One of the new 'designed' compost bins that warrants further investigation is the Aerobin 400. It was launched in Australia in 2006 after 10 years in development. The company behind it is Global Environment Management based in the United Arab Emirates which is a joint venture between an Indian and an Australian company. The product has been in trials at Swinburne University in Melbourne and consistently outperformed the other bins tested in terms of the compost quality. Now it is being launched in the northern hemisphere.
The Aerobin was designed to address some of the common problems of home composting: having to turn the compost, composting being too slow and stopping in cooler weather, protection from vermin, and loss of nutrients. The bin has an air tube in the centre, the patented 'lung', that distributes the warm air around the inside of the bin. The reason for turning compost is to make sure the decomposing organisms don't run out of air and die. The lung is to ensure this never happens. As long as microorganisms are alive and well and multiplying heat will be generated and the decomposition will be faster.
The Aerobin also has a double wall to improve insulation so that heat generated from inside remains there,even in winter. The warmer the composting material the quicker decomposition occurs and the compost is ready. The bin is soundly built as you can witness from the video clip on their website. The plastic sides slot together with a very satisfying 'c-lick'.
It is very difficult to gauge the efficacy of any compost bin because however much designers try and design the operator out of the system, you can't! Was it the bin or the loader that was at fault if it doesn't turn into sweet smelling crumb? Composting follows some simple rules. If it is too wet it will stink and not rot well. If it is too dry it will sit there and do nothing. It becomes too wet or too dry largely by virtue of what goes into it. Therein lies the art of composting.
The designers of this bin have patented a lung to ensure there is always air flow within the bin so that you don't have to turn it, but do you anyway? In fact it may not be necessary to turn compost if the pile is layered with the right materials. Alternating soft nitrogen-rich materials such as grass mowing with bulkier carbon-rich materials like straw or flower stems means that air is trapped in small spaces throughout the heap. The straw takes longer to break down than the grass which collapses quickly, so the compost is prevented from becoming anaerobic and smelly.
The vendors claim that the Aerobin generates sufficient heat to ensure weeds and seeds can't survive. This would be a major achievement for a home composting system as they usually don't get that hot. In the trials the Aerobin did reach a high of 55ËsC which would indeed kill weeds and seeds. However this was a brief peak and there were many fluctuations in temperature during the course of the test period (plus it was in an Australian summer). The temperature would not have to stay at 55ËsC for long for seeds to become non-viable but if that was only reached once during a year, when the external temperature was high plus the bin had recently been fed then you would have to wait a year before being sure that your compost was weed free. In the northern hemisphere ambient temperatures maybe considerably lower and the critical high temperature never reached in some years. Buying a thermometer to go with your Aerobin might be a good idea so you can be sure one way or the other but if it fails to get all that hot you can't take seeds out!
Despite the claims that this is a hot composter the makers suggest not putting in meat, fish and oils. In a vermin-proof closed system this seems an anomaly and if you are spending this much on a compost bin you would want it to be able to cope with these items, after all other closed systems do. It may be more to do with strict Australian laws than with what the composter is capable of.
Aerobin 400 has received high praise from the Eden Project in Cornwall and along with the Australian trials it does seem to reach the parts other bins don't. If you're seeking the holy grail of hot compost for either rapid results or to destroy seeds or pathogens, this would be worth exploring particularly if you haven't much space. This is almost the same size as a regular plastic cone but certainly will reach higher temperatures than they would. The price you pay for this luxury is GBP 250 or USD 349.00. There are other ways to achieve these results however, it's just a case of understanding a little more about how composting works. To find out how see the link below.
| Price : $142.00 | Post Date : Dec 25, 2011 16:52:53
