Royal Otolift is a leading manufacturer of stairlifts. These stairlifts assist people with reduced mobility to avoid walking up- and down the stairs. In that way, stairlifts offer freedom and access to those with reduced mobility.
Goal: Otolift produces stairlifts that are safe and compact. Their stairlift design focusses on convenient, low-noise stairlifts. To prove that Otolift stairlifts are indeed quiet, Otolift requested Demcon multiphysics to compare the acoustics of their stairlifts with stairlifts produced by a number of competitors. Measurements to quantify the noise production is one of the services in the field of acoustics which Demcon multiphysics offers.
Visualization of the origin of sound, made using a Sorama sound camera.
Approach: The measurements have been performed in the “anechoic room” of the University of Twente, one of the main testing facilities of the Engineering Fluid Dynamics group. This room is especially designed for acoustical measurements where background noise is unwanted: its walls absorb practically all noise. Consequently, it is possible to perform undisturbed acoustical measurements. The anechoic room, is extremely silent: the background noise is less than 20dB(A), a lower sound level than e.g. silent whispering.
We compared 5 stairlifts in this study. All stairlifts were placed in the anechoic room, and tested for noise production. The stairlifts were performing a duty cycle, starting in the lowest position, moving upward. Once stopped at the top position, the stairlifts returned to the downward rest position. We used a manual scanning technique to measure the intensity of each surface. The overall sound power level is computed according to the NEN-EN-ISO 9614-2 norm. Additional videos made with a Sorama sound camera helped in identifying the origin and source of sound.
Results: The main conclusion is clear from the graph: the stairlift from Royal Otolift is significantly less noisy than those of its major competitors.
We thank Otolift and the University of Twente for this fruitful collaboration.