In the description of the several types of panels presented in this catalogue, the value of K, the thermal insulation coefficient, was given as a function of the types and the relevant thickness of the insulator used. It is probably useful, however, to give you some details for an easy comparison. If x is the value of K for a polyurethane foam 5mm-thick panel, the thickness of other insulating materials that may be used is very different, when the same value of thermal insulation is required.
|POLYURETHANE FOAM||5 cm||CARBOARD||13 cm|
|POLYSTRYRENE 7||5 cm||WOOD BOARD||28 cm|
|ROCK WOOL||9 cm||CONCRETE BLOCK WALL||76 cm|
|CORK||10 cm||BRICK WALL||173 cm|
The average densities used in the building industry were used for this comparison.
SOUND INSULATION – SOUND ABSORPTION
The sound level is measured in decibels (dB), which are established by a given sound intensity and pressure, calculated in a logarithmic scale. When the sound is increased (reduced) by twofold the sound level increases (or decreases) by 10 dB.
Examples of sound pressure
|1||–||Light leaf rustling||20 dB|
|2||–||Sound level in a reading room||30 dB|
|3||–||Low-noise humming||40 dB|
|4||–||Background noise at home||50 dB|
|5||–||Standard conversation at the distance of 1 m||60 dB|
|6||–||Background noise of computing machines||70 dB|
|7||–||Compact sized car at 80 km/h||80 dB|
|8||–||Automatic lathe||90 dB|
|9||–||Turboprop engined airplane (inside)||100 dB|
|10||–||Car Hooter||110 dB|
|11||–||Pneumatic hammer||120 dB|
|12||–||Hydraulic press||130 dB|
|13||–||4-engine airplane (take-off)||140 dB|
|14||–||Launching rocket||200 dB|
The decibel scale is also used to measure the sound insulation. A barrier reduces the sound energy that hits it by a fixed ratio, which is constant for that types of building regardless of the sound source.
It is the capacity of the material to transform the sound energy into thermal energy (vibrations) and to reflect a very small portion. In environments built with traditional materials like bricks, marble and glass…., which do not have a high sound absorbing power, the echo, caused by the wave reflection, is heard, which leads to the overall increase in the sound level, with often serious consequences for occupants. A pleasant and relaxing sensation for the ears can be experienced in acoustically designed rooms.
- It is the impossibility for the sound energy to pass through any material similar to other materials that
are poor conductors of heat or electricity.
- This capacity is a function of the mass of materials limited to some mechanical characteristics that make such materials, for specific frequencies, practically “transparent” to the sound and cause the echo effect.