over heating: fan advice please

[jcarrara]

Looking for some advice: I have a 75 gal marine fish only tank. I have it sitting on a 55 gallon classic oak stand. ...I know, I know...there is a 4 inch overhang length wise. What I've done is take that 4 inch over hang and "built it into an existing wall in my home for the "see through" effect and its worked out pretty well. The only problem I'm having is that the extra insulation provided by the wall that it's now built into is causing my tank to overheat due to all the pumps, uv sterilizer, protein skimmer etc under the tank. it's only running about 3-4 degrees over, but i'm afraid once the summer hits it might get way out of control. Rather than drop a bundle of cash on a chiller...I'm thinking a few strategically placed fans I can place on the sides of my classic oak stand and top (flush mounted style) might due the trick. has anyone ever attempted this before? I'd like to have one with the "flange" on the outside for a nice clean look on the outside of the stand. Not sure of the size I would need, where to buy, do I need to hardwire them or can I simply plug one in to a socket....etc. Also, how big of a fan can I "ount to the side of my stand without risking the integrity of the stand itself. Any help would be appreciated....thanks

 

[MeuserReef]

Get some 80mm computer fans from Ebay... theyre like $1 a piece and can be wired using a 12V adapter. I have 1 on my 10 gallon and the temps are fine.

You could get a few exporting air from your stand and put a few in your canopy blowing on the water.

 

[jcarrara]

Great idea....i did some surfing and found a few that will probabley meet my needs. Should I go with AC or DC...sorry, plumbing I can do, electronics I'm a little lost.


thanks

John

 

[rdnyva]

Wish I could tell you where I got them but I can't remember. They are variable speed fans. The control knob allows you to set the speed of the fan and thus the noise level too. I turn it up in the summer when I need more cooling and down in the winter. Surf around and you may find them. Good luck

 

[bergzy]

if you have a sump...

you could place a powerful fan on top of the sump to blow air directly into the sump to get massive amounts of evap cooling.

the fan pictured is a vornado fan (read: lifetime warranty) and is incredibly powerful for its size.

it keeps my 350g system at 78 and rarely goes above 80 (when it does, i have a chiller to bring it down). plus, all my equipment is in the garage where it tends to get pretty warm in there during the summer months in good old southern california.

add a little rosie for that extra kick it up a notch!

 

[iceman5]

i have read that blowing air out away from the tank is better than blowing into the top areaof the tank. this way creates better air movement?

 

[MeuserReef]

<a href=showthread.php?s=&postid=6718401#post6718401 target=_blank>Originally posted</a> by iceman5
i have read that blowing air out away from the tank is better than blowing into the top areaof the tank. this way creates better air movement?

I guess... you are always going to have the same volume of air either way.. If you blow air in with the fan, it escapes the canopy wherever it can and if you blow air out with the fan, it will come in wherever it can. I have not tested my fan blowing out so your reading may hold true.

I have one 80mm blowing IN on my 10 gallon (96W quad PC bulb)
and I dont have any heat issues. Your evaporation will go way up but last I checked..... RO water for the auto-top-off is cheaper than a chiller!!

<a href=showthread.php?s=&postid=6715753#post6715753 target=_blank>Originally posted</a> by jcarrara
Great idea....i did some surfing and found a few that will probabley meet my needs. Should I go with AC or DC...sorry, plumbing I can do, electronics I'm a little lost.


thanks

John

Im not an eletrician either but I will say that I use 12V DC. I think every home in America has an old AC adapter lying around somewhere! Besides... the cheap computer fans are made to run on DC. I got mine from eBay. Look for the ones with the lowes Db rating. Low db = good.

I just ordered some 40mm fans for a 2.5 gallon that Im setting up. You could even consider some of those if space is of concern.
As far as wiring.. you can wire them all up to one plug as long as the combined amperage of the fans does not exceed the amperage rating of the adapter being used.

 

[jcarrara]

Thanks for all the replies....snowin here in Mass, so I have some time to kill. I just wanted to "expand" upon my problem and post some pics as well. I'm gonna check out these computer fans...they seem a little "chincy" but if they work...I'ma buyin! Thanks in advance for any more help and sugestions.....


I have a 75 gallon marine fish only tank...well I did, I had a catastrophic wipe out last summer and lost everything and I'm sure the high temps (84-86 where I should be in the 78-80 range) did nothing but speed up what ever the original problem was, so I want to address the over-heating issue before I start the tank up again. The over-heating issue is obviously more prevalent in the summer. The wierd thing is that my set up is in my finished basement, so I never thought I would have temp issues.

My 75 gallon tank sits on a classic oak stand which is designed to hold a 55 gallon all glass tank. I did this intentionally to create a 4 inch overhang on the back of the stand. What I did was build the overhang into a wall in my home to achieve the "see through look". I built a frame in the wall to support the overhang and trimmed it out. I 'm pretty happy with the way it turned out.

The problem I believe I'm having is that now that the whole system is built into the wall, there is not much air circulation in the stand itself, where it used to simply vent out the back of the stand. Not to mention the pumps, UV sterilizer, protein skimmer...etc. I have crammed underneath all creating heat and adding to the problem.

I was thinking of going down the "chiller" highway but 1) they cost an "arm and a leg" and 2) I can fit it anywhere. Considering my set up and I only need to lower temps 6-8 degrees I'm hopping a flush mounted fan or 2 on the sides of the stand and maybey 2 on my hood might do the trick....your thoughts?

-I'm not sure what size to get. I have seen many people mention the computer cooling fans...they seem kinda "chincy" to me...but if they work...I'm in!

-Should I push or pull the air (I'm thinking 1 push on one side and 1 pull on the other).

-Would a variable speed control knob be wise to incorporate, so my heaters aren't fighting the fans should I lower the temp to much ........and to lower in the winter months when the problem isn't as bad?

-I do have a concern with the depth of the fan units themselves. I would obviously prefer they intrude as little as possible into the stand itself. The sides of the stand are made of 3/4 inch thick solid oak.

-Also the sides of the stands are 12 inches in depth so I don't believe I'll risk the integrity of the stand itself if I use a fan less than 5 inches in width. I'll call the manufacturer on that one, but I have a feeling they'll tell me not to cut a hole in the stand at any costs.

Lastly...how would hardwire these fans? I have plenty of outlets available under the stand and would prefer to simply plug it in and have a speed control knob mounted as well.

Sorry for writing a "bible".....but any help you could provide would certainly be appreciated. I really donââ"šÂ¬Ã¢"žÂ¢t want to start my system up again with fixing the problem and if I give up the hobby ââ"šÂ¬Ã‚¦Ã¢â"šÂ¬Ã‚¦..Iââ"šÂ¬Ã¢"žÂ¢ll have a big hole in the wallââ"šÂ¬Ã‚¦..and that wonââ"šÂ¬Ã¢"žÂ¢t ââ"šÂ¬Ã…"œsit wellââ"šÂ¬Ã‚ with the wife.......lol. If you have any questions...please let me know.


Thanks again,

John

 

[bergzy]

just from my extremely 'limited' experience. computer fans will do a good job at removing warm air from the canopy where the lights are.

for them to provide effective evap cooling...they are profoundly lacking in my 'limited' experience.

you have already lost one tank set up due to heat issues...why risk another with obviously lacking evap cooling from small weak fans? been there done that!

hopefully, you will glean a little wisdom from my experience that to get any effective evap cooling (rather than moving warm air from the canopy), one requires a strong fan to not only move a lot of air but the power to 'strip' water (thus heat) vapor from your system.

hopefully, your tank crash didnt cost more than a appropriately sized chiller, otherwise, that would be another lesson you could learn from...getting a chiller.

my $500 chiller for my main 180g is a drop in the bucket when you add up total cost of the inhabs.

 

[keeperofthefish]

If you are ever over 82 degrees, you are likely in big trouble, unless you are talking about keeping very hardy species or species from tidal areas--but then they also have their own requirements and you need to set up a specific tank for them. Spend your money on the good equipment FIRST. I know people who have lost thousands worth of livestock because they thought a $500 chiller was too expensive. In my opinion, computer fans are really not made for cooling large areas, and they are loud and annoying. They'll work, but not well. They are mainly for cooling canopies with lighting--not entire tanks.

If you buy an AC fan, you direct wire it into the wall (check to make sure it's 115v, etc.), and you will want to check on how to wire it safely. With a DC fan, you will need an adapter that allows it to plug into the wall socket. You need to consult someone more electronics minded than me to tell you how you select the right DC adapter--but you don't want to overdrive the fan, that's for sure, or you'll run the motor hot and even risk fire. That said, I agree that the best solution is a decent, as-plastic-as-possible fan like a Vornado. Aim it across the surface of the water. Pulling air out does far less to cool than pushing air across the surface of the water.

But for the temperatures you're talking about, buy a chiller. That is what this hobby is about: spending more and more and more money until you declare bankruptcy and flee to the tropics.

 

[msmibew683]

sometimes people call me an electrician, iguess i've been called worse. keeperofthefish is right if you go with computer fan use a dc voltage you may even have one laying around. an old phone transformer or some other piece of electronics not used any more. just make sure the input and output votage are correct for the fan. but you better save for that chiller. radio shack also carries many type of plug in transformers

 

[ufans]

Yeah.. Increasing air flow where the lights are is the best way of reducing heat. PC fans are the easiest and cheapest. They all run off 12VDC but you don't have to get a 12VDC adapter....anything lower will just reduce the speed and also reduce the noise. You might just get an adjustable AC-DC converter/transformer from Radio Shack and find the least amount of voltage to keep the tank cool and that will help minimize the noise.

The obvious thing is to eliminate any heaters you are using and allow the night temp to drop a bit lower.

I use to run a PC fan but I found that the noise was too much. I think that keeping the canopy as open as possible is the best approach and then running a fan over the sump is another great one being that it isn't as noisey.

Here is my favorite link on how to create a automatic temperature controller for a PC fan that adjusts the speed (and noise) of the fan based on the ambient heat.
http://www.heatsink-guide.com/content.php?content=control.shtml