Thursday, 23 June 2011

the grinning bogan

I spotted this image on a web page today



and it mad me think for reasons I can't explain Julia Gillard reminds me of Wallace from "Wallace and Grommit"

not in the personality of Wallace, but in the mannerisms and simpleminded-ness




I wonder if "Julia Likes Cheese" ...

Sunday, 19 June 2011

solar floor heating - Part 1

Premise and purpose


Queensland winter often has sunny days which are warm outside. The paradox is we build houses which are often cold inside. I can only blame our colonial heritage.

Sitting around inside the house it is often still at 15°C at lunch while outside has risen to 20°C in the sunshine. (Its fcuking stupid isn't it!). I had been thinking about a roof mounted solution, but as it turns out the northern side of the house is actually in full sunlight most of the day. When doing any gardening on that side you have to strip back to a T-shirt or you'll start getting hot. So my goal was to work out how to get the heat of the winter northern sun into my house without spending a lot of money.

We have a reasonably typical old house here, raised 40cm or so from the ground on stumps with hardwood floors. They get mighty chilly in the winter. The solution to that from the 70's was carpet, but I think carpet is filthy stinky stuff which people don't quite get how impossible it is to clean and rarely think about it (or if they do think, quickly realize that "its stinky stuff which is impossible to clean").

discussion


So I got to thinking that the nice warm sun on the north side of our house would be able to heat my floor making the inside of the house warmer.

So for less than $200 I've bought:
  • 100m of 13mm black poly pipe for both collector and floor heating section
  • a solar powered water pump to circulate the water
  • some cable ties and staples to attach the pipe
and after a bit of crawling around under the house I have it fitted



so ... next is to add some insulation under the floor (was going to use builders paper but a better idea is some thin foam) and make a more effective collector.

Right now, with just a single circuit, its just slightly cool to the feet while the unheated areas are uncomfortably cold on my feet (read need slipers). Not bad for no extra cost as time goes by...

For my next stage I reckon that I'll change this test collector to 4 collectors of about 500x500mm with clear plastic covers (to reduce wind induced heat losses) and black backs (to capture more heat), this should significantly increase the efficiency (reduce the losses) of the heat absorber and allow me to run solar 4 pumps to shunt the water around.

Right now I'm just running a single circuit of water (say the blue line in the figure to the left) so with the extra heat collector, I'll double up and reverse the direction.

If you look at the figure left, the blue line comes in and zig zags up the floor then come straight back to the heat collector. If I run the other circuit in the opposite direction (like the green line) then any heating change (as the water cools) of one circuit will be countered by the other which will have any temperature gradient in the other direction. This way I'll get 2 pipes between each floor joist (where as now I only have one) which should further increase the transfer of solar energy to my floor.

When choosing the pumps, there were 2 types, one was 200L/hour for $80 and the other was 140L/hour for $40. I reckon that 4 pumps covering the floor area under the house will (in combination with the insulation layer under the floor) actually make the floor warm to walk on in winter!!

Another point about the solar water pump is that it only turns on when the panel gets enough energy (which means the heat collector is now hot and ready) and turn off when the sun goes down (or when it goes behind a cloud) meaning that I do not need any other regulating system in this (to prevent it pumping cold water under my floor).

Simple, effective and cheap.

Further the system is then easily adapted to have GAS heat the water (using a simple and low cost instant heat gas system and a regular electric pump) if we want to keep the floor heat in the nights or to use on rainy or cloudy days (which aren't actually as cold in the evenings as the clear days are).

Water temperature on the outlet end of the pipe (after its gone around under the house) is coming out at 34°C

Saturday, 18 June 2011

Kempsey and floods

Recent media suggests that Kempsey has dodged a bullet in avoiding a flood. If you read the papers you'd perhaps think that somehow Kempsey was getting some wild weather. People are all squealing (again) about the weather, some are even dribbling climate change.

What pisses me off is the most is people with no history in the areas (who are essentially itinerants) say stuff like:
"I've never seen anything like this in all the years (3) I've been living here."

So, for the newcomers, (and those with no memory) lets start by looking at the rainfall in the last 10 years or so..


This figure above shows the monthly totals of the years from 1996 to 2009. Looking at that there's nothing much above 200mm, only a few occasions. Probably back in 2001 or in 1996 we could mine the media archives and read about flood events.

Certainly this month has had high rainfalls in the area, with Kempsey totaling 474mm so far (as at writing) this month. So from that background lets look further back, and keep in mind we've been in a drought cycle for 10 years now.

Below is a graph with the average totals for each month since records started in 1889.



The vertical bars above each month show you the maximum recorded for each month, which in contrast to the "average" you can see the sort of peaks we can expect in rainfall.

So, well before we get into discussions of "change" lets look at what's likely and what the current climate is before we begin charging into "its changed". Since we're in June, lets look at June records where ge got more than 300mm of rain:
  • 464mm in 1889
  • 419 mm in 1933
  • 329 mm in 1944
  • 302mm in 1948
  • 556mm in 1950
  • 558mm in 1967
  • 381mm in 1991
and now something over 474mm in 2011. So it looks like something between 40 and 20 years we have a deeply wet cycle.

Lets look at what that may look like in comparison to the first bar graph above.

Below are some of the periods where there was high rainfall:

The period around the seventies:


back to the twenties:

and just a few of the "high rainfall" years grouped together.
The late twenties looked like a standout with 882mm of rain in Kempsey in Feb of that year (and the rest of the month looking more even), but with a significantly smaller population I'm willing to bet that they were smart enough to perched in places which weren't effected as much by flooding. Today when driving through areas I see time and time again development happening in places "where only a fool or an angel would build".


Lastly, lets look where Kempsey is geographically:



Gosh, its in the flood plain of a river (the Macleay River), that drains a major mountain range. Flood plains are called Flood Plains because they FLOOD ... so where's the surprise?

Even more so Kempsey is described as:
Geographically, Kempsey stretches out around a long loop of the Macleay River at the top of the flood-plain. It is famous for its floods. The 1949 flood was particularly destructive, having washed a large part of the town centre away when the railway viaduct which was acting as a dam-wall due a build-up of debris against the railway bridge gave way. The area most affected by this flood is now the site of playing fields. The shire council has a policy of buying up land in areas designated as flood plains and many houses have been transported to higher ground in recent years. Other major floods occurred in 1949, 1950, 1963, 2001 and 2009.


So my question arising this research is "who are the fools: the media or the public?" I can only feel that increasingly the media and the general public are best described by "hysterical screamers" without a clue.

Sad really

Thursday, 16 June 2011

where do bogans come from?

is it here?

View Larger Map

or is this just where many sober up after a day at the races?

Wednesday, 15 June 2011

real estate market in Christchurch

Bloggers around the place have said that NZ was having housing problems, and that the economists were concerned about the potentials for a crash.

Other than the financial issues, it seems that people in Christchurch tend to make precarious decisions on what is an appropriate location for a house.

Why is it only in hindsight that bad decisions are clear to many?

Considering that earthquakes are not unknown in Christchurch (or recent) one can only wonder what went through the designers of this homes heads when standing on the site prior to construction and looking down at all those broken rocks at the bottom of the cliff.

I'm guessing that "hmmm ... wonder how they got there" wasn't among them.


Monday, 13 June 2011

wierd weather (or is it?)

Reading the news this morning I see that the prediction for Northern NSW to get high rains and flooding seemed to have been accurate. In the 24 hour period between 11am on the 12th till the 13th 153mm of rain fell quite consistently over the period:

rainfall12-13th

The media seems to (a little less hysterically this time) be just reporting this, which I think is a good thing (for a change).

Weather has been a topic of conversation around my office a lot lately, with people feeling that somehow its all weird weather. Well it might seem that way for people who have only lived here for a few years (like say 10) but this sort of thing has certainly precedent in the recent past.

I chose Yamba to look at in the observations from BOM above as I have access to historical data on a Yamba. So since 1878 this is the average rainfalls for each of the months looks like this:

yambaMonthlyRainvallAvg

Getting wetter progressively from September and falling off in the middle of winter. The X axis of the graph looks a little unconventional as I've presented the data based around what I know (from experience and further research) that the rainfall here is seasonal, and the seasons aren't based on the European Calendar of Jan to Dec. I've wrapped it from August and back to there again so you can see the "cycle" more clearly (with the start and end points meeting).

Looking at the graph you can see that March seems to be the wettest season for that part of Nth NSW and things can and do stay wet till at least May. This being June we're only a little out of the peak periode and while the Average for May is 159mm and the Average for June is less at 132mm June has had a measurement of 548 back in 1968. High monthly averages for June include
  • 389mm (1886)
  • 369mm (1914)
  • 404mm (1945)
  • 462mm (1950)
  • 548mm (1968)
Its just that we haven't had much over 331mm since the seventys. So for the people who have not lived here long and or didn't grow up here it may seem as a surprise to get this amount of rainfall.

So far (till the time of writing) the accumulative rainfall for Yamba is 220mm, which means while we're over average already for the month we're a long way short from the peaks seen in previous years.

A quick look around in the area will show quickly how many of the older houses are build on stilts or on higher ground.

So no, the old timers weren't just "funny" in their styles, they built according to the environment and what can happen.

The reason I'm posting this is to try to start the idea in the community that before we rabbit on much about "climate change" it may be a good idea to actually KNOW what the climate of the region is. It can help you to build your house to avoid floods (or avoid buying one that some numbskull from Melbourn or Sydney has designed and built for you to rent from them) and all the heartache that goes along with that.

Its easy to go along with the herd and just burp out "climate change" as the explanation for everything, but if you don't know what it was then how do you know its changed?

Personally I wish we'd spend more time on the real environmental issues like pollution, land degradation (which effects how much food we can grow) and deforestation. People could stop creating more problems (like the foolish stuff with electric cars) and focus instead on understanding the issues and working towards solutions to them.

Of course that would require people to think for themselves and apply critical thinking ... so I'm not holding my breath on this happening any time soon. Still, I can dream.