Great Student Presentations

Another year and another brace of student presentations. This time, perhaps with the higher number of architecture students, there are more practical topics.

1. Energy independent buildings

One brave group out of seven decided to give their presentation in the penultimate week, and they set the bar high. One of them even gave the presentation in English, which I had suggested, but not mandated.

This began with a look at carbon emissions, and went on to talk about cogeneration, which is big in Northern Europe, but not common in Japan. The idea with cogeneration is basically to generate electricity on a small scale, and use the heat for domestic hot water and heating. They talked about a gas-operated system on the market, which seemed quite expensive as a capital cost, and also would be buying in gas and therefore no chance of being zero carbon. Of course the reality right now is that nothing is zero carbon but cogeneration has obvious energy savings.

2. Biomemetics is a really interesting topic, and the second group also did a great job.

They started by asking if we knew who had invented velcro, which we did not. The answer is at the bottom of thiw page. This is a great example of human ingenuity mimicking nature, as the inventor decided to copy some burdock seeds that had stuck to his coat and dog.

Bullet train design from the kingfisher

Another example was a bath that imitated cuckoo spit, otherwise known as the foamy spawn of the frog hopper or spittle bug. The foam radically reduces the amount of water required for a bath, and keeps it hot better!

Finally they talked about termite nests, which have elaborate vertical air circulation channels that change direction of flow between night and day, keeping the building cool or warm. They are also porous to allow carbon dioxide out. This natural design was imitated by the Eastgate Centre in Harare, Zimbabwe, which was designed to cool by entirely natural means.

3. The next group talked about Energy Standards in Five Different Countries.

These were the US, the UK, Germany, Korea and Japan. The introduction explained what was specified in the building standards, and went on to show how relatively lax Japan's standards were and what a low proportion of PVC windows Japan had, but also showed that Japan has
the lowest energy consumption per household.

A comparison was made between Japanese buildings and South Korean buildings, where respectively rooms are individually or collectively designed. It was argued that Japanese design allows rooms to be heated individually while Korean design, and that of Europe and the US, typically requires that the whole building is heated.

To be honest, I was not completely convinced by this, and look at it rather as holistic design allowing whole buildings to be heated, while the Japanese vernacular discourages it.

They concluded that there were many different approaches to low energy standards, that the Europeans are working hardest to lower environmental impact, and that Japan is behind other countries, but that there are plans for Japan to have low energy standards by 2020.

A questioner asked why Japan—ostensibly a developed country—has such weak building energy standards. A couple of answers were given, one by one a presenter, and one by the questioner, which was supported by another of the presenters. A discussion of this needs a whole other blog post, and in fact I've already written one here!

4. The Latest Low Energy Buildings was the topic of the next group.

The first speaker talked about the Cardboard Cathedral in New Zealand, built after the 2011 Christchurch earthquakes. Another was built in eight months in Kobe Japan, intended to last two or three years, but still in use ten years later. A good example of low embodied energy.

The second speaker talked about Ichijo Komuten's i-series of low-energy buildings, which are the closest thing to Passivhaus at scale in Japan.

The third speaker talked about ZEB—Net Zero Energy Buildings—giving an example of a building using a combination of solar power and biomass to meet all its energy needs.

The fourth speaker talked about the Zollverein School of Management and Design in Essen, Germany which the presenter rather suspiciously described as choosing geothermal energy rather than insulation. It got away with a thin concrete shell with naturally occurring hot water
piped through.

I couldn't help feeling that maybe the pipework and certainly it's maintenance would be more expensive than insulation.

Also I notice that they are only talking about Japanese buildings, and buildings by Japanese architects, which is a curious position in light of the last group's findings on Japan's low-energy building credentials.

5. The next topic was Hydroelectricity, which is probably the cheapest and least fossil-energy demanding source of electrical power.

They discussed pros and cons, different systems of generation and then some interesting ideas on microgeneration from domestic water, one taking energy out of the incoming pressurised water main, the other out of water coming out of taps. I didn't want to ask them about any conflict with the need to save water in the house, and whether the mere hundreds of milli-watts they could get from the taps was worth it, but the idea of looking for energy sources is a good one.

Habitat 67—because modern architecture means ignoring physics

6. Famous Buildings was the topic of the next group.

The Farnsworth House in one of the four seasons it is not fit for

I worried this would just be a slide show of beautiful buildings, and have nothing to do with the subject of the course, but this group set their parameters well. They were looking at a few famous buildings from the perspective of form factor, thermal bridges, materials and windows, pointing out both good and bad points. Though mostly bad!

Their buildings were by Hundertwasser in Vienna, Habitat 67 in Montreal, Canada, the Farnsworth House in Illinois, USA, and the Gassho-zukuri houses of Shirokawa village in Gifu, Japan.

They did a nice assassination of the form factor of Abita 67, and showed how Farnsworth's concrete sandwich with glass is more of a sacrificial altar to comfort and energy use than a useful contribution to architecture.

7. The final presentation talked about the Merits and Demerits of Low Energy Buildings.
They did as good a job of concluding the course as I could. The demerits included the extra costs and the lack of skilled designers and builders, and the presenter hoped that everyone in the class would be working to change this.

Answer:
Velcro was invented by Swiss electrical engineer George de Mestral in 1948. For any etymologists out there, the word is a portmanteau of "velvet" and "crochet".

Talking about Passive House. Lesson 14

This low energy building course is really just propaganda in disguise. The whole course has been framing the question, and the answer is Passivhaus. I also like to talk about differences in building culture, and mention my own experience trying to build a low energy house in Japan. I can, with honesty and some innocence, present my discovery Passivhaus as an epiphany on my road to building a house.

As usual term starts running out with too many lessons left over. In week 13 of 15 I had to get them into groups for their final presentations, and then give them some guidelines of what to do, and what not to do, when designing and delivering their own presentations. I could spend a whole lesson talking about preparing presentations. In this class I probably should, focusing on presentation construction as a piece of architecture.

They had put their own presentation ideas into a forum on the online part of the course, and then chosen their top three choices in an online quiz, so I had most of the data needed to make the groups, but of course a few students had not actually added their top choices for a presentation topic, a few others missed the lesson, and as usual a small number of the topics were very popular and they did not fit neatly into seven topics that were the first choices of exactly four students. In the end over half the lesson was taken up discussing their presentations, and I could only get through half of my beautifully prepared full lesson, with its narrative from building cultural differences between the isles on the East and the West of the Eurasian continent, to my own journey into house building, and discovery and application of the Passivhaus standard.

Energy balance for a Passivhaus

Descriptions of standards can be dry, and there's a maximum of ten minutes I can talk to any class in English before they lose attention, so tasks are needed. I like setting them problems to solve, and also want them to practice real-world calculations where possible.

First I had them brainstorm heat gains and losses in a house. They got most of these, but needed a bit of a hint to remember ventilation.

The next task was to get from the definition of Passivhaus in English to the numerical heating load. This is a fairly straightforward calculation from the floor area per person, the volume of air needed per person, the maximum temperature air can be heated to before it burns, and the heat capacity of air.

Next, I wanted them to work out what U value they would need for the walls of a Passivhaus in Matsumoto. This involves several steps, and I made the mistake of giving them too many of the steps to work out in one go. I don't think the calculation itself is particularly difficult, but I guess I'll find out because I've set that for their homework!

The first step, to make the calculation easier, is to assume that the heating load is equal to the loss of heat through the walls. Remembering the energy balance of a building, you can get to this by assuming that solar gains through windows roughly equal heat losses through windows and internal heat gains roughly equal heat losses through roof, ground, and ventilation.

The next step is to work out the wall area of the house. I gave them the volume, told them it was two-story, and assumed they'd just be able to work out the wall area from that. Half of them are studying
architecture so I think I can be forgiven for my assumption. It turned out to be wrong though. Perhaps there were too many assumptions for them to make: the height of the walls, the squareness of the building footprint, the use of square root to get from an area to one of it's sides, the number of sides on the square... Perhaps they were worried about other things: did they need to subtract the windows and doors? What shape was the roof going to be? Perhaps they were distracted from this question because they were expecting thermodynamics rather than geometry. Anyway, I think have learnt my lesson, and will chop the problem into bite-size chunks for them next time.

I should probably have realised this sooner, and modified the task, but while preparing the lesson I had been more impressed by the result of the calculation: 0.162 W/m2K. This number may not mean a lot to you, but as I scrolled down the slides to the introduction to my own house, I noticed that in fact the U value of my walls is 0.162 W/m2K. Perhaps just a coincidence, but it does show you
the power of rough estimates!

Unfortunately I didn't have time to share this bit of synchronicity with my students as the lesson had somewhat dissolved into scratching heads, spurious scribbling and many over-precise, under-accurate sums. The bell was going to go before I got to the happy ending that is Matsumoto Passive House.