A sweet smell coming from your house air conditioner when it's reaching the set temperature could be an indication of a specific issue. While I don't have access to real-time information about your specific situation, I can provide some general possibilities that might be causing the sweet smell:
Refrigerant leak: Air conditioners use refrigerants to cool the air. If there is a refrigerant leak in your system, it might release a sweet-smelling chemical into the air when the AC is running and reaching the set temperature. The smell might not be as noticeable when the AC is actively cooling the air since the refrigerant is actively circulating and cooling the coils.
Dirty evaporator coils: Over time, dust and debris can accumulate on the evaporator coils inside the air conditioner. When the AC reaches the set temperature and stops cooling, the heat from the room can cause the accumulated debris to emit an odor. This smell might be perceived as sweet.
Mold or mildew growth: Moisture inside the air conditioner or ductwork can lead to mold or mildew growth. When the AC reaches the set temperature and stops running, the moisture can create an environment for mold or mildew to release their distinct smell.
Nearby contamination: If there are other substances or objects in close proximity to the air conditioner, they might release a sweet smell when exposed to the heat generated by the system. This smell may only be noticeable when the AC reaches the set temperature and stops running.
Since the technician you called didn't find any problems with the air conditioner, it's possible that the issue is subtle or intermittent. If the smell persists and becomes bothersome, you may want to consider getting a second opinion from another HVAC professional to conduct a thorough inspection.
In the meantime, here are some steps you can take:
- Change or clean the air filters regularly to improve air quality and reduce potential odors.
- Keep the area around the air conditioner clean and free from potential contaminants.
- Ensure proper ventilation and circulation in the room to minimize the chances of mold or mildew growth.
- If the smell is persistent, consider using air purifiers or odor absorbers in the room to help mitigate the issue.
Remember that if you ever notice a strange or persistent smell from your air conditioner, it's essential to address it promptly, as it could indicate an underlying problem that may worsen over time.