We all use fans and chillers to cool our tanks, each has their own disadvantages, lose of water and cost of electricity respectively. I was wondering if we use a fan to blow at the glass of the tank, it theoretically should reduce the temperature too, albeit the fact that it may be slower, but the difference in the temperature should be present, since glass is a good conductor of heat. This would reduce the effect of water loss and negate the high cost of electricity.
I am contemplating to test it out, but I have not the time to run this project. So I am posting out here to see if anyone has tried this before.
It would not work.
The biggest lost of heat when fan blow across the water surface is through evaporation. Heat is lost when the latent heat of vaporisation is taken from the water to transform water into vapour.
The amount of heat loss by convection is much lower than that.
Glass is not that good a conductor.
BC
evaporation of water is an endorthermic reaction (takes up heat) hence the cooling effect is higher.
celticfish
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agree with bclee too! heat are lost throught water evaporation.
glass being blow by fan will not be effective enough to lower its physical temperature, unless intense cooling. somehow i feel that singapore weather are pretty warm at times, and tank temperature be on high side despite fan blowing.
and some hobbyist are more of a concern on getting their tank stay cool, hence cooling tank water are a priority over cost(monthly bill).
Alright, thanks for the input. Will stick to my fan.
mayb u could play around with heatsinks in e water?
next to useless.Originally Posted by Excalib12e
nothing to remove heat from the heatsinks.
thomas liew
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The other idea I have about cooling the tank is to immerse the filter into a container of water but using a smaller chiller to cool that body of water instead of cooling the main tank. Just a theory though, have not tried it yet.
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U can cool the tank more efficiently when it is directly connected. why would you wanna to cool a pail of water to cool the cannister? You trying to scratch your left ear by reaching behind the head with you right hand!
Blowing at glass? glass is not a good heat conductor... you might as well turn the fan to cool yourself... else it will be a total waste of energy.
What I have suggested (was shot down VERY much earlier) is to use a radiator (similar to car radiator) pass tank water thru and fan blowing the radiator... since the water is not expose to air it will not evaporate... But I was shot down, reason Ambient temp not sufficiently low to make a diff. How is 30degreeC air going to cool down 30degreeC water to 26degreeC if no heat is lost by evapouration?
using a fan to cool the heatsinks?
YOu cannot cool sufficently using fans+heatsinks unless there is a significant temperature differential between the tank and the ambient temperature. The ambient temperature is pretty close to the tank temperature. With the temperature gradient across to the heatsinks, I doubt you will ever get any cooling out of that setup.
The mechanism of cooling using a fan over water surface is primarily through evaporation rather than convection.
Similar, when you use a fan to cool your body, it is the evaporation of the moisture on the surface of your body that contribute most to the cooling.
BC
Hi, since mostly agreed that a fan is a better bet I like to know if this fan is better then normal pc fan
aero4lite.jpg
tho evaporation would be more but I think with heatsink water lost would be less I suppose
Fan blowing on alluminium heatsink does cool the heatsink but unsure of the varying degree anyone have suggestion ways to check the cooled heatsink ?
I suppose any suggestion or comments would benefits us
Ok... Let say it again...
Heatsink works on the principle of convection. Heaksinks merely create more surface area for convection. To transfer heat by convection, the body you try to cool has to be SIGNIFICANTLY HOTTER then the ambient temperature. (e.g. CPU, powersupply, transformer, etc.)
Therefore, in the case of the aquarium, it is sometimes almost the same temperature as the ambient temperature. Therefore, it will not work! You will not get any useful heat loss by the heatsink.
The only way to loose heat in this case is by forced evaporation.
When water evaporate, water molecules absorb heat that is equivalent to the latent heat of vaporisation to change from liquid phase to vapour phase. With this absorption of heat, the temperature of the bulk of water lowers.
This is how chiller works too... The refrigerant in the chiller is forced to evaporate by a trottling valve (pressure reduction) and thus absorbing heat from the water. After that the refrigerant is compressed, and it releases heat, then you have the fan to transfer the heat to the surrounding. The cycle repeats... Evaporation/heat absorbed from water ---> compression(condensation)/heat released to surrounding ---> evaporation/heat absorbed from water ---> ....
BC
Well explained.
- eric
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How about using that radiator and immersing it in a container of water that is cooled by a small refrigerant chiller other than using a larger chiller that the main tank require? Where could we find a radiator that won't rust in water? The saving of electric consumption by using a smaller chiller than a larger one is beneficial in the long run. The container of water need to maintain a constant temperature so that the chiller need not be operated constantly. I was thinking of a styrofoam box to hold the water. Is it workable?
If you've learnt, teach, if you have, give.
Don't walk behind me as I might not lead, don't walk in front of me as I might not follow. Walk beside me, as my friend.
Mohamad Rohaizal is my name. If it's too hard, use BFG. I don't mind.
This way will not reduce the demand of the chiller capacity. It will require the same capacity as if you are chilling the tank directly.
BC
E.g. 400ltr of water needs XXX power to cool.... By adding some "thing" along the way will not reduce the power required... to reduce power comsumption the only way is to buy an efficient Chiller (energy efficient Compressor) and allow proper ventillation at the condenser (hot side) so the compressor will not be working OT to cool the tank.
Infact anything along the cooling path is an additional energy sucker. I would Suggest shortest trip from Chiller outlet to tank... Best if you can "insulate" the return piping.
Since the designer of the chiller understood the physic and common sense, why didn't they put the inlet and outlet of the piping away from the back hot air , may be the side ?
At least my chiller's outlet & inlet is on top away from the hot air vent.
BC
Wa pro!!!, keep having the idea of heatsink etc radiator etc. Now understand le.... no use LOL. save me the brainwork. So Chiller or fan still the best choice for tanks. Hmmm.
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