Backyard Aquaponics
A place to discuss aquaponics

where are all the plumbers?????

Clogs has the right idea... Hooking up a car electric water pump, I think they're about $150 from repco. You wouldn't have to worry about the heat breaking the pump and with the controller you can set it to keep any temp you want, the controller should have a thermostat you can adjust. They run about 8amps max so if you got a 12v 10 amp stepdown transformer it should work no worries. might be a darn sight cheaper and it'll run continuous just like it would in a car. Have a look at a Davis Craig EWP80 water pump.

Have you thought about getting an old hot water system tank to keep reserve hot water in?

In that case, a header tank with the pressure release venting into the tank would suffice. A float valve in the header tank would ensure that the system did not boil dry on days when the heat input exceeded heat taken to FT.

There is no need for much height with the header tank. The Heat Exchanger (HEX) should be in the pipe going to the bottom of the collector panel.
A small bore pipe connects the header tank to the bottom of the panel, the top of the panel has a Tee with the bar of the tee vertical, going to the header tank and the leg of the Tee horizontal, going to the HEX.

Regards,
Tony

I wasn't planning on using a header tank (only because I hadn't thought about it), but if I have a shepherds crook then I would loose a bit of water as the pressure steams out and could potentially run the system dry. Is there such a thing as an expandable bladder that I can use instead to connect to the t off from the top of the panel. This would capture any water or steam, and then when the system cools off the water will be sucked back in, a bit like a car radiator overflow. Come to think of it, would there be a truck sized radiator overflow, around about bucket size, which I could mount on top of the panel? Any other suggestions for a cheap DIY header tank?

Had a chat to a mate (former mechanic) yesterday who didn't know of any external water pumps (thanks for the above link by the way) but suggested that an oil pump would do the trick and would be well able to handle the temps. Only question, are oil pumps able to pump water or do they require the lubrication that the oil provides?

Another suggestion he had was to use 1 inch car water tube, which will be well able to handle the temps and pressure if the water ever got too hot (I dont think poly type tubes will cut it). He thinks you could buy it in long lengths (eg 10m) but I'd have to find out if its within my budget.

Finally as a heat exchanger he suggested a air cooler "thing" from a truck turbo charger which I might be able to find at a wreckers. He thinks they may be stainless?

Thoughts?

I don't know what you have in Australia, but here in the states I would find a circulation pump from a residential hot water heating system. They arn't very expensive new, and in my area they are readily available from scrapped boilers. They are very quiet and made to work continuously for years.

Strange

Hard to source over here, not much call for hot water heating.
KE most of the intercoolers I have seen are aluminium (good heat exchange), not sure about trucks though. Steve is probably your best bet for finding out where SS heat exchangers are used (food industry tends to use a lot of SS).

Oh and car radiator overflow tanks come to mind re the venting.

Would aluminium be OK in a fish tank?

Lots of debate about that, personally I would not use it because I think it would degrade fairly quickly in FT water.

There is a product called yorkflex which is a poly pipe for hotwater. Should handle whatever temps an absorbtion hot water panel would produce. WOuldn't say the same for a reflective panel.

Simple header tank is a Toilet cistern. Plenty at the recycle shop at the tip or the kerbside swap meet. They have a built-in float valve and you can put your shepherds crook back in the top, where it sprays the hot water on top of the water there, assisting in condensing the steam.

I have one here in Vitreous china, which I may use at some time in the future.

Tony

I partially take back the comment about central heating pumps not being available in Australia.
Verge pick up yesterday scored a calorex heat pump. Comes with a Stuart Turner pump RG500 (only 80 celcius but thats not bad) used for the heat exchanger. Only downside is the motor ambient air should not be above 40 celcius (not a really problem for winter).
Condensation water was removed with a dosing (peristaltic) pump and two water level sensors (handy).
Would start looking around for old heat pumps KE

Hi KEXIV,

Any progress on your solar heater?

UMMMmm,,maybe better take it fully back. Those hot-water circulation pumps are in nearly every large building in Australia,,,I'm sitting about 8 metres away from one right-now.
In a large building , many showers , wash basins etc etc , they use a ring system ,,water continually pumped around the ring and each outlet attaches to ring so you don'thave to wait 10 minutes to finally get hot water.
They're on ebay as well. About $90.

Best of luckwith this and please keep us up to date on success / costs etc.

If you are still looking for a stainless heat exchanger how about the one on this page: http://www.beerbelly.com.au/beerequip.html

Look down the page at : Stainless Plate Chiller Heat Exchangers

He's also in Adelaide so there is no great postage costs to worry about.

It already has BSP threads and you can have your fish tank water seperated from your hot liquid.


H.