Sick Building Syndrome: Is Your Office Building in Montréal at Risk? (Key Warning Signs to Watch)

Indoor air quality in commercial buildings across Montréal, Laval, Longueuil, the North Shore, and the South Shore has become an increasingly concerning public health issue. At AirGreen, we’re called in every week to offices where employees complain of headaches, chronic fatigue, or unexplained irritation. These symptoms are often the early signs of Sick Building Syndrome (SBS)—a phenomenon that remains widely misunderstood, despite having major consequences for comfort, productivity, and health.

Understanding Sick Building Syndrome (SBS)

SBS refers to a set of symptoms experienced by occupants of a building, typically caused by poor indoor air quality. While it can affect residential spaces, it’s especially common in office buildings with central heating or ventilation systems that haven’t been properly maintained.

Most common symptoms among building occupants

The symptoms most frequently reported in offices affected by SBS include:

• Persistent fatigue

• Irritation of the eyes, nose, or throat

• Frequent headaches

• Difficulty concentrating

• Aggravated allergies or asthma attacks

What makes SBS particularly telling is that these symptoms tend to improve or disappear entirely when occupants leave the building.

Common causes found in office buildings

1. Clogged ventilation systems

One of the most common problems identified by our technicians is clogged air ducts. Dust, mold, and bacteria build up over time—especially when HVAC maintenance is neglected.

At AirGreen, we were recently called to an office building in downtown Montréal where fifty employees were reporting constant discomfort. Our inspection revealed that the ducts hadn’t been cleaned in over eight years. A complete HVAC cleaning service allowed us to remove mold growth from the ductwork and significantly improve the building’s air quality.

2. Poor air filtration

Another aggravating factor is the use of low-quality or improperly fitted air filters. A clogged or inefficient filter allows pollutants to pass through and overloads the system, reducing airflow and increasing the spread of contaminants throughout the workspace.

We recommend installing HEPA filters or at least MERV 13 filters in commercial buildings—especially those located near major roadways in Montréal or Laval.

3. Poor humidity control

Low humidity levels can lead to irritation, while excessive humidity creates a breeding ground for mold and dust mites. Offices with poor ventilation—especially those that are completely sealed off—are particularly vulnerable to drastic humidity swings.

Installing a humidifier or dehumidifier integrated into the HVAC system, combined with proper temperature control, is critical.

How to recognize a building at risk?

Visual and sensory clues

• Persistent smells of mold, mustiness, or chemicals

• Visible condensation on windows

• Mold growth on walls or ceilings

• Excessive dust blowing from air vents

Behavior among occupants

• High absenteeism due to illness

• Noticeable drop in productivity

• Frequent complaints about air quality or room temperature

In a Brossard office building where we were recently brought in, a survey conducted by the building manager revealed that over 40% of staff felt unwell within hours of starting their day. Thanks to a comprehensive HVAC inspection, we pinpointed at-risk areas and recommended a complete system cleaning, including duct disinfection and filter upgrades.

Our specialized HVAC cleaning services

At AirGreen, we offer a full range of HVAC system cleaning services tailored to commercial buildings of all sizes. Our approach is methodical and backed by proven technical expertise throughout the Greater Montréal Area.

Our process

1. Initial inspection with cameras to detect problem zones

2. Indoor air quality testing (particles, CO2, mold spores)

3. Mechanical and chemical cleaning of air ducts

4. Filter replacement with high-efficiency models

5. Disinfection using certified agents to eliminate mold and bacteria

We regularly perform this type of work in buildings across Saint-Jérôme, Longueuil, and Terrebonne, where workplace health issues are taken seriously by property managers.

Why choose AirGreen?

Our HVAC maintenance expertise positions us as a leading authority in the Greater Montréal region for preventing and treating Sick Building Syndrome. Every intervention is customized based on the building’s layout and occupants’ feedback. We guarantee:

• Fast and discreet service

• Clear and detailed reporting

• Qualified and certified technicians

• Measurable results—often within the first week

Practical tips for preventing SBS

Schedule regular HVAC maintenance

A complete annual HVAC cleaning is recommended for office ventilation systems. The higher your building’s traffic, the more frequent this maintenance should be.

Install an air purification system

In addition to cleaning, we offer standalone or integrated air purifiers, highly effective against allergens and VOCs (volatile organic compounds).

Train your maintenance staff

Raising awareness among in-house staff can greatly improve early problem detection. We offer training workshops for building managers and maintenance teams.

A healthy environment is a smart investment

Improving indoor air quality in an office building isn’t a luxury—it’s a strategic necessity. A healthy work environment leads to:

• Reduced absenteeism

• Improved focus and performance

• Lower legal risks related to workplace health

• A stronger company image

At AirGreen, we’ve been helping companies of all sizes for over 15 years achieve compliance and optimization of their HVAC systems.

Conclusion: Early detection is key to avoiding serious consequences

If you manage a building in Montréal, Laval, Longueuil, the North Shore, or the South Shore, and suspect the presence of Sick Building Syndrome, contact us today. We’ll carry out a precise diagnosis and provide a custom action plan to restore a healthy and high-performing work environment.