Dont buy a chiller ... use a heat exchenger
 

With temperatures are as high as 30C today my tank temp jumped from 24C up to 26.5C.
So i thought its a good time to put my DIY heat exchanger to use again.

All it is , is a plastic tubing line from Home Depot "T-ed" of off cold water RODI supply tap water inside plastic tubing line going from the "T" to my reef tank sump. Then its coiled up in a small coil (about 25 feet of tubing) that plastic tubing coil is submerged it in the sump water. The plastic tubing line then continues from the sump coil back to under the sink and to the drain.

http://i381.photobucket.com/albums/o...ofIMG_0440.jpg
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heat exchanger coil, i have another "vessel" inside the sump then water overflows down to the sump.

http://i381.photobucket.com/albums/o...IMG_0439-1.jpg
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flow control valve. Sorry, the picture is sideways. You can also see yellow line going back to the "P-Trap" drain.
http://i381.photobucket.com/albums/o...IMG_0442-1.jpg
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I am using RODI "waste" water line to discharge heat exchanger water to the sink drain. If you dont have RODI you can go straight to the "P-Trap"
http://i381.photobucket.com/albums/o...IMG_0441-1.jpg
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So the cooling is achieved by heat being transferred from sump warmer water to colder water inside the heat exchanger coil.

Tap water is about 12C tank water is 26C (now down to 24) This trick works and there is enough heat transfer with that temp. difference to keep 65 Gal + 20 gal sump at constant 24C.
I even have to have a heater on and to slow down the water flow inside heat exchanger plastic tubing coil down to the steady slow drip to prevent from cooling too much.

If you have a large tank, double or triple the coil size or get Stainless Steel coil to get enough cooling capacity.

Not sure about prices today but few years ago Home Depot was selling plastic tubing in 25 feet increments for about $6. The whole project cost was less then $60.
This obviously will depend on how close your tank is to the sink.
When its really hot outside the line going from the cold water tap will sweat a little.

It took 25 min for me to type this, and my my tank temp went down from 26.5C to 25.5C.
This DIY heat exchanger works !

Pros:
cheep to make (providing you tank is close to the sink)
Easy to operate and with any heater in the sump it is somewhat automated and protected from over-cooling.
Way more cost efficient than buying a chiller
No electricity involved when house power is out it will still work.

Cons:
Wasting water.
Slight condensation on the tubing
Tripping hazard if tubing running across the room (mine is going along the walls, hot glued to the floor moldings so not an issue)
Will not work if you tank is far away from the sink.

Hope some one will benefit from this :biggrin:

not the best way to do it for a few reasons, the first being it only works when you are running your ro unit, the second is that it is a pretty expensive way to cool water if you pay for your drinking water, also rather environmentally irresponsible waisting that much of a resource that is becoming limited in most of the world but that people in BC seam to take advantage of.

when I first moved to Kamloops there was a fixed charge of 20 bucks a month for water and I can't tell you how many people would run a almost empty dish washer, or water there lawn for 3 hours every second day. now that we have meters and pay for the volume we use over a base amount you don't see this happening very much.

now if you want to keep it cheep, then buy a bunch more of that plastic line and put another coil in a bar fridge then add a small pump to cirulate the water between the coil in the fridge and the coil in the sump. cheeper to set up than a real chiller but still not as good.

Steve

I am not sure you really have to waste that much water, as you can slow the flow just enough to cool the sump water. The reason I say that is that in a past house, we had a solarium off the deck that could get quite warm in the summer sun. So I installed a DIY air conditioner using a similar principle.

I got an old car rad from the scrap yard, and built a window like frame, complete with shutters (no ghetto look) to house the rad on one side of the solarium. On the other side, I installed a good sized exhaust fan (also found at a scrap yard), to draw outside air flow through the rad. I modified the rad ports to fit a garden hose, which I would connect outside. The output of the rad then went to a sprinkler for the lawn.

I controlled the flow with the outside water tap, and was surprised how low a flow was needed to provide very good cooling from the rad. We also opened the patio doors to the house, and it would be cooled down as well. I usually had the flow higher than needed for cooling, just to get enough water to make the lawn sprinkler work.

Anyway, the DIY air conditioner worked great, and the bonus was having my lawn watered, which was also needed during prolonged warm spells.

BTW, temps hit 31 C today here in Langley.

I had tried similar to warm the source water for the ro unit. Thought higher temperature better rejection rate, don't think it did anything so removed, plastic not being the best for heat transfer. Did get lot of tubing out of it for other projects.

I used to live in Langley, now I've still got snow in my yard! Where did I go wrong!!??

Just a thought but why not use the waste water/brine from the RODI unit as your cold reservoir? Direct this to a large insulated container (trash can, tote, old tank) and you have quite a large heat sink that would probably stay cold enough for quite some time if the system is only used when required.
I get drinking water from mine too, but I'd think that given the typical waste ratio on an RODI unit there'd be plenty to maintain an effective heat sink.
If you are using tap water as the heat sink, I'd adjust the flow so that your waste flow from your heat exchanger is the same temperature as the sump water, that way you know you've pumped as much heat into it as possible..

All good points and you are correct, accept one thing; it is not dependent on RODI in any way, i just used existing RODI tubing for easy hookups.
This can be used independently, just run water from cold tap through the heat exchange coil and drip back to the drain. No moving parts, one manual control valve for the flow and that's it. Simplicity = dependability and reliability

As for water wasting yes, it drips to the drain. However when it rains 20 days out of 30 and you don't have a water meter ... i am not that much concerned, and below are the reasons.

Have another look at this at a different angle:
No need for electric power to run this unit, but to produce power to run chiller it will take river water to turn the turbines , or burn coal, or get it from Nuclear plant and we all know how wonderfully "safe" the Nuclear power is, plus environmental impact of making aluminum, copper, plastics are highly toxic and this definitely will pollute the planet eventually. With that in mind my unit may be even more environmentally clean and friendly then buying running and scrapping a chiller.

jmtcw

Plastic is definitely Not the best material for heat transfer. But it works on small water volume like mine (65 Gal +sump).
My tank is 23.5 C rock solid even when its hot outside. And that is on slow drip rate.

If you search for NEU you will find that they use heat exchange principle as well.


they use same principal but they extract heat from sewer and storm water via heat pump and thrugh heat exchangers heat up water for Olympic village and SE False Creek. They make tons of money and are being able to keep heat and hot water rates below what BC Hydro charges to do the same with electricity.

If you ever get to go to any of the mechanical rooms of the building that is hooked up to NEU and look at the size of the heat exchanger that serves 4 or so story building you would be surprised how small it is. Its approximately 3 feet high by 2 feet wide !. This is not a joke. Obviously its not made out of plastic, and its thermally insulated, my point is, its very efficient.

While this might work well for you without a water meter & all the rain, it wouldn't be cost effective or environmentally friendly in areas where water is a bit more precious, like where I live. When things get too warm in the summer, I simply try to keep the room the fish tank is in cooler by running a portable air conditioner. Don't need a chiller since my lights are LED & don't add much heat to the tank.

As for your reasoning that it takes power, turbines etc. to produce electricity for a chiller, we are fortunate in BC to have mostly hydro electric power stations run by dams, not much coal burning or nuclear going on here. Still, it's never a good thing to waste power, you don't know what you got until you lose it. In any case, the water you're using to run your heat ex-changer is delivered to your house using some big honkin' pumps that the city runs using electric power.

Still, it's great that it works for you, but in my area, with the city cranking up the water rates & a meter in the basement, I think I'll keep running the air conditioner for the week or two during the summer when it's really hot.

Could also reverse the process. Fill a cooler with ice and place your coil in the cooler. Then pump tank water through it. Works well for the few days a year we need to cool our tanks.

Pretty smart system, if potable water is no issue. Like someone else said, we are blessed with cheap and plentiful water and power in BC.

And speaking of plentiful cheap power, I use a fan for cooling. Both my DT and refugium are open top, so a properly aimed fan hooked up to my Reefkeeper will turn on when the water temperature calls for it. It works like a charm!

All bring up very good points.
As for power needed to run tap water, its already there , we use it anyways to wash dishes and take a shower. Few drops per second more to the drain when our reservoirs are overflowing... is it that bad?

If so then why don't we go after chemical industry companies and metallurgy to make them stop wasting river water and to make them stop polluting and killing fish by the trillions?

I am taking clean water out of environment, and then after i cool down my tank i put it back to the environment still clean, non toxic and unpolluted with industrial waste.

Naturally people will choose electricity in places where there is no or little water and Hydro is cheaper then water, i, most likely would do the same.


The big question is ; why we talk, talk, talk about saving a planet and being environment friendly if all this comes down to money anyway?

fan doesn't work when outside temperature is like 30+ C. I used frozen coke bottle for emergency but i think I will try your heat exchanger method. Last summer I lost bunch of frags due to the heat. This time I won't repeat the same mistake again.

The fan works for me. Even when it's 30, it brings the tank temp down a couple of degrees. Remember, it's the evaporation that cools the tank, not the temperature of the air. And speaking of evaporation, you gotta make sure you replenish your top off water often when using a fan.

+1

my tanks are in the basement and during summer hours they are kept cool and I ran only leds

interesting topic, what is the highest temperature you get during a very hot summer day?

I use a fan directed right at my water surface when the temps get really high, but then my evaporation goes way up and I end up using a whole lot more ro/di for topoff. So I guess my way also wastes a lot of water. Probably on par with the OP's method.

I guess the whole point of this, and I refrained from saying it in my original post, as it has been said numerous times over the years.

we all know when it gets hot we can have problems, and we all know that the areas we live in get hot, some more than others, but we end up complaining about tank times every year, and a lot complain about die offs. so what do we do, we come up with some 2 buck inefficient way to cool our tanks. yes in a emergency in a power outage, you have a heck of a good way to bring your tank temp down.

but here is my question to you, and any others looking at this.

we spend thousands of bucks on our corals and fish, but yet we balk at spending 2 to 400 bucks on a chiller that will do a much more efficient job and will come on and turn off automatically with out you having to be home.

does this make sense to you?

Steve

The fan also turns on and off automatically, if it's on the controller, switched on by the temp. input.

Here in the Okanagan it's not unusual to be in the mid to high 30's outside for a couple of weeks straight at the height of summer. The central air in my older home hasn't worked since I moved in, yet I'm able to stay reasonably comfortable using a portable air conditioner & by opening all the windows overnight. I don't require a chiller for my fish tank. Due to the clear skies during these hot spells, it cools off substantially overnight, similar to a desert where it can drop to near freezing. Some folks simply seal up their homes 24/7 & run central air all summer. Don't think I could afford the hydro bill & if BC Hydro has their way, prices will rise substantially over the next few years. Time to invest in some solar panels & get the wind generator on the roof.

Yes, what you say makes a lot of sense, and i respect your opinion i do.
Agree wit a lot of what you saying:
2 buck system yes,
Inefficient not so much , it is efficient and it works. (how would you know if you don't try? when i built it i didn't know until i did. Now that i know it works i can share it with people "open source idea" sort of thing)

Automated; yes chiller is more automated however, because it is more complex it is less reliable. My system is less automated, But its automated enough to keep steady temperature. I have flow valve for flow control and "automated" heater in the sump which will turn on when water gets too cold. So it is efficient cooling and semi-automated. I get flow valve closed just enough to not get it too cold to prevent the heater to turn on too frequently.
My system with no moving parts is so simple and therefore way more reliable then a chiller. Plus its absolutely silent compare to a chiller that can be pretty noisy and chiller will expel heat in to your room that is already hot.

I am actually very proud of this idea its simplicity, reliability, cost effectiveness and its being environmentally friendly.

Outside temp does not go from +30C to +18C overnight in that regard this system is pretty good and stable once you set it, its good for a week or so.
If you out of the house for a month its a different story.

I also respect your choice in having a chiller there is absolutely nothing wrong. Some people build huge tanks in to their houses and spend close to 100k on it, there is nothing wrong with that, but is it a good model for everyone?
My choice is not to have a chiller and there is nothing wrong with that ether.

I wold like to thank some people on here who do like this DIY idea for support and also thank you for a PM.

So if you decide to try this, use about 25 feet of tubing (to make a coil) for every 50Gal of water volume to make a coil in the sump. If you look at the picture of the 25 foot coil it takes very little room in the sump.

For emergency cooling you don't even have to have a sump , you can submerge the heat exchanger coil tubing in the display tank for a week or so when it gets too hot.
The important thing is to have heat exchange tubing coiled loose, to have it all completely submerged, and to have it in a highest water flow area if possible.

Cheers.

This idea has my interest. My chiller ran a lot last summer, and undoubtedly contributed significantly to my hydro bill. I have an Apex incl temp probes, an IO Breakout box and a couple water solenoids. So I could completely automate a cooling system, just like my chiller.

But I don't have a lot of room in my sump. I assume your tubing was just standard RO type. I wonder if there is another thinner wall type tubing available from somewhere that would take less room and maybe even better heat exchange capabilities?

Possibly not so good for those of us on Septic systems either. Would be introducing a lot of extra water on the system. But I have toyed around with the idea quite a bit. Even using a old car rad with 12v fan as a outside heat exchanger. But what fluid to use in the cooling loop, that won't freeze? Car antifreeze would be devastating if a leak occured.

not intending to say don't use it, yes for down on the coast/Victoria or north where people have cooler climates it is a good idea for occasional heat waves, but I did try this very same thing oh probably about .. what was it Brad, 15 years ago when I was the cheapest reefer on the planet?

anyways yes it is horribly inefficient (doesn't mean it won't work though) plastic has more insulating properties than not, and its heat transfer is pour compared to other stuff. plus the non recovery of the cooling medial makes it inefficient.

in my first house in Victoria I had no physical way to use a chiller, no AC int he house, tank was in the middle of the front room and no where to hide the chiller or vent the waist heat. so I had 200 feet of 1/4" line that I would go from he kitchen to the front room and back to the sink, the rest being coiled in the sump. I did this for weeks at a time in that house as it was poorly isolated, I had lots of MH lights ect.... and yes it did work. when I bought my next house in Vic, I had a 4' crawl space and where I put the tank I could cut small holes and run lines under the stairs to the crawl space. this is where I put the chiller, no noise, no anything, wouldn't even know it was there and kept my tank to a 0.3 degree temp swing. with the poly tube system I was always watching my temp and adjusting the flow.

up here in Kamloops, I would have to be pretty crazy to use tube as a regular cooling system as our water is ok up to a specific volume then it is unjustly expensive, and if you didn't have central AC the amount of cooling you would need would be crazy. most days from June to end sept mid oct are in the high 30's at my house and I get lots of day in the low to mid 40's and unlike Vernon it doesn't cool down much at night and yes Kamloops is a semi arid dessert. usually the lows are low 20's.

so as I said, everyone should have a 100' roll of polly tune, for the 10 bucks it can save a tank during the unexpected heat wave, and for some people if the water prices are right and the heat not to extreme might work good, other it might not be enough.

I will be the last person to say an idea is bad, just look at some of the stuff I used to post 15 years ago. :mrgreen: I may point out some issues, or make some suggestions though...

I just remembers, for a while the craze was using chloroplast sheets to make tap watter chiller plates that was kinda cool to. another thing people were doing is digging big deep holes in there back yard and putting coils int hat also then making a closed loop geothermal cooling set up.

Steve

Some interesting info I read in the local paper since it's 'water wise' week here. Not saying this would be the same for everyone, but food for thought. "Running a tap for 5 minutes can be equivalent to running a 60 watt bulb for 14 hours". As mentioned, your idea works fine, but as far as efficiency? Folks would have to do a bit of math depending on where they live to see if this method would really be as efficient as an alternative such as a chiller or fan blowing across the water surface.

One way or another you and I (the consumers) end up paying for the power to run the large pumps municipalities, cities or other water providers use to get potable water to our tap. Aside from or regardless of the actual abundance (or scarcity) of water, it still has to be pumped to your house. And in BC, that often means uphill, meaning plenty of head pressure to overcome. All you folks with sumps know what that means. Multiply the fraction of a horsepower of your little pump by several thousand (or more!) and it puts things into perspective. Then there's the issue of how that power is produced, in BC mostly dams, elsewhere.... coal, nuclear.... If you don't have a water meter, the city raises your property tax or the landlord raises the rent to cover his/her expenses.

If you take time to read my OP:smile:, you will find that i am not "running a tap", a slow drip of 2-4 drops per second is far cry from running a fully open tap.
When you have a car rad with fully open tap running thrugh to cool a house that's different, but at least the guy was watering his grass at the same time, got to give him a credit at least for that. :lol:

And when I was cooling the solarium/house with the car rad, I didn't have the tap wide open either, just enough to make the water sprinkler work so I could water my grass. My point also was that it didn't take a lot of water flow to provide a lot of cooling with the rad.

As to which way costs more to the environment, running water or using electricity to run a chiller or air conditioner, I don't know...

I do know that at our cabin at the lake, we have the best solution. We have solar power for lights and small appliances, etc (no hydro connection). Fridge, stove and hot water runs off propane, and costs us about $40 per year. And in the late evening the cabin gets shade from the mountain side trees, so it is cool enough to sleep. In the daytime, when it is hot out, we just jump in the lake to cool off. When it is cold out, we burn wood (no shortage of that out there) in a fireplace.

man either you don't use it much or you have super duper high efficiency stuff. most propane fridges will burn 100 bucks of propane in a summer by themselves.

Steve

We don't run it all the time, just when we are there (or know that we will be back in a couple days). It is not a large fridge either. But yes, it is very efficient, and always amazed just how little flame it takes to keep everything cool, incl the freezer. When you put your hand over the little chimney, you can hardly feel any heat at all. My guess it that a propane fridge would probably cost less to operate than a normal home electric one (but I could be wrong).

ahh that explains it..



very wrong, propane fridges are very expensive to run, the older ones 3 to 4lbs of propane a day, newer ones 1.5 to 2lbs a day. so even if you buy your propane at costco (cheepest you can get for portable bottles) you are looking at 30 bucks per month for the most efficient fridges, up to 70-80/month for the old style.

Steve

Hmmm, quite surprised at that, given the flame size is about the size of a pilot light on your gas water heater. And speaking of which, are you going to tell me that a gas (or propane) water heater is more expensive to run than an electric one?

I am a plumber gas water heater is cheaper not sure about a propane fridge. As for the chiller idea and efficiency I think this is the last of our worries there are so many businesses-grow ops that use the same idea on a way larger scale. Flower store needs a cool room lots of liqueur stores use them most grow ops use them legal or not I hook them up often 3/4 line straight in the unit basically a radiator with fans as water in unit heats up it dumps it right down the drain and fills back up some of these units are 6-8 feet long. Also this is part of the reason city is surrey moved to water meters 5 years ago. Not so cost efficient any more with the big units.

Hmmm, you're giving me ideas here... We have central air in our house now, and electricity costs go way up every summer. If I could stick an old car rad in the big plenum duct somehow, could maybe save a lot of money... Of course, would route the waster water out to a lawn sprinkler. We are not on water meters here in Langley. Wouldn't ever want an inspector to see that though,... LOL.

Yes, RO type, sorry, i did not try any other materials.
Obviously stainless or titanium would work a lot better, if you can get it. But when you are in a pinch anything will be better than nothing.

For emergency cooling you don't need a sump you can just place the coil in the display tank or if you have large overflow box yo can place it there (watch for blockage), its ugly but still better then watching you corals cook slowly.

As long as coil is loose, completely submerged and in an area where there is flow, it will work. Get about 25 feet of tubing coil for every 50 gal, of water.(in addition to the tubing to and from the tank) .
Any ball valve will provide flow control because you don't want to sit there turning it on and off. Just get enough drip to keep it at steady temp 24C or so and your heater will turn "on" if you are not there and it gets below 23C .

Well, I've got a 230g system, so would need a lot of coil then. No room in my tanks either with the live rock and corals, esp if the tubing was stiff,... would make quite a mess with my sps.

So, unless I can find some thinner wall tubing that is also less stiff, probably wouldn't work for me. Is there such a thing as thin wall airline tubing? Plus if it all costs too much, would kind of defeat the purpose, too.

I do have a chiller, but was just wondering whether I could lower my cooling costs (electricity) during the summer.

Nat gas is way cheaper than electric up to 70% cheaper, propane is about 10 to 20% cheaper than electricity. so propane a bit cheaper than electricity, now this is for heating and assumes an average of 80% efficiency, so if you have a 98% efficient furnace like me then the gas savings is even more. for water heaters the efficiency of a energy star rated storage tank type is typical 67 to 68%

when you start talking refrigeration and such different things come into play, but evaporative cooling (gas fired style fridges) are generally expensive to run, although the new ones are a lot better than the old ones.

Steve

what about running the waste to a reservoir outside and use it to water your lawn or garden?

Got my lawn watered by rain last night, was so much water almost flushed away the dirt LOL

What do you guys think of using something like this?
http://www.newegg.ca/Water-Liquid-Co...ategory/ID-575
If you could extend the lines and put them in the sump, it may work.
Would also have to replace the heatblock/pump for something saltwater compatible.