Overflow elements: Impacts on energy efficiency, indoor air quality and sound attenuation

When planning ventilation systems for energy efficient housing, an appropriate design of the overflow elements between rooms is important as it influences ventilation losses, indoor air quality and sound attenuation between rooms. Based on calculation results of the natural in- or exfiltration rates through the building envelope as a function of the overflow element’s flow resistance, this work proposes a maximal pressure drop of 2-3Pa for overflow elements in energy efficient buildings. Measurement data on sound attenuation and pressure drop for simple door or doorframe integrated overflow solutions is presented. It shows that a volume flow of 40m³/h can be achieved with a pressure drop ≤2Pa with simple and cost effective modifications to a standard door construction, while still complying with a normal sound attenuation requirement of 30dB.