Friday, 13 October 2017

Lesson one take three

The low energy building class is now in its third year, and the make up of the students was much more like one of my regular classes. There were over thirty students, up from seventeen last year and nine the previous year. I think there is only one foreign student this year, where half the class or more has been s is much lower too, with

Around half of the students are architects, again. There are a few from the Faculty of Textile Technology, a biologist, an economist, and others studying education, humanities and American Cinema.

There are also a couple of members of the public taking the class. In the first year I also had two of these students, although they stopped coming after a few weeks. I'm not sure how much this was an indictment of my class or wether they just got too busy in their lives, and could write off the very low fees that the university charges. Anyway, I hope they will stay this year. One of them works for a large supplier of building parts, so I hope to have some time to discuss business with him.

In the first week's online quiz, I asked them what language they wanted to speak, and what language they wanted me to speak. The majority want me to mostly speak in English, and they want to speak some English and some Japanese. Nobody wants to only speak English, and only one person wants me to only speak Japanese. This gives me a mandate to speak some Japanese in class, and also an incentive to add some Japanese to my slides.

The first lesson followed the same plan as before. I gave them a few simple mathematics problems to make sure they will not be too overwhelmed in the rest of the class. They were just designed to check they can manipulate formulae.

I also threw in a different kind of question: How many pencils are in this room?

They were working in groups, but not allowed to talk to other groups. Answers ranged from 12 to 60. The middle answer—30—was remarkably close to the actual number—31. This was an opportunity to introduce guesstimation, and emphasise that usually we need to find answers based on limited information.

Friday, 6 October 2017

Graphs of words show Climate Change is still increasing, while Global Warming has stabilised

According to this graph from Google Ngram, Climate change is still increasing. Ngram measures how often words are used in our language by counting occurrences in a huge swath of publications that have been digitised. This is a form of corpus linguistics, a field of study that goes back to Vedic scholars counting the occurrences of different sounds in Sansrkit holy texts. Arabic scholars also studied the Koran, and back in 1230 Hugo de Saint Cher made a concordance of the Bible, noting where and how often each word appeared in the holy book. Computers have made this a lot easier, and Corpus Linguistics has really taken off since the 1960s.
Ngram opens that door to anyone interested in what people have been writing, and we can see here that climate change, global warming and greenhouse effect all steadily increased until the mid 1980s, where they received a bit of boost. Global warming used to be more commonly used than climate change, but slowed and then plateaued in the early 1990s, slighly increasing since. At about the same time use of the phrase "greenhouse effect" peaked.

A climate denier may be tempted to interpret this as the greenhouse effect peaking in 1992 and decreasing since, and evidence that the data for climate change and global warming have been tampered with by NASA.

My interpretation is that discussion of this topic became increasingly important from the 1970s, initially led by discussion of the greenhouse effect. This is the method by which global warming was
happening, and reliable historical temperature data began to become available from this time.

By the end of the 1980s the discussion of how global warming happened was more or less decided, and we didn't need to talk about the greenhouse effect so much. I suspect discussion of "round earth" peaked shortly into the age of discovery when returning ships removed any serious doubt about the shape of the planet.

Global warming and climate change were discussed equally, and largely synonymously until 1992. It's not clear why this happened, but in 2002 a Republican party memo by Frank Lunz recommended that the term "climate change" was used rather than "global warming", which people found frightening. It seems that George W Bush did respond to the calls to "stop global warming" by not using the phrase any more. This is not exactly what people wanted! (See also Guardian, 4th March 2003).

A more detailed linguistic investigation by Dr. Martin Döring of the Institute for Geography at the University of Hamburg into perceptions of regional climate change in North Frisia found: "six prevailing conceptual metaphors: Climate change is an enemy, preventing climate change is fight/war, climate change is punishment for human sins, climate change is overheating/heat, climate change is hot air/hoax and climate change is eco-dictatorship."

Those of us who want to "fight" climate change need to take account of the last idea: climate change as eco-dictatorship. For some people this may be overwhelming, for examples libertarians who make up the right wing of the US Republican Party, for whom denial of climate change is perhaps primarily a rejection of government intervention.

Friday, 29 September 2017

Just how smart are smart homes?

When I first lived in Tokyo in the mid 1980's I remember being out somewhere and a friend got up to use the telephone. It was a payphone since this was before the age of mobiles. He didn't say anything, but punched in some numbers then put the phone down. He told us he'd just started the bath running at home.

If you don't know what a payphone is,
you probably won't know what this is either
This seemed like science fiction to me with my perspective from the primitive plumbing of England. Indeed it was science fiction compared to the Tokyo flat I was staying in where there was no running hot water, and the bath had to be filled with cold water, then heated by circulating water through a gas burner. Once, after a long day, I got into one such bath while the heater was still on. I dozed off in the bath and woke up very hot, and when I moved I got even hotter since I had been cooling the water immediately around me.

Most bath heaters had simple mechanical timers in the switches, so they would not overheat the bath. Even in the 1980s some of them could be programmed to switch on at a certain time, so the tub would be hot when you got home.

We can't call our bath on the phone, or send it text messages, but it can be programmed to come on at a certain time, and it does know how to say "I'm filling up the bath" and will happily tell us "The bath's ready". Unfortunately it doesn't know how to say "Whoops, I ran out of water so your bath is luke warm." And the phrase, "Hey, you forgot to put the plug in, you idiot" is also missing from its vocabulary. In both cases, the light just goes off and it remains silent. It's really not very smart.

So how smart are smart houses? Not very, is the short answer. Will they help us to save energy? Our bath could have saved us a few hundred litres of hot water if it just knew to tell us that it wasn't filling up and we'd left the plug out. So excuse me if I'm skeptical of the age of the smart house and the brighter future offered us by the internet of things.

If you want energy efficiency, then it is dumb things that will deliver: geometry, wall thickness, window quality, airtightness and attention to detail in the construction.

You can get gadgets if you want, and they may make your life better, but if you want to save energy start with the thermal envelope. You can stick as much as you like onto the envelope later. This applies to solar panels too, which are probably a good idea to add to your house, but they will not make your house more energy efficient. Putting insulation under the roof is a much higher priority than putting solar panels on top of it.

But don't just take my word for it. In Bringing users into building energy performance: Learning to live in a smart home, Tom Hargreaves, Charlie Wilson & Richard Hauxwell-Baldwin tell us that smart home devices are "technically and socially disruptive", are limited by the householder who is using them, and have a steep learning curve with few people to help you climb it. They also find "little evidence that smart home technologies will generate substantial energy savings and, indeed, there is a risk that they may generate forms of energy intensification."


Wednesday, 27 September 2017

Low Energy Building Course - Open to the public!

Not only can students at my university take the 15-week Low Energy Building course, it's also open to members of the public!

You can find the syllabus here. And more information about other courses here.

(1)授業のねらいBuildings use over one third of all energy consumed in Japan, as in many other developed countries. In a world of increasing population and limited fossil fuel reserves, reduction in building energy consumption is important. As well as drastically reducing consumption, low energy buildings can be more comfortable, more healthy and less expensive over their lifetime.
This course will introduce students to the principles, the practicalities, and the future of low-energy building.
他の先進国と同様、日本で消費されているエネルギーの3割は、住宅で使われています。人口が増加し、化石燃料が限られてくる世界では、省エネルギー住宅が必要となります。エネルギー消費を減らすことで、居住者に快適で健康的な暮らしをもたらし、建物の耐用年数においても経済的です。本講義では、省エネ住宅の仕組み、その実用性と将来について紹介します。
(2)授業の概要This course will show how simple scientific principles affect buildings, and how insulation, airtightness and good windows can lead to houses with very low energy consumption. We will see how the use of solar power can make buildings that produce energy. We will look at low-energy buildings around the world, including the German Passivhaus standard. We will also consider the design process, including compromise, optimisation and guesstimates.
(3)授業のキーワード環境、物理学、建築、省エネ、熱力学、太陽光発電
(4)授業計画1. What is a low-energy building?
2. What is energy?
3. Insulation and thermal envelopes
4. Compound insulation and thermal bridges
5. Why do we feel hot or cold?
6. Air and water
7. Windows
8. Ventilation
9. Windows 2.0
10. Energy standards and low-energy building around the world
11. To zero energy and beyond: Buildings as solar generators
12. Passivhaus
13. Economics and ecology, embodied carbon and life cycle analysis
14. Presentations
15. Review

This plan may change to meet the needs of the class
(5)成績評価の基準Participation: 20%
Online assignments, quizzes, presentations: 80%

Students must complete online activities to pass this course. Students will be expected to participate in class and give presentations.
(6)事前事後学習の内容Additional information will be made available online.
(7)履修上の注意The class will mainly be conducted in English. It will be possible for students to ask questions, complete assignments and give presentations in Japanese.
本講座は主に英語で行いますが、受講生からの質問、課題の提出、発表は日本語でも結構です。

Friday, 22 September 2017

Top Ten Top Tens

I've already posted my own top ten tips for building a passivhouse and posted about Alessandro
Merigo's but I've now added eight more to give you a top ten of top tens. Please note that most of these will just appear on one internet page, and none of these are click-bait with a button for the next page hidden between several traps.

1. Here are my ten tips for building a house.

2. Alesandro Merigo's ideas are here:

3. Dieter Ram has ten principles for good design, which apply when designing anything.

4. Interestingengineering.com has an engineering perspective, which is close to my own ideas in
Ten Amazing Tips for Building Energy Efficient Homes.​

5. Think architect has Design-based ideas for building affordably.

6. Finder.com.au have the top 10 most helpful tips for building a house.​

7. NZI Architects expose 10 myths about architects.

8. Freshome.com has ten mistakes to avoid when building a new home, although I'm not sure about their advice to have as many windows as possible, and to think about skylights. I'm beginning to wonder whether I should have stuck at seven.

9.  LotNetwork.com has Ten green home building ideas, although they don't talk about the importance of insulation. Green may be more of a colour than a practical strategy to save the planet.​

10. And just in case​ you now need them​, here are ten tips on anger management from Mayo Clinic.

Friday, 15 September 2017

Too Much Humidity

When we built the house I refused to add an air conditioner for two reasons. First because I didn't think we needed to spend money on cooling when the house was not going to be so hot, and secondly because I'm from Yorkshire where we don't use air conditioners. Actually that's probably just one reason.

It may be global warming, acceptance of reality or weakness to luxury, but I think we need take active measures to remain comfortable in the peak summer heat. I need to take a closer look at passive house and high-temperature high-humidity in a different post.

The temperature is not a huge problem. It rarely goes over 28 degrees, and when it's 35 degrees outside, 28 degrees is a relatively pleasant temperature. The problem is when it is humid, and when it gets over 70% humidity it starts to feel really hot.

A de-humidfier would make the house more comfortable without making it cooler. In terms of thermal efficiency, de-humidification is a good idea since heat gain depends on temperature difference, so taking moisture out of the air makes it feel cooler without encouraging more heat to come in. On the other hand, making the house cooler means a bigger temperature difference, and more heat leaking in from outside.

Actually, we do have an air conditioner in one room, and that air conditioner does have a dehumidifier. But the de-humidify function just seems to work by cooling the air, and that room was not designed for the air to circulate through the rest of the house, so it just gets very cold in there when the dehumidifier is on.

Most dehumidifiers work by running air over a cooling element so that humidity condenses out of it. They differ depending on what happens to the heat that was taken away to cool the air. Either the heat can be put back into the air, or it can be taken out of the building. Our air conditioner does the latter, sending out cold, dry air. If you have a dehumidifer for a basement that gets damp in the winter, you want the former.

So do we want a dehumidifer that transfers the heat out of the house, or one that keeps it inside?

Should we try to dehumidify the air as it comes in through the ventilation system or should we get a standalone dehumdifier?

Would it just be cheaper and easier to get an air conditioner that can de-humidify?

Even if it was more expensive, would we be better off getting an air conditioner that can also cool and heat and do other fancy stuff? Maybe we could even get one that humidifies as well, since we need more moisture in the air in the winter.

Can I fit another air conditioner unit to the compressor that spends over 360 days of the year idle on my roof?

Or will it be cheaper to get another air conditioner with its own compressor?

How much moisture are we talking about?

The last question is easy.

If it's hot and humid outside, the ventilation system is going to be adding saturated air to the house. If it's 28 degrees, 60% humidity inside, with the ventilation system working at 150 cubic metres per hour, that is going to add 1.6 litres per hour. This is how much the dehumidifier needs to remove at peak load.

A closer look at some actual data for temperature and humidity here in July and August shows that the outside air was never actually hot and humid enough to come in saturated. But with a more comfortable 50% humidity at 28 degrees, the peak dehumidification load is 24 litres per day.


One very simple solution would be to switch off the ventilation system, or at least turn down the flow. This is a short term measure, because we do need fresh air in the house, but at night time and in the morning we open the windows and get plenty of fresh air in anyway. In fact the main demand for ventilation is to remove the moisture that we produce when we breath, wash and cook. If there are just a couple of people and a cat in the house, then we should be OK for a few hours. Turning down the ventilation would also be a good solution on cold winter nights when there is a risk of freezing in the drain from the ventilator.

References

​Assume on a hot day ​the air coming in is humid and hotter than the inside air, so humidity will rise to saturation as it passes through the heat exchanger in the ventilation. (Actually this is a pessimistic assumption.)
28 degree air at 100% humidity holds 27 grammes water per cubic metre.
Assume 60% humidity inside. That means an extra 11 g/m3.​
Air flow of 150 cubic metres per hour.
That's 1.6 kg of water per hour to get rid of.

Humans breathing out humid air:
In one hour we breathe in about 450 litres of air.
Assuming exhaled air is 100% humid at 36 degrees C; inhaled air is 60% at 28 degrees C.
1 cubic metre of exhaled air holds 42g of water vapour.
1 cubic metre of inhaled air holds 16g of water vapour.
We each contribute about 12 grammes of water per hour. Is that all?

Friday, 8 September 2017

What is Passive House? Probably not what you think

Here's my short answer:

Passive House is an excel spreadsheet.

There are loads of other definitions and mis-definitions out there. The term is frequently used loosely for any superinsulated building, and often mistakenly for passive solar buildings.

Passive House is not a way of using natural energy. It's true that Passive Houses will take natural energy into consideration, for example considering heat from the sun, but just pointing big windows south will not make a Passive House.

A Passive House is not a building without a heating system. Passive houses invariably have heating systems, but the amount of heating needed is very small. In fact the best definition of a Passive House is one where all heating and cooling needs can be met by heating or cooling the air coming in through the ventilation system.

There are many other things that Passive House is not, and in his excellent blog, Elrond Burrell gives a longer list.

My definition may put you off. I think excel spreadsheets put a lot of people off, including many architects. This is one barrier to the standard's popularity. If Passive House was a simple product you could buy to stick on your house, then lots of people would no doubt buy it. If it was a simple step you could add to the design process, designers would probably take it.

Passive house will help you to reduce your energy bill, and probably help reduce your environmental footprint. But if you want to save the planet, you need to do some sums. Laying a bit of turf on top will not make it green.

And now that we are firmly in the computer age, we can get a spreadsheet to do the sums for us. As with all good spreadsheets, you put various bits of information into the Passive House software, and you get out a simple and accurate picture of what is happening. In this case all the information going in relates to the building size, shape, location, materials and systems.

It is not difficult to find most of the information that you need to put in. But you do need to find it. You need to know the dimensions of the walls and the thicknesses and relative proportions of the various materials going into them.  The spreadsheet needs to know the insulation performance of each material, but most of them are already in there. You can also choose the hot water and ventilation systems, and their efficiencies. You need to know the size of the windows, and also their U values, and the psi values for the thermal bridges. The supplier of the windows should be able to supply these, and if not they may not be the right windows for a low-energy house. You need to know which direction each wall is pointing in. You need to know your local climate, or at least choose your location so that it finds your local climate.

The only piece of information you need to get up from your desk to find is the results of an airtightness test. If you're building an airtight house, then you probably should run an airtightness test anyway, and if you're building a house that is not airtight, start thinking about it.

W​hen​ all the information is in there, you know whether you have met the standard or not. More specifically it will tell you how much energy you need for heating over the year, how much total energy you need, and how often the house will go over 25 degrees centigrade. Even if you are not interested in meeting the standard, the software will give you a very accurate estimate of how much energy you are going to need to run your house.

Thursday, 7 September 2017

Electricity demand in southern Europe to soar with air con

After the hurricane in Texas, there has been a lot of news about how the weather will affect energy use. Of course the big story is how energy use is already affecting weather! I'm sure I heard people twenty years ago warning about global warming making storms bigger and more frequent. 

Another angle is news from the Guardian here about the increase in electricity demand in southern Europe for air conditioning due to increased temperatures. The UK will probably also need more cooling, but will need less heating, so in terms of energy may break even. Obviously the increase in temperature depends partly on whether we do anything about carbon emissions, and of course there will be some feedback if Europe does not de-carbonise the electricity supply.

The article does mention increasing insulation as a way to maintain comfortable temperatures, which is good.

The picture accompanying this shows an array of air conditioners from four different manufacturers, all Japanese.

Here is a report on global demand from the Japan Refrigeration and Air Conditioning Industry Association which shows that demand for air conditioners is already increasing around the world. They estimate 2016 global demand to be around 100 million units, growing 2.9% from the previous year.

In terms of market size, China is the biggest with 40% share, followed by Rest of Asia, North America, Japan, Latin American and then Europe with 6 million unit sales. In terms of market growth there is a very different picture, with Europe growing at over 12%, followed closely by Latin America, then Rest of Asia growing at over 8%. The more mature air conditioner markets of North America and Japan show the lowest growth rates of 1.8% and 2.8% respectively.

Since they can work as heaters as well as coolers, and since they run off electricity which is the medium of choice for renewable energy, split-unit heat-pump-based air conditioners may increasingly become the unit of choice for domestic heating and cooling needs. I may even get one myself.

Friday, 1 September 2017

These solar panels... are they going to last?

Ugo Bardi writes about the energy return on photovoltaics. Citing an article from Bhandari et al. that looked at 231 studies on ​how much energy comes out of photovoltaics​, and how much energy went into producing them, he comes up with an average return of 11-12 for southern Europe. ​This sounds worthwhile.

(From Dale and Benson)
​This graph paints a slightly different picture. It plots the number of years it takes for panels to generate the energy it took to make them against the growth rate of solar production. The payback got at least three times better in ten years, and the growth also increased three times. This means that, so far, more energy has gone into making solar panels than has come out of them. Hopefully, the growth will stop at some point, and the line will swing into the green as panel production stops growing while the installed panels keep generating. That depends on economics. 

Older estimates were that panels would still generate 80% rated power after 20 years, but according to Engineering. com, panels produced after 2000 will still be producing over 90%, losing only half a percent per year. So technically the panels will still be generating.

Economics is about resources. Somewhere human time is factored into ​it. We consider this resource very precious. ​I remember large scale road building projects in the UK that would decimate forest, destroy habitat and create pollution ​just to take a couple of minutes off people's car journeys. There is an economic pressure to reduce the amount of human time needed for tasks.

Another view is that human time is infinite, and the natural resources are limited. The classical economic view looks at productivity and considers environment assets to be externalities and essentially deems them infinite.  

​Hopefully growth of solar panels will go down, and they will become net energy contributors, but there is a powerful economic mechanism supporting production. If growth increases and we start throwing away the old panels, then that line may stay permanently in the wrong part of the graph, and photovoltaics will have just helped in our longer mission of depleting the world's resources.

The only redeeming feature is that they work very well in space, so we can take them with us when leave the planet! 

​References:​
Bhandari, K. P.,  Collier, J. M., Ellingson, R. J. and Apul, D. S. (2015). Energy Payback Time (EPBT) and Energy Return on Energy Invested (EROI) of Solar Photovoltaic Systems: A Systematic Review and Meta-Analysis. Renewable and Sustainable Energy Reviews​,​ 47(July): 133–41. doi:10.1016/j.rser.2015.02.057.

Friday, 25 August 2017

How to build a house in Japan Part two: Two-by or zairai?


One choice that you probably won't be given by any architect or builder in Japan is whether to build in zairai koho or two-by-four. If you're building a wooden house it's a choice that is made early in the project.

Zairai koho is the traditional wooden building technique in Japan. It consists of a framework of pillars and beams,​ fit together with joints carefully designed to avoid excess stresses, and​ originally held together without any nails or screws, hence the nickname nail-less construction. The standard section size of the pillars is 120 by 120 millimetres, and the beams are multiples of this.

Two-by-four refers to a building technique using beams of two-by-four inches. Rigid panels such as plywood or OSB are added so the structural strength is based on the walls, where zairai traditionally relies on the pillars and beams for the structure. Just to add a little confusion, 2 x 4 beams measure half an inch less by the time they've been cut and dried, measuring 38 x 89 mm rather than around 50 x 100 mm that you might expect.

The two-by-four construction technique developed from balloon framing in the 1830s in the US. It allowed standard sizes of timber to be put together with mass-produced nails by relatively unskilled wood workers.

Compared to zairai, two-by-four constructions is probably cheaper, stronger, easier to build, and easier to insulate. Since the beams are rectangular rather square in ​section, the building more efficiently derives structural strength from the wood. Insulation can be added between pillars and studs, and the wood make​s​ up a smaller proportion of wall, so the insulation performance will be better than a building with square pillars. If the same technique uses 2 by 6, 2 by 8, 2 by 10 or​ even​ 2 by 12 beams, a suitable thickness of insulation can​ easily​ be added between the beams.

It's difficult to find tangible advantages to zairai construction, but I will try.

Zairai construction is traditional.

That ​is probably enough to illicit approving nods from fans of tradition, and disparaging scowls from anyone who has been paying attention since the Age of Reason.

Zairai construction is based around standard sizes and scales that suit the human body. Measurements are in the traditional units of shaku and sun. One shaku is within a hair of an imperial foot, and was standardised in 1891 to 10/33 of a metre. Traditional Japanese units are decimal, so a sun is one tenth of a shaku. Traditional zairai beams are 6 shaku, or 180 cm, from the floor. That's around my height, and​ after a few years living ​in a traditional Japanese house I was beginning to develop calluses on my forehead and a stoop in my back. The average height in Japan increased 8 cm in the second half of the twentieth century, so I suspect for most of the history of Japanese architecture, the lintels were at an appropriate height. ​In modern houses they are higher. Of course there is nothing to stop you from using human-scaled dimensions in a two-by-four construction. Also, you may have noticed that the shaku is remarkably close to the imperial foot, and the standard lengths of two-by-four (inch) beams are all in feet.

Zairai construction is based on a woodworking tradition at least a thousand years old, which can be seen in the oldest and the largest wooden structures in the world. By building a house in zairai you are helping to keep this tradition alive. But what exactly is being preserved? Why do home builders have to pay more to preserve it? They still make temples and shrines, so couldn't the fantastically wealthy priests preserve their tradition?

The joints of zairai are all supposed to fit together without any nails, except now they do use nails.
bolts​ or other connectors for the joints. And since the traditional pillar-and-beam structures do not meet modern earthquake regulations, to get planning approval for zairai buildings, you need to add structural walls, just like they do in two-by-four construction.

The square beams were traditionally prepared locally from​ round​ trees. Now timber is usually cut in saw mills, often using state-of-the art CNC machinery.

​So is your modern zairai building just a two-by-four construction with more wood in it, and more complicated joints?

I guess you could see an advantage in it being more difficult to build, since that means you have more highly-skilled carpenters. You have to squint a bit to see this, since you are also making the job more difficult, but there are some places where more highly skilled wood workers will make a tangible difference to your house.

---

Our house uses zairai koho, and it is on the list of things I would probably have done differently. Luckily ​that​'s a short list! The point when I realised that there had been a different option to this vast array of square-section wooden pillars was at the stage in the process where it was not possible to change the building technique.

You're always at some ​stage in a process.

There had earlier seemed to be a great rush to get the structure all sorted out, coinciding with a busy time in my day job. I was a bit disappointed as I was quite interested in structures, and would have liked to have had some input into it. It seemed like a lower priority than the insulation work and the systems we were considering, so that was a battle I chose not to fight. Qualified architects in Japan, or anywhere else, can be trusted to make structures that will not fall down.

After this urgent decision had been made​ to finalise the structure​, there seemed to be a couple of months when absolutely nothing happened. Ben talks about a similar artificial deadline in his retire Japan Blog and I think this is a common technique in the building trade.

When we were looking at ways to fit at least 250 mm of insulation into walls with 120 mm pillars, I had an idea of using two-by-tens as studs between the ​load-bearing ​pillars, which would have allowed one insulation layer rather than the three we have ended up with. This seemed like a bad idea as it was mixing two different techniques, and would leave a few awkward sized gaps. So I wondered about getting rid of the square pillars ​altogether ​and just using two by tens throughout.

As you will remember from lesson 4, the calculation of the thermal performance depends on how much wood there is in the insulation layer. This information needs to be added into the Passive House software, and I was checking the figure of 18.1% that we had. A more conservative estimation put it more like 25%, so a whole quarter of the wall was made up of wood, much of it by square pillars. This could have been halved by switching to rectangular sections. That would also have meant less wood​ to pay ​for​.

I suggested this to the architect who said it would take a month or two to change the structure, and he'd need to get someone else to calculate the stresses.

So we have a house beautifully built in wood, but ​we can't see any of it it, since it had to be covered to meet fire regulations.

Friday, 18 August 2017

How to build a house Part Zero: A world of pain!


A lot of people have an idea about an ideal home.​ Some have dreamed of it for years, some have an evolving plan in their heads. ​But unless you are very humble or very rich, the ideal home will be beyond your budget​, and ​unless you are very practical​ or somewhat unimaginative it will ​probably ​not be physically possible to build.

​On top of this, people tend to embark upon building projects with partners, spouses or other family members​, and the chances of two people sharing the same aesthetics are small. ​The process of building a house involves a steady erosion, and sometimes brutal ​dismantling of your dreams.​ The paradox of the creative process is just how much destruction is involved. Rather than lofty ideals, the battle is ​usually ​won by our incredibly low standards ​for acceptable living conditions​, and our ability ​to adapt to our environment. We are often like lobsters in pans of steadily warming water, who will never try to jump out even as the water boils.

Des res in Ishigaki.
We have ​a stereotype of the cavemen, living in dark, damp caves. I'm sure some of them did, but for the most part that is probably just where they died, especially if they did something as stupid as build a fire in an enclosed space. The only reason we have such ancient archaeological remains from caves is because the caves preserved them so well.

They said they'd be putting the roof on next Tuesday.
​Evidence of other structures goes back​ to​ remains​ found in Japan half a million years ago. A couple of years ago we visited the Saxon village at West Stow in East Anglia where they found some remains of structures a mere one and half thousand years old. At first they thought these were pit-houses, and they tried to reconstruct these dwellings with a roof over the pit in an enterprise called experimental archaeology. After trying to live there, the experimental archaeologists soon found how unlikely they were to have been pit houses, since the pits rapidly filled with mud and water. Instead they hypothesised floors were built over the pits. So old buildings were probably less primitive than we think. At the same time, it's hard to believe that shoddy building is a new phenomenon. Here's a story ​from the BBC ​of someone who found hundreds of things wrong with his new house, in case anyone thought building in the twenty-first century was perfect.

Brand new sling.
We also visited Greece, and saw throughout the countryside partially finished houses which people had begun to live in but left floors or walls missing for tax reasons. As I visited ​some of the ancient remains I begun to wonder whether they were really in a state of decay or whether they had just been half-built in antiquity. 

Same old rock.
So back in the new house project, at some point Stockholm syndrome sets in. Stockholm syndrome was named after a bank raid in the Swedish city when bank employees were held hostage over five days in 1973. The hostages developed emotional bonds and loyalty to their captors over this time. It took less than a week. Five days was enough to not only develop love of an aggressor, but also coin a term that we still use half a century later. And this is about the time it takes for you to become a hostage of your house. You may develop the syndrome with your architect much earlier.

And then when it's finished, you'll end up being sent something like this satisfaction questionnaire.

Read about Ben's housebuilding adventures here on Retire Japan.

Monday, 3 July 2017

A plastic bottle house and other stories

​I've always had a problem throwing things away. A lot of people see an empty bottle and think it needs throwing in the bin. I think what a fantastic piece of engineering it is, how many possible uses it could have, and how long its life could be. So I found this article from the Guardian about buildings made of plastic bottles particularly interesting.

​In other news, here's an examination from the Zeitgeist Is Changing blog debunking the "wind farms kill birds" meme. It puts fossil fuel power stations fifteen times more dangerous to birds than wind farms. 

This is supposed to be following on the coat tails of Solar Impulse, which set several aviation records and was a genuine testament to the state of renewable energy and a gauntlet thrown down for bigger and better air craft to follow.

But this green boat is not going to come anywhere close. For a start any claim to be the first zero-carbon circumnavigation of the globe ignores at least five hundred years of wind-powered journeys starting with Magellan. And even then, most of the places he travelled were already inhabited, and the natives had not arrived there by jumbo jet.

There is a claim that this will be the first round the world trip using renewable energy and hydrogen fuel. And it will probably be the last. Hydrogen is a ridiculous way to store renewable energy. As we have seen in EROI, solar power is just becoming a viable source of power in terms of the energy it will generate over the lifetime of an installation compared with the amount of energy needed to install it. Electrolysis is a great way to produce hydrogen... in your bedroom. As a commercial process, it is very energy intensive.

The comments below newspaper articles are usually full of profanity, insanity, and complaints but these comments contained a lot more insight than the article itself.

Friday, 30 June 2017

How to build a house in Japan Part One: Who is going to build it?


If you want to have a house built in Japan, you have three basic choices: a large-scale "house maker" 大手ハウスメーカー, a local builder ("komuten" 工務店), or an architect ("kenchiku sekkei jimusho" 建築設計事務所). It's unlikely that any of these people will tell you about the other options since they have their own commercial interests in the way they do things.

Around a third of new homes in Japan are built by large-scale builders. They​ are​ usually​ relatively expensive, you have a limited range of designs to choose from, and variation may be impossible or charged extra for. What you get will look very similar to the catalogue or the model house, and the support will be good. Actual energy use will often be a lot higher than predicted, but that applies to most non-Passivhaus buildings. If you can find a house maker you like, building through them will be the smoothest path to your own home. Some of the house makers are working hard on low energy buildings, and Ichijo are getting close to the Passive House standard. ​Most are governed by market considerations and long-term relationships with suppliers, so standards are often minimal. ​In theory large​-​scale builders can use factory assemblies to produce high quality at low cost​, so in some cases these houses may be cheaper, and if the economies of scale really do work, that's the way house building may ultimately go​.​ We buy cars off production lines, so why not houses?

An architect should be able to build anything you ask for, or at least will be​​ able to draw it. There is a risk that you may not get what you want, either through miscommunication, practical issues or the fact that architects have their own agendas ​and aesthetics, ​and your house is one​ small piece of that jigsaw puzzle. Perhaps worse, you may get exactly what you want, but find when you move in that you didn't want that after all! Building through an architect will often cost less than a house maker, but there is no guarantee. This ​route ​will work best if you find an architect who shares your idea of an ideal home. If you​ can​ find an architect ​​interested in ​building a ​​low-energy house, with some experience in highly-insulated highly-airtight buildings, then it should come out cheaper​ and higher quality​ than the house makers. If you treat the architect as if you were commissioning a famous artist to create an artwork, then this will go smoothly. Smother still if you imagine the artwork will be displayed in a gallery that you can visit if you want to. Of course, back in the real world it's going to be a house that you'll be looking at it every day, and usually concerned about its function rather than its form.

Going straight to a komuten will give you more freedom than a house maker, but not as much as an architect, and they will probably be cheaper than either. A komuten will ​often employ ​at least one ​qualified architect who ha​s​ all the technical skills and legal qualifications to build a house. Ninety percent of the building companies in Japan produce fewer than ten houses a year, so there is a very long tail in the construction industry. Finding the right one for you, in the right place, may be more tricky.

There is a grey area between ​a​rchitects and ​k​omuten, in terms of finances and project management. Architects do not build houses, and ​the construction of ​your house will probably be​ carried out by a komuten whether you choose an architect or a komuten. In fact even some of the large​-​scale builders contract work out to komuten, so it's possible that exactly the same people ​will be building your house whichever route you chose.

The basic role of architects is to design the building, and in the simplest case they will do that​ only, and hand over the plans to a builder. ​More often the architect will see the whole project through, and may act as the project manager. When it comes to payment, ​the architect may charge you for the whole lot, and subcontract the komuten and other contractors. Or you may pay the komuten and the architect works for them. In either of these cases there is one person to negotiate prices with, and as a customer it is clear who is responsible if something goes wrong​.​ ​W​hich it probably will since houses are complex, and building is more art than science. Alternatively, the architect may charge a fee and you pay the komuten separately, but the architect will stay on to oversee the project. This may be less ideal.

The carpenter is really important if you're building a wooden house, and in fact carpenters used to build houses in Japan without architects, ​and they are part of a long tradition. This may not always be a good thing ​if you want to build a ​low energy house​ since​ you sometimes need to go against building tradition. ​Many of the older people in the building trade have basically decided on the way things should be done, and it may be very difficult for them to try new approaches. In fact they may see new ideas as direct threats to their livelihood and will be hostile towards them. Younger people may be much more open to ​new ideas, but of course they have less experience!

​Another potential danger ​is choosing a friend to build your house. ​You may feel a great sense of security relying on someone you know well since building a house is a daunting process. However, there is always a danger working with friends, and w​ith as big an investment as a house​,​ the danger is potentially very big. If things go wrong, then you may lose your friend​.​ Even if things go well, ​you may feel that you are helping them as a customer by giving them work, and they may feel they are helping you by working for you, which could strain the relationship. ​If it is a very good friend, then your friendship may be too much to risk for something as trivial as a house, and if they are not a very good friend, you have no reason to choose them above anybody else. You should be choosing the people who are going to build the best house for you. Of course things may go smoothly, and ​it may turn out that your friend is the best person to build your house, but that should be the end point, not the starting point.


​Note: ​In Japanese, Ichijo somewhat confusingly calls itself Ichijo Komuten, but they would not be described as a komuten​.​ ​I​n fact​ they​ have operations in the US and Australia as well as in Japan.



Monday, 26 June 2017

Jargon - A glossary for the low energy builder

​Here is a brief glossary of jargon related to low-energy building, including English, Japanese and an English ​definition. It will soon move to a permanent page, where I hope to update it.

A​r​gon​ アルゴン​​: An inert gas used in multi-pane windows. It insulates around 50% ​better than air.

Astroturf movements​ 人工芝運動: Groups paid for by large corporations to appear to be grass-roots organisations, often supporting their projects or fighting against regulation. A victory of capitalism over morality!

​Cellulose insulation セルロースファイバー: Fibre-based insulation made from wood fibres, sometimes loose and blowable, and sometimes pressed together and bonded with its own resins. (Not universally acclaimed.)

Eco​ エコ​​:​ see green

EPS​ 発泡スチロール​​: Expanded polystyrene. Low-cost foam-based insulation material.​ Being foam-based it does not allow much air or water vapour to pass through. When installed it is important to avoid gaps, which can halve the performance. If used within a wooden structure in earthquake prone areas, it's possible that gaps will appear after quakes. Don't confuse with XPS​, which is much stronger, although can retain more moisture.​

​Fibre​glass​ グラスウール​​: Low ​cost fibre-based insulation material. Being fibre-based the insulation perfomance comes from air trapped between the fibres, which can move allowing water vapour through. A vapour barrier is therefore necessary to keep the building airtight. Not particularly pleasant to handle, but once installed there are no health risks until the building is butchered or demolished.


Green​ グリーン​​:​ see eco

Green bling (derogatory and somewhat archaic)​: Devices, fittings and coverings that can be added to building to make them "green". According to an arbitrary calculation, 90% of the ​building's environmental performance depends on invisible elements integrated into the structure and integral to the conceptual design. The effect of green bling is often like ordering a salad with your steak in the interest of becoming vegetarian.

Green wash​ing グリーンウォッシング​​: Portraying ​products, processes and activities as environmentally friendly without making any fundamental exchanges except in the advertising copy. (See sinsofgreenwashing.com.)

Kazoo blow​er​​ カズーブローアー(告発を不正にする者): ​Person who creat​es​ a lot of noise that will support the status quo and drown out ​voices of concern or dissent. (cf whistle blowing; see also astroturf)

Krypton​ クリプトン​​: Another inert gas used in multi-pane windows. ​This is another 50% better at insulating than argon, and allows windows to be much thinner while reaching high performance. Since the frames will also be thinner, and frames and their thermal bridges lose the most heat in window installations, making window panes thinner may not be such a high priority.

Low-e​ ​低E: A coating applied to internal window faces which has low emissivity. This reflects low-frequency back into the building, and improves the performance of windows.

​Mineral wool​ ロックウール: Another fibre-based insulator like fibreglass, but made from ceramics. A little more expensive than fibreglass with the same performance, but not as nasty to handle

Natural materials​ 自然材料:​ ​A somewhat vague term usually ​referring to products with no synthetic chemicals, made from trees. Often these trees were planted in neat rows, cut with chainsaws, transported by diesel-powered vehicles to processing mills running on thermal power stations.

Polyurethane​ 発泡ウレタン: ​​Another foam-based insulator that performs better than polystyrene.

​Thermal bridge サーマルブリッジ・熱橋: ​An extra loss of heat caused by joins between insulating materials, geometry of external structures and additional non-insulating materials. Which heat losses are usually calculated over areas, thermal bridges are calculated over lengths. As insulation improves, thermal bridges become more significant since a larger proportion of heat is lost through them, and also more critical as they can result in cold spots that will attract condensation.

​Vacuum 真空: ​In theory the best insulation material available, since vacuums contain nothing which will conduct. This is sometimes used in multipane windows and insulation panels. I can't help being skeptical about the long-term performance since there is a big pressure difference between the atmosphere and the vacuum, leakage will not be zero, and eventually this will be filled with air. This may take one month, one year or ten years, but you should be planning a building to last for fifty or a hundred years.

Vapour barrier​ 蒸気障壁:​ A membrane usually applied on the inside of the external walls, or within 25% of the insulation from the inside. This stops moisture from the internal air from getting through the walls where it would cause condensation. Some wall finishes act as vapour barriers. Highly insulated buildings should also be air tight, to prevent heat being lost or gained through leaking air. Depending on the performance, vapour barriers may also act as air barriers.

Warm edge​ ウォームエッジスペーサー: ​A technology used around the edges of multipane windows which prevents heat leaking through that weak link in the window assembly.

XPS ​押出ポリスチレン​​: Extruded Polystyrene. The same chemical composition as EPS, but extruded rather than expanded, and stronger. Suitable for use under and around foundations.

Friday, 23 June 2017

Satisfaction questionnaire

Here is a satisfaction questionnaire for house builders to get feedback, inspired by one of the questions on the form we got when we moved in. 


Congratulations on moving into your new house!

Now that you've moved in, how does it feel to be in your new house?
Great
Wonderful
Fantastic

Were the extra building charges adequately explained?
Yes, the explanation was excellent and I was in no way shocked by the unreasonable and unexpected price hike
The explanation could have been better, but I got the general idea
Perhaps you need to tell us again

How many problems have there been since you moved in to your new house?
Only about half a dozen
Ten or so
Definitely less than a hundred

When there were problems, was it easy to get in touch with us?
Yes, the phone was always picked up quickly
Yes, the email I sent didn't bounce
Yes, I knew you were there when I came round to the office, although it did seem strange that you'd turned the lights off

How many times did you have to complain about the problems before we actually did something?
Twice
Three times
I gave up complaining after the fifth time

When we finally did get in touch with you, how good a job did we do at pretending we cared?
It genuinely seemed that you didn't have anything better to do than listen to us
I think I saw you nodding
Not sure, you were too busy looking at your phone

Did we tell you about our other satisfied customers?
Yes, I heard about them several times
You told us about one satisfied customer several times.
You have other satisfied customers?

(Note: Clicking these buttons will make no difference to anything, much like the satisfaction surveys you are often asked to fill out!)

Friday, 16 June 2017

Just planning ahead to make a battery charger for electric cars

"Are we nearly there yet?" the kids ask from the back seat.

"Yes we'll be there soon," I say, and I'm sure we will be. Soon is always too late for some but takes others by surprise.  

So we are half way through the ten-year contract with the Chubu Electric Power Company, and when it ends there is almost no chance that we will be paid as much as the 48 yen per kWh we are now getting. The tarriffs have been steadily falling each year, as was originally planned. Solar panel prices have also been falling, so the calculation of return on investment remains a little short of the ten-year contract that electricity companies are tied into for domestic installations of less than 10 kilowatts. Installations over 10kW are considered commercial, and they are tied into a lower price for twenty years. The prices of solar panels, as with all commodities, is somewhat arbitrary, and it is not completely clear whether the government is deciding the feed-in-tarriff rate based on the price of the panels, or wether the price of the panels is being set so that the feed-in-tarriff will pay the cost back. 
   
I think this graph shows that costs of solar installations over ten years met the residential electricity rates in the middle of 2014. At that point​, in theory at least,​ incentives become moot since it's cheaper for people to buy their electricity in the form or solar panels than it is to buy electricity company​. Of course not everyone has the capital to be able to do that, but the feed-in-tarriff was still above the price people were paying for electricity. According to solar partners.jp, the amount you get for selling electricity is dropping by 2 or 3 yen per kWh per year. You could sell 1kWh for up to 33 yen in 2016, and it will be 30, 28 ​in 2018​ and 26 ​in 2019. So if I'm lucky and still able to get a new contract with my old panels, I may get over 25 yen per kWh when my contract runs out.

At 25 yen per kWh it's still worth my while to connect to the grid. My income from the panels will halve, but it will still be three times more than I pay for electricity. 

A worse scenario is that I get paid some market value for power generation, which could be around 11 yen. ​It may be a fixed rate or a floating rate. The worst scenario is that they don't pay me anything, but just expect that power to flow into their grid. I think that is very unlikely.

There has apparently been a deregulation of the electricity market, which in theory means I can shop around for the highest bidder for my electricity. Japan For Sustainability has an interesting story here about Renewable Energy Hopes and Hurdles Amid Full Liberalization of Japan's Electricity Market. "In April 2016, Japan woke up to a fully liberalized electricity market" the article begins, although even by ​June 2017 I can't help feeling that most people are still oblivious to this new reality. ​

Increased competition tends to bring down prices, which may be bad news for people trying to sell​ electricity​. You can find out here whether changing your electric company will give you cheaper bills: https://enechange.jp/try. It's easy to find companies that will sell you electricity, but it's harder to find those that will buy it off you, unless you have larger sources. I searched around the website for https://ne-greena.jp, who offer 100% renewable energy, but ​they are not interested in buying renewable energy​ from my roof!

At some value less than 20 yen per kWh, it stops making sense for me to pay the electricity company the monthly flat rate to connect to them, since we​ make more electricity than ​we​ use. The big question going forward for anyone investing in renewable energy is how much electricity will cost. Jay Carlis claimed in 2013 that electricity prices are not going down and he​re's a Guardian article from 2011 about electric cars taking over.

More information:

Monday, 12 June 2017

10 tips to design Near Zero Energy Building

Alessandro Merigo, architect from Lumezzane, Italy, has written ten tips to design Nearly Zero Energy Buildings (NZEBs). In Italy all public buildings will be near zero energy from 2018, and all other construction from 2020. 

Read about refurbishing buildings too

1. Start with the shell 
2. Use appropriate software
3. Input real climate data
4. Avoid thermal bridges
5. Ensure air tightness
6. Think about air exchange
7. Reduce HVAC
8. Use renewable energy
9. Check the budget
10. Collaboration is the key of success

Note that only one of these is about producing energy, and seven are about reducing energy losses. 

Friday, 9 June 2017

Do solar panels have a dark side?

While browsing through the battlefield of prejudices and preconceptions that is the internet, I came across the graphic below, proudly showing how much better coal and oil are than solar power. This was a retort to Bernie Sanders boasting about the great contribution solar power was making to job creation. They cite the broken window fallacy, which is the mistaken belief that breaking a window is good for the economy, because of all the work it for glaziers, carpenters and painters. I can't help feeling that the broken window that this metaphor really applies to is the global environment, which the economy has been breaking for the past couple of hundred years, and has yet to seriously think about repairing. ​Anyway, the author's conclusion was ​that it takes 79 solar workers to produce the same amount of electric power as one coal worker produces.
Of course, he is missing the fact that almost all coal workers' 2016 efforts have now been burnt, while most of the solar jobs were installing production capacity. If all of these workers stopped for 2017, then coal and natural gas would produce zero kWh. Solar, on the other hand, would produce more or less the same amount. In fact those panels installed in 2016 will still be producing power for at least the next quarter century. In addition, many of the jobs in the solar industry are leading directly or indirectly to increasingly efficient solar panels and better ways of using them, so when those panels eventually need replacing, their replacements will be more efficient, cheaper, lighter, less energy intensive and with a lower environmental impact in their production and disposal.

This guy has a similar story, and once again it seems to be coming from the right, and firmly putting renewable energy on the left wing, and the left field. "Our lives are improved by finding ways to reduce the amount of labor in them, not increase it​," they both claim​.

​Of course, a lot of labour-reducing measures have not lead to a reduction in labour but an increase. In the 1930s John Maynard Keynes predicted that ​his grandchildren would be working 15 hour weeks. He didn't actually have any grandchildren, so that part of his prediction was wrong to start with. But his sister's grandchildren, interviewed here and now retired, worked a lot more than fifteen hours a week. In fact one claims it was more like fifteen hours a day. Work has expanded to fill the available time. Computers have not yet liberated the masses from work, but have enslaved millions behind their keyboards. Cheap products have just allowed people to buy more. One of the​noble aims of the industrial ​revolution was to provide every man with his own shirt, but it has just led to many overflowing wardrobes. ​A kind of Jevons paradox exists here too, as we spend all our time using these labour saving devices. But I digress from the solar issue.

​The bottom line is, of course, that solar panels do require work, energy and resources in their production, and looking backwards it's difficult to argue that they are using less carbon. Looking forward there is a different picture, and solar power and other renewables make zero-carbon energy production possible. Burning fossil fuels does not. There is no reason to ever build another coal plant in the United States​, or anywhere else for that matter.

Friday, 26 May 2017

Troublesome Doors

In March 2014 we got our front door working better than it ever had, with the help of people from Wald in Nagano City. Our experience importing windows and external doors was not without problems, and if we were building today we would probably use the best available domestic windows. When we built there were no domestic windows with suitably specifications, and our passive house would have been a cave! Since we were importing windows from Europe, and since I was also using some savings from the UK to pay for the house, it seemed like a good idea to try to pay for the windows in Euros, so that there was only one currency exchange rather than two. This meant that the windows were not paid for through the builders, which I think added to their foreignness and made them "someone else's problem".

Most of our windows have been problem free, with the large exception of the triple paned door on the south. The doors have had several problems, and it's difficult to classify them into design, construction, installation and use. Five years later, wear and tear cannot be ignored, but the doors on my twenty-year-old Toyota still worked fine, and I paid more for the doors of this house than I did for that car. 

For much of the first couple of years the front door was not closing properly, and it never locked fully without a struggle. There was even a time when it didn't lock at all. When the door is open, the key could be given two full turns, but usually it would only go around 360 degrees.

For a while the door was scraping on bottom of the frame, and you can see the remains.

The genkan (the area immediately inside the front door, where you take your shoes off) seemed to be colder in the third year, but it's difficult to quantify as it's always been colder in there than in the house.  In the winter it always feels cold when you open the door from the living room, but then it always feels really warm when you come in from the cold outside.

I wasn't paying full attention when they were putting the door in, but I think it may be resting on a bit of concrete, which will act as a thermal bridge between the insulated slab and the tiled step outside the front door. Also the washer on the outside of the handle has partly worn away, which may be allowing cold air to leak in. We've been trying to fix this, but it needs parts from Europe.

The other external door needed trimming so that it would fit within the frame when it was open. A careless oversight that the architect was unnecessarily gleeful to blame on the drawings from the foreign supplier. More recently part of the latch plate broke, stopping it from shutting smoothly. Another part we need to get from Europe. In fact that door also needs some adjustments to align it properly with the frame.

And then at the end of March we had some workmen in to look at some internal doors. Even when the front door has closed properly, people often either push it too softly while turning the handle, which stops it from closing, or push it too hard, which slams and sends rattles around the house. So we asked about fitting a door closer, which would stop the door from slamming, but make sure that it closed. They noticed that the top hinge was broken.  Luckily there are two more hinges, but they will now each have significantly more weight on them, and a higher likelihood of following suit. This fracture may partly have been caused by the single stopper for the door as it opens, which is on the door frame at the bottom. When the door wings open and hits it, this will act as a pivot to translate the considerable momentum of the swinging door into a shearing force on the hinge at the top.

We are looking forward to getting this repaired, but it will be a major task.

Monday, 15 May 2017

The western sun is strong

There is common wisdom in Japan that the western sun is strong. Of course it is not—the sun delivers just as much radiation in the West as it did in the morning in the East. And it delivers the most when it is highest and due South. In fact, less radiation may get through in the West as the air may be more hazy and dusty in the afternoon than it was in the morning.

Panels on a west-facing roof titled to the South
Some people are retrofitting solar panels onto pyramid roofs that slope four ways, and are encouraged by the wily sellers of panels to add them to the East and West sides as well as the South side. Panels facing due south will generate the most, and you could generate 20% less if the panels point East or West. The installers will charge the same wherever the panels go, and when grants are available they often do not depend on where the panels go. Orienting panels in different directions will give peak generation at different times of day which may be more useful than maximum total generation. Given a choice, people recommend the East side for panels, rather than the West side. If the western sun were stronger, they would be recommending panels on the West side.

One of my favourite local solar installations.
I wish they all had servos and tracked the sun! 
What is happening in both cases is that the temperature in the afternoon is higher, and in the normal state of affairs, the western sun is going to feel a lot hotter as the ambient temperature is already hot. In the morning it is relatively cool.

For the panels, efficiency drops as temperature rises, so the eastern panels will produce more electricity in the cool morning than the geometrically identical ones on the west that have to wait until the hotter afternoon to produce their electricity.

Friday, 12 May 2017

Shelves for an airing cupboard

My telephone sometimes tries to be smart and puts together photos I've taken into cute albums of what I have been doing. Unfortunately, I use my phone more as a note-taking device than a scrap book of life-defining events, so a significant proportion of my photos are of the dimensions and prices of items in hardware shops, as you can see here.

Five years into living in this house we still haven't reached peak shelf. The new airing cupboard presents a particular challenge to storage.

I realise that the concept of an airing cupboard may be confined to the UK, or at least to northern Europe. It's a simple enough idea though. You have a cupboard next to the hot water tank, which stays warm and is a good place to dry clothes. Hot water tanks have been standard in UK houses for a while, and damp weather has been around even longer. These hot water tanks are always inside so that any heat lost from them goes into the house, in contrast to Japan where hot water tanks are become more common but are invariably outside the house, even in areas like mine where it drops ten degrees below freezing.

Airing cupboards are particularly useful in the UK where it is often raining or damp, especially in the winter, and drying outside is not an option. I remember my Australian friend talking about hanging out washing in the summer, and the first bits being dry by the time they finished hanging out the last bits, so airing cupboards are probably not so important there. Years of cheap electricity in the US mean that people dry laundry in machines, and it has been suggested that hanging it anywhere else is a confession of poverty.

Drying outside is possible in Japan for most of the year, although the rainy season can sometimes give you few opportunities. Another problem we have is with allergies and when it is pollination season for all the now mature cedar that were planted after the war, we don't want to hang washing outside.

We have an indoor hot water tank, and I'm not really sure why we didn't make it into an airing cupboard from the start, but I have recently converted the door into it, and there are nice spaces around 30 cm wide on two sides of the tank.The door is diagonal, so you can easily get into these two sides. The one on the right is about 50 cm deep, the other on the left almost a metre. 

I was trying to work out the best way of utilising the space. The shallower gap on the right is about one hanger-width deep, so the best plan is a couple of things sticking out of the wall to hang hangers, one high and one low. There were various options available in shops, but the best things I saw were the shop fittings that their products were hanging off, and I haven't seen them for sale anywhere. As usual Japan seems to have a massive range of products that are all tailored to a very standardised set of architectural constraints. So there are hangers designed to fit on the backs of doors, or on the frames for sliding aluminium windows. Not much is available for screwing into a wall. 
Not the hangers, the thing the hangers are hanging from

I imagined some kind of drawer system to pull out racks to hang socks and things on, that would then push back into the deeper space on the left. Several sketches of ropes and pulleys, levers and pivots, and rails on rails followed, but in the end, simplicity prevailed. I got a foldaway hanger that can be screwed into the wall, but it is a little too narrow. There are also extendable poles that fit on the wall on one side and the boiler on the other. Luckily the boiler is square.

The best solution was simple brackets sticking out of the wall, with some nuts and bolts at intervals along them. Then we can hang hangers off them.