Backyard Aquaponics
A place to discuss aquaponics

GF, whats pex?

Its a cross-linked polyethylene pipe. used for potable water, under floor heating and I believe heat pumps where the pex is burried in the ground and the heat is transfered to or from the earth, heating or cooling the home, in a geo-thermal heat pump application. It replaces pvc and copper in homes. Many different types depending on the application and the process used to create the cross-linked structure. Comes in coils of various lengths, size, and of course price, again dependant on the type. Pant

Oh, ok, yeh i see much of this new water lines in domestic roofs when i'm running refrigeration lines.

Couldn't be 1/10th the conductor of heat as what copper is though. Would be a very poor heat exchanger.

catch 22

Not sure about the numbers Steve, it does have better heat retention than copper for sure. Since its used in radiant floor, and ice melting applications, (under the driveway), I would think a big coil of it in a blue barrel would transfer the heat. The 3000 btu from the table top unit only gives enough for a one degree increase in temp (roughly) for a 100lt fish tank, unless my math is off. That's not considering any system losses. If it was easy we could all just buy a kit. Love the trouble shooting. Back to the drawing board.
Pex I believe has a problem with ultraviolet light so not sure if its the same as what you see on roofs.

In roofs Gofish

In roofs! Slap me with a fish, my bad. My math was off also or rather I ment 1000lt fish tank.

We all have those days.

In the unit as it is, how are you going to attach it to some pex for this heat transfer?

If I purchase the table top unit, I emagine I'll go from the copper header, to pvc to the pex coil. 75 meters or 250 feet? coiled in a barrel.

Has anyone thought to use warm air as a heat source, aeration is required so what I was thinking of is to introduce warm air to the system.

Instead of diverting water through a solar heater, introduce warm air via venturi principles. We have all experienced walking into a metal shed that has no air circulation and feeling the heat difference to outside the shed.

The simple act of up-ending a glass aquarium or a metal toolbox in the sun will quickly raise the temperature of the air trapped to well over 30 degrees celcius.

Put the container about a metre above ground, put up a periscope inside the container and suck the air into the water flow, there are a lot of variables to consider but we are not trying to boil water, just increase the temperature gradually.


Les

good thinking there Les.
I like where your heading.

Guys, don't take me as being negative, i'm just playing devils advocate. I reckon anyone with a new idea should go for it!

Just a few thoughts on it

You may find that the temperature drop created by the venturi may cancel out the temp increase from the warm air, but maybe not! (lick your arm and blow fast (37C from your mouth) air onto it. see what i mean?

I'd be more inclined to use warm air fed around the tank walls rather than into the tank.

But go for it!

Yeh - I was thinking that there is a lot of hot air trapped in garages etc and this is mainly where systems are being built close to (ala Monya and even Joel has a covering above).

Will keep the thought and see if I can build on it, see what comes up

Les

I meant to add that this may be a source to tap into

Steve- I agree that there is a chill factor with fast moving air.
So I am thinking the best way to reduce wind chill factor, is to provide a barricade/wind brake though thinking this would reduce gas exchange for the fish.
I am starting to agree with you as the mass of air as aposed to the water mass I feel would be insignificant.
Coming back to creating warm water to increase temp via solar or maybe a header tank within a heat exchanger(solar tent).
To many compromises with added engineering=cost.

yeh, it can get a bit complicated.

Joels gonna be so "i told you so" but, KISS. stock the right fish for your climate and insulate.