The test procedure consisted of pressurising the dwelling to approximately 60Pa then taking a set of measurements of the building pressure differential and flow rate through the fan. The fan speed was then reduced in several steps and the readings repeated at each of the speed settings. The dwelling was then depressurised, and the test procedure repeated. The result is two sets of measurements; one for pressurisation and one for depressurisation.
The following temporary seals and measures were in place at the time of the tests:
• The mechanical extract fans in the utility room, the bathroom, the ensuite and the cooker hood in the kitchen were all sealed.
• All the trickle vents were adjusted to the closed position.
• All water traps and U-bends were filled with water.
• All external doors were closed.
• All internal doors were opened.
• A faulty first floor window and the unfilled front door threshold were sealed.