Sound has a tendency to travel through materials with the highest possible velocity. In the case of metal systems, sound travels because the velocity of sound in metal is higher than that in water, leading to noise emissions. However, in uPVC systems, sound will travel through water as the velocity of sound in water is higher than that in uPVC. As a result, uPVC systems are designed to be as quiet as physically possible, minimizing noise transmission and ensuring a quieter operation overall.