hot, hot, hot...

Here in Adelaide, we're in the middle of our third 40C+ heatwave for the summer (which only technically started 17 days ago. I think a good case could be made for starting summer on October 15th in Adelaide). It has not been a hot spring overall, but we have had some very hot weather and have had very little rain. According to the BOM, Adelaide had only 15mm of rain in November (I would have guessed less!). October was hot and dry too, with an average maximum of 27 C (compared with a historical average of 21.3 C) and only 9 mm of rain.

Today, I went out in the garden at 3:30pm. It was 43 C, and we're in our 3rd day of a 5 day heatwave. Here are some photos I took.

2 year old walnut tree, showing dead burnt leaves from our last 40 C + heatwave. It will lose more leaves after today -- notice the wilting present on its leaves.

2.5 year old apple tree, showing burnt apples and wilting of leaves. I hope that, as the tree gets larger, it will shade more of its own apples and reduce the burning.

tomato plants in a non-wicking bed. They are very stunted, with lots of wilting and burnt leaves. We have been harvesting fruit, about 1 kg so far, but there's not that much fruit there. I think they need more water than I've been giving them (about 2 times per week)

I showed these images partly to show the effects of Adelaide heat waves, but partly to contrast with the wicking bed photos below. Note that neither of the wicking beds have been watered for 5 days, and the average daily maximum has been about 38 C in that period.

The better (and older) wicking bed. There is a little bit of wilting on the zucchini, but remember -- it's nearly 43 C outside! As you can see, the plants are blooming.

This is one end of the newer (large) wicking bed, that leaks a bit. But it still is working, as can be seen from the very happy curcurbits and beetroot shown here.

The other end of the large wicking bed, showing more happy curcurbits (with no signs of wilting) and happy silverbeat.

So, the wicking beds are an absolute, resounding success. I had been thinking that we wouldn't want more, because giving tomatoes too much water leads to poorer fruit (because the plants don't grow such extensive roots). I now think that we definitely need a wicking bed for tomatoes, but that we'll just keep it drier than the other beds. I think eventually, all our annual vege beds will be wicking beds.

Grey water project

In a previous post, I described a grey-water system to process the washing machine water. This is a failed project. I used 25 mm poly pipe to send the water, and I knew that it would block. I assumed I would be able to just blast it through with high pressure water to clear it. Unfortunately this doesn't work. I don't know if this is because

• the pressure isn't high enough
• the blockage is too intransigent, or
• the pipe is just too long (15 m)

or a combination, but it is just not working so I've abandoned it. For now, our washing machine water is just going down the drain.
What I plan to do instead, is dig up some weedy reeds we have near the fence (which is only about 3 m from the laundry), and pipe the washing machine water there, and plant some bananas there. I'll do this with 50 or 70 mm PVC. Anyway, we'll see...

Secondary glazing

This is a success, and the house has performed well in the hot weather. We've run the reverse cycle A/C split system (a 2 kW system, so not particularly large), to try and keep the living area cooler while our solar PV is producing, and the temperature in our bedroom has stayed below 30C, which is quite bearable with the ceiling fan on low. Having the washers around the screws means that the acrylic sheeting stays sealed around the sides of the window.

Secondary glazing

My house has lots of windows. Windows are very poor insulators, and my windows let a lot of heat out of the house in winter and a lot of heat into the house in summer. Improving windows' thermal performance is very worthwhile if these things are already done:

• drafts reduced/eliminated
• Summer sun is excluded from the house (no direct sun on the windows in summer)
• roof insulation is improved

I've done work on all these. The drafts project is not complete, but I've gone around 2/3 of the house with gapfiller, and have closed all the internal air vents. We've put external blinds on all the East-, West- and North-facing windows (though most of them were there when we moved in) and I've put a lot of insulation in the roof (not a fun job, but a very worthwhile one).

Secondary glazing is a cheap retrofit to get some of the benefits of double glazing. It doesn't insulate as well as double glazing, but it's a lot better than single glazing. The basic principle is that a second pane of glass is installed close to the first. It needs to be about 10 - 20 mm away. Too close, and heat transfer is too great (the air barrier isn't wide enough), too wide and an air current is established within the window and heat is transferred by convection.

For my house, I ordered acrylic sheeting which was cut to size. It was about $1100 for about 23 windows. I had an idea to attach it using double sided sticky tape so that it would look neater (than having screws in the corners). This seemed to work well, and I put some desiccant into the window to absorb moisture and prevent condensation. They looked great and I was very happy with them. Very schmick, so I kept going and did more windows.

Problem 1

What I found was that all the desiccant absorbed water (perhaps from the dobule-sided tape itself, though I'm not sure) and the desiccant turned to drops of sticky crap within the window. To cut a long story short, I don't recommend that people attach secondary glazing with double-sided tape. It may be that if I had done it on a cold winter's day and foregone the desiccant that condensation would not have been a problem. However, it will be very difficult to remove the glazing if there are problems down the track.

Hence, I've put all the rest on with small screws, one in each corner. This still looks good, and performs well.

Problem 2

We have sliding sashes in our windows, and the way they work means that the secondary glazing on the upper window needs to go on the outside so that it doesn't interfere with the opening of the window. This raises another problem. The acrylic is now exposed to the hot outside air, which causes it to expand more than the indoor sheeting (acrylic expands much more than glass as it heats -- up to 5 mm per meter of length). Because the corners are fixed in place, this is causing the sheeting to bow out in the middle (which means there are air gaps down the sides of the sheeting. To improve this, I plan to drill larger holes in the acrylic, and use rubber washers underneath the screws so that the acrylic can move relative to the screws, and hopefully avoid bowing. I will post about the success (or otherwise) of this plan.

Potential problem 3

The other potential issue with having the secondary glazing outside is that it is exposed to the elements. It is fairly UV stable, but will lose clarity in time if in direct sun (I'm being careful to keep it out of the sun). Also, I'm a little concerned about rain ingress into the glazing. I'm unsure how best to prevent this, but plan to put a bead of silicon along the top of the acrylic on the outside and see if that is enough (all the glass is under eaves so shouldn't get much direct rain on it).

What's left?

We have two enormous windows (1500 W x 1800 H) which it is possible to secondary glaze. I'd need to use 10 mm acrylic (vs 6 mm for the smaller windows) which would be extremely heavy and unwieldy and expensive (the two windows would cost nearly as much as the rest of the house). For this reason, I'm getting a quote to replace the existing glazing with a double-glazed plane. This is possible because the existing frame is nearly 100 mm wide and there is plenty of room. This will perform better than the secondary glazing, but it is not feasible to replace the glazing in all our sashes without replacing the sashes themselves (prohibitively expensive).

Performance

Our house definitely has better thermal performance than last summer. We've had a few days up around 40 already this summer, and the house has stayed about 26. This weekend, we'll have two consecutive days at about 40, it will be interesting to see how it goes. It's about 23 inside right now.
Note also, that our secondary glazing does not have the benefit of low-e glass, which is reflective to infra-red frequencies and helps prevent heat transfer. If we buy double glazing for the large windows, we will definitely get this (our's are South facing. For windows benefiting from winter sun, you may want to avoid low-e glass).

Cheaper options

Instead of installing secondary glazing, it would be much cheaper to make and install kume blinds, which provide possibly better insulation (at the cost of light and the view). We decided to improve the glazing.

Wicking beds

UPDATE: wicking beds lined with builders plastic do not last -- they develop leaks. Please read here for more info.






It's been a while between blog posts, particularly those concerning house projects. I have a lot to catch up on, and I've now finished one of my employment contracts and so should hopefully have a bit more time to blog. There are a few things I want to write about:

1. wicking beds successes and failures (below)
2. acrylic secondary glazing and some of the learnings there. Not all is resolved, but is getting there
3. failed project: Washing machine drain to front yard (pipe blocks)

I won't write about all these here, I will just focus on the wicking beds, but I hope to get to the others in coming weeks.

Gardening Australia (the only TV program I've watched for the past 6 years -- about an episode per year) has a great website about wicking beds. Basically, they cause the garden bed to be watered from below, by the process of the water wicking upwards through the soil. This means that the driest soil is right at the surface which minimises evaporative losses. In our ongoing attempts to reduce our water use, we wanted to build some so that we didn't need to water so much.

So far, I've built two using different materials, but both employ the same principles.

We built a round one first, using some salvaged corrogated iron, with help from permacultureSA.  I cut it so that the corrogations are vertical, and then pop riveted it into a circle (diameter ~ 2 m). The top was sharp, so I put a piece of hose all the way around held on with cable ties through holes I drilled into the corro. Underneath, I removed all the soil/mulch down to the clay, and made the bottom smooth. I made the inside walls of the bed as smooth as I could. Into this went builders' plastic (orange). This holds the water. I put two layers, but if I did it again I'd put 4 layers -- it is essential that it doesn't leak. There is an overflow pipe about 1/2 way up the walls, which are 400 mm high.
Into the builders' plastic, I put upside-down polystyrene broccoli boxes (these can easily be got for free, since they are not allowed to be reused), cut to a height of about 200 mm. I drilled holes in their bottoms and cut wedges from the tops to allow water to easily move through them. I also put a length of PVC pipe across the bottom, bending up and poking out the top. On top of this I lay geotextile, allowing it to form pockets all the way to the bottom of the reservoir in places. Then I filled the top with soil, being careful not to let soil get below the geotextile. First time around, all of the filling steps were done by the permacultureSA working bee -- unfortunately, we used poor plastic and it leaked and had to be taken apart and made again with better plastic :-(. Not good.

 I built a second bed using exactly the same method, but larger. This one is 4 m by 2 m. The sides of this are made of some old timber I had lying around, and it doesn't actually go all the way to the clay -- I let the deep mulch around the bed hold in the builders' plastic. This one leaks a bit, so I can't fill it much with water. It could be that the mulch has punctured it, but I think the plastic had a few holes (it was kicking around in my dad's shed for years and has been moved back and forth) -- also I only used two layers again -- silly! Use at least 4 if you do this -- moving all the soil is hard work!
(There are some volunteer tomato plants in this bed that need to be moved ;-)

Results

The beds seem to work pretty well, and hardly use any water. We're putting all our water-loving plants in there (not tomatoes!)

Learnings

1. You really don't want leaks in the reservoir. Make sure the base (in particular) and the sides are smooth to avoid punctures, and that the plastic doesn't have holes. Use the thickest builders plastic, not the thin stuff you get at B------.
2. It's really important that the base of the reservoir, and the bed above it, is level. Use a spirit level for this
3. Don't shove a garden fork or stakes into these beds once they're done ;-)
4. Don't walk on them
5. I'd like to think that, when I build the next one, it'll have a concrete slab at the bottom and rendered brick walls, but I'll probably just hack it again...
6. The beds take a long time to fill, particuarly gravity fed. Always use a timer otherwise you will forget which defeats the purpose of the beds (saving water).

I think they're great and we will use them henceforth.

Income equality

I have had many interesting discussions recently about income equality between the sexes. This post is an attempt to organise some thoughts.

Australia has a gender pay gap of nearly 18%, and women are very underrepresented in leadership positions. To start with, this is clearly unfair, unjustifiable and to the detriment of our species (numerous studies have shown that diverse teams make better decisions -- I'll leave the research to you if you are interested).

My idea (which I now find to be written about already -- see below) is that income nonlinearity contributes to the gender pay gap. I outline the idea here:

In Australia, at modest income levels, incomes rise in (approximate) proportion to the experience and responsibility of the employee. However, at higher levels this breaks down -- the trend becomes nonlinear and incomes rise exponentially with experience/responsiblity. The graph looks something like this:




In households where both a man and woman work (clearly not all households are structured like this but many are) there is a simple pressure to focus on one person's career because of the exponential rewards for seniority. Couple this with society's chauvanism (women need to challenge stereotypes to attain seniority in the workplace) and the fact that if the couple wants children the woman must take some time off, it makes sense for couples to in general focus on the man's career.

Note here that I am trying to understand what is happening in Australia now, not to argue that this is a good or just outcome.

This idea is described in detail in A Grand Gender Convergence: Its Last Chapter, by Claudia Goldin, who writes:
Whenever an employee does not have a perfect substitute nonlinearities can arise. When there are perfect substitutes for particular work- ers and zero transactions costs, there is never a premium in earnings with respect to the number or the timing of hours. If there were perfect substitutes earnings would be linear with respect to hours. But if there are transactions costs that render workers imperfect substitutes for each other, there will be penalties from low hours depend- ing on the value to the firm.

What to do?

If you think, as I do, that something needs to be done about gender inequality then what needs to be done? I think a good start would therefore be to reduce income inequality at all levels: reign in top incomes to be more proportional to experience/responsibility -- ie. return the exponential income increases to a more linear progression.

This will have the added benefit of a more egalitarian society in general.

The relative cost of things

My idea regarding ideas for public transport has resulted in conversations about the problem of smart phones. This post is not a defense of smart-phones -- I see them as a decidedly mixed-blessing (perhaps one day we'll be wise enough to get their benefits with fewer social costs). I wanted to briefly talk about our (me included) inability to estimate the cost of things.

In a previous post, I wrote about a new battery I installed on my ebike. I was shocked to learn that it is estimated to take 500 kWh to build a 1 kWh Lithium-ion battery. This is a lot.

Similarly, many environmentalists object to smartphones and other computer technology because of the environmental cost. A large part of this, though certainly not all, is the embodied energy contained in the device (much of which is sourced from fossil fuels). For a smart phone, this is estimated to be about 280 kWh.

This is also a lot of energy.

However, consider that 1 liter of petrol contains about 10 kWh of energy. That makes the lithium battery equivalent to about 50 L of petrol (or one tank of fuel in a car) and the phone equivalent to about 1/2 a tank of fuel. That doesn't sound like so much, and is largely because we don't think about the ludicrous amount of energy that petrol contains and cars consume.

I see this as a problem with the way we compare energy use. High tech gizmos seem like they use a lot of energy to make, but the good old-fashioned internal-combustion-engine uses orders of magnitudes more. In my opinion, a smart phone that allows someone to efficiently use public transport and avoid car transport (without requiring a large-scale re-organisation of suburbia) would be an excellent use of resources, and would hugely decrease our reliance on motorised transport.

With Europe as an example, it is clearly possible to have an excellent public transport system without a fancy mobile phone based setup. However Europe also has population density that Australia
lacks. For Australia to provide public transport service equivalent to Europe's (given our sprawling cities) would be expensive (it either requires replacing housing stock with higher density dwellings, or having lots of public transport routes). Using an idea along the lines of my dynamic route generation plan could let us service our cities more cheaply (in terms of energy and money!).

Some may argue that such a proposal requires a lot more than just a smart phone. Of course, that is true -- a setup like the smartphone network and google maps requires broadcast towers, routers, repeater stations, network infrastructure, GPS satellites, computer server farms, etc. All this infrastructure already exists. It is being used, right now, by many applications. From an environmental viewpoint, it is a sunk cost: the environmental damage is done, I think we may as well get what good we can from it.

Public transport in the age of the smartphone

Summary

Now that most people have smartphones, why do we need fixed timetables for public transport?

Detail

My wife and I visited Sydney a while ago. We haven't spent much time there and don't know the way around well. To navigate, we used Google Maps and selected public transport as our method. It is quite amazing -- Google is able to tell us where to walk, which bus/train/tram stop to wait at and it  even designs connections allowing time to walk between them. In my experience (and I now use it exclusively when planning a journey via public transport) its performance has been flawless.

It got me thinking -- 85% of Australian adults now own a Smart Phone. If we reach a situation where people can be relied on to have a smart phone, how can we take advantage of this to (re)design public transport?

Imagine

It's 2017, and you want to go somewhere by public transit. You use your smartphone to plan where and when you want to go (whether it is now or in 30 minutes' time). The app lodges the journey request with the local public transport authority (PTA), where there is a computer that dynamically generates the routes and timetables to minimise waiting times and maximise the directness of routes. The transport fleet is different -- there are still many large buses/trains/etc but in addition there are now a local fleet of small mini-buses (say 8 - 12 seats) that facilitate relatively local movements or act as feeders to the larger/faster routes.
The novelty of this idea is that the routes and timetables are dynamically generated -- there are no fixed routes or timetables -- these are designed on-the-fly in response to demand. There are New Years eve fireworks in Sydney and 1.5 million people want to go home at 1am? No problem -- feeder shuttle buses take people to the trains and larger buses take people to places where rail service is poor. Because the route planning is centralised, it can even avoid bus-jams (traffic jams comprised almost entirely of buses) by rerouting accordingly.

From the users' perspective, the service would operate similar to using Google Maps to plan a journey.
From the drivers' perspective, it would be like using a GPS navigator that tells them where to go and whom to collect/deposit.

Why?

Public transport is hugely under-utilised -- many buses/trains are well below capacity. Yet one often needs to wait for service. A system such as this would be much cheaper to roll-out than additional vehicles, and would result in a leaner service that was much more agile and efficient.

How is this different to Uber?

(disclaimer: I've never actually used Uber)
There are a few ways I can see

1. It is designed with systemic efficiency in mind. Because the drivers are employees and can be relied on to work particular times, the central planner organises them collectively to move people. This will achieve much greater performance than a system where individual drivers compete for individual passengers. This point can't be overstated -- as a hybrid system, performance would be excellent.
2. It's publically owned/operated. I would envisage that this is state-subsidised. Also, because journeys are shared (just like a bus/train), trips would be very cheap compared with a taxi service.
3. It still uses connections to maximise efficiency. Of course, because connections are planned, you would never miss one. For example, your shuttle bus deposits you at the train station, the train waits until people have boarded and then departs. There is no timetable.

Problems?

 There are two (related) problems that I can see

1. 15% of Australians lack a smart phone [1]. A service such as this would exclude non-smartphone users. I think a government subsidy to give all low-income people a smartphone would still give savings in public transport alone if this were implemented.
2. Technology barrier. Old people and people with sensory or cognitive impairment could tend to be excluded. This would need to be carefully managed to ensure access.

----------------
[1] This number is changing rapidly. This article states that 30% of Australians who lack a smart phone are planning to buy one in the next 12 months. If that eventuates, by 2017 only about 7% of Australian adults would lack a smartphone.

Vasectomy

this post contains comments and judgements about medical practice and attitudes. Although I'm fairly knowledgeable about such things, I am not a medical doctor, surgeon or allied practitioner. Please consider this post as opinion only and not as a basis for medical decisions

I've got two kids, and it's enough. My wife and I decided that I'd get a vasectomy to be sure (well, fairly sure) not to have any more.

I had a vasectomy on Friday September 14th. The actual procedure seemed very simple and quick, and I was home that afternoon. I had a very quiet weekend, just relaxing on the couch, I followed the advice of my urologist to apply ice and take neurofen. He had previously told me that Monday "might be the worst day", so I  wasn't too concerned as the pain become more acute throughout the weekend. By Tuesday I could hardly stand up, and the pain was so acute that, even lying down, I couldn't tell when I needed to urinate because of the constant pain and discomfort.

My scrotum was approximately double its normal size.

At this point I phoned the urologist's surgery to get some advice, but was told that he was on a week's holiday and that his colleague (also a urologist) was also on holiday. There was no post-operative support (!)

When nothing had improved by Wednesday, I went to my GP, who thought I might have an infection, so put me on antibiotics. This did seem to help, and by Thursday the pain had reduced to the point where I could walk, but was still extremely uncomfortable (it felt like I had an extra pair of testicles).
I saw the urologist the next Monday (when he returned from his holiday) and he was quite concerned, diagnosing a hematoma (bleeding from the operation), and advised that I continue taking the antibiotics.

It's now 5 weeks after the procedure, and things have mostly settled. I can ride my bike again, though I still regularly get pain, especially at the end of the day.

Thoughts

I think that we take vasectomy too lightly. It's a surgical procedure, and thus vulnerable to all the complications that other surgical procedures can cause. In my case, my scrotum wasn't shaved before incision (I would expect that would increase the risk of infection).
As an example of people's attitudes, I heard a story about a guy who cycled home from his vasectomy (ie. it's such a trivial thing), and had a couple of veiled comments along the lines of "toughen up and stop whinging".
But, speaking with other men, I have heard many stories of problems. One guy I spoke to said he still gets pain from his two years after the procedure. Another guy had an infection that required hospitalisation.

Conclusion

Vasectomy is a very minor operation. It is routine and is usually successful. Despite my experience, I would recommend it. But -- do not take it lightly, do not attempt to be tough, and do not ignore symptoms afterwards -- if you have significant swelling or pain, see someone straight away.
Also, remember that the experience of surgery is hugely varied -- just because your brother has a vasectomy and jogs home does not mean that will happen for you.