Backyard Aquaponics
A place to discuss aquaponics

Ok, this may not be that environ friendly but it is a solution to getting lots of hot water from burning wood.

I run a wood manufacturing company and on the farm where we process reclaimed timber into useable materials for the manufacturing process we land up with massive quanitities of scrap offcuts. We decided to set up this water heating solution at the staff dorm. This type of system is known as a donkey is SA. Usually it is a tank on top of a fire, but this does not last very long as the tank burns through. I decided to build a system with a small thick steel boiler tank in the fire and a large holding tank above which is seperated from the fire. Hot water moves from the boiler tank to the top of the holding tank by convection and forces cold water into the boiler. After making a fire it takes about half an hour for the 300L tank to be heated, and in 45 mins the water is coming out of the TP valve on the tank because it is so hot.

This was my first atempt to do something like this and I am now working on mark two for my own DHW requirements.
We threw a u shaped foundation and built u shaped walls to about two feet and then cast a slab 100mm thick with steel reinforcing on top of the walls. We then built a tunnel for the fire using overburn bricks. A hole was left at the back of the tunnel for the chimney.


A tire was used to form the tunnel. The chimney was built on top and walls built up to contain the tank. The boiler tank was made from a 300mm long piece of 150mm 5mm wall steel pipe with a 5mm top and bottom welded on . Through the top of this two 25mm pipes are welded in. one extends to the end of the pipe and one only just goes through (hot). I will draw a diagram of how the plumbing works. Here is what the whole thing looks like with the fire going.

the pics landed up in the wrong order but you get the idea....

Wood pellets, biomass, wood drops...all wood. bioata will turn it into co2 eventually anyway. I like the use of it from a conservation standpoint. It saves some fossel fuels for the future so our generation doesn't use it all up. And the ash is good for somthing unlike that of coal or the byproducts of nukes. Forest companies replant the areas and it will all be reconverted back into wood. Renewable.
Something smaller could be used to house a small pellet stove for a greenhouse. I like it.

Not knocking it... but an old "technology" revisited...

All the old homes in NZ... which were heated by fire-places, often day & night...

Incorporated what was known as a "wetback".... which cycled the hot water system through pipes in the back of the hearth...

You can actually still buy them in NZ... and they're becoming quite popular again...

Here's a sketch I saved yonks ago.... wetback, solar, and electric backup boost...



Actually seriously considering building something like this, perhaps gas powered... to both heat an AP greenhouse... and the tank water...

I've already got the solar heater....

I am sure before the days of electricity such things where commonplace. My dad tels me that many of the old victorian houses in cape town have copper coils in their flues and those where linked to an open tank in the attic which had a ball valve to control the level and an overflow to let out the water as it got hotter and expanded. I like the idea of combining solar wood and electricity but it is quite herd to do on a practical level as the geyser is normally below the solar panel. \I guess a solar powered pump would need to be employed to carry water to the solar panel. On the subject of smaller... My mark 2 is going to use a small geyser inner for the fireplace with a copper coil in it and it will stand on three legs. I am going to get a new geyser and hook that up to it with a electric backup. There is plenty of stuff on the net about this stuff. Just be warned that insurance companies don't like these ideas

I had a wetback "Everhot" wood stove/oven in the kitchen of an old house I once had. It had a massive all copper tank in the roof space, solar panel and electric booster. It is a great idea as you take all the free heat you can before you need to draw from the grid.

Just remember... using copper piping in an AP system.... is definitely NOT a good idea... especially when the water is both heated... and acidic...

you should look into wood gasifiers. They are far more efficient than doing a standard open-air burn. Usually over 80% and muck lower emmissions. Something like this for a commercially available option: http://www.woodboilers.com/product-detail.aspx?id=45. tons of people also make homemade ones.

Rupert.. if copper is bad for fish, is it not also bad for us?

Deb... Krikey, that looks more like some kind of hightech piece of silicone valley manufacturing plant equipment. I wish I could see how it works. Its like these newfangled motor car engines where all you see is a black plastic box under the hood. I will do a search on homemade ones. I have no shortage of material to burn but would like to have as low a carbon footprint as possible.

I think you will be surprised that the gasification has been around for a long time. It was used in WWII by farmers to run their tractors and trucks when they couldn't get fuel. It's quite impressive what they would piece together!

Both... beyond certain limits.... and with crustacea, those limits are infintesimal... fish not much better...

Humans have a higher tolerance... and generally don't consume water directly from copper piping...

Copper is ionised very readily... especially if the water is heated and/or acidic.... which is why most hot water services are now plumbed with high pressure thick walled poly tubing, rather than copper tubing as in the past...

In AP systems... both the heat and acidicy... often in association with CO2 in the water.... are prevalent.... and constantly recirculating... a death knell for fish....

Hi BF
Ever thought about converting the waste to Bio Char
May be a good way to value add to your business