Monday 30 May 2011

Ne'er cast a clout till May is out

Not that that has much to do with the pictures. It was a glorious day when they poured concrete, and they were worried it would be too hot and dry too quickly. There's been a fair bit of rain since, reminding me of the old Yorkshire saying in the title. This is a little ambiguous, as "May" could mean the month or the flower, but either way, it's best not to get all your clothes off just yet. It hasn't really got hot yet this year, and the rainy season has already started. I think it's a little earlier than usual. Then there's been a typhoon and the rivers are all close to bursting their banks, filled with chocolatey water gushing down where we have barbecues.

This is what the concrete pouring looked like, anyway:

Sunday 29 May 2011

Are windows being framed?

While many Japanese manufactured products are among the best in the
world, it became clear very early that Japanese windows are not.
Within Japan there seems to be a stark difference between domestic
production and exports. Companies that do export usually have
completely different product line ups, and different marketing
strategies. International competition is tough and competitive, while
the domestic market is characterised by franchises and conglomerates,
so that choice to the consumer is limited.

Looking from an anthropological perspective, this may have something
to do with low context and high context societies. In the west,
generally the best solutions must be found for problems. In Japan,
relationships, and especially long-term relationships are most
important. If you're buying vegetables, then the relationship between
you and the green grocer is important. While building a house, I can't
help feeling that the most important long-term relationships are those
among the architect, the builder, the suppliers and the
sub-contractors. It seems like the poor sods who have to pay for it
all and usually live in the building for the rest of their lives are a
bit of a nuisance and an interruption to this cosy clique. After the
house is built, it's pretty unlikely the customer is going to be going
back to get another one, and if they do, there's a fair chance it
would be with someone else.

So, generally the building industry seems to be resistant to imports
and happy with what it gets. I'm quite sure this is not unique to
Japan, and the building industry the world over is conservative. In
fact people in general will usually choose the status quo rather than
leap into the unknown.

The situation with windows is that the performance of imported
windows, in terms of insulation and airtightness, is much higher than
Japanese manufactured windows, and in fact when we were trying to
compare the performance, it was quite difficult to find any quantified
figures for the Japanense windows, although this may have changed with
the new ratings. The Japanese windows are cheaper, but in order to
make a comparison, you need to know how much heat they are going to
let out over their lifetime.
As I wrote before
, the windows we are using from Pazen
and the fact that they are mostly on the South of the building, will
bring in over twice as much heat as they lose. Lower spec windows are
effectively leaking heat throughout the winter and will cost more the
longer they are used. If you knock the house down and smash them after
17 years (which I think is the average life expectancy of a building
in Japan) it's not such a big problem, and the economics change, but
the windows will last 50 years, and the calculations I'm making for
energy savings are also based on that. Without high spec windows, the
only way to get high energy performance from a building is to make the
windows very small.

It has not been completely smooth getting the windows, partly
exacerbated by the fact that we've dealt directly with the window
supplier, Albero rather than ordering them
through the builders. At first the architect wanted us to use some
Japanese windows, perhaps where they were not so critical, but the
reality is that we're looking at a building envelope with a
more-or-less uniform temperature, so everywhere is critical. We
ordered the windows last summer, as part of an application for a 2.7
million yen NEDO grant, which was dependent on the building being
finished by the end of January. Working back from this deadline, the
windows needed to arrive in November, ready to be delivered onto the
building site. Unfortunately, it doesn't seem that anybody was working
forward to this deadline, and when we eventually got a building
schedule, the date for the windows to go in was 23rd May, over six
months later. They have since been delayed another month due mainly to
the weather, and partly due to a shortage of building supplies caused
directly by the recent earthquake, and indirectly because of the
demand in rebuilding. Also, I can't help feeling that the delay has
its roots in the same place as the last delay, but it's probably best
to write about that after we've safely moved in.

I don't think there is a systematic attempt to keep imported windows
out of Japan, but there are several mitigating circumstances.
* Japanese builders have long-term relationships with Japanese window
manufacturers.
* There is little knowledge or understanding of insulation and what
the numbers actually mean.
* Higher performance windows are more expensive, and the budget for
windows is usually very small.
* Customers are unlikely to ask for high performance windows, and if
they do, they are likely to be told it is impossible, unncessary and
or expensive.

Windows make a massive difference to a house. When people are asked what they did wrong, windows is the most common answer.

Friday 27 May 2011

Exhaust air and heat pumps

As well as being a highly insulated, highly airtight and wind-tight structure, the house has an active ventilation system with a heat exchanger. It's a good idea to have active ventilation with an
airtight house as it will stop us from suffocating. It's a good idea having a heat exchanger because this will mean we lose less heat in the winter, and gain less heat in the summer. It's a good idea having
an airtight house with active ventilation because this means the air goes in and out through the heat exchanger. Try sucking through a straw with holes in it, and you'll see what I mean.

The heat exchanger is over 90% efficient, so most of the heat will be recovered from the exhaust heat, and transferred to the fresh air coming in. This means if it's 20 degrees inside, and zero outside, the air coming into the house will be 18 degrees and the air going out will be 2 degrees above freezing. In the summer, if it's 20 degrees inside and 30 degrees outside, air will come in at 21 degrees. There is an over-ride so, for example on a summer night, if it's 25 degrees inside and 20 degrees outside, rather than trying to exchange heat, it will just get rid of the hot air and bring in the cool air.

There is a heat pump on the roof which is used by the "Eco Cute" water heating system. This takes heat out of the cold air and pumps it into hot water in a way that is worthy of another post, if you're not careful. The ventilation system is in the loft and will be sucking air in from the East wall and blowing out of the north wall. I was quite seriously suggesting that the exhaust air should be directed straight towards the heat pump. In the winter, exhaust air is going to be a couple of degrees above ambient, which will make it slightly more efficient, and less likely to be below freezing. The heat pump is set to run at night time, using cheap electricity, and in the summer, when the ventilation system is in over-ride, the air being pumped out is also going to be hotter than ambient. Even though it can exceed 35 degrees in the day time, it's usually below 25 degrees at night. In 1983 there were two days when it stayed above 25 degrees all night, and that was a record.

The only time it is likely to be warmer than ambient is in summer daytime, when we're least likely to be making hot water.

Monday 16 May 2011

Waiting for the sun and waiting for the rain

It somehow feels more like a funeral than a birth, with the rubble to rubble and cement to cement going into the foundation, before the pillars start to rise towards the roof.  According to the original discussions, by this time, we would have passed our fist first winter in the house and be looking forward to a cool summer. Later estimates would have us moved in and settled. Looking at the dates on the contract with the builder, the structure should be up and the painters would be in. On the building schedule that appeared three months after we signed the contract, the structure is up and the roof and solar panels are on and the windows are just about to go in.  However, as you can see, on the ground nothing much has changed.


Into the foundation is going some aggregate, and on top of the that a concrete floor, but just when they were about to start filling it up, the rain came. Then they waited for the rain to go, pumped the water out, and just as they were going to fill it up, the tail of a typhoon lashed through, and filled it up with water again. They've pumped it out again, the weather is set fair, and this week the aggregate is going in over the next couple of days, then the piping for the under floor heating, and on Saturday they're pouring another layer of concrete.  After that things should start moving a little more quickly. 

Apparently concrete gets stronger if you leave it in water, so this may have been good for the foundation.

The part that worries me, that I'll write about later, is the rather thin looking pipes marked for supplying hot water that are heading to the bottom of the foundation, all the way from their source upstairs, to pop out into the washing machine and kitchen sink. There seems precious little space for any insulation, and they seem to meander around without any consideration for pipe length. Although I've been talking to the architect for the last two years about low-energy building, the last time we spoke he was saying that it didn't matter where you put hot water appliances in relation to the boiler. I didn't ask him till later, but I'm hoping he can actually back that up with some numbers of how little heat will be lost, because I have yet to find any advice on energy efficiency that does not mention keeping hot water pipes as short as possible.

Friday 6 May 2011

An end to fossil fuels?

I went to buy some more kerosene yesterday. Hopefully for the last time, although I thought I was buying kerosene for the last time last year. It's now May, but it's still cold in the morning, and the heater goes on. Hopefully the new house will only need heat for January and February, and it should stay warm on its own from March. I got three cans of 18 litres, so all five cans are now full. I suppose we could have got a tank by the house and had it delivered, but that would have been more expensive and I couldn't thoil to pay. In the middle of winter I can get one tank in the front panier and one in the back panier of the bicycle and ride to the nearest petrol station, on the lines of the Russian proverb, "chop your own wood, then it will warm you twice". 





Most of the heaters we use are fan-heaters which blow out up to 3 or 4 kilowatts of heat. We also have some older heaters that will work with no electricity, and on which you can put a kettle or a pan of food. A friend in Sendai  used some old ones after the earthquake when it was bitterly cold and there was no electricity. In situations like this, movable heaters make sense, as they need no infrastructure, and there are no gas pipes to leak. We have nine rooms in the house and four electric fan-heaters, so we can be flexible about which room we heat. Usually it's just the ones we're in. If we heat more of the house, we'll get through an 18 litre can every day. 

To put that into carbon dioxide and into perspective, 18 litres of kerosene will release about 54 kg of CO2. It may seem strange that it can release more than its own weight in gas, but it just releases the carbon, which is the main constituent, somewhere between 6 and 16 atoms per molecule. Each carbon atom takes two oxygen atoms hostage from the atmosphere to make one carbon dioxide molecule.  The lowest twenty CO2-producing countries emit less than 100 kg per capita per year, so in a couple of cold days with a couple of cans, we're well over our average, and that's before we've switched on the TV, done any cooking, or got into a car, bus or train. Average emissions in Japan are a hundred times this, at around 10 tonnes per person per year, very close to Germany, and about half the US.

It makes more sense to me to have a high level of insulation and keep the house warm the whole time. In spite of poor insulation levels, Japanese houses use very little fuel for heating. I think this is down to an idea "gaman" which translates fairly neatly into "keeping a stiff upper lip". People quite happily put up with cold, because it's good for them. This is a great thing in times of crisis, although I can't help feeling there are times when people need to stop putting up with hardship and make life better.

There seems to be a kind of wisdom in the philosophy of Japanese architecture that there's something wrong with a house if it doesn't reflect the outside temperature.  If it's cold outside, it should be a little colder than normal inside, so that people are in touch with the seasons.This is ironic in a culture with such a strong sense of "inside" and "outside". Luckily there is no such sentiment regarding rain, as the same philosophy would mean that you should get slightly wet when it rains. Actually, I have heard many stories of newly-built houses leaking, but I'm sure that's not deliberate. There does seem to be a resistance to my quaint idea that houses should maintain a difference between the temperature inside and outside and it is not just a case of inability or incompetence. This is not just a matter of comfort; there are health consequences.  Levels of stroke are much higher in Nagano Prefecture than in Hokkaido. Hokkaido is colder, but insulation is standard, and the temperature inside is much higher. Nagano is still one of the coldest parts of Japan, but only 18% of new houses meet the "next generation" energy standards, which correspond to European energy standards a couple of generations ago...