Lights in the bedroom

For a start, the main purpose of a bedroom is sleeping, so you have to wonder exactly what the light is for. We're going to get some bedside lights, so we can read before going to sleep. These can be fitted on, or beside, the bed. It seems foolish to permanently fit bedside lights as we may realise the bed is not in exactly the right place.

The room has a window very high on the north wall, so it should get plenty of light in the daytime. So the most likely situation in which we will really need lights is if we get up very early in the morning and need to choose which clothes to wear. There are a couple of built in wardrobes along the west wall, probably opposite where the bed will be along the east wall. The door comes in at the south east corner of the room and sliding doors along the north open into the walk-in closet. The a walk-in closet in the back has its own lights anyway, so even in the scenario of getting up really early, we may not need much light. 

The ceiling is diagonal, underneath the solar roof, but there is a horizontal part in the middle where a beam runs east-west, and a couple of ventilation ducts run alongside it. This seems like a good place to fit some lights. There are several options, below. In each
case, I'd like to choose LEDs, although in view of how little it seems this light will be used, I'm not entirely sure. In a very short time, I suspect fluorescents will look rather silly in a low-energy house.

1. A duct rail with spot lights on
2. Universal downlights that can point in different directions
3. A single, variable light in the middle of the ceiling
4. Regular downlights
5. Double LED spotlights
6. An LED strip light, running east west
7. Single LED spotlights

I started off thinking 1. The duct rail seems like a good idea, as you can move the lights back and forth and twist them around to illuminate what needs illuminating. They seem pretty expensive though, at least for LEDs. You have to get the rail, of course--5,000 yen for a 4m Toshiba rail--and any light fitting that is reasonably priced (under 2 or 3,000 yen) has "bulb not included". Maybe I'm being stupid, and I'm probably not being economical, but I have a problem with any fitting that is designed to exchange LEDs, in a country where the life expectancy of LEDs is longer than that of houses. There are, of course, some existing fittings that LED bulbs can be retrofitted into, but three lights is probably going to end up around 20,000 yen. There are some reasonable duct rail fittings for E26 bulbs, for under 2,000 yen, then with a bit of shopping around, it looks like there are LED bulbs to fit in them for 2 or 3,000 yen each for 5 or 6 watts, corresponding to a 50 or 60 watt incandescents. If the house is delayed much longer, the bulbs are likely to become even cheaper.

The architect's first plan had a row of down lights, two with universal joints to the west, to illuminate the wardrobes, and two fixed to the east. When I started looking at prices, I noticed how expensive the universal down lights were. The cheapest fixed downlight I could find with a built in LED was 3,650 yen. This was 5 watts, corresponding to a 40 watt incandescent, with a CRI of 70. For higher wattage and better colour referencing, they get more expensive. The cheapest with a universal joint was 8,620 yen. In terms of design, uniformity seems like a good idea, so if we need the lights on the west side to move around, then having a row of three of the same lights will look least offensive. Not that people are going to be spending much time looking at the ceiling. Three of these will come in over 20,000 yen.

So by the time we've made these allowances, we could just get one of the central ceiling lights that we're putting into the living room and the Japanese room downstairs. These follow the simplicity of a "traditional" Japanese ceiling light, that is stuck to the middle of
the ceiling, usually with a pull-cord dangling from it. They have two or three circular fluorescents, and a mini night light, so if you pull the cord it toggles between being on at full brightness with all the lights lit, to partially on, to just a night light. We have a couple in our house and converted them several years ago to being low-energy by taking out one of the circular fluorescents. Actually, we just didn't replace one of the tubes when it stopped working. It's still perfectly bright enough. Anyway, a year or so ago, I think Sharp brought out an LED ceiling light that looks like one of these ceiling lights, but is filled with
LEDs of different colours. It has no pull cord, instead sporting a remote control which can vary the brightness and the colour. They started retailing around 70,000 yen, and have been followed by other manufactures, and I've recently found a Toshiba light for 20,000 yen. The advantage of these lights is that they are very flexible and can fill the room with the right colour and amount of light for the circumstances. They have remote controls so, although the manufacturers recommend you add a wall switch, you don't really need one and can fit a holder for the remote control wherever you like on the wall. I think this won't look so good on the bedroom ceiling though.

Another option is to just put a row of regular downlights east to west. If they send out a 55 degree beam it should cover all of the floor and most of the wardrobe, except possibly the top right and top left corners. These lights should be bright enough and would look good. This solution would come in a little under 20,000 yen.

It would also be possible to put a double spotlight bracket on the ceiling, pointing to the wardrobes. One of these is available from Odelic for 11,000 yen, but I'm not completely sure it comes with bulbs. There's another from Koizumi for 15,000 yen, also with exchangeable bulbs, I think included. If we put a double spot to the west, then for aesthetic balance we should put another double spot to the east. This solution would also come in a little over 20,000 yen.

Another option is LED strip lighting. This should be an economical option as strip PCBs with LEDs added every few centimetres are cheap, however one problem is the fittings. There are some from Neo blue 1.2 metres long for 13,860 yen. These run on 24 volts DC, so a transformer is necessary. It would be easy to dim them, but I don't think dimming is a high priority for this room. Either we want it light or dark. There are some 100 volt strips from Mini Bee for around 10,000 yen for 90 cm. There's also a 590 mm strip from Noatek for 2,700. Most of these cost around 1000 yen per watt of LED. There's a 420mm strip for 1750 yen that is about half that, but
it is 12V and needs a power supply. All of these are manufactured outside Japan. Another problem with these is how bright they will be. This kind of lighting seems to work very well inside cabinets, for corridor lighting or for ambient lighting, and it will certainly stop the room from being dark. It may not be bright enough to help choosing clothes. As the light comes in strips, it could run along the edge of the horizontal bit of ceiling and would be practically invisible when not on. This kind of lighting fits the lines and spaces of buildings and the manufacturing processes of LEDs, but at the moment it doesn't fit into the imaginations of architects, the mindsets of electricians or into the spaces in the market.

Option 7 is then single bracket spotlights, arranged in a row from west to east. Three would probably be enough, if they are wide-beam. Again we're limited by the range and cost of spotlights, which seem to start at 7 or 8,000 yen with bulbs built in or included.

After the first round, I think we can eliminate 2, 3 and 6. The more I look at it, the better the duct rail of spot lights seems. It will probably come out cheapest, and has the advantage that if it's not bright enough, we can get another couple of fittings to put in there, or replace the bulbs with higher wattage ones, notwithstanding my earlier comments about the irreplaceability of non-replaceable LEDs. There are some 12 watt bulbs for 7,500 yen and 16 watts for 8,200 yen. Those prices will probably halve in the next year.

Low cost and high flexibility. So I'm back at my original idea and it seems like I've been wasting my time prevaricating and writing this. I hope it wasn't a waste of time to read it!

More mind-numbing numbers about solar panels

I was thinking of using all the bits of paper we've received somewhere in the house. They could wall paper most of it... Probably two layers in some places.

Of course some of the information has come electronically.

One of the more interesting files has a list of the power ratings for each panel. Although they are nominally rated at 190 Watts each, the test results for each panel all come over 190, and average 195. So while the array is rated at 9.12 kW, it's actually 9.36. All extra kilowatts over their lifetime. The panels are guaranteed for 25 years. More specifically, at 95% for 5 years, 90% for 12 years, 85% for 18 years and 80% for 25 years, so I guess their lifetime will pretty much correspond to the rest of my lifetime. Anything we get out of them (or me) after another quarter century is going to be a bonus. Unless something drastic happens, the panels will still be there producing electricity long after I've stopped consuming it.

36 views of Matsumoto Passive House

A couple of weeks ago I clocked the camera memory stick. I've been taking pictures of the site since they first laid out bits of string to mark the footprint of the house, back in December last year. I've been deleting old pictures from the camera each time to make space for the new ones, and just caught up with the first pictures of the plot.

At the beginning I took four pictures, one from each corner of the plot. I'm still taking the same four pictures, adding each one to a separate album.

Actually, there are many more than 36 views. There are now over 90 albums, most with a series of pictures taken each day from a fixed spot inside or outside the house. On a busy day I'll take over 100 photos.

The slideshow above is the biggest album, the view from the South East corner of the land, with 130 photos. To the right is the latest angle, looking at where the boiler as going. I wish I'd started taking this shot sooner. The back wall is already finished. 

You can see all the albums here on picasa.

I've wanted to change the name of an album a few times as the situation changes. Unfortunately, the name of the album is included in the link to the photo, so once I've used the link it's not a good idea to change the name. The names each made sense at the time.

Another thing that seems to happen is that I'll start taking a shot from an angle, then something will appear right in front of the camera, blocking the view.

This happened with two of the original angles, when a wire frame appeared in the shot from the North East corner, and a portaloo appeared in the view from the North West.  

More recently they moved the boiler, still in its box, right into the middle of the shot from the South East corner inside the house. 

I think this view of the four corners of the house is nice, and shows how the walls are developing.  

Built to last or built to lose

It is sometimes hard for me to come to terms with the disposable nature of house building in Japan. Apparently the average life time of a house in Japan is 17 years. In the UK, it would take 1700 years to replace the entire building stock. Although those two numbers are not equivalent, it gives some idea of the difference. I come from a country where houses are built to last. I grew up in a house that was a couple of hundred years old, which was not particularly unusual. The house we rent here now is about a hundred years old, and it's a constant surprise that it is still here.

It is easy to write this off as bad workmanship or see it in terms of a nation that loves new things and is obsessed with the disposal of the old. It has been suggested that Japan needs a large construction industry as there are periodic needs for mass rebuilding after natural disasters. It seems that the construction industry is a powerful lobby and they can veto any suggestions to improve building standards. There is also no doubt something left over from the post-war rebuilding of Japan where fast, cheap building was the only option. I think there is no simple reason.

There is a vicious circle, as I found when I was asking the bank about loans. As far as they are concerned, and as far as the taxman is concerned too, a house is worth nothing after twenty-five years. The biggest drop in value is the moment you move in. In most cases, the house is worth less than you paid for it as soon as you turn the key and walk over the threshold.

The people at the bank weren't particularly interested in the building specs when they were valuingthe property, instead they look at the houses in the neighbourhood andtake an average per floor area. In fact as far as collateral, they don't really take the house into consideration and just look at the value of the land. So unless you're building with cash, and have lots of it, you're at the mercy of a bank that is not going to encourage you to increase the spec. There is little incentive to build something that will last more than 25 years, although a standard for a hundred-year house has recently been introduced, that can open the door to lower mortgage rates.

Houses in the UK, and probably the rest of Europe, the US and Australia, steadily increase in value. From when they are built, they start to get more valuable. After a while, when they hit an unfashionable or unserviceable age they stop getting more valuable, but even then they will hold their value. A little later they start to go up again. There are certainly stories of people with negative equity and people who lose out, but that's usually short term and a combination of local conditions and some measure of extra bad luck for the house owners, forcing them to sell at the wrong time.

As we were looking around Matsumoto for houses and land, we often saw old houses for sale that were very reasonable. If they weren't sold after a year or two, they were knocked down, and the price of the land, without a house, would go up. There is a common wisdom here that renovating old houses is more expensive than building new ones, and I think it may be true if you're comparing a low-cost new-build with restoring a ruin to its ancient form. I think it's more likely to be propaganda by the building trade, a symptom of few people or businesses that renovate, and the prevailing trend of not looking after houses, but letting them wear out until they are knocked down, which is all part of the vicious cycle.

Having said that, if I look at the house we are in now and if we were to bring it up to a comfortable level to live in, we'd have to replace the roof, replace the windows that make up the north and south walls, and pull up the floors and do some work on what's underneath. By the time we'd taken all the bits off that need changing, we'd be left with a wooden frame, and that probably would have to be made earthquake proof as their are no diagonal supports and the whole thing is a mechanism (see here). Also, I'd want to raise all the horizontal beams so the doorways are at least twenty or thirty centimetres above my head rather than two or three centimetres below, just where there is a permanent bruise on my forehead.

One way of looking at this difference is in terms of agriculture. The UK traditionally has pastoral farming, so buildings have been essential to provide shelter for people and animals, so that animals can feed off the surrounding land. Buildings have intrinsic value in this sense. Japanese agriculture is arable, so that land itself is valuable for intensive planting of crops. Any building is going to reduce this value by stopping the production of crops.

Another consequence is in the notion of "home". For the British, a home is a solid thing. An Englishman's home is his castle. For Japanese people, any building seems arbitrary and the sense of belonging is to a community of people.

So while I see what I am doing as an investment, and put myself on a mission to make a small change to the way houses are built and treated here, I'm probably just pouring cash into a hole in the ground, and the main interest of most of the people involved is to catch some of that cash as it falls. I'm sure the house could be built to a similar specification for less cost, and hopefully everyone involved will learn something onthe way, so if another idiot comes along asking for a house that doesn't consume, it'll be easier for everyone concerned.

Keeping those panels cool

The people from Caname, the roof makers, and Rooftech, the roofers, came to visit the other day. My concern was with the air channel under the panels, which seems to me to be just too small. I've started measuring the temperature of the air coming out of the top, and it was getting up to 70 degrees centigrade. You can see a graph of the temperatures below, showing also for references the ambient temperature, the temperature inside the house and the temperature at the bottom of the slab, which comes pretty much to a straight line. The heat of the actual panels is going to be more than the temperature of air in the channel. 

So what? I hear you ask. 

I can hear some of you replying that solar panels produce less electricity as they get hotter. With the Suntech STP190S-24/Ad+ panels we are using, the efficiency drops half a percent with each one degree increase in temperature. 

As a thermodynamic system, incoming heat is beating down in solar radiation. This heat is lost in four ways: the panels are losing some heat to the wind from the top of the panels by convection, they are losing some heat by convection to air passing through the channel between the panels and the roof, they are losing some heat that is converted to electricity and they are losing some through the top by radiation. A small amount of heat will be conducted from the panels to the roof, but the roof is well insulated, so this heat is not really going to go anywhere very quickly. Heat that is not lost will make the panels hotter, and the efficiency will go down.

Directly fitting panels onto roofs as solar tiles is a bad idea because of this heat loss. Even conventional arrays that have been added onto a roof with a gap underneath will suffer efficiency loss of around 20% in the summer. 

Caname have done some research with panels fitted directly onto a roof with no air channel, some fitted in the conventional way, where air can flow north to south and east to west, and some fitted in their roof system where air only flows south to north. Their results over a year peg the conventional roof at 100%, find that fitting the panels directly to the roof with no gap drops to around 80%, while their roof is 99.5%. In terms of average panel temperatures, the conventional panels and their panels averaged around 65 degrees, while the tile style was over 70.   

In my opinion, rather than treating the conventional way as 100%, they should be treating ideal output as 100%, and ideal output means either full rating of the panels, or the projected power output at ambient temperature, in other words with perfect cooling.

The fact that they are building a roof system should mean that they can do better than panels that are added to an existing roof. Setting this as their target seems to be aiming too low. For example, they mount the panels on corrugated steel. Corrugated steel roofing may sound like a really bad idea, but it should work very effectively to cool the panels, both by channeling the air from bottom to top of the roof, and by increasing the surface area to conducting the heat from the panels.

Temperature and heat of the slab

So we're getting all this temperature data from the thermometers in the slab. Not sure exactly what to do with it, or exactly what it all means yet!

There are ten thermometers in the slab: two in each corner, and two in the middle. One at the bottom in the foundation slab, and one in the screed floor.  They are numbered from 1 and 2 in the middle, 3 and 4 in the north-east corner, then clockwise until 9 and 10 in the north west corner. Odd numbers are at the bottom and even numbers at the top. 

You can see eight of these on the graph. The software from T&D will only show eight bits of data at a time. If you look at the graph you can see the lines at the top moving up and down rapidly, fluctuating with the temperature in the house, in turn affected by the outside temperature. The bottom lines, at the bottom of the slab, are much more sedate. 

One highlight is 6th July when the windows were installed and the fluctuations at floor level were quelled. 

The weather changed after the middle of July and it got a significantly cooler. Luckily this was just after we got back from a camping trip. You can see the peak of the temperature at the top around 20:00 on 16th July, which didn't reach the bottom of the slab until 05:00 on 19th July, two and a half days later. 

As a thermal system, I think there are nine ways in which heat can move:

Going in:

1. From the sun to the screed

2. From the boiler to the screed through the under floor heating pipes

3. From the air in the room to the screed (when the room temperature is above floor temperature)

Going out:

4. From the screed into the room (when the floor is warmer than the room)

5. From the screed through the walls around the foundation to the external air.

6. From the bottom of the foundation to the ground under the house.

Within the slab:

7. Up and down (depending on temperature difference between top and bottom)

8. North-south (especially when the sun is heating the floor in the winter.)

9. Through the underfloor heating pipes (when there is a big difference between north and south).

This heat will all pass according to the second law of thermodynamics, that you can hear more about here on you tube from Flanders and Swann.

According to the calculations in the Passive House software, for the heating season between October and April, 5,195 kWh of heat are going to come in through the windows on the south. January will get the most heat. This is a combination of fine weather and a low angle of the sun. On average there will be 31 kWh per day. January also has the coldest temperatures. 

I'm not sure how much of this heat is going to go straight into the slab. Some will hit walls or furniture, some will be reflected from the slab and the heat that does reach the slab may leave it quickly.

Also according to the Passive house software, most heat will be lost through the slab in February, and the figure it gives is 4.6 kWh per day. 

The slab is like a box, representing the structural foundation, filled with some gravel and topped with a screed floor.  According to the builder's invoice, there is around 40 cubic metres of concrete; 16.5 at the bottom, 4 standing up around the edges and 20 on the floor. At a density of 1600 kg per cubic metre, that's 65,000 kg. 

There's around 22 cubic metres of gravel in it, which amounts to 26 tonnes, if the density is 1200 kg per cubic metre. 

It's difficult to be sure of the specific heat capacity, but 0.8 kJ/kg seems a reasonable estimate. 1kWh is 3,600 kJ, so the whole slab holds around 73 kilowatt hours per Kelvin. In other words, if it drops one degree it will release 73 kilowatt hours.

In the very worst winter weather, the whole house will lose 55 kilowatt hours in one day, so even with no sunlight or heating, the temperature of the slab should drop by less than one degree. 

Shimo bashira

Now that we're in the middle of summer, it's a good time to publish some pictures of ice.  They're called Shimo bashira in Japanese. Apparently "needle ice" in English.

I think these are quite unusual, geographically speaking. I heard somewhere that they need volcanic soil that's wet and above freezing,  and air that is below freezing.

Obviously we haven't had any for a while.  
Charlie has a better picture. Have a look!

0.3

The conditions for a passive house seem fairly simple, although they are by no means easy. As far as I can tell, they amount to three things.  Insulation: the Building must lose less the 15 kWh per square metre of floor space per year. Airtightness: the building must lose less the 60% of its volume with a pressure difference of 50 pascals. Energy use: the building must use less than 120 kWh of primary energy per square metre of floor space per year. These measurements seem fairly straightforward. In Japan, insulation (Q value) is measured relative to wall area rather than floor space, and draftproofing (C value) is measured in square cm per square metre, and indicates the area of cracks in the walls. Airtightness is tested the same way in both places: by sticking a blower on a door or window, dropping the pressure and seeing how much air leaks in.

The insulators tested the airtightness yesterday, and it came to 0.3 square cm per square metre.  Apparently this is a pretty good score. In Japan 2 square cm per square metre is considered good, and less than 1 is a target for super-insulated super airtigthness. Our builder's previous best score was 0.8, and the insulators have done better still. The Passive House standard corresponds roughly to a C value of 0.2 so at first sight it looks like something is wrong.

However, we know that something is wrong. We know that there are issues with gaps around some of the windows. We know there is a gap under the door. We know that the big window doesn't close properly.  Here, the front row of the building team are doing their best to keep it shut. While the test was taking place, we went around the building sticking fingers in corners, and feeling cold air coming in in various places. 

As we know that there are problems, and the value is this close, hopefully it should reach the target when the windows are all sealed, the door has no gap under it, and the big window is fixed.  

And would you like some ramen and udon with your spaghetti?

So on top of the electric wiring, there are also water pipes and air ducts going around the house. Wire is relatively straightforward as electrons are pretty tiny and don't mind going around corners. Fluids tend to dislike corners as it disturbs their flow. They also take up a lot more room. In both cases there is a loss per unit length. This is most critical with hot water pipes with no insulation, running at 100 watts per metre. It may be least critical with return ventilation pipes, which will only lose or gain heat within the thermal envelope. On a small scale losses in wires are not a big deal, but in the bigger scheme of things, less than 40% of electricity produced by power stations reaches consumers, so well over half is wasted heating up wires.

The plumbers were in again the other day to move a drainage pipe that they had put in. Somebody had forgotten to mention that there is going to be a laundry shoot coming down from the bathroom to the utility room where the washing machine is. I suppose this is another kind of conduit, further confusing the electricity, water and air.

Presumably this is business as usual in the building trade, going back at least to "Twas on a Monday morning" by Flanders and Swann in the 1960s, and probably well beyond. Probably back to the first time humans tried to knock through from one cave to another, or had an extension built on to their mud hut. Getting crap around the house, and I mean the word mainly in the engineering sense rather than the vulgar sense, is probably not given enough consideration. 

The loft is one place where these conduits come to the fore. In most places, of course, we don't want to see wires, ducts or pipes, and I go along with whoever it is who described the external piping of the Pompidou-centre as wearing a colostomy bag outside your clothes. In the case of the loft, pipes and wires all need to be visible, as that is the room's job. 

The ventilation system is in the loft, so fresh air must come in from the outside, then be sent all around the house in supply pipes, then come back in the return pipes to be sent outside as exhaust. Electricity is also vying for this space, as the sixteen wires from the eight solar circuits, each of six panels, come in through the top of the wall into this room. They must go through two distribution boards, then through two power conditioners, preferable as soon as possible as the loss is higher on the DC than when converted to AC, although this difference may be marginal. The priority for the electrical wiring is to be as short as possible. The power conditioners must be placed next to each other, not one on top of the other, as they put out a certain amount of heat. Each corner in the air ducts increases the resistance and makes more work for the fans insides. And of course, extra length also costs more in piping, wiring or ducting. 

Optimisation

Perhaps it's having studied engineering but in a lot of places I'm looking for optimisation. House building is full of compromises, often between material cost, installation cost, appearance, functionality and energy efficiency. Maybe sometimes between the egos and prejudices of the various players. Energy efficiency usually comes last on people's lists, if at all, although I'm sure recent marketing must be having some influence. Perhaps we'll have to wait another twenty years until the children being exposed to it are practicing architects. 

I feel I scored a great victory in persuading the electrician to run the wires from the power conditioners, which convert the DC from the solar panels into AC for the grid, straight down the wall to the distribution board. Both the power conditioners and the distribution board are on the same wall, facing South in the middle of the house. The distribution board is a metre or two from the East wall on the ground floor; the power conditioners a metre or two from the East wall in the loft. The shortest distance between two points is a straight line, and this one is vertical. Upstairs, between them, is the bathroom. In the original plan, the wires were to circumnavigate the bathroom, adding at least a metre to their length.

A metre is probably not a big deal, although the current has to get through whatever resistance there is in the wires and will lose some of the power, and there will sometimes be over 9 kilowatts. Financially, the important distances are from the panels to the power conditioner, and from the power conditioner to the electricity metre. There are two electricity metres, one counting the electricity we buy, the other counting the electricity we sell. 

It's more a matter of principle, and if it's possible to make it shorter, then it should be made shorter. 

The problem is, people are all busy doing their jobs. The architect's job is to draw lines on paper, and the more lines he draws, the happier he is! The electrician puts in wires, the plumbers put in pipes. The cost of pencil lead, wire and piping is relatively small, and the client is going to pay for it anyway.

We have spent hours thinking about where we want each sink or basin, and where the electrical appliances and outlets should be, and we will spend years using them and living with the consequences. For the plumbers or electricians, it's just another hole to drill in a wall or a floor.

Decisions decisions decisions

There are times when things seem to be following some master plan, and rather than being a series of random events, there appears to have been some purpose to my life. For example, when I started on this building project, the things I'd learnt twenty years ago about finite elements, thermodynamics and electricity found a practical application. The threads of life start to tie together, and make me worry that the credits are going to start rolling up and I find I've been in a Hollywood movie. Thinking about decision making is another thing that ties together some ideas about how I can get my students to speak English, and why usually they don't.

I've been aware for a while about differences in decision making between Anglo-Saxon and Japanese models, or to generalise even further, Western and Eastern norms. These difference lead to cultural mis-communications and misunderstandings, and can waste a lot of time. One way of looking at it is in terms of democracy, consensus or dictatorship; another is in terms of high context or low context.

The fundamental ideas behind democracy are that each person's opinion is equally important, and that the majority should make the decision. This comes from ideas about equal rights of individuals to having opinions. The west has a long history of democracy and individualism, going back to the Greeks and probably beyond. This leads to dialectics and voting. This leads to meetings where people advocate their points, disagree or challenge other opinions, and concede, albeit often grudgingly, to the majority when they are in a minority. It also leads to low-context meetings where the agenda is transparent, and the issues being decided are explicit. Ideas and opinions are brought to meetings, and people leave with decisions.

Consensus, on the other hand, is based on ideas of harmony, and the importance of the group. The east has a long history of collectivism, rather than individualism. Japan has a sense of wa and expressions such as "the pole that sticks out will be hammered in". This leads to lengthy discussions, and goes with long-term relationships. Meetings are high-context, so the important issues are the relationships between participants and the hierarchy among them. The agenda is less clear, and issues being decided are vague. Opinions are usually left out of the meeting, ideas may be generated, and the participants leave in harmony with a stronger group. The actual decision may be made after the meeting, and may be arbitrary. 

Dictatorship is a much less partisan system that can flourish whether the society tends towards individualism or collectivism, whether East or West. In terms of decision making, dictatorship is the most straightforward; one person makes the decision and everyone must follow it. In both democratic and consensus-based systems, one person can take control of the whole show. Dictators often have long, successful careers if they give the impression of democracy or consensus. 

What's the price of freedom? Perhaps not strictly relevant to this discussion, but John Philip Curran, Ida Wells, and Thomas Jefferson would all tell us that it is eternal vigilance. I seek the freedom to live in the house of my dreams and desires, but will only get it through eternal vigilance.

So whether the meetings that have been held between us, the architect and the other players in our evolving charade have been a battle between democracy and consensus, or whether they are a battle between two dictators, I'm not sure. 

Colour

I would go along with Henry Ford, "any colour you like as long as it's black" but unfortunately this doesn't really work with lights. 

Colour has something to do with the frequency of light, although it's not really that simple. 

We can see about one octave of light. If it were sound, this would be equivalent to being able to hear 12 keys (7 white and 5 black) of the 86 on a piano. The eye is a fairly precise instrument. 

I'm sure there are slight differences in each person's range, and different people are no doubt sensitive to different colours. The architect was talking about westerners seeing light differently to Japanese people because they have blue eyes, but this sounds like nihonjin-ron. I pointed out that my eyes are brown. 

The conventional theory of the way the eye works is that there are rods and cones. The rods are numerous and sensitive to low levels of light, while the cones are more concentrated around the middle of the retina, can pick up colour but are not so good as it gets dark. You can observe this as the colours are sucked away when it gets dark, and there's also a phenomena when you can see a dim star, but if you look at it directly, it vanishes. 

More recent research suggests that many cones tune into particular colours, so it seems very likely that the range of colours in the environment in which we develop will shape our colour perception.

A lot of animals can only see whether something is dark or light. Some can sense one colour, for example green. Very few can also sense red, and have the colour spectrum that we do. Apparently there is a correlation with hairless-faced primates. A possible connection is the ability to see face colour, which depends on the red blood running through the veins, and the importance of this in determining emotional states of fellow members of social groups. We now use language, and people have been using make up to cover up or enhance their face colour for a very long time, but the ability to distinguish puce from beige remains.

When it comes to the colour of lights, our first point of reference is the sun, which sends out radiation across a broad spectrum. We've been brought up on incandescant lights, which are like miniature suns in that they are not so discriminating about the frequency that comes out. As a results, and to their detriment, most of the radiation is not visible, and comes out as heat. 

LEDs start from exactly the opposite situation, emitting light at a very precise frequency, a function of the material the LED is made of. This makes them efficient as they are not emitting heat as invisible radiation. Also, because insects are attracted to light outside the spectrum visible to humans, they are not attracted to leds, making leds perfect for camping, and indeed for lights in or outside a house in a country with insects. LEDs are used for indoor plant growing, and researchers have been finding that different plants respond to different frequencies of light, corresponding to receptors in their DNA.

The first LEDs were red. I can still remember when a boy turned up to our school with a digital watch. You pressed a button on it, and the LEDs lit up the time for a few seconds. Green LEDs were invented a little later, then blue. First attempts at domestic LED lighting involved arrays of red green and blue LED, which combine into white light. Today this all goes on at a much smaller scale, with the colours being mixed up within individual LED chips, or broad spectrum blue LED substrates are mixed with green and red fluorescent materials. 

The problem is how to express this in numbers, so that you have a good idea of what you're getting when you buy a light. Gone have the glorious days of incandescents when you could have any colour you like, and in fact every colour, whether you liked it or not, and the wattage would tell you how much light came out. For a few years, different colours of fluorescants have been sold, under names like light-bulb coloured, cool light or warm light. Colour temperature is one measure of the colour of light, rather confusingly measured in kelvin, partly because it was Lord Kelvin who thought of it. Colour temperature represents the colour given off by a black body heated to that temperature. To add further confusion, low temperatures, under 3,000 are warm colours while high temperatures, over 5,000 are cool colours. If you consider that blue-hot and white-hot are hotter than red-hot, but red is a warmer colour, this makes some kind of sense. As things get hotter, they produce more light at higher frequencies. In terms of frequency, "warm" colours mean more light at the lower end of the spectrum, and "cool" colours have more light at the higher end of the spectrum. 

The question is not simply the colour of the light coming from the bulb, as if it was on a spectrum from red to indigo. We usually don't want light of a single colour, unless we're aiming for a dark room motif in our interior design. We want the light in the kitchen to shine on red, green and yellow peppers, and for each of them to come out strongly in their own colours. We want this for our kitchens and dining room tables in our houses, but supermarket owners want this much more for their shelves. There is a lot of electricity to be saved, especially in the refrigerators where inefficient light not only means higher bills for lighting, it also means more work for the heat pumps. 

Anyway, you need to know how much light is coming out of the light at each frequency of the spectrum. The machine-gun approach of the sun, or incandescent light means that there is an even light, so each frequency is rendered well. The measure of this is Colour Rendering Index (CRI), which is a number up to 100.

LEDs get a CRI of up to 98. Anything under 80 may not be ideal for kitchens or dining room tables.