Friday 27 December 2013

Two dangerous assumptions

First is the belief that a few well-meaning individuals can make a difference.

Turning a few lights off is not going to stop global warming. Turning a power station off could. Reducing your own consumption of oil by a few litres is not going to make a big difference. Reducing a country's imports or reducing a company's output by a few million barrels is. Throwing a few tins into the recycling is not going to save the world. It's just a tiny drop, and the drop is probably of molten melted in an oil-fired crucible.

The second, much more dangerous assumption is that a few well-meaning individuals won't make a difference. Most of the critical decisions that could affect our survival are going to be taken by individuals. The important actions are going to be made by individuals. Leaders of businesses, heads of governments and representatives of organisations are all individuals. Every policy and paper starts from the pen of one person. The only people who can make a difference are well-meaning individuals. You may be one of them. Somebody you know may be one of them. Somebody who happens to see one of your trivial deeds may be one of them.

Human actions are influenced in many ways, and it's not always clear why things happen. This is why people can get advanced degrees and influential jobs in economics and still sound like complete idiots.

But just when I was worrying about my own actions making no difference at all. Just as I was settling into the realisation that the main results of my noble attempts to change the world through building a house had all long since gone in and out of the bank accounts of various agents in the industry, who are now back to their inevitable unecological tricks. Just when I thought it was all a waste of time, the water bill came. Nothing unusual about that, but on it was a piece of advice. It said something like this: to avoid your pipes freezing, be sure to put some insulation, for example expanded polystyrene, around the main tap.

Now I know this is a small thing, and it would be a lot more useful if the invoice for heating bills suggested you insulate your whole house, but that may be like expecting the people in the hamburger shop recommending you drink water rather than a large container of brown fizzy sugar, or saying "are you sure you want fries with that?"

But it's a positive thing. It's much better than the usual solution, which is wrapping pipes with an electrical heating element that comes on whenever the temperature gets anywhere near zero. I'm sure it does not directly result from my building project, but somebody out there is making some sensible suggestions, and I'm not a lone crazy voice shouting into a wilderness.

Sunday 22 December 2013

Shovelling snow and suffering pain

Winter is here, and that means sooner or late it's going to snow. And that means sooner or later having to shovel some of it. Not only does this seem a largely futile activity since you can walk over snow while it's there, and if you leave it, it's all going to melt before too long. Also, it tends to result in back pain, either chronic, acute or both. 

I've always assumed this is because snow appears to be light and fluffy, but is in fact much heavier, so the body is unprepared for the amount of work and the strain each lifting will take. 

I think there may be more to it than that. Snow also has air in it. This does not make it any heavier, but does make it more massive. The extra air is not going to make a difference to the weight, since the snow is already floating in air, but it is going to affect the mass since you have to move all that air as well as the snow. 

Japanese science-hero Denjiro-sensei performed a really good experiment to show the difference between weight and mass. He took a large balloon, something over a metre in diameter. First, he threw it uninflated across the stage at a foldable chair, which had little impact. Next he threw an inflated balloon at the same chair, causing it to fly across the stage. You could probably repeat this experiment in your own living room using a regular balloon and something like a pet bottle. 

So back to shovelling snow, not only does snow look much lighter and fluffier than it actually weighs, so we are not fully prepared for the strain of the lift. It is also more massive than it is heavy, so we need more strength to move it around, changing its inertia, than we would guess just from holding up a shovelful.

Tuesday 17 December 2013

When did we turn the heating on last year?

Ask the slab. 

We have ten thermometers in the slab, recording and logging the temperature every few minutes. There are five buried at the bottom of the foundation, one near each corner and one in the middle, and another five in the screed, hopefully a safe distance from the underfloor heating pipes so that they are measuring the temperature of the floor and not just the pipes. They should give us an idea of when the heating went on though.

The best one to look at is probably the thermometer in the middle of the floor. Before the heating went on, it was nicely cycling day to day with the temperature at its lowest mid-morning, then rising from 10 or 11 am, as the heat of the sun found its way into the slab. The heat either does this directly by hitting the floor and conducting through the tiles and concrete, or indirectly by heating the air in the house, and the air heating the floor. My instinct is that solar radiation is going to have more effect heating the floor than ambient air, probably because I've been indoctrinated into the mantra of hot air rising, and the consequence that not much heat will be going down from the air into the floor. 

The data is a bit grainy, since we only have precision to a tenth of a degree while  James Joule reckoned he could measure the temperature of his beer vats to 1/200 of a degree Farenheit. Making the best of our 21st century tools, the floor seems to stop warming around 3.30, which is about when the sun stops reaching it directly. The room temperature is still a couple of degrees warmer at this point, but can be five or six degrees warmer around noon. Hopefully you can see this in the first chart, where the green line is the room temperature, the red line the temperature just under the floor, and the blue line the temperature at the bottom of the slab. Of course a bigger temperature difference means more heat would be conducted from air to floor, and in fact the ambient thermometer is half way up the wall on the south side of the house, so it's possible that the air temperature at the floor is only above the floor temperature until 3:30. Anyway, this is not strictly relevant to my question. 

On 5th December, we must have switched the heating on from around 5:30 am because the slab started to heat up then. From then, depending on the weather, there's a double peak effect when the morning injection of heat starts wearing off and the solar gain hasn't kicked in yet. 

On some days there was obviously no solar gain, and the temperature just falls after the morning boost. This happened on December 8th, 9th and 10th when there was a fair bit of snow. 

Then from 12 December we get a triple peak effect when the heating was also on from 7:30 or 8 pm for half an hour. This only lasted for a couple of days, perhaps until my Yorkshire genes got the better of me. 

The triple peak starts up again from 19th December, this time the heating going on from 10 pm for half an hour. 

We went away from 22nd December for 2 weeks, leaving the heating off. The screed went back to the diurnal cycle, with the temperature at the bottom of the foundation plumetting to an all-time low of 19.2 degrees centigrade. The lowest trough in the screed was 18.7 degrees. 

The heating went back on again in the mornings from 3rd January, and I can't tell exactly when it went on in the evenings. There is a rise in screed temperature around 8pm on 7th, 24th to 26th and 30th Janary, and 2nd, 3rd and 8th February. On other days there is a slight plateauing of temperature around that time, before the fall over the night, so I guess night time heating was on at least until 16th February. There are a couple of days when the heat went on around 10:30 pm.

We turned the morning heating off on 8th March, and just turned it on again 12th December. Instinct once again tugs at my coat tails, urging me to switch on the heating so the house doesn't lose too much heat making it more difficult later. Knowledge of thermodynamics suggests that making the house warmer is just going to mean losing more heat, so if we can survive the temperature, we should be OK. Experience also shows that it's not going to get that cold. It was still above 18 degrees in the middle of the slab with no heating on for two weeks at the end of December. Also, experience of the underfloor heating is that the response is not so bad, and while it doesn't give the instant blast of hot air you get from a fan heater or air conditioner, it feels warm within ten or fifteen minutes of switching it on. And if things get really desparate we can switch on the air conditioner, or do something really drastic like put socks on.

Whether to turn it on in the mornings or evenings is another question for another day.

Thursday 12 December 2013

If NEDO had been done

I should write about the plan of the man who wanted to supply heat but not much light.

We had had reservations about his system from early on. During discussions about the chances of actually receiving the NEDO grant, I asked their boss and the builder's boss whether they would cover the grant amount in the event that we didn't get it because they hadn't built our house within the deadline. I think they thought this was funny. Evidently there was no concept of a penalty for not meeting a deadline. The Supplier of Heat but Not much Light suggested a place where I could get a loan to cover the cost. 

The radical part of it was a solar thermal system, providing hot water in the summer, and heating in the winter. 

Most people assume the problem with a solar thermal system is what to do on days when there isn't enough sun, but in fact that is a fairly simple problem. You need a back-up heating system. There are any number of ways to heat water from gas or oil burners, to a heating element from a kettle in the boiler. You don't see them so often but it's certainly possible to have an electrical heating element at the tap. A low-tech solution would be an electrical shower unit, which may be expensive to use but if you only need it a few days every year, then the total cost would not be so much.

The biggest problem with solar thermal systems is failure in the face of too much solar heat going in and not enough hot water going out. 

My simple question about the system was, what if the refrigerant boiled? This seemed likely to happen sooner or later. The behaviour of liquids heating up is quite predictable. As the liquid gets warmer it expands slightly. Then it starts to boil. The amount of gas steadily increases, with the pressure rising. When all the liquid in the solar collector turns to gas it will probably stop circulating and the system will stagnate. Gas tends to have a low thermal capacity so it won't take much more heat, and low conductivity so very little heat will get into the rest of the system, and the liquid in the circuit beyond the solar collector will not start boiling. The gas will reach some temperature at which there is an equilibrium between the solar heat getting in and heat radiating out. 

If the system survives this high pressure and high temperature, the next challenge is what to do as it cools down.

The gas will start to condense into liquid, and the collector must fill up again, so that it can continue to flow and get heat where it is needed.

A robust system should probably be able to cope with this. The Victorians were using steam systems for heating, so the pressure should not be a problem. 

In the plan of the man providing heat but little light, the solar elements used vacuum tubes, with a refrigerant pumped through them all the time. The pump was served by a dedicated solar panel, ensuring that the refrigerant would not stop, which would lead to disaster. This was his answer: it's not going to happen. 

That was one worry about the system.

In discussions around the same time as I found that penalties for not meeting deadlines were from an alien world, I asked what kind of guarantee they had on the solar thermal system, having heard that many solar thermal systems fail within about five years. He could only offer a one-year guarantee.  This did not reduce my worry.

Another minor worry, which I would have lived with, was that the back-up heating system used paraffin oil. Having spent too many winters lugging tanks of the stuff to my house, syphoning it into the small tanks and ferrying them to the heaters inside, and spilling several litres of it in the process, I really didn't want the stuff anywhere near my house. 

I know that in terms of environmental impact directly using fossil fuels is less wasteful than getting electricity off the grid that has come from gas-fired power stations, but given a choice I didn't want to build a house that took any fossil fuels. 

The delays meant that we were no longer going to get the 2.7 million yen NEDO grant, but once we had established this, it also meant we were no longer bound to this elaborate and expensive system that was included in the grant application. 

This system was certainly going to cost us at least an extra million yen, but if we had been able to get the grant, we probably would have been financially better off.

But, I suspect that if we had gone for the grant and followed their plan, by now we may have been stuck with a system that didn't work properly, and seeing a lot of their repair men, so it's probably a good thing that we got out of the grant.

Or perhaps if we hadn't even thought about applying for the NEDO grant in the first place, we may have bashed the plans around a bit more, changed the windows on the south side from triple to double and got some curtains for them, or given up on the concertina window, and found ways to save a great deal more than the 2.7 million of grant that we would have got.

And then it may have taken another year to build, and we would have paid another million in rent and bills on the old house. 

As it is, we have a great house where the good points far outweigh the bad points, so there is not much to complain about, and it doesn't help much to wonder what might have been.

Monday 9 December 2013

NEDO - No Deal

So the discussion of the NEDO grant started early in 2010, dangled in front of us like a piece of bait to lure the client into the contractor's trap.

We got the applications in to the Suppliers of Heat but Not much Light, and they sent them in to NEDO in May. The approval came back in July. 

From May their plan had been pretty much part of our plan, at least as far as I was concerned, and from the arrival of the piece of paper bearing the red government seal, their plan was a fixed in ours. This set the project completion date before January, since that was one of the conditions of the NEDO grant. In fact January 2011 was already a lot later than October 2010, which had been the completion date in earlier plans. I had hoped to be moving out of the old house before the winter of 2010, but January became March, and then seemed more like it would be May 2011. In the end everyone was rushing around like blue-arsed flies because I was holding the site foreman to his promise that we would be in by Christmas 2011. 

In order to meet the deadline of January 2011, we needed the windows to arrive by November 2010, so they had to be ordered pretty quickly to be assembled and delivered from Germany in time. Although we'd basically decided what windows we wanted when they made the semi-fictitious invoice for them for the NEDO application, it took a while to specify the exact details, including which way they opened, the style of the handles and whether they needed mosquito screens. Then we had to send this order to the importer, and at this point we learnt that the hinge of a window is indicated in opposite ways on Japanese and European drawings. So the order went back and forth a couple of times as we checked various things before it could be sent to Germany.

We were then rushed to hold the ground breaking ceremony in September. This is a Shinto ceremony that basically clears the way with the local spirits for building the house. I'm not a particularly religious person, but I am quite superstitious. This is partly because other people are, and they may be upset if you don't follow their superstitions. It's also partly because however unlikely it is, there's a chance of a grain of truth in superstition, and taking Pascal's wager, the stake of following the superstition is relatively small compared to the potential cost of not following it. So it's worth getting a couple of bottles of sake and a pineapple, and putting a bit of cash in an envelope if there's a chance it will stop your house being swallowed up by an earthquake, even if there is no obvious scientific connection. Or who knows, maybe the local shrines are in league with the local mafia. 

From the ground breaking ceremony for another couple of months, nothing seemed to move, except the steady realisation that the January deadline and the NEDO grant were impossible, and that there had been absolutely no hurry at all to hold the ceremony. I'd started taking pictures of the plot everyday, and this period is a little boring. A piece of string appeared in the middle of December, then a digger was there until the end of the month. Then the hole sat there until March. 

In October, we still hadn't signed the contract with the builders, although they had been at the ground breaking ceremony and there was a spoken understanding that they would be building the house. With hindsight I think a few things were happening: The builders wanted precise plans to work out a price. The architect didn't have precise plans and the price he'd promised us was not going to be the same as the price the builders were going to come up with. I wanted a price to be fixed and expected some teamwork between the architects, the builders, the passive house lady and me to work out the exact details to proceed, so we could get on and start pouring the foundation before we decided what colour the bath taps were going to be. Also the architect was probably busy on another project and his next invoice, and not paying full attention to ours. 

This was another point at which we should probably have sacked the architect. The first time was when he said that calculating the energy efficiency of a building was too much like hard work. By this time I think we were suffering from Stockholm Syndrome. In a very real way, the architect was holding us hostage in our own house, except it hadn't been built yet. We'd already ordered the windows and felt we needed him to have a house to put them in. We should probably have told him to give us the pretty pictures and leave us and the builders to work them out. This had not been offered to us as an option, but in life we often don't understand our options until it's too late.

Monday 2 December 2013

Walking to an eco house?

A colleague recently asked where I parked. Parking is very draconian where I work, and a big issue for drivers. I told him I didn't drive to work, but came by bicycle, bus or on foot. This surprised him as he knew I had an eco house, and assumed it was somewhere in the mountains.
There seems to be a perception that eco houses should be deep in nature, perhaps in primeval rain forest, and accessible only by Tarzan swing or four-wheel drive. My house is a ten-minute walk from the city station and a twenty-minute bike ride to work. And I suppose eco houses have the image of being off-grid and self-sufficient, but why be off grid if there's a chance of supporting a smart grid? Urban living has less impact on the planet than rural living, if you look at it per capita.
Probably.
There is a sense that The System is destroying the planet, so in order to stop destroying the planet you need to get out of The System. But you're still going going to have an impact on the planet if you leave the system, and we stand a much better chance of survival working together than seven billion people, and counting, going off on their own.
Anyway, I don't really understand how it would be an eco house if I had to drive to work each day from it. Back to carbon accountancy and walking to work, if I was to drive the 4km to and from work each day, something like 250 days a year, and with my car doing 10 km to the litre, that would use about 200 litres of petrol per year, emitting half a tonne of CO2. That's already over half of my share of the 2.7 tonnes the house emits a year. Build an eco house in the wilderness and you risk blowing all the benefits commuting from it to work.
I know it's not a terribly efficient car, but it was second hand, and I reasoned that since we drive so little, it was much better for us to get an inefficient car than for somebody who was going to be driving it every day to buy it. I'm not exactly sure my logic is sound here, but anyway, I'm not going out to buy the latest super-efficient hybrid just to write this post.
According to some websites, walking and riding a bicycle produce no carbon at all, but once again it's not so simple. If you walk to work, you're using your body as a machine, and the fuel going in is the food you eat. If you were to grow all your own food, use local, natural fertilisers, and pick it by hand, then you'd be carbon neutral.
In fact the production of food is not at all carbon neutral. From preparing the ground to harvesting crops and from sowing seeds to stacking the packaging on the shelves, energy is being used. The industrial production of ammonia and its use as a fertiliser are now an essential part of the supply of food to our growing and greedy population, and we probably could no longer survive without it. Our dependence on oil is so great that we are virtually eating it. You can see more details here on shrinkthatfootprint.com about the carbon footprint of different diets, and some in depth comparisons here on www.pacinst.org. On a very rough average, every calorie of food we eat has used a calorie of oil to produce. So the calorific content of food is not just the number of calories inside it, that are organic in the chemical sense that they are based on life, and carbon-free in the climatological sense that they have a net zero effect on CO2 levels.
It also depends what you have for breakfast. If you're eating food flown half way around the world, or your diet consists of large amounts of beef, walking or riding a bicycle could actually be producing more carbon than driving.
Bicycles are much more efficient at turning our energy into food than walking, so on the surface that's going to be low carbon. We have to think about the cost of the bicycle itself though, even though I have a bike anyway, and it's not going to make much difference whether I use it or not. But we do need to factor in the capital cost of the technology into the running cost of the calories in our food.
Which reminds me, if you're going to treat your food as carbon neutral, you shouldn't be using any iron tools either.
Of course you could argue that you'd be eating all that food anyway, and you shouldn't be looking at it as an extra environmental cost, and it's certainly true there are plenty of people sitting in cars who eat as much as cyclists. Some of them are even driving to the gym to burn off all those calories in an oil-heated pool or on an electrically-driven treadmill. This may be a rather ridiculous exercise, but I think any attempt to assess our impact on the planet is worthwhile
And sometimes I get the bus. I'm not exactly sure how to calculate the carbon for that. I could take the view that the bus is moving anyway, so it's just the extra carbon used to carry my weight. This may be close to the truth when it's packed and I'm standing at the back, but sometimes I'm the only person on the bus. In that case, it's going to be doing a lot less than 10 km to the litre and I'd be better off driving my own car.
I'd really like to find a definitive answer to how much carbon each of these transport options produces, but I've already spent enough carbon surfing the web without an answer, so I think the definitive answer is that there isn't one. Just, rather obviously:
  • walking and cycling are better than driving
  • if you're going to drive, living close to where you work could make a bigger difference than building an eco house
  • if you're concerned about the environment avoid eating beef.

Also, if any bus companies are reading, you should consider providing taxis instead of buses for off-peak routes, since it would reduce carbon and your bottom line.

If you are want to know more about the carbon coming out of your food, you may be interested that in 2007 the Guardian reported Tesco's plan to label all their products with a quantified carbon footprint, only to report in 2012 that  they had dropped the plans. www.carbontrust.com is still working on it though.