Enabling change in our Society, Environment and Economy (SEE)

OBFT-Air Leaks

26 July 2012

by Leigh Duxson, SEE-Change Woden

Finding and Fixing Air Leaks

A small but very keen group of people gathered at Audrey and Luis’s house to test out some ideas on how to find & fix air leaks to reduce heat loss from a house. Audrey and Luis had very kindly allowed their house to be the experimental laboratory for this workshop. What were they thinking?

I demonstrated the basic principle for finding leaks, which was to turn on all the exhaust fans in the house to induce air through the cracks then to use some simple leak detectors such as wet finger tips, incense smoke, a children’s stethoscope without the diaphragm (to detect outside noise through a leak point), noses (yes noses)and infra-red thermometers.

Winter Breeze Buster 2What works best? Believe it or not wet finger tips or noses on a cold morning or hot afternoon – both are very sensitive to temperature changes. Incense is hard to see against white ceilings and may leave the owner with an aroma in their house that they don’t particularly like and not everyone has a kid’s stethoscope or an infra red thermometer.

WARNING – if you are going to try this experiment yourself do not use a naked flame as curtains catch fire very easily and candle wax can be hard to remove from materials.

Did we find any leaks? Yes, but not as many as expected because the size of the fans in the house was small so the air infiltration was low and also because Luis had been busy over the last few years patching up the leaks, but we found a few. For most normal houses in Canberra finding leaks is easy.

After I outlined the types of sealants to use and demonstrated the sealing technique we loaded the guns with sealant and headed off to the various leak points. Some participants showed their great prowess in applying sealant (Sara) and others found that, whilst they were slower, it wasn’t that difficult and in any case if you made a mess it was quite easy to clean up with some water and a rag after you had finished the sealant run.

At the end of the afternoon we sat and had some tea and cakes and discussed how easy it really was; all you need is time and encouragement.

With thanks to our


  • ACT Government Environment and Planning
  • The Association of Independent Schools of the ACT (AISACT)
  • Catholic Education Office (Archdiocese of Canberra and Goulburn)
  • Education and Training Directorate
  • ACT Government