fan cooling powers.

[ctenophors rule]

so I am being told that fans would be a viable cooling source for an aquarium in a 90 plus temperature room, keping the water below 86 degrees.

now I am wondering how this is possible. I would think that the fan would increase the rate of which the tank water equalised with the room temp.


thanks for helping me to understand. if you need more information let me know.

 

[billsreef]

It's called evaporation cooling. As the water evaporates and changes state from liquid to gas it caries off energy in the form of temperature. Google "swamp coolers" for a bit more info.

 

[JHemdal]

...and it won't work really well in Florida, where you live - too humid (grin).

We took that idea a step further and connected the fans to digital temperature controllers. Now - if the water temp rises above the set level, the fan turns on. When it cools back down, the fan turns off. Saves energy and avoids over-colling.

Jay

 

[usefulidiot213]

Where did you get the digital Temp Controller?

 

[GreshamH]

Do a google search for Ranco EMC Controllers... many people carry them and they're pretty much bullet proof.

I know places like Marine Depot carry them.

 

[ctenophors rule]

It's called evaporation cooling. As the water evaporates and changes state from liquid to gas it caries off energy in the form of temperature. Google "swamp coolers" for a bit more info.

ok, i have looked into the concept but can not for the life of me figure out how the movement of air will cause the evaporation? if your heeting up the water it will evaporate faster, but that seems like it would be counter productive. and the friction of the air moving across the water, plus water having a lower temperature would make the water gain more heet, no?

 

[kev24k]

Pour a bucket of water over your head. Sit in a room with no air movement, and then go run around. Report back which feels cooler.

 

[ctenophors rule]

ok kev, why does this occur?

also is their a difference between cooling non water objects like our hand and water? the water would almost certaintly have less time to interface with the air in a tank...?

 

[cham]

I'm in Florida and my sump and frag tank are in the garage (110+ degrees). The main tank is in the house (76*) and fans have no problem keeping up.

 

[kluivertfan2]

I'm pretty weak on physics but this is how I understand it.
Evaporation is a naturally cooling action because it takes energy away from the source of evaporation.
As the water evaporates, though, it saturates the air directly above the source (100% humidity or so). Because of this that air can no longer tolerate any additional evaporation, thus stopping the evaporation/cooling process. (This is also illustrated in "dry heat" folk wisdom. Dry heat is more tolerable because your seat evaporates easier, more effectively cooling you off.)
Now, in order to stop this from happening you need to constantly provide lower humidity air to keep the process going, this is where fans come in.
If you are in a place that has naturally occurring high humidity, fans are less useful, because the new air is already saturated, but if you are in a "dry heat" region they are.

 

[ctenophors rule]

I'm pretty weak on physics but this is how I understand it.
Evaporation is a naturally cooling action because it takes energy away from the source of evaporation.
As the water evaporates, though, it saturates the air directly above the source (100% humidity or so). Because of this that air can no longer tolerate any additional evaporation, thus stopping the evaporation/cooling process. (This is also illustrated in "dry heat" folk wisdom. Dry heat is more tolerable because your seat evaporates easier, more effectively cooling you off.)
Now, in order to stop this from happening you need to constantly provide lower humidity air to keep the process going, this is where fans come in.
If you are in a place that has naturally occurring high humidity, fans are less useful, because the new air is already saturated, but if you are in a "dry heat" region they are.

so will the water still evaporate if the air temperature is higher than the water temperature? especialy with a significant gap of 10-15 degrees?

 

[kluivertfan2]

so will the water still evaporate if the air temperature is higher than the water temperature? especialy with a significant gap of 10-15 degrees?

yes, the only thing that will stop it from evaporating is a when the humidity gets too high. In fact since warmer air can hold more moisture it will evaporate better.

EDIT: Just to clarify the temperature of the water is more responsible for evaporation than air temperature, but air temp is also important.

 

[NadMan01]

the amount of water that will evaporate is dependant on how much humidity is in the surrounding air and the temperature of the surrounding air. Here are a couple articles i found on the subject.
http://wiki.answers.com/Q/Why_is_evaporation_a_cooling_process
http://www.newton.dep.anl.gov/askasci/phy00/phy00130.htm

 

[phishybiz]

I was able to lower the temp in my tank from 82 down to 77 with the addition of a cheap 4" fan from Walgreens ($9.99) I set it up on left side top of the tank and blowing to the opposite side of tank. But the evaporation really increased. I now need to add up a gallon of water a day! Tank is only 75 gal.

 

[digitalchrisg]

I was able to lower the temp in my tank from 82 down to 77 with the addition of a cheap 4" fan from Walgreens ($9.99) I set it up on left side top of the tank and blowing to the opposite side of tank. But the evaporation really increased. I now need to add up a gallon of water a day! Tank is only 75 gal.

I am in Florida and do about the samething in the summer time. You may want to look at getting something to auto top off if your not already doing that.

 

[Maivortex]

Your body cools itself in the same way-perspiration

 

[usefulidiot213]

My tank will get up to 89 degrees during the summer. I have a camping fan that I have turn on about 30 minutes after the MH turn on, and my tank stays around 78 - 79 degrees.

 

[epstein]

I do the same except with my aquacontroller jr.......Fans clip to sump.....and in Summer .....I will also utilize an oscillating fan standing in front of tank on same temp trigger

 

[vitalik4eva]

don't mean to be pessimistic here, but with all pumps and lights you'll find it impossible to cool tank down below the ambient temperature. I'm having hard time keeping tank temperature 10 F above ambient (it raises higher) at my place: room temp at 70 F and tank temp at 80 F (fan goes on quite frequently)

 

[smcfall176]

don't mean to be pessimistic here, but with all pumps and lights you'll find it impossible to cool tank down below the ambient temperature. I'm having hard time keeping tank temperature 10 F above ambient (it raises higher) at my place: room temp at 70 F and tank temp at 80 F (fan goes on quite frequently)



I think you need more fans then. I run 2/ 250 mh and 1 400 watt mh and wil fans only on a acjr controller I keep my water at a steady 78.0- 79.5...I have one fan on each mh and two pulling air out of the canopy. Works great!