chill

bpeugh · #1 03/26/2007, 09:43 AM

It looks like summer is coming up soon so now I have to find a way to cool down my tank since I do not have air conditioning. I was wondering what people in this area use for cooling their tank besides a chiller. And how do you keep the median temperature so it does not get the tank too cold that the heater would have to keep kicking in? Maybe have the cooler kick in when it reaches 83 degrees and the heater kick in when it reaches 76? I guess I could try to use evaporation to cool the tank but I do not think that would work too well. Thanks.

seldon · #2 03/26/2007, 12:07 PM

Actually, evaporation works pretty well, the only downfall is you either need to manually top off often or would need an auto top off system.

Seldon

syrinx · #3 03/26/2007, 06:02 PM

There is the obvious running lights at night when its cooler- somthing I kind of do anyway due to nightowling. My first reef many moons ago was in a non ac house and I never lost anything because of it- but it seemed touch and go at times. Evaporation is definatly your friend, but I wouldn`t expect a big swing from it- if you want to try it whole hog get some airlifts or other bubblers that will help break surface tension and do the fan thing. you may have to also decide if flow or heat produced by the pumps is better/worse- and maybe use less or more efficient ones. There is the concept of blowing 100 bucks on a cheap AC and running it as sparingly as possible to get you through the few strings of 90+ days is also out there for the grabbing.

Horace · #4 03/26/2007, 08:31 PM

A simple solution is to freeze two liter bottles and just float one in the sump during hot days. Your heater will come on if it cools too much. I would prefer using fans personally because of less hands on.... but if your in a bind...ice works just fine

bpeugh · #5 03/26/2007, 09:16 PM

I don't have a sump and I am running a Hydor Koralia 1 and a Majijet 900 on a BakPak2 skimmer. That is about 11Ws total. I guess I could always freezer a few cooler rod packs and just rotate them out daily in the tank. I wold love to use an AC and there is one in the window but the house is so old and has so many holes it would be cheaper to run a chiller. I plan on using at least two 120mm fans on the metal halide so I guess I could always add a few more during the summer months to blow across the top of the tank.

ChemE · #6 03/26/2007, 09:19 PM

Evaporative heat loss kept our 55 in South Florida 5F cooler than the room. I had to add a gallon a day of RO/DI but that wasn't really any big deal.

Vitaly · #7 03/26/2007, 10:42 PM

You all keep mentioning "evaporative heat loss." Does this imply evaporation facilitated by fans blowing across the water surface...or just plain old, natural evaporation?

Thanks.

ChemE · #8 03/27/2007, 01:03 AM

They are both evaporative heat loss but without a fan it won't happen at a high enough rate to be useful; so fan assisted. You can run through the calculations as to what rate evaporation must occur to dissipate a given thermal load but for my 55 with minimal power going in I needed to evaporate about 2 gallons/day to keep up with things. This was possible with 2 80mm PC fans blowing sideways across the surface of the display. If you're smart (unlike me) you'll position the fans so that they blow from the return side towards the overflow so that they help the surface active proteins find their way into the sump.

Vitaly · #9 03/27/2007, 01:29 AM

What about setting fans to blow over the sump? Are there any major disadvantages compared to blowing over the surface of the display?

ChemE, is there an actual formula that one could use to determine what amount of evaporation, for a given size/volume tank, that would have to occur to lower the temp by X degrees relative to the ambient temperature?

Mind you I purposely avoided P.Chem and I intend to...so if it is complicated I would rather not know ;-)

ChemE · #10 03/27/2007, 01:39 AM

Not as complicated as P-Chem 2 think Chem 101.
http://en.wikipedia.org/wiki/Latent_heat

The latent heat of vaporization of water is 2,272 J/g so for every gram (mL for the uninitiated) of water you evaporate you'll lower the energy in the system (tank) by 2,272 J.

Let's keep things simple: say you have a return pump which draws 100 watts according to a Kill-A-Watt (manufacturer's ratings are max draw not normal operating). This means that we are pumping 100 watts of heat into the tank (debated to death, physics wins). A watt is a J/second (again for the uninitiated) so we need to evaporate 100/2272 mL/second to keep up with the heat the pump is adding. This works out to 1.005 gallons/day to dissipate the heat from the pump.

Hopefully my explanation is clear enough for everyone to work out their own evaporative heat loss needs but if not you know where to find me.

john eichwedel · #11 03/27/2007, 07:24 AM

Horace is right,easy and cheap.Float a frozen 2 litre bottle in your sump.Keep a couple in the freezer for backup.

syrinx · #12 03/27/2007, 07:32 AM

Brett decided about 7 weeks ago not to use a sump on this system. Ice is fine for large tanks but can be problematic with wide swings in temp for a smaller tank.

Horace · #13 03/27/2007, 08:10 AM

Quote:

Originally posted by syrinx
Brett decided about 7 weeks ago not to use a sump on this system. Ice is fine for large tanks but can be problematic with wide swings in temp for a smaller tank.

Another reason to have a sump

bpeugh · #14 03/27/2007, 09:08 AM

I was thinking about using the food-grade super ball sized balls you can freeze and putting some of those in the protein skimmer. I think I would try out a system over a week as to how much I would have to add given the predicted temperature outside. I have also been thinking about the evaporation method and tying to combine it with some of the DIY nano chiller methods that use thermoelectric components from portable refrigerators. and maybe tie that to a thermometer cut off switch for the power.

I did think about adding an under the tank sump at one time but the most I would probably get out of it is 5-6 gallons and it would just be too much a pain. It would probably be better for me just to add a few gallon refug/sump on the back.

Horace · #15 03/27/2007, 02:00 PM

I would not recommend putting things in your protien skimmer. They are already very finicky as it is. Adding some objects in there is almost certainly going to cause it to function improperly. For a small tank like yours, I would just put a good size fan or two in your new light fixture or canopy, that should be plenty. You had just better be on top of your top off or your salinity will change drastically on a small tank like that. Point the fan so it blows across the water.

bpeugh · #16 03/27/2007, 02:19 PM

I was thinking of putting it in the return chamber of the BakPak2. Fans should be on this weekend.

medic29 · #17 03/27/2007, 03:46 PM

I had to add a fan to my sump today. Temp yesterday got up to 84. The original fan I had over my sump began making noise a while back so I took it out of service. Had to run to Wal-Mart and pick up another. Got a 7 inch fan this time. Ought to help cool things off!!

medic29 · #18 03/27/2007, 03:47 PM

It seems the key may be venting around the lights and making sure that ventilation is adequate. I'm curious to how English's tank is doing now that he make those vent holes.

Horace · #19 03/27/2007, 10:41 PM

My canopy has two 1.5" gaps on top that run the length of the canopy. I have fans blowing air in the bottom across the water. The heat is then pushed up or out the back of the open canopy. My tank typically does not get above 82, even on a really hot day.

I am hoping the RK2 I just picked up will help control the heat even better

.

puddldude · #20 03/28/2007, 01:55 PM

I started using a fan yesterday since my chiller wont start. I was very impressed with the temp drop.