Factory unit vibrates: mounting isolators perished
A Sungei Kadut factory office had an outdoor unit that started vibrating audibly against its own frame, worse through the hottest part of the day. Heavy industrial operations sit close together across this estate. Sustained heat exposure can perish mounting isolators long before anything inside the compressor is actually wrong.
By Team Snowflake | Updated 28 Jul 2026
Case summary
Gree Wall-mounted10 years oldIndustrialSungei Kadut, Singapore
- Concern
- The facilities manager worried the compressor itself was developing a serious internal fault that would need a full, costly replacement.
- Found
- Mounting isolators perished from sustained heat exposure, letting the compressor vibrate directly against the frame
- Key check
- Checked the isolator rubber's condition against the unit's heat exposure before assuming an internal compressor fault
- Result
- The vibration dropped back to a normal, quiet level even through the hottest part of the afternoon a week later. The compressor kept running as it always had; only the perished isolators were renewed.
What we were told
The facilities manager said the vibration was mild in the morning but grew steadily worse by mid-afternoon, then eased again overnight once things cooled down. Cooling held up fine through all of it. It sits on a metal frame with direct sun exposure for most of the working day.
What we checked
Vibration that tracks the afternoon heat pointed at something thermal and external, so we followed the temperature before opening the compressor. A genuine internal compressor fault tends to stay fairly consistent regardless of ambient heat. Vibration that tracks the hottest hours of the day usually points at rubber isolators softening or perishing under sustained heat instead.
The compressor ran smoothly throughout, with no unusual internal noise when tested in isolation from the frame.
The rubber mounting isolators had visibly perished and lost most of their original shock-absorbing give.
Vibration from normal operation was transmitting directly through the perished isolators into the metal frame.
No refrigerant, electrical, or airflow fault was found anywhere else in the system at all.
What we found
Direct sun exposure for most of the working day pushes the frame and mounting hardware well above typical ambient temperatures on this site. Sustained heat like that accelerates how quickly rubber isolators perish compared with a shaded install. Once the isolators lost their give, the compressor's ordinary vibration transmitted straight through into the frame, and that transmission grew more noticeable as the metal itself heated further through the afternoon.
What fixed it
We replaced the perished isolators with new ones rated for higher sustained heat exposure. We did not open the compressor, since it tested normally throughout the visit. The isolator-inspection interval should shorten. This frame sees far more direct heat each day than a shaded installation elsewhere on site would.
Outcome
The vibration dropped back to a normal, quiet level even through the hottest part of the afternoon a week later. The compressor kept running as it always had; only the perished isolators were renewed.
What this case teaches us
Vibration against the frame often means perished isolators, not a compressor fault
- Vibration that worsens through the hottest part of the day often points at heat-damaged isolators, not the compressor.
- Heavy industrial estates can expose outdoor units to more sustained heat than typical commercial sites.
- Ask for the mounting isolators to be checked and replaced before approving any compressor work at all.
Questions this case answers
Why does our outdoor unit vibrate more in the afternoon?
What does heat do to aircon mounting rubber?
Vibration that changes through the day: is the compressor at fault?
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Tell us what’s going on. Symptoms, setup, photos, anything we should know. We’ll assess and come back with the right next step.