Today we received the thermal imaging photos that were taken of the houses before we started the retrofit work.

Thermal images are photos taken with a heat sensitive camera that shows the temperature of the subject.  Photos were taken of the houses before we commenced the retrofit work to illustrate the areas of heat loss from the building.

Similar photos will be taken after we have completed the retrofit work, and will hopefully tell a very different story.

The photo below illustrates the high level of heat loss from the bay of number 28 – the lighter the colour, the higher the temperature, and hence level of heat loss from that part of the building.

If you are surprised by the level of heat loss from the bay, the video below will show you the reason why.

[youtube=http://www.youtube.com/watch?v=JFiC9o6RvwY]

Don’t be misled by the light colour of the roof; the loft space was quite well insulated, and we believe this high temperature was caused by direct sunlight falling on the roof.  Additionally of course, it could have been caused by heat escaping up from the bay, as we saw in the video above.

The bays are being removed as a part of the retrofit, so will no longer be an area for concern.

Thermal imaging of a property enables you to see where heat is escaping through the fabric of the building.

All properties involved in the Retrofit for the Future competition are having thermal imaging carried out before and after the retrofit by an independent testing organisation, BSRIA.  By comparing before and after images we will then be able to see how successful our retrofit has been in insulating the properties.

The “before” thermal imaging of our properties was carried out today, and the video below summarises the day’s events.

[youtube=http://www.youtube.com/watch?v=awBxmZewdbk]

For the thermal imaging tomorrow, the internal temperature of the properties needs to be at least 10 degrees celsius greater than the external temperature.  Given that the vacant property has been unoccupied for at least two weeks and therefore unheated, this poses a bit of a problem, as it is currently colder inside than outside – when we went in there today it was 10 degrees inside, and about 13 outside!

This problem was further exacerbated by the fact that the gas supply has been disconnected – not a long-term problem as we’re removing the gas central heating system as a part of the retrofit – but it would have been nice to be able to whack on the gas boiler overnight in such a thermally poor property.

So we had to resort to electricity.  A minor problem was that there was a £50 debt on the keycard meter, so we had to pop down to the local Post Office to clear that and add some credit to cover our heating need.  It was then time for an electric heater amnesty at Hockerton (OK, the secret’s out; even we heat our houses occasionally.  But with the sun being strong for at least the last week our houses are now back up to 20+ degrees internally, and the heaters are well and truly back in storage for at least another 8 months).

So having rounded up about 20kW capacity of heaters, our next problem was that the house only has two ring mains (the kitchen and the rest of the house), each with a capacity of 8kW, so we couldn’t even deploy them all!

Anyway, we got about 12kW of heat output running at about 2pm, so hopefully by 10am in the morning the temperature inside the house will be 10+ degrees above that outside; I’ll be there early to check though …

Here’s a quick video of the heaters in action; apologies for the poor video quality – a new camera and a new operative – but I promise the video quality will improve!

[youtube=http://www.youtube.com/watch?v=R15PXY2mw6E]