Frame by frame

December 31st, 2007 - Posted in eco-building - by Sarah|

We have managed to start cutting the untreated Lawson Cypress timber for our workshop before the end of the old year.  We cut the top and bottom plates and the studs for the 6m long rear wall this afternoon.

The timber lying flat along the back  of the workshop where we will assemble it before lifting it into position.

The morning was spent sorting our timber by size and planning what cuts should come from which lengths in order to ensure that we minimise wastage and don’t run out of wood (and have some contingency just in case).

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Chilling thoughts

December 29th, 2007 - Posted in eco-building - by Sarah|

We have decided to buy a fridge that will live in our caravan awning for the time being and then be moved into the house once it’s ready. The small 3-way fridge in the caravan pumps out heat – which was very welcome in the winter but is stifling now. It also doesn’t have room for any veggies and we’re finding that they go limp and slimy before we can eat them. Finding the right fridge was a matter of balancing out the amount of space against the initial cost and the ongoing energy usage. The most useful resource we found for selection of model was the Australian Energy rating website, where we got size and kWh (kilowatt hours) figures for the different models shown below. While this doesn’t have every single latest model, it covers enough for some clear patterns to emerge. The most significant of these is that many manufacturers are obviously not trying very hard to make their fridges energy efficient. They also have pretty rigid views on the size of fridge that people want.

Our main concern was to minimise energy usage. About 60% of New Zealand’s electricity comes from renewable sources but many of these are hydro schemes that are environmentally questionable as they disrupt eco systems that have developed over thousands of years. The other 40% comes from the burning of fossil fuels. On the west coast alone there are literally hundreds of resource consent applications currently under consideration in relation to proposed new hydro generation schemes designed to meet NZ’s ever increasing energy requirements. We hope to move off the grid at some point in the future so it was also important that the energy required by the fridge was in a range that we could feasibly generate ourselves.

We felt that the first step in ensuring we were only using as much power as absolutely necessary was to pinpoint the size of the fridge to what we actually needed. We narrowed our search down to single door refrigerators in the 100 to 200 litre range. There are 103 fridges in this group. The average size is 120 litres and the average kWh per annum is 294. More tellingly 90% of the fridges are between 108 litres and 130 litres in size and used between 270 kWh and 315 kWh.

We wanted somewhere between 150 and 200 litres as less than this would mean more frequent supermarket trips (our ideal is to limit these to once every 3 or 4 weeks while we’re building and tail them off to nothing once we’re concentrating on growing food). More than this would mean that the fridge would only ever be full if we added stuff specifically to fill it up (eg water bottles) in order to keep it running at maximum efficiency. This size requirement limited our choice to 4 models from 4 different manufacturers.

We quickly narrowed our choice down to 2 – the cheapest, F&P at 192 litres and the most energy efficient, Gram at 153 litres. The F&P was on sale locally for $799 (normally $999) in Noel Leeming’s 20% off 3 day Boxing day sale. The Gram was available from GoSolar in Rolleston for $975 plus $55 delivery. In the end it was the energy efficiency that made the difference. If energy prices stay as they are now for the next 10 years the Gram will have cost us $41 more than the F&P, assuming that we were able to run the bigger fridge at peak efficiency by keeping it full of cold stuff. The cost does not have to go up by much for us to be better off with the Gram fridge.

So we have been able to buy our preferred option (ie the lowest energy usage) AND feel that we’ve made the best value for money decision too.

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