What to do now the 21st century is not even a teenager any more

Here is the third part of the Building Culture presentation, and the final video recording of the course.



Being the last video it should probably include a short summary of the main points, but it probably just ends rather abruptly, with more questions asked than answers, and many things left unsaid. A bit like this post.

Beating the heat

Just because we live in a low energy house, it doesn't mean we can completely ignore the summer. In fact there are lots of things we can do to keep the house cool, now that it's going to get over 30 degrees centigrade oustide pretty much every day for the next two months. Some of these you may be able to try at home. Some of them rely on infrastructure such as high insulation, airtightness and good windows. Having a low energy house is one thing, but being a low energy person is another. Some try to tread lightly on the planet and make their carbon footprint small, but attempts are thwarted because they are surrounded by energy inefficiency. Others have all the low energy tools at their disposal, but they have so many of them, and use them so much that their energy consumption is even higher. The goal of low energy design is to make it both impossible and undesirable to consume energy copiously.

1. Shut the blinds in the morning. Tempting though it is to shut them at night and open them in the day time, as the sun starts getting higher and further south, we really don't want it's rays to reach into the house. After the summer solstice in June, the sun starts getting lower, so as summer builds up pace, the solar gain is also increasing. External blinds are more effective at keeping heat out.

2. Shut the windows when it gets hotter outside than it is inside. Also counterintuitive, but this will keep the heat out. There is an argument that opening the windows will get some breeze going through the house, and that breeze will take the heat away from us and cool us down. This is true if the breeze is blowing past us, but in terms of temperature, a breeze of hot air is going to heat up the house. If you have an air conditioner on, it will work much better with the windows shut, just like a heater works better with the windows shut, and a fridge works better with the door shut.

3. Open the windows when it gets cool in the evening, or early in the morning.This will let some of the heat out and let cool air in.

4. Use cold water. If you have to use hot water, use as little as you can, and turn it off as quickly as you can. Hot water is going to heat up the house, and the more airtight and well insulated you are, the more it will heat your thermal envelope. If you have a smart boiler, which I think we do but it's too smart to give itself away, a secondary effect of this is that using more hot water will encourage the boiler to make more hot water, in other words keeping its water at a higher temperature. This will mean that more heat leaks into the house.

5. Switch electrics off. They're all giving out heat too. Don't use them unless you have to. Switch them off as soon as you've finished.

6. Cook at night or early in the morning, especially if you're using an oven. If you boil a kettle it should just have as much water as you need in it. Any more means more heat in the house. I get really annoyed when I see a kettle or pan of water being kept on the boil with the cooker on low. Much better to boil the water when you need it, and switch off the heat and use it as soon as it's ready. If you don't use it as soon as it's ready it could be there putting out heat for half an hour, and in fact it often is.

7. Stop using ice. It may cool you down, but the fridge puts out a lot of heat to make it. Iced tea is probably the worst as it involves boiling water then adding ice. To be honest ice makes less of a difference than the things above, and a couple of lumps is not going to make a big difference to the heating effect of your fridge, but I'm with the Chinese that you should drink hot drinks when it's hot. Cold drinks just confuse your body. I grudgingly confess that ice improves gin and tonic.

8. There's a whole load of really obvious stuff like wearing light clothes and not doing much exercise, and slightly less obvious things like not eating so much, and eating food that will cool you down rather than heat you up. Cucumbers and bananas are good. Meat and potatoes are not. 

9. Also there's probably a lot of subliminal stuff that will make you feel cooler starting with the colours, patterns and textures you can see around you. Having an electric fan in the room, even if it's not switched on, may make a psychological difference. 

10. Use LEDs. The above are all about using or not using what you have. LEDs make sense for two reasons. First, they are more efficient so they add less heat to the thermal envelope. Second, while incandescent and fluorescent lights give of heat in their radiation, LEDs just radiate light, so you won't get hot standing under an LED. Also, LED light does not attract insects, in stark contrast to incandescent and fluorescent light, so there is less threat leaving windows open at night time. It's a good idea to get other low-energy appliances too.

And now, in colour

We're going through the magical experience of seeing the plans really turning into a house. The black and white two-dimensional drawings had appeared in three dimensions, and now the drab colours of raw wood and plasterboard are being transformed by paint and wallpaper.

The choices have been involved and traumatic, but the results so far look great. We have now chosen every wall and every door, except the ones for the cupboards in the bedroom. We need to give a final answer on those tomorrow. 

Most of the walls are going to use a material called "Chaff Wall" which is made from scallop shells. Another option was a product from Europe called "Clay Paint". Both are Eco products which contain natural products, allow the wall to breathe, and absorb rather than emit harmful and unpleasant odours. Chaff wall also absorbs and releases moisture, helping to stabilise humidity within the house, and apparently works as an insulator, although this may be negligible compared to the 230 millimetres of insulation beyond it. 

The most important considerations are probably to allow any formaldehyde in the wood or other materials to escape, and to let moisture pass in or out of the wall, so that we don't get any condensation build up anywhere. 

Of course colour and texture are also important, and at first I was keen to get off-white, although none of the off-whites looked very nice, so we just went for White. Chaff wall looked nicer than Clay paint, and being a local product, it is used more widely so the painters will handle it. If we'd chosen Clay paint, the builders would have had to buy the paint, then get painters to use it, and they'd be lumbered with any left over.

Another choice we had to make was whether the paint should be applied by roller or spray gun. At first we were told that spray guns use about 50,000 yen more paint, so will cost us more. We began trying to choose from tiny samples, on which the spray finish looked much better than the rougher roller finish.  Once we ordered a colour, the painters made bigger samples for us, around 50 cm square, and the roller-finished one looked really good. We then spoke to the painter, who was also impressed by how good the samples looked and how difficult it would be to make the wall look like that as the roller needs to leave the wall at some point, where there will be some kind of a line. Small bits of wall would probably be no problem, although the ceiling, 10 metres across, may be more of a challenge, and he seemed to much prefer the idea of a spray gun. He was encouraged to tell his boss this, so that we won't have to pay too much extra for the paint, in view of the fact that we're making the job easier.

So when it comes to cupboards in the bedroom, which cover the bottom part of the west wall and the north wall, beyond which is the closet, I'm inclined to go for something dark, as there will be several metres of white wall above them, and on the whole of the east side of the room. We'll have to wait for tomorrow to see what the decision is.