I was down at the Centre for Alternative Technology (CAT) last week doing some lecturing and running a practical on airtightness for their Architecture Professional Diploma students and the MSc Sustainability and Adaptation course.
It was a great 2 days with loads of questions from the students – Prof Dip students on the Wednesday and MSc Students the following day. I also gave an evening lecture on ventilation and aspects of my research on the Wednesday evening – and an impromptu one on data logging case studies on the Thursday evening!
![air tightness thermal imaging camera](https://greenfootsteps.co.uk/wp-content/uploads/2017/01/CAT-air-tightness-test-thermal-imaging-300x225.jpg)
The practical was titled Why air tightness test existing buildings? and the aim of the day was to answer the question! The students had hands-on experience with 4 different models of thermal imaging camera followed by the airtightness testing of one of the buildings on the CAT site, using a blower door and then examining the building defects using thermography and smoke.
![airtightness testing smoke test](https://greenfootsteps.co.uk/wp-content/uploads/2017/01/CAT-air-tightness-test-smoke-test-225x300.jpg)
The calculations by students of the surface area and volume of the building proved interesting – there was around a 45% variation between different calculations – that made a very significant difference to the test results!!!