Natural and mechanical ventilation rates in a detached house : measurements.

Presents results of measurements of ventilation rates in the SEGAS test house. Describes the house and its heating and mechanical ventilation systems. Measurements of ventilation rates were made using helium as a tracer gas. Tests were made both with the house sealed to block obvious paths of infiltration and with it unsealed. Tests were also made with the house mechanically ventilated and with supply and extract systems working. Presents results of tests and examines the effect of variation in mean wind speed on ventilation rates. Discusses results and concludes that sealing the external windows and weatherstripping external doors reduces the air change rate by about a third. Finds that the mechanical ventilation systems exceed the design air change rate when the house is unsealed.