The solar herb dryer under construction at Living Waters will be the largest of it's kind in the southern hemisphere. The aim of the project is to stimulate a herb industry in the region as a viable alternative to the entrenched wheat-sheep-canola agricultural systems. These are inherently unsustainable in their use of synthetic nutrition and high dependence on fossil fuel.
Over $25 million worth of herbs are imported into Australia annually, most of which could be grown here given our diverse climate and geography. Many herbs thrive in less than perfect conditions, and being less hybridised, are not so prone to the usual diseases and pests of agriculture. They compliment small regional economies, provide opportunities for value adding, and it is a market where quality and organic count!
The building forms the focus for us as a community at the moment, and will offer various facilities to enable residents to make a living from home. As well as drying up to a tonne of herbs a day, there will be a registered kitchen for value adding or catering for functions that could be held in the facility.
Funding has been from private and government sources. Rural Industries Research and Development Council got things off the ground, and it is now 75% complete. The RIRDC web site will have details of the project outcomes.
The design of the building is based on the Golden Mean, a number by which all living things are structured. Classical architecture uses these proportions, and it generally produces a very pleasing result. Whereas Pi is the formula for circles, Phi is the formula for spirals. Starting with a chosen dimension, in this case 20 metres, the next wall is calculated by dividing 20 by 1.618033 (represented by Ø) giving 12.3 metres. That figure is divided again by Phi, and the result is ever decreasing room sizes. When an arc is drawn from one corner to another, connecting all the rooms a spiral emerges, and a spiral staircase will be at the "heart" of the building.
Load bearing walls are made of rammed earth by a local contractor, and the upper storeys are of locally milled timber, put together by some skilled carpenters, a lot of wwoofers and other helpers. Upstairs will be space for teaching, meetings and workshops and catering for the needs of those kind of functions, including a library and computer room for "quiet study".
A verandah to the south overlooks the beautiful Wilson Inlet, an inspiring place to work, rest and play.
OPERATING PRINCIPLES
The innovation in the process is in the storage of heat gained on a sunny day. 1800 square metres of solar collectors on the roof, heat up water that is pumped down to below the drying chamber. In the floor are "Eutectic salts", or Phase change materials, that are encapsulated and melt at specific temperatures, absorbing excess heat during the day as they melt, and releasing that heat as the temperature drops and the salts become solid again.
With this system a steady temperature can be assured, and it cannot become too hot. Air will be circulated, and pre-heated in a glass houses on the northern aspect, using the rammed earth trombe walls to maximise natural air flow.
