DIY Chiller ideas?

[stefanm]

Ok, my tank is located on my balcony, the sump area is in the garden directly behind the tank, I've got the thermocol/polystyrene sheets to insulate it.
I live in the tropics very close to the sea, we're at the beginning of summer here, the next 3 months will be as hot as hell (not really so hot, the high humidity makes it feel like that). So I want to finish this off and get the tank running asap...

So options to chill my tank.

1) ready made chiller, no warranty, very expensive and may not be durable.

2) This is my preferred option, second hand window AC installed in my sump box, only issue is people here are selling old junk at silly prices, I had a look at one today, in allegedly working condition, the compressor didn't even switch on, maybe a faulty relay? I guess over the next few weeks, more will be available as people upgrade their window shakers for split AC's as the weather becomes hotter.

3) Turn my sump into a fridge, literally have copper cooling coils in the sump box, condenser and compressor outside, the copper pipes would be below the sump glass, so no direct contact with the water.

4) Similar to above, but a drop in titanium coil, quite expensive over here.

5) As 4. but a cheaper PVC coated copper, is less efficient and longevity.

So what I'm looking at,my preferred option, no. 2 cheap and easy and secondly no.3 much more involved, but should work well (in my mind) Option 1 is financially out of the question right now, option 4 would be great, but will be troublesome to get the titanium coil fitted by an AC tech. Option 5 would work ok, but I'm sceptical about the PVC coating getting damaged.

Whichever method I end up with, will be controlled by an Arduino based tank controller, which is already up and running.

What do you guys think?

 

[djbetterly]

I’ve tried a lot of things, in the end, nothing worked better than a real aquarium chiller.

I spent money on all sorts of options and in the end had I just purchased a chiller I would have saved money.

 

[EmdeReef]

Interesting question, curious to learn what you end up with and how it works out.

Not sure if one option is better than another. Intuitively feels a bit like you're trying to boil the ocean. In any event you will probably use A LOT of energy so the upfront chiller investment is likely to pale in comparison.

 

[stefanm]

I’ve tried a lot of things, in the end, nothing worked better than a real aquarium chiller.

I spent money on all sorts of options and in the end had I just purchased a chiller I would have saved money.

The problem is they're stupidly expensive in my part of the work and without warranty sucks.

 

[djbetterly]

Where do you live?

 

[tablesalt]

I have heard of people running water lines through refrigerators to cool their tanks, although last I looked into this was 10 years ago and was talking about doing this to a nano-cube. Another option that would require some maintenance, but be essentially free would be running a water line through an evaporative pot. These require relatively dry air though... https://en.wikipedia.org/wiki/Pot-in-pot_refrigerator

 

[djbetterly]

You could also get a mini fridge, run ALOT of coiled up tubing through it and set the pump up on a temp controller like this Temperature Controller

Thermostat Inkbird Digital Heating and Cooling Outlet 1100W, 110V (ITC-308) https://www.amazon.com/dp/B077N22T3W/ref=cm_sw_r_cp_api_x.gJAb9T4035J

 

[stefanm]

Interesting question, curious to learn what you end up with and how it works out.

Not sure if one option is better than another. Intuitively feels a bit like you're trying to boil the ocean. In any event you will probably use A LOT of energy so the upfront chiller investment is likely to pale in comparison.

See, my thinking is that is if the sump area is chilled it'll take care of the DT, bear in mind my DT is 320 litres (85 gallons) and the sumps total over 200 litres (50+ gallons?) I can't see much difference to having a chilled sump compared to running a tank in an AC'd room or using zonal central heating for a fish room/remote sump in cooler climates.

The max temperature here is roughly 35c (95f) daytime. So not quite the hottest place, but hot enough..

 

[stefanm]

You could also get a mini fridge, run ALOT of coiled up tubing through it and set the pump up on a temp controller like this Temperature Controller

Thermostat Inkbird Digital Heating and Cooling Outlet 1100W, 110V (ITC-308) https://www.amazon.com/dp/B077N22T3W/ref=cm_sw_r_cp_api_x.gJAb9T4035J

I've looked at that option, seems too inefficient, I have a thermostat/controller as mentioned earlier.

 

[EmdeReef]

See, my thinking is that is if the sump area is chilled it'll take care of the DT, bear in mind my DT is 320 litres (85 gallons) and the sumps total over 200 litres (50+ gallons?) I can't see much difference to having a chilled sump compared to running a tank in an AC'd room or using zonal central heating for a fish room/remote sump in cooler climates.

The max temperature here is roughly 35c (95f) daytime. So not quite the hottest place, but hot enough..

I'm sure it will take care of it, but it will use a lot of power to cool it and whatever chiller you end up with will have to be significantly oversized so it doesn't run non stop. About 7-8 yrs ago I tried running a chiller in tank assuming that it'd save me money if I didn't have to run the AC in my living room while at home...it caused a lot of trouble with temp stability. Keeping the temp within 1-2F was a nightmare, basically the thing ran non-stop and I got an oversized unit. My LR temp never exceeded 85 either.
You are basically aiming to keep the temperature about 10-15F lower than the ambient temp.

 

[stefanm]

I'm sure it will take care of it, but it will use a lot of power to cool it and whatever chiller you end up with will have to be significantly oversized so it doesn't run non stop. About 7-8 yrs ago I tried running a chiller in tank assuming that it'd save me money if I didn't have to run the AC in my living room while at home...it caused a lot of trouble with temp stability. Keeping the temp within 1-2F was a nightmare, basically the thing ran non-stop and I got an oversized unit. My LR temp never exceeded 85 either.
You are basically aiming to keep the temperature about 10-15F lower than the ambient temp.

True, though I have the benefit of being outdoors, hoping it will help. I also built another sump tank, so I have a lot of water in the sump going through the cooler area, any hot air generated from cooling will be away from the tank and sump, so hopefully eliminate the issue that most have with chillers being inside their homes. Another thing is the tank itself isn't running on a lot of juice either, return pump 38 watts, skimmer 18 watts, wave maker 22 watts, the lighting is LED and during testing hasn't added any noticeable heat to the water. I'll be running a gravity fed turf scrubber, which may benefit cooling with in the sump box, fingers crossed, lol...

 

[EmdeReef]

True, though I have the benefit of being outdoors, hoping it will help. I also built another sump tank, so I have a lot of water in the sump going through the cooler area, any hot air generated from cooling will be away from the tank and sump, so hopefully eliminate the issue that most have with chillers being inside their homes. Another thing is the tank itself isn't running on a lot of juice either, return pump 38 watts, skimmer 18 watts, wave maker 22 watts, the lighting is LED and during testing hasn't added any noticeable heat to the water. I'll be running a gravity fed turf scrubber, which may benefit cooling with in the sump box, fingers crossed, lol...

Good luck! Looking forward to hearing how it goes! Sorry can't help you with options but I'm sure there are people here who can provide good tips!

It'd be cool if you could build a mini geothermal cooling system. I thought I read about a facility that was doing that to keep the tanks cool.
My neighbors in Aruba did that and never use the AC at night anymore.

 

[Mandelstam]

I don't know how many degrees you'll need to cool down but just digging down a coil of hose deep in the ground and then pump the water through that could help. Only needs a pump basically.

 

[stefanm]

I don't know how many degrees you'll need to cool down but just digging down a coil of hose deep in the ground and then pump the water through that could help. Only needs a pump basically.

I would have done that, but I live in a flat, may not go down well with an idiot of a neighbour, no one else would be bothered though.

I picked up a second hand, working window A.C. Today and I've enquired about a titanium cooling coil, hoping for a reasonable price, if I can stretch to fit my budget then I'll convert it to a drop in chiller.

 

[Daniel@R2R]

Interesting! Following to see the outcome!

 

[Paul B]

I built this evaporative chiller for my reef. But I live in New York so my chiller needs were not as much as yours. My tank is 100 gallons so this was way undersized. It is an evaporative chiller. Water enters at the top and flows down the plates where it returns to the tank. A computer fan at the top blows air over the film of water as it descends causing it to evaporate, chilling the water. These chillers are on top of every office building.
Mine only cooled the water about 3 degrees but thats all I needed. If I made it much larger, it would have cooled it a lot more. Very cheap and uses almost no power.
It may not work in your situation depending on how much you need to chill.
This also oxygenates the water. Now I use it to cool my blackworm tank.

 

[stefanm]

Where do you live?

Goa, India, the chillers sold here are only Chinese brands, without warranty or product support.

However if the titanium coil is priced reasonably, then that's the route I'll take. The A.C. I picked up is 1.5 ton, so should chill the water quite fast.

 

[stefanm]

I built this evaporative chiller for my reef. But I live in New York so my chiller needs were not as much as yours. My tank is 100 gallons so this was way undersized. It is an evaporative chiller. Water enters at the top and flows down the plates where it returns to the tank. A computer fan at the top blows air over the film of water as it descends causing it to evaporate, chilling the water. These chillers are on top of every office building.
Mine only cooled the water about 3 degrees but thats all I needed. If I made it much larger, it would have cooled it a lot more. Very cheap and uses almost no power.
It may not work in your situation depending on how much you need to chill.
This also oxygenates the water. Now I use it to cool my blackworm tank.

Thanks, I had seen this sometime back, the big problem here is that night time temps can be 80ish Fahrenheit, right now it's 8.50 PM and I'm sweating and it's only the end of February, it gets worse through March to early June, until the monsoon rains cool us down, add to that humidity is high for at least 9 months of the year, so really not even worth trying evaporative cooling, that would be nice though....

 

[stefanm]

Right. the Ac I had picked up seems to be 1 ton (12,500 BTU) I had gotten a good price on the titanium evaporator, unfortunately the tax was 28%! obviously sucks, right? anyway I've ordered it.

This is not going to be a full DIY as I don't have the equipment or proper knowledge to get the work done, however I'll keep the thread updated to the finish, in case it can help someone else out in the future.

So basically I've quadrupled my budget, however I feel this would be the most efficient way to cool the tank, long term. I do also feel if I'd dropped in the window AC into the sump, it would've worked ok, kind of like having a cellar or basement.

Hopefully it'll workout well, stay tuned, lol...........

 

[stefanm]

Right. the Ac I had picked up seems to be 1 ton (12,500 BTU) I had gotten a good price on the titanium evaporator, unfortunately the tax was 28%! obviously sucks, right? anyway I've ordered it.

This is not going to be a full DIY as I don't have the equipment or proper knowledge to get the work done, however I'll keep the thread updated to the finish, in case it can help someone else out in the future.

So basically I've quadrupled my budget, however I feel this would be the most efficient way to cool the tank, long term. I do also feel if I'd dropped in the window AC into the sump, it would've worked ok, kind of like having a cellar or basement.

Hopefully it'll workout well, stay tuned, lol...........

Done!!

Really efficient, very happy with the performance...a bit ghetto though...