Sunday, April 3, 2011

Insulation, Technology and embodied Technology

3rd April '11: Reflecting on our time at EcoBuild, and the annual results from our PV/GSHP/ Sunbox combo, I wanted to say something about Technology vs Insulation - remembering what our final target must be - to reduce carbon emission into the atmosphere.

Insulation is undoubtedly the first thing we should do, it is a must for all new building, and we should over insulate in these cases, i.e. go far beyond existing UK Building Regs to meet the standards of Passivhaus.

For existing buildings, it can be extremely difficult, even if one is not in a conservation area. One experiences the full trauma of builders, scaffolding, redecoration etc, without an easy way to compute payback. There are the arguments about whether to do it internally (in a rather limited way) or go the whole hog and do it properly, external insulation. Payback is not strictly computable unless you were keeping 5 yrs of energy records prior to the installation, and keep 5 yrs after the insulation, to compare. However, the Comfort return is immediate. If you know someone who has had the exterior insulation, they will say how the house got warmer and the boiler less noisy even in the first week while the work was still being done. If you are going to have external insulation, it is advisable to take it at least half a metre below the ground line, if your paving or flowerbeds can be lifted briefly. In the 1980s, I had my Semi in West Bridgford comprehensively drylined, and whatever it cost then didn't matter, as we had 5 yrs of thermal comfort, and we got the money back when we sold it, the high insulation being a good selling point.

Advocates of Insulation can be a bit single minded (as can be advocates of Technology), but it is clear there has to be a balance in their favour - in high rise for several decades we have had generations of buildings which ignored insulation in favour of glass, and used Active technology to counter solar gain and heat loss by cramming the building with HVAC equipment - the Seagram generation of high rise to name only one - their only concession to passive design was to use very dark glass, which reduced solar gain, but added greatly to the energy cost of lighting. Millions of ordinary houses in the UK have been fitted with central heating systems in the last 40 years, without adding to the insulation.
   The insulation-boys have an overwhelming case for major improvement in the 98% of the existing housing stock - but it should not stay there - we need to consider the overall Energy equation, and find ways to reduce our Carbon emission, beyond just insulating.

Technology: Once you have insulated, what next? Well, the Passivhaus standard is dependent on MVHR, because part of insulation strategy is to make the building airtight. On my house, the ventilation heat loss exceeds the fabric heat loss. On a PassivHaus the fabric heat loss becomes incomputably small compared to the comings and going of incidental heat gains, solar gain, and heat lost through ventilation. Therefore, MVHR is a mandatory part of the Passivhaus standard - this is technology. However, it is not much use in a leaky house with few people living in it - the result is to blow cold air in.

Even if the building performs so amazingly that somehow it doesn't need active heating most of the time, it would not be possible to sell a house or apartment that had no heating system in present market conditions. The advocates of Passivhaus believe that a no-heating house would be possible, but I ask: How about taking into account Lifestyle conditions? the Architect cannot predict or prescribe the occupants, whether they are elderly, ill, very young, or not good at opening and closing windows or keeping the MVHR in good order. Incidental heat gains cannot totally be relied on as energy efficient lighting and A-rated appliances all produce less waste heat that in former times. You cannot tell them that they will have to wait till next Thursday when there is a forecast of sun, just because they left a window open.

My reference to EcoBuild was that Prof Wolfgang Feist told me that our New York skyscrapers should be able to work without any heating - but I would reply that this is forgetting that these people are 200 metres altitude with a biting sea wind, bitter winters, and the occupants are Americans not Germans, and they just expect things to work - they won't all live the ascetic lifestyle. You do not buy an apartment in a billion dollar building in the classiest residential location in the entire city (one block from Broadway, overlooking Battery Park and the Statue of Liberty) and then find it has no heating system, and that they have to walk up the stairs because the elevators have been omitted!
  (No Joke, I recently heard from a student in another module, designing 5 storey flats in Nottingham city centre had been told to leave out the elevators to save energy - but had not been told about Passivhaus construction for the apartments! Elevators are likely to use only about 3-5% of the building's energy bill)

Another thing, argued in an earlier page on this blog, is that we are biologically conditioned to rely on technology. We lost our hair many millennia ago, and have relied on clothing. Look at your clothing now, notice the weave of the fabric, and consider how better that is than a skin peeled off a slaughtered bison (and did you wrestle the bison to the ground or did you use a spear?). Go to the fridge (technology) and consider whether you would eat the meat in there raw, or whether you would eat your potatoes raw. Unlikely. The salad and fresh fruit came from Kenya or Peru. Almost everything you eat has to be cooked, and if it is a preserve, it was cooked then, and put into a container that required technology to make. Unless you live in a climate where salad foods grow all the year round, you are dependent on food preservation and cooking - technology. If you buy fruit or salad out of season, this is Embodied technology, otherwise known as food-miles. Insulation itself is a major technology, even if it is not active. It also has an embodied energy of manufacture, and there is a science to its application.

I have colleagues who regard Renewable Technology on buildings as 'Bling' but I notice that they don't apply it that restriction in their own lives. They have an iPhone (surely it's easier to write someone a letter or shout than use that?) and drive sophisticated cars like a BMW Mini (surely it's easier to walk to London, or perhaps get a bicycle?) They live in georgian or victorian houses and think that a condensing gas boiler is enough technology to save energy with.

The reality is that we live in a world of technology. We expect planes to be fail safe, GPS to get us home correctly, pharmaceuticals to be correctly formulated and labelled, Google to find the information we are seeking. To do without technology now reminds me of the spiritualist healer who rejects all modern medicine and relies on prayer until their children die (recent court case in Paris, March 2011). Buying a car now, even the simplest one will be expected to have a heater, a radio, fuel injection, independent suspension and a catalytic converter.

It is possible to improve the climate of buildings with less reliance on electrically operated systems, such as solar shaders, vertical solar chimneys, wind catchers, water pools etc. and some of these transform the appearance of the building. To me they are Technology - Passive technology, not ones with motors, things we incorporate into buildings that are not merely rooms to live in. Their construction can involve extra investment in materials, and are technology, just as the weave of the fabric of our clothing or the glass of our preserving jars are technology.

With very little dependence on materials, but good adaptation of our IT knowledge, we can use Smart technology, such as thermostats and sensors, building management systems which recognise climate, time and the activity of users, and reduce the power consumption of the Active systems, and by opening or shutting louvres, to make the Passive systems work better.

I believe that our Peveril Solar house is adequately insulated, and I cannot do much to improve it further.  Partial MVHR is something I may try to build in, in the future. However, at this moment, the virtuous triangle of technology - PV, GSHP and Sunboxes - has taken it the extra distance to make it Carbon Zero, all working around the firm foundation of a well insulated house.

Surely it's time for Architecture to accept 'technology' as much as we have done in our phones, cars, planes and media - whether it is active, smart, passive or embodied - accept its inevitability! Enjoy! But we must learn from the mistakes of the previous century. Slapping active technology into bad buildings can be very stupid, and we don't need any more dark glass Seagram Buildings or their descendants which litter the boulevards of Dubai. We don't need experts saying that fitting a condensing boiler into an uninsulated brick house is suddenly making us eco-efficient.
      We need an integration of well performing environmental design with passive and smart technologies that make best use of a new generation of active technologies, and reduce the emission of carbon to zero. To compensate for the millions of inadequately insulated houses, new ones should go beyond Carbon zero and generate more power than they use. 

2 comments:

  1. An interesting and detailed article! Hope you enjoy your time in New York!

    ReplyDelete
  2. Well I have been up the Empire State today. Although the weather down below is balmy and pleasant, there was a biting cold blast at the top, and all the permanent staff there were dressed with balaclavas and greatcoats, not the slightest bit warmed by the sunshine. The 86th floor at 320metres is not as high as our New York towers which were 60 storeys, but the amplification of wind still applies.
    So my argument that a well insulated apartment without heating would not work is reasonably proven.

    ReplyDelete

Comments will be moderated before showing. Please make them relevant to the subject of the posting. Comments which advertise commercial products will usually be deleted.

Popular Posts

There was an error in this gadget