Chiller Needed

Discussion in 'Tank Talk' started by skywindsurfer, May 31, 2011.

  1. skywindsurfer

    skywindsurfer Architeuthis Registered

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    I have never used a chiller for my home aquariums and I have never purchased one either. I am looking for one that will allow me to keep my 250 gallon aquarium (96" long x 25" tall x 24" deep) with a standard sized 55 gallon acrylic aquarium as a sump with about 30 gallons of water at temperatures from 60F to 75F. I must aslo added that I am a bit strapped for cash so I cannot go out and get a thousand dollar chiller. Can anyone help me here? What should I get?
     
  2. Thales

    Thales Colossal Squid Staff Member Moderator

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    I wouldn't skimp on a chiller, especially if you want that kind of pull down. You are looking at at least a 1/3 HP and a pump to run it. If you are really strapped for cash, don't forget about the extra 500-1000 watts of electricity you'll be running 24/7. A cheap chiller is loud, will break, and will hog even more electricity.

    These are good: https://www.tecous.com/chillers/seachill-tr20/
    $760 plus $120 shipping plus pump to feed it.

    I wouldn't do it if I couldn't afford it.

    https://www.tecous.com/chillers/seachill-tr20/
     
  3. skywindsurfer

    skywindsurfer Architeuthis Registered

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    Well my wife gets extremely cheap electricity. 1000 watts an hr would only add $23 dollars to our monthly bill. My wife really doesn't want to spend that much for a chiller, but I'm trying to convince her otherwise. I have two cortez rays that I would like to see in cooler water.
     
  4. skywindsurfer

    skywindsurfer Architeuthis Registered

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    I have spoken with my wife, and until we can purchase a decent chiller we are going to try and chill the tank another way. I have removed the large 2600 gallons/hr pump and replaced it with a significantly smaller pump that still does a good job but with much less heat transfer. I'm also switching all lights with cheap, dim LED strips that give off absolutely no heat. Thirdly we have agreed to lower the thermostate in our apartment to 70F and take the glass covers off of the tank so that the ambient temperature can chill the tank with little mechanical heat transfer. Lets hope this works. lol Of course this is not a permenant fix. My wife agreed that when we are able to afford a $900 chiller we will get one. All of my tropical animals and inverts are going into my 40 gallon estuary tank. I'll post again in a week to let you know how cold the water stays.
     
  5. Joe-Ceph

    Joe-Ceph Haliphron Atlanticus Supporter

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    I really like my JBJ Arctica 1/4hp chiller. It is almost silent (some chillers are very noisy) and has a very good reputation for reliability. I got it used on Craigs List for $250 ($300?) and it has been running perfectly for me for about four years. New price is about $800, so I'm a huge fan of used chillers. I later got 1/5th hp JBJ Arctica on Craigs List for $150, because it had a bad thermostat. The guy threw in the high quality external thermostat he was running it with, so it works fine, and was cheap. If you live in a heavily populated area, and watch Craigs List for a few months, you'll see a couple of deals go by. Just watch a couple times per day and be the first guy there with cash in hand. Know which brands are good and which stink, test it first, and if it works, buy it!

    I run a cold water system (Bimac) that I keep at 62 degrees, in a room that is kept at about 72 degrees. I used to keep my tank at 54 degrees, and over the years I've learned a lot about what it takes to keep a tank cool. It's great that you get cheap electricity, so it sounds like you are concerned with the purchase price of a chiller, and want to know what size chiller will work for you. Think of a chiller as a device that removes heat from tank water, and puts it into the air that runs through the chiller. The size of the chiller you need depends entirely on how much heat (per hour) is getting into your water. You need to estimate the amount of heat (in watts) that is getting into your water from each source, add that up, and get a chiller that can (easily) pull out that many watts of heat per hour. The sources of heat are:
    1) Heat from Warm room air conducting through the surfaces of your tank, sump, and plumbing.
    2) Heat generated by the warm parts of pumps that come in contact with your water.
    3) Two types of heat from lights: a)Heat radiating into your tank and warming the rocks or whatever it hits, and b) heat conducting from the warm air around your lights, and the warm parts of the light housing touching the tank.

    There is a lot you can do to keep heat from these sources from getting into your water, and needing to be removed by a (larger) chiller.
    1) Room Air - cover every surface you can with insulation to slow the heat coming in from room air. I use 3M Styrofoam (brand) insulation panels (From Home Depot?). It is easily strong enough to not crush when put under your tank, and you can cover 5 sides of your sump with it. Also insulate all pipes (Home Depot). I cover the back and sides of my tank with this insulation, after covering the insulation board with black vinyl (for looks and water resistance). Styrofoam has an R-Value (resistance to heat transfer) of 5 per inch, and you can look up the R-Value of glass and acrylic. You can look up the formula to calculate heat transfer rate given R-Value, and temperature difference between the water and the air. Then for each sq. in' of tank, sump, pipe surface, add up the rate of heat gain per hour (in watts).

    2) pumps - Submersible pumps dump about 90% of the watts they use into the water as heat, so just read the back of the pump to get that number. If you can use external (air cooled) pumps, like Iwaki, it will put most of that heat into the air, and probably only 10% of the watts they use go into heat in your water, so consider switching to external air cooled pumps. I use a single Iwaki pump on my system. As a return pump, to push water through my chiller, and to push water through my Aqua-C skimmer. Korallia type pumps for flow inside the tank are okay because they move a lot of water for just a few watts. A closed loop system run by an external air cooled pump would also be a good way to get flow without adding much heat. For each pump you have, multiply the watts used (from the label) by 0.9 (submersible pump) or 0.1 for external air cooled pumps. For pumps with plastic housings that can go either way, multiply by 0.5 (WAG (Wild A$$ guess)). Add up the results, and add them to the number (watts) from 1) above.

    3) Lights - a) radiant heat. This is harder to calculate, and differs for different types of lights. If it feels warm just shining on you (like sun light) then probably about 25% of the watts used by the light are going into the water as radiant heat (WAG), so multiply by 0.25. If the light feels cool (fluorescent or LED?) then maybe a lot less (0 - 5% ?). b) Conducted heat from lights - Don't let a warm light fixture lay on top of your tank. Laying it on wooden spacers with 1/2" air space in between will make a huge difference. Also, take the temperature inside your hood to see if the air in there is much hotter than room air, and use that temp (heat difference) in step 1) for the top surface of the tank. If it's hot in your hood, an exhaust fan can fix that. None of my animals use light for food, so I use dim cool lights, and so can't advise you much about how much heat bright lights will add (maybe a lot) but the 25% guess might be close enough.

    Get a total for the number of Watts of heat you are adding to your water from all sources. You can convert that to BTUs/hr by multiplying it by 3.4, so if your total watts added to the water from all sources is 250, that is about 850 BTU per hr (BTR/hr).

    Chiller cooling capacity is given in BTU/hr (ignore the horse power rating), and you since you don't want your chiller running all the time, look for a chiller with a capacity of about three or four times the BTU/hr you calculated above (so it can deal with hot days, and not beat itself to death running more than 50% of the time). So for the above example, a chiller with a capacity of 2500 to 3500 BTU/hr would be perfect.

    My tank is a 60 gallon with no sump, it's super well insulated (double pane on front and top, 1.5" - 3" Styrofoam on 4 sides) and my pump and lights add a minimum of heat, so my 1/4 hp chiller is probably larger than I need, and it only runs about 10-25% of the time (depending on room temp and tank target temp). Even so, it adds a very noticeable amount of heat to the room, and I have to run the AC to keep the room temp down to 72 much of the year. Don't enclose your chiller, or any other air cooled thing (pumps, lights) in a poorly ventilated place. You need lots of cool air to carry the heat away or the pumps and chiller will wear out prematurely.

    If the external surface temperature of your tank is cool enough, and the air is humid, you could get water condensation ("sweating") on your tank, obscuring the view. Acrylic insulates better than glass, if the water temp is 60 degrees, the outside surface of a glass tank will be 60-61, while the outside of an acrylic tank will be 63-66 (WAG), so an acrylic tank will be less likely to sweat. If you have AC to keep the humidity and temp down in the room, and/or your water temp isn't too low (65?) you probably won't have any trouble with sweating, but think about it. One way to predict sweating is to look at weather reports for where you live, and note the "Dew Point", which is the temp at which dew will form (water condensing from the air) on a given day (based on the temp and humidity that day). Whenever the surface temp of your tank is below the dew point, you will see sweating on your tank (except for the effects of AC or heating in your house).

    Cold water tanks have little or no evaporation (I almost never need to add fresh water to my 62 degree tank) so that's an advantage. Cold water dissolves more oxygen, and cold water animals tend to be more robust, so there are some nice advantages, especially if your animals don't need big expensive lights (what you save in bulbs and electricity in five years might pay for a chiller?)

    You don't have to pay $900 to have a cool tank. Get a used chiller, no larger than you need, with a good reputation, don't let dust build up on the radiator, and you can probably get the job done for $300.
     
  6. Joe-Ceph

    Joe-Ceph Haliphron Atlanticus Supporter

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    Here's a 1/3 HP JBJ Arctica chiller for sale RIGHT NOW on Craigs List in Dallas. He's asking $400, so $350 would probably do it, but even at $400 it's a good deal. (it says "barely used")

    http://dallas.craigslist.org/dal/for/2390919172.html

    the 1/3 hp is rated for up to 4000 BTU, which would almost certainly be enough for your tank, even with minimal insulation.
    Get over there now!
     
  7. skywindsurfer

    skywindsurfer Architeuthis Registered

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    Thanks a lot for your input. My goal is to have a temperature rang of 66-72F. I achieved this before in a 55 gallon with no lights and one power head for water circulation. There is a used 1hp chiller on craigslist for $1,500 but said they'd sell it for $750. There are also two used ones at my LFS for $300 and $600. But again we are a bit strapped for cash, trying to pay off bills and buy a house.
     
  8. skywindsurfer

    skywindsurfer Architeuthis Registered

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    Thanks, but right we just spent $300 for a class for our daughter. I'll keep an eye on craigslist though. Thanks for your input you've been very informative.
     
  9. Joe-Ceph

    Joe-Ceph Haliphron Atlanticus Supporter

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    I hate to see deals like this go by. I don't know about the Dallas area but in San Diego (25% larger than Dallas), I can look for many months before I see a deal on a quality chiller of the correct size (most are 1/10th - 1/15th HP). If you're planning to miss this deal anyway, maybe you can call the guy and make a low ball offer, like $250. If he says "okay" (not likely) then (if possible) you could scramble and find a way to come up with $250 (sell your lights?).

    It sounds like your daughter owes you three bills, maybe you could lean on her a little :smile:
     
  10. skywindsurfer

    skywindsurfer Architeuthis Registered

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    Lmao ya she's a cash spunge(only 18 months old). I would sell my lights but I need them for my corals and mangroves. Maybe it'll still be up for grabs in a little while and he/she will be more willing to accept a lower offer.
     
  11. skywindsurfer

    skywindsurfer Architeuthis Registered

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    So far my tank has dropped 6°-8°F and is still dropping. When I checked this morning around 7:00am it was at 74°F. I'm hoping that it will drop well below 70°F and stabalize on the low end so I can raise the thermostat in my apartment.
     
  12. Joe-Ceph

    Joe-Ceph Haliphron Atlanticus Supporter

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    You're probably aware of it, but blowing a fan across the surface of your water (tank and or sump) will cause a lot of evaporation, which will lower your temperature 2-6 degrees. You'll obviously need to add RO/DI water often to keep salinity stable, but it's an easy way to knock off a few degrees.
     
  13. skywindsurfer

    skywindsurfer Architeuthis Registered

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    Lol I was literally JUST thinking about adding a small fan to my sump. My wife says its still at 74°F and that she's freezing. This might persuade her into allowing me to get a chiller sooner hehehe...
     
  14. Nancy

    Nancy Titanites Staff Member Moderator

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    The fan on the sump really works to lower the temperature a few degrees.
    Another way I kept my tank cooler was to run the skimmer only ay night, when the lights were off.

    Thanks, Joe-Ceph, for going into such detail about your methods of cooling.

    Nancy
     
  15. Joe-Ceph

    Joe-Ceph Haliphron Atlanticus Supporter

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    You said that you changed to a lower wattage pump, which was a good move. If it is a submerged pump, then that's where most of your heat (above room temp) is coming from. If it is external, it might help to set a fan to blow on the pump, and make sure that it's blowing cool room air, and not just recirulating hot air inside a closed stand. The same goes for the fan on your sump. If it's just recirculating humid air over your sump water, you won't see much evaporation or cooling.

    I built my stand with an open end, split so that it takes air in on one side, and exhausts hot air back into the room on the other side. The air circulates through a furnace air filter, through my chiller, over my Iwaki pump, and back out into the room, pushed by one of those dual fans designed to fit in a window. That would be over kill for you, but my point is that you need to actively circulate a lot of room air through a stand if you want to use fans and/or evaporation inside a stand.
     
  16. skywindsurfer

    skywindsurfer Architeuthis Registered

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    I don't recall the name of the pump off of the top of my head, but it is an exterior/submersable pump. Right now it's sitting in the water, but I may be able to prop it up out of the water and just run a line down into the water and then blow a fan across it. My stand is compleletly open except for four doors on one side, so there is plenty of air flowing through it. This(http://www.alibaba.com/product-gs/451212757/sump_pump_AP10000.html) is the sump pump I was using. It easily kept my tank at a steady 80 - 82F. Fully open at 0 head pressure, it's supposed to pump out 2,600 gallons per hour. It only cost me $60 plus shipping.
     
  17. Thales

    Thales Colossal Squid Staff Member Moderator

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    Nice! You should post this as a blog on TONMO.

     
  18. skywindsurfer

    skywindsurfer Architeuthis Registered

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    As of right now the tank has dropped to 72F. I'm still going try and raise the pump out of the water to reduce heat, It's just going to be tricky. I have a Rio+ 3100 Sump Pump. the intake should be the right diameter for me to slip this short hose that I have over it. My only concern is that it will not be able to pull the water up out of the sump if I have it sitting in the sump but raised out of the water. I guess we'll see. I'm confident that with temp will continue to drop even if I don't mess with the pump, but it will allow me to raise the room temp if I do.
     
  19. skywindsurfer

    skywindsurfer Architeuthis Registered

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    I just put both of my 48" two bulb T5 fixtures back on to see how they affect the temperature. So far there has been no lights on.
     
  20. skywindsurfer

    skywindsurfer Architeuthis Registered

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    Lights and pump are running and temperature is almost to 71F. This is great because that means that I don't have to buy new lights. The pump will not work the way I was trying to do it. I don't think it's adding that much heat anyways. When I was handling the pump it wasn't warm to the touch. I might still add the fan though. I want to wait and see how far the temperature drops first. I'm going to bet it drops to 69F. I think my 55 dropped to almost 65F when I had about thirty gallons and ran it with just a MaxiJet1200 for water movement, and we kept our apartment much warmer. Ironically I was actually trying to warm that tank up but couldn't and I'm trying to chill this tank but can't lol.
     

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