200 gallon reef tank cooling plans ?

[Magnus Petersson]

I am in a planning phase for designing a new 250 gallon reef tank with a 100 gallon combined sump/refugium. Based on experiance form my current 150 gallon tank, I expect I will need a cooling system to bring down the temp with 4-7 degrees if I do not use fans for boosting evaporation.

This is my idea: (I would very much like your comments on if it will work or not).

I live in an apartment in a stone house build in the 1920s with thick stone walls/floors that can serve as heat absorbers. I will totally rebuild a spare bathroom. I plan to imbed a system in the concrete bathroom floor platform that is usually used for waterbased house heating. The system consists of ca 20 meter plastic 20 mm tubing that will be imbedded in the concrete floor platform. The platform will be ca 20 cm thick and casted in direct contact with the stone structure of the building. The idea is that the heat will be absorbed by the concrete floor platform and transfered away into the stone structure of the building. I will circulate the tank water from the sump, thru the 20 meter plastic tubing in the floor and then back to the sump again.

The floor "heating" system is originally designed to circulate water of ca 30 degrees Celcius to give a pleasent temperature in the bathroom. I expect that the unheated temperature in the floor is ca 20 degrees celcius (68 degrees F).

I expect that the temperature in my new tank will be ca 30-35 degrees Celius (86-95 degrees F) without any cooling and with all the equippment i plan to use is in operation. That means I need to get 4-7 degrees cooling from this system without using other cooling devices (like fans for additional evaporation etc...).

For my current 150 gallon open top ref tank i use 2x30 watt fans sweeping over the water surface during 5 hrs daily to keep the temp in range (25-28 degress Celcius / 77-82 degrees F). The fanning result in 2 gallons of evaporation per day.

I would like to avoid fans for my new tank (that will have a closed canopy) due to the noise and high evaporation, without using an electric cooling system. As a bonus I will aslo get my bathroom heated for free. :idea:

Is there anyone who have tried a similar solution ? Will you think it will work ? :?:

 

[Microcosmos]

I think it will work based on your logic and the way you described it, but I have no experience in plumbing or heating/ac to base that assumption on. FWIW, if the setup you propose to design doesn't work well enough with the evaporation above and the heat transfer below, you could always install a chiller somewhere in the pipeline. But that's an expensive alternative. I'd leave room for a chiller, just in case, but my gues is if there's enough contact with the concrete you'l be A-okay. Are any of the sides of the tank going to be in contact with the concrete as well? That maybe could help, but again I'm far from an expert/never tried it myself.

 

[danmhippo]

I thought those floor heating system use metal pipes. I believe there are good reason to use metal pipes because PvC pipe does not transfer heat well.

Not sure if you can overcome this problem.

Not sure where you lived, but does your place room temp dips down to single digits in the winter? It takes more energy to heat up the water then cooling them down via evaporation. I am afraid you are wasting your money in heating up the tank and keeping it warm.

 

[holry7778]

I give you props for the idea first of all, glad to see people trying to break the box... but I think you'll run into several problems...You are based on the fact that the slab will allow you to "dump" as much heat into it as possible. This is not the case. Secondly that slab may want to reverse your efforts and be dumping heat into your system instead. Also the temp difference between the slab and your tank may not be great enough for it to be an effiecent heat transfer.

I think you really need to look into a chiller...the price may not be all of that different by the end of the day.

 

[tom1356]

You can tap into the cold water supply of your house for a DIY low cost chiller.
Use a refrigerator ice maker hook up kit. Add 200 feet of 1/4" poly tubing coiled in your sump and out to the drain. Add a "normally closed" solenoid from a washing machine and a temp controller and you are done. I've use this on systems up to 700 gallons with excellent results.
Good Luck!

 

[Anonymous]

tom1356 described a heat exchanger that use cold water to chill the reef tank. It can be a great idea if the water is cheap. Some use it on water well, and just recycle the water right back into well. Some has a chilly stream running near the property, and use the heat exchanger method.

However, if the price of water is high, you may want to reuse the water for RO/DI (some people are trying to heat up the input water for RO to get more filtered water out of it, and why not try to kill two birds with one stone?), or run the water to a swimming pool.

 

[Anonymous]

tom1356 described a heat exchanger that use cold water to chill the reef tank. It can be a great idea if the water is cheap. Some use it on water well, and just recycle the water right back into well. Some has a chilly stream running near the property, and use the heat exchanger method.

However, if the price of water is high, you may want to reuse the water for RO/DI (some people are trying to heat up the input water for RO to get more filtered water out of it, and why not try to kill two birds with one stone?), or run the water to a swimming pool.

Take your origional idea outside. Bury 2-300 feet of plastic tubing underground (below the frost line) and you can then use a heat exchanger to cool your tank. This method is often used for tanks in a greenhouse.

 

[Anonymous]

Isn't there a fellow reefer use buried PVC pipe to chill reef tank in a green house? I think he lives in FL, and pick up a few tons of SouthDown sand in his pickup for like pennies a pound... anyone know who I am talking about?

 

[Anonymous]

I know the project you are talkning about, but I can not remember his website for the life of me.