Tuesday, July 14, 2009

Thermal picture of Worcestershire 2

Just chatted to someone who followed the link from my entry for the Thermal Map. Their house has a certificate stating that it conforms to the highest insulation blah blah; so of course their house shows up as brown - "Average Poor".

Turns out their house faces South and has a dark roof which is at least one of the points made in the 'hidden' details if anyone bothered to look.

Essentially it goes like this. Taking a hypothetical situation if you heated your house to 30° and had insulation that blocked off a third of that you'd register as 20°; if you heated your house to 20° and had no insulation you'd share exactly the same rating as the first house. If you heated your house to 10° and had no insulation you'd show up as better than either of them with an unheated and uninsulated building beating the lot.

Except of course you don't know that because it's set by an average. So there's no way of knowing if a building shows up as it does because it has bad insulation or just because you're heating your home above the average. Add to that the fact that you don't know when the image was taken and thus what temperature the building might have been and the whole exercise, as presented, starts to look a little futile especially as it has been mentioned it cost £75k to do.


Dan H said...

More to the point, how much aviation fuel was expended in getting these aerial photos, and how much CO₂ (let alone the other pollutants that air transport generates) did it generate? I would bet a tidy sum it turns out to be greater than the savings caused by the scheme.

FlipC said...

You know I bet that, for some reason, no-one has done that calculation.

I'll ask on the Shuttle site on your behalf.

Orphi said...

It's probably satelite imagery. (Judge for yourself how much less or more CO2 that involves…)

FlipC said...

"The thermal data used in the Warmer Worcestershire project is collected by a thermal camera on board an aeroplane" from the About Thermal Data link.