Sustainable Tangle Ball
This project is about making Tangle Ball run independently - i.e. off the grid.
All are welcome to join in, whether helping, learning or making suggestions.
- collecting rain water for washing, flushing, drinking, etc.
- processing waste water - grey and black
- generating electricity
- anything else we come up with
Feel free to add your thoughts, suggestions and ideas below.
Rain water to toilets
We aim to start simply, with the collection of rain water to flush Tangle Ball toilets.
The building roof is 25m x 10m, so the roof area is 250m^2
Auckland gets an average of 1.1m of rain per year, spread unevenly across the months http://www.metservice.com/towns-cities/auckland
Thus, we can collect around 270,000 litres of water per year.
A full toilet flush is 9 litres, a partial flush anywhere up to that, but generally around 4 litres.
We envisage holding major events once a week, with an estimated 60 people attending and drinking alcohol, for up to 3 hours.
We then assume 3 flushes per event, per person.
Thus total water per major event is: 3 x 9 x 60 = 1620 litres
Assuming it does not rain during the event, we would need to store this amount of water
This is out of scope for an initial foray, as it would require a tank 1.6m x 1m x 1m
We will aim to supply one toilet with rain water, but allow it to be switched from mains to rain water as necessary. This would cover small events/general daily use, but no more.
For one week of general use, we will cover 5 flushes per day, i.e. 35 flushes per week, 9 litres per flush (conservative) -> 315 litres
So, we require a container of some type, at least 300 litres capacity.
A tank has been procured and we are waiting on delivery - should be some time early july 2011. It is 300 litres capcity, and is a re-purposed mussel float, obtained from a mussel farm in the Coramandel.
It is roughly cylindrical, with hemispherical ends and large lugs with a flat surface sufficiently large to support an inlet and outlet connection to a pipe.
The tank position and support
The tank needs to be above the level of the toilet cistern, to provide enough pressure to fill it.
The tank will be situated behind the building, as this is near the downpipes from the roof, and is away from view/interference by passers-by.
The top of the toilet cistern is 1.2m above the internal floor, which is 1m above the outside ground level behind the building.
Thus, we need a support for the tank which is at least 2.2m high.
We could attach to the building, but this would require a lot of large fasteners (probably concrete anchors or similar). These are expensive and will likely cause damage to the wall
We could also support it on a frame sitting on the ground - 300kg would not require foundations, so long as the earth is flat.
Edit: concrete anchors are acceptable in conjunction with a timber frame - this means we can use a narrower frame, as it will be supported from toppling at the top.
We do not have any suitable timber, but there are demo yards, etc. We require 150mm x 100mm treated framing
http://www.jacobdemolition.co.nz/whatwedo.shtml - Drury Lane, New Lynn
http://www.finda.co.nz/business/listing/383w/timber-recycling-company-ltd/ - Glenfield
http://www.nsdemolition.co.nz/ - 1795 Great North Road, Avondale