Radon Mitigation using Heat Recovery Ventilation system in a Swedish Detached House

Balanced ventilation with heat recovery has strong effects on radon mitigation and energy saving in residential buildings. This new technology enables improvement of both indoor air quality and energy efficiency without sacrificing either. Reducing radon by means of forced ventilation requires an increase in outdoor supplied air (i.e. ventilation rate), which in turn can increase energy use. Energy losses in ventilation systems are inevitable, but new technologies such as heat recovery systems make it possible to recover most of this ventilation heat loss. Heat recovery ventilation systems, which recover energy from exhaust air, can significantly reduce ventilation losses, and balancing the indoor air pressure plays a positive role in the effectiveness of ventilation to reduce and mitigate radon levels and control indoor air quality. This paper describes a case study which considers the effects of a heat recovery ventilation system on the radon concentration and energy consumption in a detached house in Stockholm, Sweden. The performance of the heat recovery ventilation system is examined with respect to radon mitigation and energy saving by measuring the radon concentration and analyzing the life cycle cost in winter. The results of the measurements and dynamic simulation showed that a heat recovery ventilation system was able to reduce the radon level from around 600 Bq.m to below 100 Bq.m and reduce energy loss from ventilation by 80%, equivalent to around 3500 kWh per year. The results of life cycle cost analysis used to assess total costs showed that this system is cost-effective and investment would pay for itself in 12 years. It should be noted that this saving is a representative sample, and that actual savings would be influenced by a large number of factors. IDA 4.0 Indoor Climate and Energy software was used to perform the dynamic simulations.