The atmospheric environment in six energy efficient single family houses.

Air pollution due to volatile compounds in six unoccupied houses with intended low energy consumption was measured. The measurements included air temperature, air humidity, ventilation rate and concentration of organic gases and vapours. On average 14 different compounds were identified in concentrations exceeding 0.005 mg/m3 in the samples, and Toluene and alpha-Pinene were the most frequent compounds. A total concentration of organic gases and vapours averaged for the five periods of measurements 0.46 mg/m3 (0.032 - 5.5 mg/m3). The concentration decreased systematically during the year, and was halved after, on an average, 112 days (63 to 187 days). The concentration of organic gases and vapours of the solvent type was similar to that found earlier in other Danish houses. Differences in indoor air pollution could not be explained by the materials used for the houses.