DIY room cooling with Water experiment.

[theTinker]

I've been looking for ways to cool my room down. Even if it helps only somewhat. Next grow i plan to seal it up the tent so I cannot exhuast the air.

I've been toying with Water cooling idea except I dont have funds to buy a chiller or ice boxes!

So i've been mentally designing something like a water cooled heat exchanger using passive cooling of a 240L outdoor tank.

I wanted to buy a big heat exchanger like these:
http://www.brazetek.com/water-to-air-heat-exchangers
However, Im poor. :(

I want to connect a heat exchanger to a fan, and run cold water through it and back to the Res. Or you could do drain to waste if you dont pay for water. Im hoping the hot air will pass its heat to the cold radiator water, then back to the res for passive cooling. This may not work at all. It may work a little, or it may work alot but only for a short time till the water heats up. But sure we'll see! the fun is in the anticipation..

So today i was able to locate a Scrap car radiator. Big enough one, about 23" * 18".
PLUS, this one already has the frame still attached to it WITH FAN! yippeeee!

Its down in my trunk of my car now, so ill go grab that now. Anyone feel free to leave comments.

 

[theTinker]

Plan:

Front of radiator:

Back of radiator: includes Fan, input and output tubes, and female power connector.

Its filthy so time to get it cleaned up. I'll try disconnect the fan + moter from it if its easy so i can thoroughly clean the radiator in the bath. However I dont think water will make much difference as i've seen people clean them with a hose when they are still attached to wires in a car!

 

[ttystikk]

YOU DIRTY ROTTEN THIEF !! YOU STOLE MY IDEA!!! Good for you!!!

I'm thinking you're gonna want another car radiator for outside, unless the garden's excess heat is so small it can effectively dissipate through the walls of your 'reservoir', aka metal drum. I'd plumb it into the return from the inside chiller, before the reservoir. This way, you'll only need one continuous loop of fluid, instead of a multi-manifold cooling system.Also, place your water pump in the circuit downstream of the inside chiller, yet upstream of the outside schiller, so it can dissipate whatever heat the pump adds to the system.

 

[theTinker]

YOU DIRTY ROTTEN THIEF !! YOU STOLE MY IDEA!!! Good for you!!!

I'm thinking you're gonna want another car radiator for outside, unless the garden's excess heat is so small it can effectively dissipate through the walls of your 'reservoir', aka metal drum. I'd plumb it into the return from the inside chiller, before the reservoir. This way, you'll only need one continuous loop of fluid, instead of a multi-manifold cooling system.Also, place your water pump in the circuit downstream of the inside chiller, yet upstream of the outside schiller, so it can dissipate whatever heat the pump adds to the system.

haha, when i read some of your posts i thought the exact same time! thief!

It never even occured to me to use an outside radiator. Thanks for that. Ill try it with this one i have first. Measure the results and feasibility and then add another if needed/if able!

Im at a bit of a bind when it comes to how much i can put outside. Its an apartment so its on a balcony and must be hidden well, visually and sound wise. I can hide a res behind some screen and no noise from it so that shouldnt be too hard.

I might pump water from the res to the inside chiller, then back out to the outside chiller to be cooled before returning to the res to be cooled passively.

About to start work on it again today. busy busy atm. Thanks for the outside rad idea.

 

[Chillville]

I like it alot, keep us posted on the results. How cold it is outside? That is the biggest factor in how well it will work. I might also suggest a second reservoir, use one for 24 hrs and then use the other for 24 hrs, it will give the res a chance to chill back off and it will double your cooling btu's for very little extra expense. Make sure you are getting at least 5 GPM out of the radiator that you are using, the more the better. Make sure your return water line comes in the top of the res to make sure its getting stirred up, this will help cool it off.

 

[theTinker]

I like it alot, keep us posted on the results. How cold it is outside? That is the biggest factor in how well it will work. I might also suggest a second reservoir, use one for 24 hrs and then use the other for 24 hrs, it will give the res a chance to chill back off and it will double your cooling btu's for very little extra expense. Make sure you are getting at least 5 GPM out of the radiator that you are using, the more the better. Make sure your return water line comes in the top of the res to make sure its getting stirred up, this will help cool it off.

Thanks for the input man. All much appreciated.

Outside varies greatly. right now its a warm 14C for October, in winter last year for 2-3 months it was -4 -> +8.

As for the extra res. Yeah i was thinking about a way of joining smaller res's together to make a larger one. Maybe a pipe near the top of each connecting them. Like an overflow.

Ill take from one res, and return to the other. That way the return res fills up and overflows into the res i take from, this would constantly mix things, use the surface area of both res to dissapate, and give twice the BTU capacity as you said. I like this design because its foolproof, can never overflow too much, and is expandable by just adding a 3rd res etc.

Honest if its a BTU capacitiy issue. Thats a problem i look forward to fixing :) loll. I'm much more wary of the exchange mechanism not being efficent enough. Car Rads are designed with a much higher variance in temperature in mind!

I'll give it a go anyways.

 

[iscrog4food]

Holy shit I was literally just talking to my brother about a variation of this Idea like 15 min ago. I actually signed in to post a thread about it haha. I live in the CO mountains where is it very cold. I was thinking of having one radiator outside and a smaller one inside and running antifreeze to cool in between. I was wondering if I was gonna need a res in the loop but I think if the size differential between the two radiators is large enough you would not need a res (though it would improve cooling capacity!). The next issue is pump selection. I was thinking of using an inline aquarium pump due to the limited heat production and the fact that I could eliminate the use of a res if I had an inline pump.

 

[theTinker]

Holy shit I was literally just talking to my brother about a variation of this Idea like 15 min ago. I actually signed in to post a thread about it haha. I live in the CO mountains where is it very cold. I was thinking of having one radiator outside and a smaller one inside and running antifreeze to cool in between. I was wondering if I was gonna need a res in the loop but I think if the size differential between the two radiators is large enough you would not need a res (though it would improve cooling capacity!). The next issue is pump selection. I was thinking of using an inline aquarium pump due to the limited heat production and the fact that I could eliminate the use of a res if I had an inline pump.

haha, it seems cheap water cooling is on peoples minds these days! the ICE box by GI/GH gave me the idea a while ago. Great lil idea they have. I do love this business of making your own solutions.

So your idea would be to have 2 radiators, with a coolant between them, and constantly recirculate the coolant between the outside and the inside one? When the inside one picks up heats, it sends it to the outside one, and the heat is dissapated from the coolant and returned to the inside again?

Its a good idea. It'd have to be some major cooling outside though..

hmmm A further idea would be to keep the res and place the outside radiator in the res and allow a much greater conduction to take place. But.... I can see already that if you are going to have a res that cools by submersed conduction. You might aswell drop the outside radiator, and run insulated hosing from the inside heat exchanger, through some hose, then into some wort chiller/copper tubing that is placed inside the res. It would cool better i suspect as its designed for that sort of thing.
This would only be benefical to do if the coolant used was never to mix with the res for some reason, or was a better heat transferer than water and needed to be kept sealed. If your using water as coolant, it might aswell mix and also provides a HUGE buffer.
I'd go with just water out of safety and ease of use!

The inline coolant pump and closed system is interesting though. If a res is not suitable for the situation, this makes alot of sense.
This idea would be more efficent than the res idea if the outside radiator can dissapate heat quicker than the res can, and if the heat can be completely dissapated too. Any build up would lead to the closed system heating up and becoming inefficent quickly i'd imagine.
Your idea cheaply imitates a mini split style :) sort of

 

[theTinker]

ok update

I dissassembled the radiator and fan set tonight. And washed the both of them down. They were full of soot and dirt and oil residue. Took a couple of hours to get them clean enough that i'd put them nearly my plants. I wouldnt want any of that stuff to be blowing around my room for the sake of the plants and myself!

Oven cleaner with Sodium hydroxide worked well.Mr Muscle. Spray it on. Let it foam up. Leave for 15 minutes, then rinse off. Black water ran quickly.

I flushed the interior of the radiator using lots of warm soapy water.
I then flooded it with a limescale remover tablet from my washing machine/dishwasher and allowed it to dissolve any build up. slightly yellow water came out, so im sure this was coolant and deposits.
No leaks found in the radiator so far:)

So far cost is 6 bucks for cleaner and wire brush. and 30 for the fan/radiator set up.

Diassembled fan.

Fan connection:

Tomorrow I shall tackle three steps.
1 Connector for the fan.A car shop should have these i hope.

2 The power issue. This fan runs on 12V DC power, my home is 240V AC. I am hoping i can buy an adaptor that outputs 12V and enough amps to make this bad boy spin like a tornadoe.
Would anyone care to estimate how many amps would be required to spin this guy? I tried a 12V DC 1500ma and it wasnt strong enough to get pass the startup friction.

3 The large intake and output size of the radiator. its at least 1" in circumference. I'll look for a water to reduce these to a more regular size! 15mm approx.

I've found pumps that use 1" outputs but this would be alot bigger hosing than i'd like, plus i'd have to buy a big pump and run 300watts!! Im aiming for something much smaller!
If its effective at all. I can always increase these later :)

 

[theTinker]

Studying the power issue. A couple of things popped up.

Amp draw is not static and varies greatly on fan, and on fan speed.

it looks like this: (example only)

35 amps.............27 amps...............18 amps..............8 amps <--draw
==============================================<-Equals 1s time
0 to 1 rpms.........500 rpms..............1500rpms............2500rpms <--speed

Inital start up is the big draw. After that, it drops quickly. However, Im now doubtful of the ability of adapter to provide this mean amps at 12volt. The wire would be big.
I will look for an adapter, but failing that. I may need to run this thing on a battery or power source, while simultaneousily charging the battery.

Ideas welcomed, ill keep studying and thinking.

Heck.. maybe I can even get a regular fan attached to the radiator and skip the whole power issue entirely. I have 2 fans im not using at the moment. I shall test these out and see what the air flow is like throught he radiator.

The radiator fan though is designed to pull air really well through the radiator so it'd be nice to use that!

 

[theTinker]

oscillating fan and honeywell fans do not work well at all!

oscillating fan sucked ALOT. barely any air makes it through.

the other honeywell fan did better. It has a flat front so i could place it against it. It worked ok. Nothing impressive. It also get loud the moment it presses against the rad, not from vibration though. It seems to up its power draw to compensate for the increased pressure, but its loud, and the increase is not impressive.

 

[iscrog4food]

The reason I was suggesting antifreeze is that I would like to hook this thing up to a thermostat so that it would turn off if it gets too cold and I wouldn't want the outside radiator to crack from water expansion. I think you could use a fan to pull air over the radiator instead of trying to push through it . THat is how an A/C works at least.

 

[ttystikk]

Outside compressorless chilling considerations

Holy shit I was literally just talking to my brother about a variation of this Idea like 15 min ago. I actually signed in to post a thread about it haha. I live in the CO mountains where is it very cold. I was thinking of having one radiator outside and a smaller one inside and running antifreeze to cool in between. I was wondering if I was gonna need a res in the loop but I think if the size differential between the two radiators is large enough you would not need a res (though it would improve cooling capacity!). The next issue is pump selection. I was thinking of using an inline aquarium pump due to the limited heat production and the fact that I could eliminate the use of a res if I had an inline pump.

Hey Bro- I live in the Frozen Highlands, too! All that free cooling all winter long, seems a damn shame not to put it to good use, right? Drop me a PM and I bet I could help you get this up and rockin'!

With all respect to Tinker's comments, I am not sure he understood what you're trying to do, or what the limitations might be.

First, you're on the right track with a radiator in your sealed room inside, with a fan blowing through it. The faster that fan blows, the more heat transfer you'll get. Be sure not to let air leak around the radiator fins when you build your unit. I'd hang it from the ceiling, aimed somewhat downward, so it gets warm air from the top of the room, and blows it down.

Second, you damn well better put antifreeze in your cooling circuits if you want to run them outside around here! This ain't Florida! Therefore, you aren't going to be mixing working chiller fluid with nutrient reservoir water or anything else. This is actually the biggest reason you DO want a reservoir, so you can be assured of having a place to keep the fluid when -not if- you need to service your system. I'd run it half full or so, and keep it outside with the outside radiator. You could even mount your outside radiator ON the reservoir, and just drop the cold water into it... simplifies things.

Be sure the pump you use sits below the waterline of your res so it always sees water, and then you're going to find yourself doing what I'd doing- wrestling with how to manage temps, and you'll have several to keep track of:

1. Outside air temp: if it gets too warm, you're gonna want to shut down the outside fan, and possibly the entire system. Otherwise, you're HEATING, not cooling.

2. Working Fluid temp: this would control whether the outside radiator fan runs when it IS cold enough. Keep in mind you don't want the working fluid to get too cold, either- it can lead to cold shock in your sealed room and worse, condensation issues.

3. Air temp in your sealed room: For obvious reasons. For that matter, why not also use it to cool your nute reservoir if you run DWC? Just plumb the cold water thru the coil in your hydro system before running it thru the car radiator inside the sealed room.

So far, you're fine running all this on one circuit. Be sure the pump you run is up to the job, so get at least 550gph or better, every item adds some resistance to flow, as does simple distance of waterlines. If you decide in the future that you have enough capacity to start cooling more stuff, I can help you through the setup process for building inexpensive manifolds to manage all the cooling lines.

 

[ttystikk]

The reason I was suggesting antifreeze is that I would like to hook this thing up to a thermostat so that it would turn off if it gets too cold and I wouldn't want the outside radiator to crack from water expansion. I think you could use a fan to pull air over the radiator instead of trying to push through it . THat is how an A/C works at least.

Word. Gotta have antifreeze if it freezes where you plan to use this.

Definitely the right idea with the thermostat.

Rule of thumb on heat extraction: PUSH room air thru the inside exchanger to cool the growroom (think of this as heating the working fluid), and PULL air thru the outside section to cool working fluid. I could get all technical about the whys, but the main thing to remember is that as long as you follow this guideline you'll get maximum efficiency: PUSH thru radiator/iceflow box to heat, PULL thru radiator/heat-x-tractor to cool.

 

[theTinker]

The reason I was suggesting antifreeze is that I would like to hook this thing up to a thermostat so that it would turn off if it gets too cold and I wouldn't want the outside radiator to crack from water expansion. I think you could use a fan to pull air over the radiator instead of trying to push through it . THat is how an A/C works at least.

Ah good Idea. I'd like to deal with that problem when it arrives :) My big fears with this right is power issues and noise. Car fans are hugely load.

Yes pulling is a must. The fins are way too densely packed to push thorugh with most fans. The fan will need to be practically touching the radiator or else the air bounces off it like a wall.

 

[theTinker]

Good news. I was able to power the fan today using one of these:

Its a simple 12V DC battery charger for Cars. This one worked so well, that i returned it, On the low setting, the fan spun so fast it was overkill and REALLY loud.
This fan input was 160Watts. at max output of 12V, this is 13 amps. The low setting was about 9amps i reckon and spun it VERY fast.
It seems the huge amp draw from cars is only to get the fan spinning really fast with sub second start up time. For our application, a couple of seconds before max speed is reached is perfect so this greatly allows us to reduce our power needs. Which makes this all cheaper.

Later on, I shall be collecting a lower powered one from my brother to try out. The lower powered one is free! and im really stuck for cash for 2 more weeks so might be perfect.

These types should work well too.



One with a FAST and NORMAL mode would allow you to switch between 2 speeds.

 

[Chillville]

Holy shit I was literally just talking to my brother about a variation of this Idea like 15 min ago. I actually signed in to post a thread about it haha. I live in the CO mountains where is it very cold. I was thinking of having one radiator outside and a smaller one inside and running antifreeze to cool in between. I was wondering if I was gonna need a res in the loop but I think if the size differential between the two radiators is large enough you would not need a res (though it would improve cooling capacity!). The next issue is pump selection. I was thinking of using an inline aquarium pump due to the limited heat production and the fact that I could eliminate the use of a res if I had an inline pump.

With 2 radiators you shouldn't need a res I don't think. An inline aquarium pump would be great....just don't use antifreeze! Use propelyne glycol instead, antifreeze will eat your pump alive. PG is food safe and non toxic, you will need 100% PG, not the already mixed version.

I want to know how well these do, it barely ever gets below freezing here so this isn't an experiment I can do.

 

[Chillville]

Just use that car battery charger, should work just fine

 

[ttystikk]

Just use a car battery charger, should work just fine.

Word. Get one with a 2 amp trickle charge feature, you may well findthis is entirely enough power to run your fan and still keep it reasonably quiet.

 

[ttystikk]

Why a reservoir wouldn't suck

With 2 radiators you shouldn't need a res I don't think. An inline aquarium pump would be great....just don't use antifreeze! Use propelyne glycol instead, antifreeze will eat your pump alive. PG is food safe and non toxic, you will need 100% PG, not the already mixed version.

I want to know how well these do, it barely ever gets below freezing here so this isn't an experiment I can do.

Strictly speaking, you don't need a reservoir, but the reason I suggest one anyway is because sooner or later you're gonna want to modify/repair/disassemble your system, and you will want to have someplace you can keep all that expensive propylene glycol you're investing in. Using a good sized drum as a res, and especially locating a valve right at the outlet, will allow you to conveniently pump all the working fluid into a container so you can work on the system. And while it's there, it will help keep your system running efficiently as well, by adding a little thermal mass to the working fluid to help reduce temperature swings.

P.S. I think Chillville means don't use a mix of propylene glycol and something else. But you do want the working fluid to be a 50/50 mix of p. glycol and water, the glycol isn't a very good working fluid on its own... Correct me if I'm wrong on this point, Chill?