Evaporative Cooler

[sphelps]

As requested a fairly easy DIY project for effective energy efficient cooling.

The idea is similar to simply running a fan over the water surface. However with this method you're increasing the surface area and contact time between the air and water. In addition it presents the ability to vent the exhaust humid air outside or to a more appropriate location.

It's efficiency is based mostly on the humidity of the air fed into the cooler. The less moisture in the air the better it will work. However the water and air flow should be controllable as it's important to be able to control contact time in order to tune the cooler.

This is one I built myself. More as a prototype, once I figure out what will work best I'll redesign it and likely build it into my new sump.





I designed to fit in the new cabinet.




I built it from clear acrylic, you could use various other materials. Next time I would use mostly black acrylic to prevent light and algae growth.






I connected a 3" PVC pipe line to connect the cooler exhaust air to an outside vent. I also ended up mounting it a little lower than planned for better water flow.



I'm still working on the final design. As it stands it can produce about a 4 degree temperature drop from 84 to 80 degrees on an average day.
System volume is approx. 200g
628W of lighting
2 reeflo pumps
Everything is pretty sealed up and has little exposure to the surroundings for heat exchange.
On the really warm days my place has been getting up to 26 degrees C indoors. It has also been fairly humid lately so the cooler has only been able to drop the temp to 82 degrees. If I run the air conditioner to keep the room with the tank only (not filtration) at 23 degrees C the cooler will maintain about 80.2 - 80.7.

Ideally I would like the new design to maintain the tank temp at 80 without having to run the AC.

I'm open to questions and suggestions.

[michika]

Thank you!

How did you learn to do this? Something job related?

How do you tweak it and adjust it?

[crtrcrzy]

sphelps is an engineering graduate ive seen alot of his stuff first hand and hes also built me alot ,like he says hes always reingineering his early work. i have never been disapointed

[spreerider]

ive used a few evaporator coolers and they all used wicks and a mesh but this method looks alot more reliable for salt water.
good idea, but i bet you will be using alot of water, do you have an auto topoff?

[sphelps]

Originally Posted by michika

Thank you!

How did you learn to do this? Something job related?

How do you tweak it and adjust it?

No problem.

I was researching various heat exchanges and their adaptability to the aquarium and found the evaporative cooler design to be most logical. Researching that I found a few on the market but as stated they use foam which to me seemed troubling so I decided to try something a little different.

I adjust it by paying around with various flow rates of air and water until I find something that seems to work best. The fans are controlled by a variable 3-12 volt adapter and the water with a ball valve. The cooler is fed by overflow from the skimmer so it doesn't require an extra pump. Only power it uses is from 4 low wattage computer fans. Uses less than 12 watts.

Originally Posted by crtrcrzy

sphelps is an engineering graduate ive seen alot of his stuff first hand and hes also built me alot ,like he says hes always reingineering his early work. i have never been disapointed

Thanks Greg, good to see you're happy. We'll have to get you to post some recent pics of your setup. It's been a while

Originally Posted by spreerider

ive used a few evaporator coolers and they all used wicks and a mesh but this method looks alot more reliable for salt water.
good idea, but i bet you will be using alot of water, do you have an auto topoff?

Yes I have an ATO, direct RO hook up. Not sure how much water I use but water is cheap.

[brizzo]

Do you get much salt creep from your design? I'm assuming the pics were fresh after install

[sphelps]

been up and running for a month and no salt creep yet. It's likely to show up eventually but that's why the unit is designed to be easily removed and cleaned.

[rdnicolas]

Interesting idea, how much has your water consiumption increased?

[sphelps]

Originally Posted by rdnicolas

Interesting idea, how much has your water consiumption increased?

No idea, but probably added about a half gallon a day.

[Jack]

The Deltec evaporative coolers use rolled up "DLS"; the closest DIY equivilant I can find is gutter guard from Home Depot. I would give that a shot. It doesn't look like the egg crate is giving you maximum surface area for cooling.