Asphyx Posted February 25, 2012 Report Share Posted February 25, 2012 I'll post more detail on this in my tank build blog at a later date but just wanted to share. Having endured tank water temperatures in the low 20's over much of the summer I have been very keen to get myself a chiller. With commercial aquarium chillers out of my budget and a bit of a DIY streak I thought I might be able to build my own. As usual Google proved to be very helpful in this regard and after much research I decided to give a chiller based on a dehumidifier a go. I found myself an old Ebac dehumidifier on Trademe for $20. If you find the right kind of dehumidifier the evaporator coils in the rear (the bits you need) will be plain aluminium tubing without any attached fins (as opposed to one with copper tubing encased in aluminium fins). My internet research revealed all sorts of relatively straight forward methods of using the dehumidifier to chill the water. Mostly these revolved around building a container of some sort around the evaporator coils and pumping the water over them. i.e. http://www.jonolavsakvarium.com/eng_diy/chiller/chiller.html This is all well and fine if you have the time and inclination and space but I figured I could go for something much simpler. After removing all the extraneous bits from the dehumidifier I figured if I could just immerse the evaporator coils in the water it should work just fine. The aluminium coils are very soft and easily bent so all I did was extend them sufficiently so that a decent length of them was under water. I appreciate that this is not the most aesthetically pleasing solution but it was really only intended as a feasibility test to see if sufficient cooling could be generated. I turned the dehumidifier on at bedtime at a temp of 21.7 and woke up the next morning at 16.4 - success! Hopefully not too rapid a drop for the fish but I was not quite expecting it to work so well. Over the last week I have fine tuned the system to be on for one hour then off for an hour for a period of ten hours a day (the limit of my programmable timer) and am maintaining an average temp of around 16 degrees. (Not very good) pics here https://skydrive.live.com/redir.aspx?cid=b59aa470e3a65a17&resid=B59AA470E3A65A17!818&parid=B59AA470E3A65A17!155&authkey=!ABzdVnLVaR2W0YU Again, the coils hanging down in the water aren't the best look but for emergency relief over summer I'm prepared to live with it. Eventually I will modify the piping to suit my needs or find some nice driftwood to disguise it all. The only question remaining regards the toxicity of the aluminium. I would appreciate any feedback but my understanding is that within the pH range we use and in conjunction with the oxide layer on the tubing this should not be a problem in a fresh water aquarium. If need be I will epoxy coat the tubing or isolate it from contact with the water. I know it's not rocket science but I am pretty pleased with myself. Appreciate your thoughts/ideas. Quote Link to comment Share on other sites More sharing options...
Ira Posted February 25, 2012 Report Share Posted February 25, 2012 Shouldn't be any toxicity issues. Aluminum is pretty harmless. If you really want to do it right you could get a temperature controller. THere are some relatively inexpensive ones around, but I can't find any at the moment. Also, little and swimming are spelled wrong. :slfg: Quote Link to comment Share on other sites More sharing options...
Sheepsnana Posted February 25, 2012 Report Share Posted February 25, 2012 If for some reason toxicity becomes an issue, create a smaller tank to sit inside your larger tank. It would reduce your cooling a little, but you could colour the inside of the smaller tank to hide the chiller. These are thoughts based on not seeing the images, as I'm browsing via my smartphone Quote Link to comment Share on other sites More sharing options...
Asphyx Posted February 25, 2012 Author Report Share Posted February 25, 2012 Also, little and swimming are spelled wrong. :slfg: You have no idea how long I searched my post for the words little and swimming before I realised what you were referring to! Yes, I am yet to give the tank its final paint job but in the meantime the kids thought it would be amusing to decorate it for me. And no spelling is not their best subject. &c:ry Quote Link to comment Share on other sites More sharing options...
blueether Posted February 25, 2012 Report Share Posted February 25, 2012 Have you had much of an issue with condensation this week with he high humidity? I have found even at 17 deg that I get a lot of condensation on the warm/humid days Quote Link to comment Share on other sites More sharing options...
spoon Posted February 25, 2012 Report Share Posted February 25, 2012 http://www.ebay.com/itm/All-purpose-Temperature-Controller-STC-1000-sensor-/220812377568?pt=LH_DefaultDomain_0&hash=item3369717de0#ht_3985wt_1110 these work good they have a adjustable compressor delay as its not good to switch them on every 30 seconds or so you should also swap the humidstat out of the dehumifier for a thermostat or just bypass it so low humidity dosent switch it off Quote Link to comment Share on other sites More sharing options...
Asphyx Posted February 26, 2012 Author Report Share Posted February 26, 2012 Have you had much of an issue with condensation this week with he high humidity? I have found even at 17 deg that I get a lot of condensation on the warm/humid days No I can't say I have noticed any at all. Possibly because the house has been mostly open during the day and perhaps the warm air from the dehumidifier keeps it at bay at night? http://www.ebay.com/itm/All-purpose-Temperature-Controller-STC-1000-sensor-/220812377568?pt=LH_DefaultDomain_0&hash=item3369717de0#ht_3985wt_1110 these work good they have a adjustable compressor delay as its not good to switch them on every 30 seconds or so you should also swap the humidstat out of the dehumifier for a thermostat or just bypass it so low humidity dosent switch it off Agreed, that would be the next improvement. I have no trouble with the humidstat switching me off as I just leave the knob in the always on setting. Quote Link to comment Share on other sites More sharing options...
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