DIY Chiller 600g System

[FishyDP]

Hello- I am looking for some input regarding a do-it-yourself chiller, on a fairly large scale. I am in the very early stages of a 600ish gallon system build, which I hope to complete over the summer. The system will consist of a 210g display, 200g in frag tanks and 125g dedicated to a small scale fish breeding project. All of this will be plumbed into one sump. I will also have an isolated 55g quarantine.

My main challenge is..this system will be in my garage, in SW Florida. The garage has one standard window, but I will not be cooling the garage constantly with AC, only when I am working on the system. My guess is that my electric bill would be..pricey, if I ran AC 24/7 in a garage that is not insulated. The 210g display will be in-wall, view-able from my LR, but most of the tank will be in the garage.

Now to the question at hand.. I am considering using two full size refrigerators with as much 1/2" hose as I can fit in them, inside of 5g buckets of water. I read on another thread that hoses inside of buckets of water will cool more efficiently than hoses directly in a refrigerator. I will be using two refrigerators, for redundancy, in case one of them fails. Water will be pumped from the sump, through the hoses inside of the refrigerators, and into the rest of the system, and back into the sump. I will use a temperature control switch inside of the sump to kick the chiller pump on at say 79, and off at 77. I see people selling perfectly good refrigerators regularly, probably to upgrade to stainless steel etc...in the $100 range. This entire DIY chiller system will probably cost around $350, tops. I estimate that buying a sufficient standard aquarium chiller, that will cool this system sufficiently, will cost $1500. Not to mention electricity consumption and noise.

Reminder, I am in SW FL. Summer lasts like 9 months, and are particularly brutal May-Sept. Evaporative cooling/fans are almost useless with the humidity.

I will be running mainly LEDSs, with some T5 supplement. I will also be running an exhaust fan in the window for moisture build up in the garage.

Thanks for any input.

 

[DLHDesign]

I ended up buying a chiller for my tank, but before I did, I looked into a DIY chiller. Some thoughts;
- Some fridges have fully-encased enclosures. This makes drilling through them difficult. These are rare, however - especially at the lower price points - so unlikely to be a major concern. Still; check to be sure about that first.
- The "hose running through a bucket" is true; direct contact with something cold (water) is better than indirect contact (air). Even better, however, is something that is specifically designed to transfer temperature. Since I came from a brewing background, I already have a plate chiller on hand. I don't know if these would be worth the cost or not for a tank chiller build, but there's no doubt in my mind as to the improved efficiency of these types of plate chillers (I used to take ~10gal of boiling wort down to fridge temps in 15min). The question is whether it would cost less to use the plate chiller, or just run the line through the fridge as you are thinking. Never did the math on that one, myself. Plus; cleaning the chiller could be a pain...
- A good option for the "in bucket hose" in terms of temperature exchange is to use copper tubing. But copper and saltwater don't really go together (not unless you want to risk killing everything, at least). They do make stainless steel tubing, however. This would be better than plastic tubing for heat/cold transfer.

 

[Lingwendil]

Insulate the garage, and chill the room- it will work much better...

 

[DarkSky]

Insulate the garage, and chill the room- it will work much better...

Agreed. If you store the refrigerators in the garage, the heat they produce and pull from your tanks is just going to dump right back into your tank. It'd probably be cheaper to insulate and cool your garage, imo.

 

[FishyDP]

All great points above. That is what I was worried about with a traditional chiller, dont they produce heat like a fridge, thus cancelling each other out somewhat? I didn't know that some refrigerators can be difficult to drill as well..with the input above, I am getting the feeling a fridge chiller just will not work..probably going to forget about it at this point. If I get into metal piping or cooling plates the cost savings may go down..but if I had some of that stuff on hand I would probably try to use it for the fridge idea.

I cannot run anything outside, as I live in a semi strict HOA community. So no mini splits or window ac that would alter the outside appearance. I could however run a portable ac with a hose venting out the window, and insulate the garage..this idea makes the most sense. Was trying to save some money with the DIY, but looks like no way around it, have to cool the garage. Does anyone know the ball park cost of doing this? It is block construction here in FL..I have a standard size 2 car garage, maybe on the small end of 2 car garages, but has 9 foot ceilings, with a bedroom above.

A traditional chiller is not out of the question, if anyone has any suggestions on a unit.

 

[DarkSky]

All great points above. That is what I was worried about with a traditional chiller, dont they produce heat like a fridge, thus cancelling each other out somewhat? I didn't know that some refrigerators can be difficult to drill as well..with the input above, I am getting the feeling a fridge chiller just will not work..probably going to forget about it at this point. If I get into metal piping or cooling plates the cost savings may go down..but if I had some of that stuff on hand I would probably try to use it for the fridge idea.

I cannot run anything outside, as I live in a semi strict HOA community. So no mini splits or window ac that would alter the outside appearance. I could however run a portable ac with a hose venting out the window, and insulate the garage..this idea makes the most sense. Was trying to save some money with the DIY, but looks like no way around it, have to cool the garage. Does anyone know the ball park cost of doing this? It is block construction here in FL..I have a standard size 2 car garage, maybe on the small end of 2 car garages, but has 9 foot ceilings, with a bedroom above.

A traditional chiller is not out of the question, if anyone has any suggestions on a unit.

Is your garage finished? Or are the studs visible?

 

[rcpalmer1]

I live in Fl. I put a wall across my garage and insulated. Threw so insulation in the attic and ran I new trunk from the ac box. From the outside everything looks the same. Inside the garage looks just like any other room and is heated and cooled with the central unit.

 

[Erica-Renee]

Chillers are Super inefficient , The money the chillers would cost is much better spent on a Mini split unit and Proper insulation in the garage. Using a fridge is even worse of a idea as they put out a lot of heat into the same space your trying to cool.

Best solution.
In the garage area where the tank and sump are at. Build a well insulated closet to surround the tank and sump. Connect that closet to your hvac system for your house .. This will be cheapest and less work ... also most efficient

Good Luck ..

 

[FishyDP]

My garage is "finished"..in FL that means 2 of the walls are completely block. One wall has the garage door, and the last wall is drywall connecting the garage to the house..this is where the in wall tank will be placed and viewed from my living room inside, and will be maintained from the garage. A closest enclosing the tank in the garage and connected to house HVAC is a great idea, if I was just doing the in wall display and thats it..but the plan is to have multiple additional tanks plumbed into the display. I want to turn my entire garage into a reef/filtration room, with about 600g total between 3-4 tanks, and I still have to park one car inside the garage.

With all of the above suggestions and some more research, I think cooling the entire garage 24/7 is my best bet. I am thinking of doing this by insulating the garage door, running a portable ac unit venting out of the window, and running a dehumidifier. I may also install a ceiling fan or large industrial fan to keep the air circulating. I guess my electric meter will get a workout, and my wallet.

The second best option that I am seeing is to get a chiller, but as others have stated they are inefficient..so cooling entire garage looks like the plan. Thanks for the suggestions, and if anyone has additional thoughts or input I am glad to hear them.

 

[Lingwendil]

Do you have attic access? If so, it may be easier to run additional HVAC ducting to the garage, and run it off of the central air in the house- worst case you may need to upgrade the main unit, but then you get into a bit of complication if you don't tend to cool the house at the same time as the fishroom.

Another, maybe easier option, is to simply run a larger window mounted AC system, but bring it further inside the room, with a dedicated set of exhaust ducting to it, that either feeds to the window, or has a feed through the attic to vent outside. That way it still works as well, but looks unmodified from outside the house. I've seen a couple done like this for similar situations, and they seemed to work well. Basically running a wall-shaker like a large portable.

 

[ca1ore]

You'd have to check carefully to see whether a refrigerator would even have enough HP/BTUs to do what you propose. They are designed to cool a defined space, not 600 gallons of water. My suspicion is that it would not work.

I don't agree with the comment that chillers are 'super inefficient'. I think a purpose built water chiller would be much more efficient than cooling the entire garage and hoping that suffices for water temperature - unless of course you want to cool the garage for some other purpose. If you are unable to put the chiller outside, you can place it adjacent to a window and vent the heated exhaust outside. The only better chilling option is a heat exchanger - but that only works if you have access to cold tap or well water.

 

[FishyDP]

I am definitely dropping the DIY fridge chiller at this point. Everyone seems to be in aggreancee that it is unlikely to work. I do not have an attic above the garage, there is a bedroom above it. The bedroom actually gets hotter than the rest of the house, it is the only room above the garage. In a perfect world, I would just like to chill my tanks in the garage without having to chill the entire garage 24/7.

I guess a better question at this point is whether a traditional aquarium chiller is efficient enough to cool a 600g system, without cooling the garage itself. I would more than likely run two of them in case one fails. A reminder, I am in FL, I will be running the chiller 75% of the year.

I just moved to FL last year, and came from the NE. I have been keeping aquariums for a decade, but never had to deal w cooling them..this will be a decent size build so I really want to do my homework. If anyone would like to chime in, here are the questions I have:

1) Will two traditional aquarium chillers be efficient enough to cool a 600g system, without cooling the garage itself?

2) Is the electricity consumption of a chiller similar to a portable ac unit? Which would cost more to run 24/7?

3) If you were in my shoes, would you opt to cool the garage, or utilize a chiller?

If I did decide to use a chiller, I would still be running a portable ac unit in the garage, and use it only when I am in the garage maintaining the system. It will be too hot otherwise..

 

[ca1ore]

Chillers are sized based on the volume of water they can drop down a specified amount; so it's not 'efficiency' necessarily. You'd have to figure out how much the chiller would be tasked with dropping the temperature in order to size one properly. TradeWinds make some very nice large units. My guess is that you'd be looking in the 1/2 to 3/4 HP range. Whether you'd have to cool the garage is unclear. Most chillers lose efficiency as the ambient temperature climbs and can even shut off if the air gets too warm. With a chiller in an uncooled garage, in FL, you would likely need to find some way to get cooler air to the chiller. In terms of electricity, depends on the size of the chiller versus the size of the portable AC unit - they come in all sizes. My 3/4Hp TradeWinds chiller certainly draws a lot more than any of the portable AC units I have ever owned. It's also likely that to adequately cool a garage down to the level that would also cool the tank, you would be looking at a sizable portable. I'd insulate the tanks as much as possible and use a dedicated water chiller.

 

[FishyDP]

Ca1ore, very useful information, thank you. Opinions seem to be split on whether to cool the garage, or use a chiller. You mentioned that the 3/4 hp chiller that you use draws more (electricity consumption?) than any portable ac unit that you have used. You also mentioned that chiller efficiency goes down if the ambient temp of the room is high. This is concerning because the ambient temp of my garage will be very high, without an ac unit running 24/7. I agree, I would need a sizeable portable ac to get the garage temp down to where I need it.

With all of this info, there seems to be no way around it, I will need to cool the garage whether I use a chiller or not. This will be my focus. I may end up cooling the garage, and using a chiller. So much for saving money, ha. I am thinking of using cinder blocks or 2x4 stands, and maybe I will go all led, and my buddy is getting pretty good at drilling tanks, so maybe I can save some $. I will also look into the tradewinds chillers.

 

[stefanm]

I built a DIY chiller using a second hand window AC and a titanium drop in coil, super efficient, never comes on for more than a few minutes at a time, back pressure is also very low so the compressor should last a long time, we also used the standard capillary, the AC technician was concerned about that, thankfully once we tested it was all fine.

My tank is on a balcony and the sump in the garden. I live in the tropics and day time can get quite hot, especially March to early June, my tanks electric consumption is negligible according to my bills.

Your best option is to run a split AC with a drop in coil, unless your garage gets very hot, then insulate it well and run an AC full time.

 

[FishyDP]

Ok..so I insulated my garage doors and ran a few tests by blowing cold air from my house into the garage for a 24 hour period. While I did see a 10-15% reduction in humidity, the temperature drop was almost non existent. Long story short, I am scratching the idea of cooling my entire garage and running a chiller. I am having too many doubts of this being effective, especially living in an extremely warm climate.

This week I had 2 different contractors come to my house and give estimates for building essentially a separate fully insulated room, more like a walk in closet, to enclose the tank inside of my garage. I will cut a viewing hole in my living room wall, and on the other side the fully insulated room will enclose the tank, in the garage. Luckily I found out that the wall is not load bearing.

I will be installing a double door (each door 36") to access the tank from the garage. Since the stand will not be visible, I am going to save some money by building it out of concrete/cinder block. I got this idea from watching Tidal Garden videos. To give it a bit of a cleaner look, I will spray paint the blocks white..but again the stand will not really be visible.

To cool the new room, I am going to run a portable ac inside of it. I figure that it will be much easier to cool this smaller space, rather than the entire garage, as some have suggested. The ac will be vented out of the window in my garage. Cooling issue solved.

Now...I have some other challenges, and am looking for some input regarding some ideas I have to add some frag tanks to the system. The frag tanks will not be inside of the new room due to space limitations. I still have to park 1 car in the garage, so the new room is going to be just big enough to enclose the display and filtration/sump ect going under the stand. The display tank will be 8ft. I am undecided on the exact foot print, but it will be between 240-300g.

My question is regarding adding the frag tanks, which will be plumbed into the main display. As stated, the frag tanks will have to be outside of the new room and in the garage itself. My thought is that the frag tanks will be very shallow, probably 8", to keep water volume down. Most likely 2 - 48x24 frag tanks, totalling 100 gallons, roughly. I am thinking, since the frag tanks will be plumbed into the main display, the cooling of the main display via the enclosed room and ac, will keep the the entire system cool. In other words, cooling around 350 gallons inside of the new room, will be enough to keep the frag tanks temperature stable, as water will constantly be circulating from the main display, into the frag tanks, and back into the display. The water in the frag tanks will never have a chance to heat up. Hopefully I have explained this clearly...any input is welcome.