The current recommended minimal ventilation level for the cold deck flat roof design is evaluated using an experimental roof. The work suggests that there may be a need for ventilation to be increased above the minimal level in instances where natural draught ventilation is low or where roofs are of complex plan. Results of this work are under consideration by the British Standards Institution as part of an overall review of flat roof design recommendations.

Passive stack ventilation is a means of removing unwanted moisture from dwellings. The proper design and installation of these systems is vital to their successful performance. This paper gives detailed guidance on this subject and is in support of the 1995 edition of the Approved Document to Part F of the Building Regulations.

Fungal spore content in dust accumulated in air ducts was investigated in 24 mechanically ventilated single-family houses of which 15 had also a central air heating system. Dust was collected from the ducts simultaneously with cleaning of the ventilation systems. Besides spore concentrations and flora of culturable fungi, total fungal spore concentrations were determined in dust samples by the aqueous two phase technique and spore counting with epifluorescence microscopy.

During the past 10 years the U.S. Environmental Protection Agency (EPA) has pursued a national strategy to address radon remediation in buildings to meet its goals of radon risk reduction. Initially the approach developed and demonstrated remediation methods and techniques in existing residences with specific attention to the effect of regional climate variations and the differences in housing construction. A number of studies and demonstrations were undertaken to accurately characterize and evaluate the effectiveness of several remediation methods and techniques.

A new mechanical ventilation system which continuously controlled the indoor-outdoor pressure difference was installed in six houses, where the long-term radon levels ranged from 670 to 3 080 Bq/m³. When the new system had operated for several months, the indoor radon levels decreased to levels from 120 to 600 Bq/m³ , the effective dose reductions being from 40 % to 88 %.