Novena clinic outdoor unit buzzes: compressor mount rubber hardened
A Novena clinic had an outdoor unit that buzzed noticeably between patient sessions, loud enough that staff commented on it. Medical-belt units often run for far longer stretches than a typical home system. Hardened mounting rubber from those long runtimes is easy to miss until the buzz starts.
By Team Snowflake | Reviewed 11 Jul 2026
Case summary
Daikin Ducted5 years oldClinicNovena, Singapore
- Concern
- The clinic manager worried the compressor itself was overheating or beginning to fail during the unit's long, unbroken daily runtime.
- Found
- Compressor mount rubber hardened from sustained heat over long duty cycles, transmitting vibration into the frame
- Key check
- Checked the mount rubber's condition against the unit's actual daily runtime before assuming a compressor fault
- Result
- The buzzing stopped completely once the new mounts were fitted, even during the quietest gaps between sessions later that week. The clinic avoided paying for compressor work that the unit never actually needed in the first place.
What we were told
The clinic manager said the buzz was most noticeable in the quieter moments between patient sessions, when the rest of the clinic was silent. The unit ran for most of the working day without a real break. It had been in service for a few years without any reported issue before this.
What we checked
We treated the unit's long daily runtime as the first lead rather than opening the compressor itself. Sustained heat from many hours of continuous running can age a mount's rubber faster than a typical home system ever sees. We checked the mount's condition before assuming anything mechanical had failed.
The compressor itself ran smoothly throughout, with no unusual internal noise when tested in isolation.
The rubber mounts beneath the compressor had visibly hardened and lost almost all of their original give.
Vibration from ordinary operation was transmitting straight through the hardened mounts into the surrounding frame.
No refrigerant, electrical, or airflow fault was found anywhere else in the system.
What we found
The clinic's unit runs far more hours per day than a typical home system, and that sustained heat gradually hardens rubber mounts faster than normal residential use would. Once the rubber lost its ability to flex, it stopped absorbing the compressor's ordinary vibration. Instead, it let that vibration transmit into the surrounding frame, which was most noticeable in the quiet gaps between patient sessions.
What fixed it
We replaced the hardened mounts with new rubber rated for continuous, longer-duty commercial use rather than a standard residential mount. We did not recommend any compressor work, since it tested normally throughout the visit. We advised a shorter mount-inspection interval, given how many hours this particular unit runs each day compared with a typical home system.
Outcome
The buzzing stopped completely once the new mounts were fitted, even during the quietest gaps between sessions later that week. The clinic avoided paying for compressor work that the unit never actually needed in the first place.
What this case teaches us
A buzz between sessions often means the mount rubber, not the compressor
- A buzz that appears during pauses in a long daily runtime often points at mounting rubber, not the compressor.
- Units running many hours a day age their rubber mounts faster than typical home-use schedules do.
- Ask for the compressor's mount rubber to be checked before approving compressor work on a clinic system.
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