Backyard Aquaponics
A place to discuss aquaponics

Hi all i have been trialing a cooling system with radiators from the scrap heap at work ,2 radiators conected in series inside my old beer fridge which justabout freezes all the time,over 3 weeks the difference is only 1 deg maybe some more modification will make it more efficent, at this stage i dont think it is worth going on with it, but nothing gained nothing lost.
Jim.

Radiators as in cars? They are filled with copper and the chemicals that run in the water. Okay if you are using a heat transfer to the FT and not running AP water through it.

Yes auto radiators with ap water running through they are aluminium with plastic tanks and have been dismantled cleaned and modified.

Jim , I'm not poo poo-ing the idea ,, just trying to get my head around it.
So you mounted two car radiators in the fridge and plumbed the tank water through the radiators?
I think the problem is heat ( cold ) transfer ,, radiators work with large air flow.
probably better off somehow having the water actually in contact with the cooling coil ( the cooler plate? ) trather than trying to use the cold air to cool the water.

Guys, kilowats of heat from the sun, versus 100's of watts of heat removal from the fridge. Guess what wins.

shade:)
I get the point OBO ,, but still worth a try.

Yes, it was worth a try for the first couple of people that tried it, but not when 20 have tried

It works for an aquarium, but not an outside system.

Lay the beer cooler down, line it and use it for the tank
But what about the beer

I hear you OBO ,, but what about heating ..... copper ,, solids removal
It does get repetative ,, but who knows , one day maybe someone tinkering with cooling a system may accidentally find a way to heat a system that was not thought of previously,,, highly unlikely but who knows.

Beer ,, AHHHHHH it's cruel to mention Beer at 1:00am AND I am at work

Some people get the idea and instead of searching to see if anyone else has tried it, they try it themselves.
Other people even through they know others have tried it, still have to try it them selves since they learn by their own experience rather than trusting others.
Then again, many just don't even think to search or when they do search the returned answers seem to have no relation to the info they are seeking so they give up and try it for themselves.

Now I know of a system for heating and cooling that the same hardware will work for both. The same black tubing that will work as a solar heater when run during the day, can be a very effective radiant chiller when run on a clear night. (The chiller option isn't as effective here in humid Florida but in a dryer climate that has clear nights, radiant cooling could probably give you more temperature drop for the electrical usage than any beer fridge.) Just hook up the pump feeding the cooling system with a timer that turns on at dusk and off at dawn (or probably have it wait till later to turn it on if the weather is really hot.)

I also understand that in a dry climate, evaporation cooling is effective. Simply place a fan such that it blows air across the surface of the fish tank water.

The sun is approximately 1kW per sq metre.
So a small system would need a bigger aircon to cool it than most houses use. At great expense.
A fan and avaporative cooling of the radiators would be an interesting trial though.

Or a bush fridge principle. Evaporating water keeping an inner chamber cooler. FT would have to be the inner chamer so a big fridge.

Dufflight, we have just had a day of 42.6C and I managed to keep water temp below 27 by using your Coolgardie fridge system. I insulate the FT's and sump and place wet bedsheets over polypipe hoops across the GB's with a mist sprayer and tent fan inside for evaporative cooling. Works well on short sharp high heat days like today, but I've managed to keep it below 28 when we've had 4 or 5 days of hot weather in a row. I sometimes have had to add extra cool tap water when temps are getting too high (no Chloramine in our water here).

Talk about raising a topic from the dead...

The question to ask about the usefulness (or not, and ignoring metal toxicity) of using a bar fridge to cool your AP water, is how long does it take to freeze 1 litre of water? See p1 of the below thread to see what 1kg of ice will do in 1000l of water.

viewtopic.php?f=11&t=26563&hilit=laws+of+thermodynamics

My small system has just hit 23C on a 38C (so far) day, but daily maxima have been in the range of 30-37C all except 2 days in the past 4 weeks. The main cooling system I'm using is running the water pump 30-45mins/hr in the cool of the mornings before the sun hits, and cutting back to 5 mins/hr through most of the day, before gradually increasing pump times a few hours after sunset. I might drop in some 3kg ice blocks over the next couple of days to clip the maxima a bit, which are forecast to be as hot or hotter than today.

Talk about raising a topic from the dead...

Yes Gunugulla, it was a resurrection of an oldie alright LOL.

But keeping fish cool in summer is still as relevant as ever. I think evaporative cooling is the best option in hot and dry conditions like here atm.(I know Sydney is suffering in 47C plus this week and I assume that would be much higher humidity so I really hope all the up APers that way are coping OK).