Sleeping peacefully in a well-ventilated home is a luxury you quickly get used to—especially after installing a solid HVAC system. But when strange noises start to surface at night, that comfort is quickly disrupted. At AirGreen, we often get calls from clients in Montréal, Laval, Longueuil, as well as on the North Shore and South Shore, concerned about mysterious sounds coming from their ventilation system. These noises—sometimes subtle, sometimes alarming—should never be ignored. In this article, we explain what these sounds actually reveal about your ventilation system, and how we eliminate them effectively through our professional HVAC cleaning and maintenance services.
Why do ventilation noises mostly occur at night?
The quiet of nighttime amplifies mechanical sounds you wouldn’t notice during the day. A whistling, a clanking, a creaking, or even a steady thumping in the ducts or vents can feel unsettling. In reality, they’re often signs of an emerging issue—one that can worsen if maintenance is neglected or if the installation wasn’t done properly.
Here are the most common noises, what they mean, and what AirGreen recommends to resolve them.
The most frequent noises and their technical causes
1. Whistling or intermittent whistling
These sounds usually come from a clogged air filter or a poorly adjusted vent damper. When airflow is restricted, the system compensates by increasing pressure, resulting in that high-pitched noise.
-
Our AirGreen solution: A full inspection of filters and ducts, filter replacement if necessary, and damper adjustment to ensure smooth airflow.
2. Clanking or popping sounds
A dry, rhythmic clank often points to metal ducts expanding or contracting due to temperature changes. While some thermal movement is normal, if it becomes noisy, it usually means poor insulation or improperly supported ducts.
-
Our AirGreen solution: We identify problem sections and address them with insulating materials or anti-vibration supports to reduce the noise.
3. Persistent creaking
Creaks are generally associated with unlubricated mechanical components, like the blower motor or its bearings. If left unchecked, these noises can be early warnings of a breakdown.
-
Our AirGreen solution: We perform a thorough mechanical cleaning, lubricate all moving parts, and check motor alignment to prevent premature wear.
4. Vibrations or humming
These noises often stem from an unbalanced blower, dust buildup on the fan, or a loose duct panel.
-
Our AirGreen solution: Full fan cleaning, balancing of the blades, and duct re-securing to eliminate vibrations at their source.
Real-life AirGreen intervention cases: Solving nighttime noise issues
At AirGreen, we’ve resolved hundreds of similar cases across the Greater Montréal area. In Saint-Hubert, a client called us about dull thuds coming from their central ventilation system at night. After inspection, we found a heavy buildup of dust and mold in the ducts, causing irregular air pressure and poor return flow. A deep cleaning with rotary brushing, followed by antibacterial treatment, completely eliminated the issue.
Another case in Laval: a poorly installed central heat pump was producing a sharp whistling sound. Our technicians adjusted the main duct, secured a loose section, and recalibrated the return airflow. The result: total silence… and one very happy client.
The importance of regular HVAC cleaning to prevent noise
Nocturnal noises in your HVAC system are often symptoms of neglect. A system clogged with dust, debris, or mold has to work harder, wears out faster, and becomes noisier.
Here’s why annual maintenance is essential:
-
It preserves the proper mechanical function of your system.
-
It reduces noise by keeping airflow balanced.
-
It extends component lifespan.
-
It improves indoor air quality, especially for families with kids or those sensitive to allergens.
Why choose AirGreen for your HVAC cleaning and maintenance services?
We don’t just make the noise disappear. At AirGreen, we go straight to the root of the issue:
-
Complete diagnostics with robotic camera inspection if needed.
-
Detailed before-and-after reports.
-
Use of professional-grade cleaning technologies with brushing and simultaneous vacuuming.
-
Optional antibacterial and antifungal treatments.
-
Certified technicians, courteous and experienced, serving all of Greater Montréal, including Longueuil, Laval, North Shore, and South Shore.
What you can do while waiting for our visit
-
Check whether your air filters are clean.
-
Avoid blocking any air vents or registers.
-
Take note of the time and type of noise to help us better diagnose.
But above all, don’t attempt to disassemble any components yourself. Some noises stem from electrical or mechanical issues that require intervention from a qualified professional.
A quiet HVAC system is possible!
Strange noises in your ventilation at night are never trivial. They signal imbalance, blockage, or worn-out mechanical parts. Thanks to our specialized HVAC cleaning services, we restore your system’s full performance and silence—so your nights can be peaceful once more.
AirGreen responds fast, anywhere in Greater Montréal
Whether you're in Brossard, Repentigny, Terrebonne, Saint-Jérôme, or Châteauguay, our team is ready to inspect, clean, and repair your ventilation system.
Contact us today to schedule your personalized diagnostic. Together, let’s silence those noises once and for all.