Stuart Allan's investigation of a fire discovered that new air tight buildings have given rise to a new fire risk.

A brand new house, constructed under the new air tight regulations, was badly damaged by smoke from their log burner. The smoke had spread through the house thanks to the heat transfer fan. The insurer needed to know whether the heat transfer fan installation was to blame for the smoke damage, so asked Stuart Allan, Principal Lecturer in Electrical Engineering, to investigate.

Stuart drew on his long experience of fire investigation to determine exactly what had happened. As the heat transfer fan drew warm air out of the room where the log burner was situated,  the air pressure in that room dropped enough for smoke to begin to flow out of the log burner through its air vent into the otherwise airtight room. As the room filled with smoke, the heat transfer fan continued to operate as intended, but now it was sucking smoke through into the rest of the house.

Stuart's investigation cleared the heat transfer installation company of any responsibility for the smoke damage, which was attributable instead to the combination of airtight construction and an open air vent on the log burner.

With sadness we report that Stuart Allan passed away recently. We acknowledge his contribution to the teaching of electrical engineering at Otago Polytechnic as well as his forensic fire investigations.

Read more of our stories here.