The ventilation performance of houses - a case study.

Describes a programme of ventilation measurements performed on a group of energy efficient houses built in the mid-1970's and situated in Abertridwr, S.Wales. Pressurization, tracer decay and British Gas autovent techniques were employed. Results show satisfactory whole-house ventilation rates (0.5 ac/h), but the living room and bedrooms had very low ventilation rates. Some cases showed serious condensation. "Trickle" ventilation installed in 18 of the houses improved internal ventilation patterns and condensation levels were substantially reduced. Reports on a design methodology for naturally ventilated energy efficient dwellings derived from the measurement programme.