Measurements of air change and energy loss with large open outer doors.

The paper describes measurements made on large doors - 10 to 20 m2 in 2 buildings in Narvik. The air change was measured with the tracer gas (SFg). The method of constant concentration or decaying concentration of the tracer gas was used. The dosing, measuring and calculation of the air change was made with a Briiel & Kjaer gas analyser type 1302 and computer. Use of the decaying method was best with short opening times. The opening of the door in 5 to 7 minutes gives an air exchange of 500 m³ to 1300 m³ or an air change from 0.2 to 1.0. The energy loss is from 2 to 8.5 kwh for each opening. Aiter opening of a door it takes from 0.5 to 1 hour before we have stable temperature and air change again. The results are compared with the theoretical formulas for gravity driven flow air change from open doors. The number of openings and opening time of large doors is gives an energy loss that is much larger than the transmission and infiltration loss.