Humidity and temperature

There's a good table of the absolute humidity and temperature here at Transport Information Services, if anyone is intereste.

For a range of temperatures and relative humidities, at five-degree and ten-percent intervals, It shows the absolute humidity and dew point. The absolute humidity is grammes of water per cubic metre of air. The dew point is the temperature the air must drop to if water is going to start precipitating from it, or the temperature the air must not drop to if you don't want condensation. 

The issue of humidity and temperature is in fact very complex, since you're looking at the properties of droplets of water that are behaving like a gas. More information in general is available here on wikipedia. 

Also, you get forums like this one with lines like "We all know the ideal gas law, PV = nRT. But the number of moles, n, can be written as m/M where m is the mass of gas, and M is the molecular weight in g/mol. Then PV = (m/M)*RT."

If you do know that, then there are plenty of forums out there, and a great deal of physics. In the meantime, I'll stick to relative humidity doubling with every ten degree temperature drop, or use the table if I need more precision.

DIY ventilation maintenance

A couple of weeks later I went into the machine room. I think that's the best name for the loft with the power conditioners and the ventilation heat exchanger. That's all that's in there so the only reason to go is for the monthly cleaning of the filters or if the batteries need changing for one of the temperature data loggers in there. And of course whenever there's a problem from leaking condensate.

I just learnt that word from the Stiebel manual, which I've been reading to find how to clean the heat exchanger. The manual says in one place that it must be cleaned every three years, but elsewhere that it should be cleaned every year. The suppliers of leaky ventilation systems mentioned a three-year maintenance, and wanted us to sign a contract with them, which we did not. The system has been leaking for about the third time, and two weeks ago they came to fix it, which they did not.

I'd left a bowl under the system where it had been catching drips. I knew there would probably be a bit more water to drip through as everything dried out. I didn't expect it to be overflowing two weeks later, and still coming out after I'd emptied the bowl. I called the builders once again to tell them that the problem hadn't been solved. It was still leaking, a little less than before so it wasn't urgent for somebody to come, and since it was a snowy Friday, the following week would be fine. I got a call back to say he was in the area anyway and would be there at 6pm. He also said that the ventilation experts had asked me to contact them directly, which I'd evidently forgotten, misheard or ignored. Then a few minutes later another call came to say they'd be charging us. I asked why they'd be charging us this time, when they were just finishing the job that they hadn't done properly last time. Then I told them there would be no need to come, and I'd be in touch if necessary.

The first thing I noticed as I was following the instructions to get the heat exchanger out was that he'd put the filter back in the wrong way round. This is probably not a big deal if it's a clean, new filter, but it had been filtering a few weeks of crap from the air coming in, and since he put it back the wrong way round, that crap was all going to go straight into the innards of the machine, which the filter was supposed to protect against. My confidence is not inspired if he didn't know which way the air was flowing, or couldn't read the arrow on the filter, pointing in the direction of airflow.
Maybe I'm being hypercritical. I shouldn't be so harsh on these people who are innocently going about their business of importing European technology to Japan without properly understanding how it works.

Removing the bypass unit from the ventilation system revealed a large pool of water in the bottom, with a drain in the middle that was not letting anything through. A screw driver helped unblock this.

Once it was draining through the drain, it became apparent that the system was not level. The housing of the ventilation and heat exchange is all expanded polystyrene. Underneath the diamond-shaped heat exchanger unit there is a small reservoir with a drain in the middle. If I'd been designing it, I would have made it slope towards one corner and put the drain there. A few millimetres of water were still settling towards the front, so it wasn't very effectively draining. You can see the effect this has had of leaving a dirty residue. I remembered their boss saying that it was a good idea to drain the bath every night since the Japanese custom of keeping and re-heating bath water is an invitation to legionnaires disease. I'm sure he'll be shocked to hear about the stagnant pool of water he has installed in my house.

I don't know whether their failed attempt at fixing our problem was a gambit to get us to subscribe to a maintenance contract, or a genuine failure to fix it, but either way I don't think we've even got to the stage of maintenance. We are still dealing with getting a suitable system that has been correctly installed.

It sounds like the manufacturers are also culpable. This system was designed in northern Europen, and I think works very well there. Apparently there have been a lot of problems in Japan with systems leaking in the summer. The diamond-shaped heat exchanger fits in the middle of the unit, with air coming from outside going from bottom right to top left, then the air being sucked out of the house going from top right to bottom left. There's a collector and a drain in the bottom left chamber for the air being expelled during the winter, when it will be precipitating moisture. There is no drain for air coming into the house in the summer. This is not likely to be a problem in summer in Europe, where it is not so hot and not so humid. When it is high in the thirties and close to 100% humidity in a Japanese summer, there is going to be some precipitation on the other side, and no drain for it to drip through. Since hotter air carries so much more water, this could result in a lot more condensate than in the winter.

Another issue is that Japan just seems to have a lot more bugs, germs, particles and general small crap. The average temperature is significantly higher and presumably this just multiplies a lot of stuff.
But the real question is, is anyone really interested?

If they are, then there are immediate and long-term solutions.

Long term, the system should have more rigorous drainage, so that it will handle regular and irregular condensate, both from expelled air in the winter and incoming air in the humid summer. Parts should be easy to clean. Build-up of crap in the heat exchanger itself is inevitable, and it may be that a lower-cost disposable material would be cheaper, long-term.

Short term, we need to get our system level, so that there is no pool of stagnant water in there. Another possibility is to put a collecting pan in there, that would funnel water from the heat exchanger through the drain.

Even more short-term, and probably medium-term, I need to contact the suppliers, the manufacturers, or their agents in Japan, and try to get someone to take this seriously since heat exchange ventilation systems are crucial to low energy building, and it is bad news if they are being driven around by cowboys.

Snow architecture

The Winter Olympics were held in Nagano sixteen years ago. With less than a month to go, there wasn't enough snow, and there were worries about events needing to be cancelled. Some of the organising committee went to a local shrine and prayed for snow. The gods answered their prayers and on 15th January it snowed. And snowed and snowed. Although Matsumoto wasn't holding any of the events, it was affected by this divine intervention, with a snowfall of 69 cm, the biggest since records began. This was hailed as one of those once-a-century snow falls, although 1946 seems to have been a bit snowy too. 

Last week it snowed 49 cm. Another one of those once-a-century snowfalls, then on Valentines day and into the next day it snowed 75 cm, so these once-a-century events seem to be getting a bit more frequent. Climatologist James Hansen, formerly of NASA claims that global warming means once-a-millennium weather events will happen once a century, and once-a-century events every decade, and decadal events every year. Read how warm was this summer here.

Anyway, one big impact locally is that there is a metre of snow on the ground. My obvious reaction is one of joy. People pay money to go on holiday for this kind of stuff, and there it is, right outside my window! Everyone else is muttering and grumbling about having to clear it, which is a civic duty here, since there are no municipal snow-clearing facilities. It's the height of shame in the neighbourhood if you're not out there shovelling snow the moment there's more than a few centimetres. 

As well as the mechanical implications of this, and the dangers of injury from shovelling too much or too quickly, I realised the worst thing for your health could be to not enjoy shovelling snow. So rather than digging from the road and the drive into a big pile against the neighbour's wall, and increasingly falling over the neighbour's wall, I decided to roll some of the snow up into giant snowballs and start making an igloo. At the beginning I was making an igloo while  clearing snow, but pretty soon I was clearing snow as a consequence of my igloo building project.

I've tried making igloos before, but never been successful. I've managed to dig a hole into a large pile of snow, but that doesn't really count, and usually doesn't get very big. I've managed to make a ring of big snowballs before and started contemplating the roof, but usually the snow needing clearing has run out, and the problem of making the roof has been too great. 

An igloo is a dome. An arch rotated into three dimensions. As such, it's a very strong structure. The weight of each part is transferred laterally, and I've heard that the bigger arches get, the stronger they get. The problem is that they only have this great strength when they are complete. Until the top-stone is in place, an arch is just two bent walls that are likely to fall over. 

So it was easy enough to make the bottom of the wall, and another layer of snow balls on top of that slightly further in. Then I started to worry. The form was fine but the process perplexing. My respect for those ancient arctic architects grew.

After a while I realised that I could keep building the structure upwards with smaller arches, not going through the middle of the dome, but from adjacent snowballs, then further apart. 

I also got better at making snowballs. In fact they were more like snow-bricks, from forcing my snow-shovel in, and packing the snow onto it. Better still were those cut out of trampled snow with a spade.

A big snowball made the lintel over the doorway, and then it was easy to fill the hole at the top. Next I used the same principle to build an arched entrance, just like they have on real igloos.

So this first igloo has taken me 46 years to build, but the next one should be a bit quicker!

See how the experts do it

Inflation - Yes please!

Soon after taking office, the current prime minister of Japan announced a target of 2% inflation. For most of the twentieth century, in most places, 2% would have a been a target to get inflation down to. Not push it up to.

As far as my wallet is concerned, with a fixed rate loan, the higher the better. This means the value of my property goes up and the amount I owe goes down.

The biggest worry is sustained deflation. If salaries go down, money becomes more valuable and the value of my property goes down, it will be more difficult to pay interest and the value of the property will be less than the amount I owe. This would not be good, but I think it's unlikely to happen.

Although I stand to gain personally from inflation, politically it seems like a bad idea, and it would be much better if things just stayed around the same prices, and money kept the same value. This has been the case in Japan for most of the time I've lived here. 

I may be looking through rose-tinted spectacles, and I'm sure a crash will come sooner or later, but most people in Japan seem to be surviving in relative comfort and the the doom and gloom from economists about stagnation seems misplaced. There is certainly a declining manufacturing industry here, but I think that has more to do with natural cycles of boom and bust, and stagnation in schools, where innovation and thinking outside the box should be encouraged.

Inflation was certainly a great invention that gets people to put their money in banks instead of keeping it safe somewhere. At first sight putting your money in banks seem like a good idea, since they are paying out interest, but in fact the banks stand to gain the most, since you are giving them money. Overall, inflation favours wealthy people, as wealthy people tend to own a lot of things, and their wealth is not in cash. 

So I'm sure the economy will be fine. After all, so many powerful people have got so much invested in it.

You need a creel

Some friends of ours are planning a house. They have a long list of requirements, which is a very good idea. One of them is a hoist, or dumb waiter, for getting laundry upstairs. The problem is they want the washing machine downstairs, but to hang the washing upstairs. I suggested they get a creel. Not sure how to say that in Japanese, so I googled a picture. 

At first it came up with lobster pots and some town in Mexico, so I modified the search to add "laundry", and found this. 

The first picture was from a website of a company in my hometown. The next picture was from the town next door. I have seen one of these in a house in Japan, but it was the home of a lass from West Yorkshire.

I'm not sure if that's where the technology is from, but I think the name creel is Northern. Apparently in Scotland they're called pulleys. 

We had one in our sun lounge and always used to call it a creel. Apparently they are making a comeback as people try to cut their electricity bills by using tumble dryers. At least that's what the website selling them said.

Maintenance, corrections and adjustments for humidity

I wrote that relative humidity doubles every ten degrees centigrade, but in fact that's not strictly true. It's more like 9.2 degrees. That's an approximation too, and in fact it's closer to doubling every 9.24 degrees at 20 degrees centigrade, and every 9.19 degrees at freezing, so it's not purely exponential. These are pretty trivial differences I know, and as a rule of thumb to understand the workings of humidity it's enough to know that it will approximately double every ten degrees.

It's also something of a rule that if you have water moving slowly and occasionally stopping, sooner or later there will be a build up of gunk. The inevitable impurities will accumulate, particles will appear and biology will happen.

This is what happened to our ventilation system. 

We called the builders, and they called the ventilation experts, who have regularly appeared in these lines. A maintenance engineer turned up within a couple of hours and fixed it, putting an end to my empirical research into the amount of water held in air. The first thing he did was take the cover off while the ventilation system was still running, which at least my manual recommends against. I wasn't watching him the whole time as I didn't want to breathe down his neck, and the next time I looked he had switched it off. I always find it difficult to balance my interest in what workmen are doing with their need to get on with their job in peace.

After a while the engineer produced a small plug that had grown into the top of the hose pipe that drains the humidity. He recommended that we take off the hose and clean inside every couple of months to stop this.  I wish they'd told me that a couple of years ago!

Since there is going to be an irregular flow of water through there, and at least some particles from the air will reach it, there's bound to be some biological build up sooner or later. The water is going at around half a litre per hour, so it's not exactly the Niagara Falls in there, and anything that builds up on a surface that is not perfectly smooth will just keep building up. There will probably be times in the year when the system is completely dry, but I suspect for over half the year there will be some water coming out for some of the day. It's at room temperature, so the growing conditions are ideal for some bacteria and fungi.

When we moved in, they had offered us a maintenance contract, and I said I'd get back to them later. At the time I didn't want to sign a contract with them because I didn't really trust them. This engineer seemed to know what he was doing. He told me that the pipe coming out of the system needed a loop in it otherwise we'd hear the noise of water dripping out. I don't know whether he realised that I'd told his company this, since they hadn't put a loop in when they installed it, and it we had dripping and gurgling noises all night.

Also they had said that maintenance needed to be done every three years, but in fact in the manuals it recommends cleaning the filters every year. 

His advice to clean the hose is probably good, but the build up was actually not in the hose, and probably not coming from the hose, which was downstream. The problem is coming from above.

So, I need to find someone else to maintain the system, learn how to do it myself, or go back and humbly ask them. There is a more local heating engineer who may be able to do it, and I'd like to ask him, but there are probably invisible walls that would be impossible for them to cross.