Noisy rides
- Description of defect
Noise from the elevator operation can cause uncomfortable feeling to the passengers. This air-borne noise can be produced from the elevator door, and noise from the hoistway. Meanwhile, structure-borne noise in walls can create annoyance to the building occupants as the sound radiates into the adjacent rooms. The noise produced are not equally distributed, which depending on the nature of noise, the relative background noise and on psychological aspect
- Causes
- wearing hoisting rail
- insufficient lubrication for the brakes
- misalignment of brakes
- elevator cooling fan
- main machine drive
- relay switching noise
- door noise
Other sources of elevator noise are:
- Noise produced from traction and hoist machinery
- Noise produced from switchgear of traction elevators
- Noise produced from pumps and machinery of hydraulic elevators
- Noise produced from unaligned elevator car guide roller or bumps in rails
- Noise produced from door annunciators
- Diagnostic/testing method
Demand for low-noise elevator traction machine is increasing as the increment on the application of Machine Room Less (MRL) elevator, which equipped the traction is installed in the hoistway. Besides, as the shafts are becoming narrower due to space constraint, the machines are being created thinner and hence testing shall be conducted to avoid penetration of noise into the elevator car.
Noise analysis usually be combined with testing for vibration analysis. The measurement is done in standard decibel rating (dB-A-weighted) to comply with local standards requirements, and sound transmission class (STC) is used to measure transmission of a wall structure
- Good practices
Maximum permissible A-weighted sound level LpAmax in adjacent rooms is 30dB(A), SPL of 75dB(A) in the hoistway and 65dB(A) for the door noise (VDI 2566-2:2004). Hence, the building designer need to ensure that the walls and roof of the shaft provides an adequate air-borne and structure-borne noise attenuation.
- Corrections
Elevator system that used silent brakes can reduce noise produced from braking operation. This type of braking system provides a quite ride and hence minimizing the noise transfer to the adjacent spaces. Besides, noise produced also can be reduced by improving the insulation of the lift car structure, including the guide shoes that made up from a low-noise sliding material.
Example of silent brake [8]