The new facility

The new facility
The main specifications of the project were: •very low background noise, no vibration transmission; • double acoustic insulation of the reverberation rooms; • ideal proportions for the reverberant rooms, possibly in a new building; •a minimum of parallel surfaces in the reverberation rooms; • twin reverberation rooms to measure indoor and outdoor sides simultaneously; •two additional rooms to install the units and measure in-duct sound; • good control of the test conditions (temperatures, humidity and flows).
Additionally, the laboratory was also meant to allow determination of the coefficient of sound absorption of materials in accordance with EN 20354:1993 “Acoustics. Measurement of the sound absorption in a reverberant room (ISO 354:1985)”.

Bedrock-source

Bedrock-source systems are mainly applied in the Nordic countries and Switzerland. Typical drilling depths are 70-200 m with diameters of 125 mm. For a house, one hole is usually sufficient. Boreholes are not filled with grouting material. They are filled with groundwater for good thermal coupling, also under freezing conditions. Grouting is applied in other regions of Europe, notably Switzerland and Austria, and in areas with unstable bedrock. In the Nordic countries usually two loops (40 mm) are inserted in each borehole; elsewhere 4 loops are sometimes applied (32 mm).
New houses can benefit from so-called ‘free cooling’, if a ground-coupled heat pump is applied. During the summer, cold brine is simply pumped to the house without operating the heat pump. The heated water is recharging the heat pump’s heat source. This concept has become popular in some countries, stimulating the use of heat pumps.