The impact of various ventilation remedies on radon levels and local building environment in a UK test house * some preliminary results.

The Building Research Establishment is currently investigating the impact of various radon remedies at a radon affected test house. Tests aim to assess how different ventilation strategies affect indoor radon levels and the building environment. Those examined include natural underfloor ventilation, mechanical underfloor ventilation (supply and extract), and whole house pressurisation. The test house has a suspended timber floor with an inaccessible underfloor space and is typical of much of the UK housing stock except for indoor radon levels regularly in excess of 1000Bqm^-3. It is fitted with a comprehensive range of monitoring equipment which closely records important environmental parameters. This paper presents some preliminary results including radon levels and whole house ventilation rates. Mechanical underfloor extract ventilation is shown to produce a 94% reduction in indoor radon levels, the greatest recorded. Mechanical underfloor supply ventilation causes the largest change in house ventilation rate with an approximate energy cost of £50 per year. These results, and future data, will allow for the assessment of remedies to be based on their total impact to the building rather than radon reduction alone.