Backyard Aquaponics
A place to discuss aquaponics

Water... that circulates from the inner core... see above....

That's how I read it, but I thought I must have misread. I don't understand how this would be anymore efficient than just runing it through a finned tube???

To circulate it VB... you'd have to have a loop pump>array>exchanger>pump...

This way you can pump from array to exchanger... back to array...

Not sure on efficiencies... and really don't want to talk about them just at the moment...

Just a design as a result of a general scenario... still to be tested by myself... and I'm still to be convinced as well..

Not sure that first part made sense.... I'll think about it.... can't edit it....

Ahhh, so there IS a heat exchanger!
Does that go inside the vacuum tube, or inside the fish tank rupe?

Rupe - yes, it doesn't make sense

Steem - now you are really confused, or are you just taking the piss

If the heat exchanger is in the tank, then you can run separate water (or any other fluid) in the tubes, and use copper like a normal household hot water system. If it's in the tubes then you can run fish water through the whole system. In which case why use a heat exchanger

lol. There is no heat EXCHANGER as such. the water is EXCHANGED from the tank at the top of the array to the fish tank ....

Or I could just read this I swear it wasn't posted yet when I wrote that tho VB
Monya, you just confused me even more. Off to read the thread again

wasn't trying to... honest...

No, no , no... the water from the solar array... in the trial system case... fish water...

Is pumped through the tubing in the fish tank...(not into the tank)... thus the water heated in the array passes/exchangers heat from the stainless tubing into the tank water...

And yes Steem is absolutely correct... as there's no exchanger of "water" from the array to the fish tank...

The array itself can be the traditional copper heat pipe/copper exchanger/header tank style utilised for household hot water systems.... which by there nature generate heat from the array of about 60+ degrees...

The intentions are...

1) To trial this as a seperate scenario... to compare it to the current setup...

i.e.... would running a high heat solar unit exchanging heat to the fish tank... be more effective than circulating the fish tank water through the stainless array as in the current array....

OR.....

2)
Can we utilise this stainless exchanger (in conjuction with the current setyup)... to extract/heat a smaller (seperate) insulated body of tank water that can pumped via a timer during the night perhaps.... ... perhaps with supplementary electric boost heating of the "smaller" incorporated tank....

3) By adjusting the delta temps on the controller, can we heat the fish tank directly in conjunction with the current setup... remember the volume of water passing through the exchanger tube will be very small... as such wont require a huge amount of energy to heat.... and will be almost continuous...

All just ideas/refinements....

Looking on your spreadsheet, there's a couple of fairly large temperature swings over a couple of days. Do you think the fish will be able to cope with this?

Yep, a concern KEII... both significant temperature drops occurred during extreme and very rapid weather events, where the air temperature dropped 8+ degrees in a matter of hours...

Remember the tank in the trial system is uninsulated and exposed ... although covered...

In many ways its similar to an aboveground pool in a backyard....

Also, as i noted... there's no agitation, other than the inflow from the pump cycle (usually about 5 mins, 2-3 times/hr).... no airlines, and only small volumes of flow...

As opposed to a normal return from a series of flood and drain growbeds... the tank turnover is probably only about once a day max...

And circulation within the tank is minimal...

I believe in both occurrances.. the tank was probably stratified... with the top layer of water suddenly cooling below the temperature of the water lower....

"Inverting"... mixing... and pulling the temperature down quickly...

Think you'd see a similar situation occur in any exposed small body of water... ie backyard pool...

But I recognise (and foresaw) the possibility that such swings could occur any present problems....

Hence the pending refinements... including utilising the controller to trigger heating element(s)/source(s) if the tank falls below a set point....

Just too much going on at the moment with a pending trip to Grafton and immenent arrival of fish...

Well returned from Grafton on Saturday morning... 28 degrees by 10:00 am....

Tank was registering 26 degrees... .... didn't seem right....

Realised the pump didn't sound like it was kicking in.... checked the array tank temp.... 43 degrees......

Turned out the pump had sucked some half eaten carrot into the grill and was hardly pumping....

Cleaned it, .... dumped about 50% of the tank water, which was getting a distinct algael tinge... and re-filled it...

Tank temp came down to about 24/25... restarted the solar pump and dumped a couple of hundred litres of (quite) warm water into the fish tank.....

Tank was back to 28 degrees by 15:00... and everything was good....

Note to self.... recheck all the silicone joints on Sunday.....

Basically spent Sunday morning snoozing/recovering from hayfever... and the afternoon in the gardening and measuring up some pipe.....

With the intention of cutting in an extra line from the solar array pump....

To supply a couple of trickle tower bio-filters... so I could move the yabbies and stock the 1500ltr tank with Silver Perch fingerlings....

With the added bonus of being able to open the pump out... rather than running it throttled back as it has been...

All fine.... figured I'd do it Monday.....