the heat is primarily passing through the glass as radiation.

You just need to add an ac to your op and play with bringing very cold air into your room, allowing it to be heated or whatever, and then exhausting it OUT of the house entirely.

[faithlessxxx]

Interesting Stinky, thanks.

[Al B. Fuct]

*swoon* I heart girls who know their science. :D

[Al B. Fuct]

Arse. iv decided to have my lights on at night un till i get aircon. :)

heh, you've discovered nature's aircon. :D Most growers run flowering lights at night just for this reason. I sure do.


what about window units? I've seen some of the smaller ones for under $100..I'm actually considering getting one for future grows to aid in cooling and dehumidification

Should work great, provided that absent the ability to put the unit through a window or wall, you can put the 'hot' end of the a/c unit in an airmass where the warm air won't bother anything. I've seen small window units put in an attic above an op with flexi ducts, creative duct taping and inline fans used to bring cool air down to the op and return warm, moist air back up to the a/c unit. Another approach I've seen is to run the window unit within the grow room and duct outside airmass air into the 'hot end' and back out again. Allows access to the a/c unit front panel from within the grow room instead of having to go into the attic.

[Tomthehippie]

Swoons a great word! :D lol

[stinkyattic]

*swoon* I heart girls who know their science. :D

Awwwwww thankx!

Now don't even get me started on the heat capacity of water and why a 'swamp cooler' works on the same principle... but oh so very much better!!!! :D

Oh fuckitall, here goes...

You can strip heat out of the air with cold water mist much better! Water has an extraordinary heat holding capacity, so if you introduce mist, allow it to heat up, and exhaust it from the room, you can strip a LOT of heat out FAST. We used to use this at a commercial greenhouse I worked at... HOWEVER your humidity goes through the fucking ROOF (duh!) and it's not practical for in-home setups or flowering plants.

[Al B. Fuct]

Yep, stinky (and it's really hard to call someone you LIKE 'stinky' :D) water evaporation is a great cooling mechanism- indeed, if you can dump the humidity... but when you do that, you dump your cool air too. :(

[stinkyattic]

if you can dump the humidity... but when you do that, you dump your cool air too.

Well the benefit is that you have stripped all that heat from the lights and ballasts out of your room and basically put it in portable format, lol! Like soaking up an oil spill with kitty litter... it is just SO much easier to get rid of when you concentrate all the oil (or heat) onto a carrier.

Oh... and as for the Stinky... my house stinks. It's a known fact. MY clothes probably smell like skunk too but I can't tell any more. I take it as a compliment to my ability to grow smelly houseplants.

[cture]

So now that summer is here, both my fellow farmer and I have seen our temps go through the roof. We shouldn't be even trying during the summer, but we both thought, wtf, lets try anyway.

So our temps shot up to about 35C. We've both got massive fans etc, he has a cooltube, I chopped off the room halfway up with a sheet of polythylene, but we realized that the problem is that if the air going in is warm already, you're screwed.

We started philosophizing about different ways to cool things. Computer processors, motorbike motors, lots of other things are cooled by having a fan blow over cold metal.
We thought that if we could think of a construction whereby the intake has to pass over a fair sized amount of metal, it should cool it.

Then I went home. Sat there thinking that glass should be just as bad a conductor of heat as metal, so I fitted an old stormlight cooltube that I had lying around to the intake, shut the door, left it alone for 20 mins, then checked again. The temps dropped 3c.

I was really surprised at the difference it made. This idea could be developed further, I'm sure.

Thoughts?
Go for LED lighter