Backyard Aquaponics
A place to discuss aquaponics

Hey Hex, I'm googling tonight and I found this link:
http://www.graham-mfg.com/heliflow.html

I've been looking for some thin wall tubing but haven't had any luck. The latest plan involves the black vinyl tubing I'm already using. It is about as thin as I can find, and it isn't too rigid to make a coil from.

The designs in mind were to wrap three layers of coils around something about bucket-sized in diameter, with the tubes touching in a hex-shaped pattern to try to help the heat flow from one tube to another. Looking at it in cross section, the fluids in the tubes would be going in opposite directions from their neighbors.

Tonight I am thinking about saving money on tubing and using the idea that would be similar to pipe-in-pipe and the helical coil types where the tubing is totally immersed in the other fluid. I am thinking now about wrapping a coil inside a wide diameter PVC pipe with the other fluid running between spaces between the tubes. That would transfer better because it avoids the crappy contact of separate coils and double layers of tubing material. So to make that it would involve a pipe inside a bigger pipe with the tubing coiling in the space between them, hopefully just enough to fit the coil inside the gap. Caps and/or reducers to take the coil out of the middle and to pump water into the big pipe.

Nine months later, I've finally made a pipe in pipe heat exchanger. Haven't hooked it up yet but high hopes!

The idea is that a pump in the sump will go on maybe twice a day, pumping solids that have accumulated in the sump up to a growbed outside. The warm water goes up the zigzag in the inner pipe (3/4" thin wall PVC). The bed will overflow immediately and drain down the zigzag in the outer pipe (1 1/2") back to the sump.

Will post more pictures after it's been tested.

okay, I finally got to read what the modern art was about looks intriguing Dave

Whats the ambient air temp of the basement Dave?

That is "cool" DD! Let us know what temperature differential you get on the return flow.

Did you have many difficulties assembling the pipe-in-pipe?

In short it was kind of a PITA until I figured out a less-half-assed way of putting it together.

The ambient air temps in the basement are comfortable, because we watch TV down here and I have a heater running in the fish area when the weather is cold. I will be covering the pipes with insulation at least to keep the warm water from getting cooled down by the wall rather than the incoming water.

I'll get you better pictures this weekend when I hope to try it out.

My prediction is that the return flow will be kind of restricted, and I will have to dial the pump flow back using a bypass. I was also concerned about "latency", that the return flow would be slow to commence and so heat would be pumped outside instead of exchanged with incoming water, but I think that if I make the drain outside with an adjustable level that I can push it down to just at the water line before starting the pump, so that water starts draining down as soon as possible.

hey dave!

i was having pretty much the same thoughts i think

i have choosed to use trout and therefore i was thinking on how to remove some of the heat

i have a cooler place behind the house, the sun never gets there, so i was thinking on pumping the water from the FT to a second tank behind the house, slowly throughout the worst heat of the day, and over the night i would stop the cycle and let both tanks to cool off,
so basically i'd use the tank behind the house for cold storage that can be used for cooling my system

i will also mount a fan blowing on the FT surface, that helps a lot with removing the heat if the pump is running

i want to avoid any kind of heat pumps or generators, that is my moto, low energy

Are you still trying to work out how to capture the heat from the warm fish tank going to the greenhouse?

If you are then perhaps do what the WVO guys do when they heat the vege oil with the warm coolant from the engine.

They use a lenght of tube inside another tube to transfer the heat from one fluid to the other.

WHat you would do is run the warm tank water to the greenhouse through the outside hose and the return water to the fish tank through the inside hose. Thus transfering the heat to the return water line. Insulate the whoe thing with foam tube to make it more efficient.

There is an entire thread on various versions here:

http://www.biofuelsforum.com/svo_users/ ... anger.html

Does this help?

And here is some more info:

http://www.bio-power.co.uk/exchanger.htm

Thanks H, that is exactly what this is. It only looks funky because it has to fit on the wall so it's a zig-zag shape.

I tried to demo it for JP when she was here on Saturday and it turns out one of the pipes is loose or the drill holes are leaking a lot or the pipe is clogged because there was almost no flow outside. I haven't had a chance yet to look into it. I may have to take it apart to figure it out and I'm not looking forward to that.

When it was first hooked up there was some leakage but there was flow upstairs too. I am wondering if I didn't get it back together securely when I plumbed up the irrigation grid for the bed upstairs.