Sick Building Syndrome in Montreal: When Poor Ventilation Makes an Entire Office Ill

Poor ventilation at the heart of health issues in Montreal office buildings

In Montreal, Sick Building Syndrome (SBS) is an increasingly common issue that affects both office workers and building managers. This phenomenon occurs when a building — typically a commercial property — causes widespread symptoms of discomfort among its occupants, without any specific medical cause being identified. In most cases, inadequate ventilation is at the core of the problem.

At AirGreen, we regularly intervene in office buildings throughout Montreal, Laval, Longueuil, the North Shore, and the South Shore to diagnose and correct HVAC ventilation issues that directly affect the health and comfort of building occupants. Here's a deep dive into this too-often overlooked issue and how we address it with precision, efficiency, and expertise.

Understanding Sick Building Syndrome

Sick Building Syndrome refers to a collection of symptoms reported by people working in a building — usually offices — without a clearly identifiable medical condition. These symptoms include:

• Chronic fatigue

• Frequent headaches

• Eye, nose, and throat irritation

• Dry skin

• Difficulty concentrating

• Dizziness

These issues generally disappear once the employee leaves the building, which is a clear sign of an indoor environmental problem.

The most common causes of SBS

Some of the major causes include:

• Poor humidity control

• Deficient mechanical ventilation

• Poorly maintained air conditioning or heating systems

• Pollutants accumulated in the ventilation ducts

• Inadequate filtration of outdoor air

These factors often accumulate in older buildings or those that were not properly designed from an HVAC perspective.

Case study: our intervention in an office building in Griffintown, Montreal

A commercial building manager in Griffintown recently contacted us, concerned about high absenteeism rates and repeated employee complaints about discomfort. After conducting a complete inspection of the existing ventilation system, we discovered:

• An ineffective exhaust system

• Severely clogged filters that hadn’t been replaced in over 18 months

• A lack of adequate ventilation in closed spaces (meeting rooms, archives)

• A high accumulation of dust inside the ducts

We proposed a three-step solution:

1. Full replacement of filters and deep duct cleaning

2. Installation of a high-efficiency air exchanger, with built-in CO₂ sensors

3. Adjustment of airflow levels to meet current standards (ASHRAE and CSA)

Result: After six weeks, absenteeism dropped by 40%, and there were no more complaints related to indoor air quality.

Why proper ventilation is crucial in a work environment

A well-ventilated office does much more than just "move air around." It must:

• Provide a constant supply of filtered outdoor air

• Eliminate pollutants from building materials, furnishings, and electronics

• Maintain a stable humidity level (between 40% and 60%)

• Keep CO₂ levels under control, which directly affect focus and alertness

In Montreal, where buildings are often designed to maximize thermal insulation, ventilation is sometimes an afterthought. Yet a well-designed HVAC system is the backbone of a healthy work environment.

How AirGreen solves commercial ventilation issues

At AirGreen, our approach is based on rigorous technical diagnostics, followed by customized implementation. Our services include:

• Inspection and mapping of the existing ventilation system

• Indoor air quality analysis (particles, CO₂, humidity, VOCs)

• Cleaning and disinfecting of ventilation ducts

• Installation or replacement of mechanical systems: fans, air exchangers, HEPA filters

• Ongoing preventive maintenance

We work with top brands such as Venmar, Fantech, Lifebreath, and Aldes, adapting each project to the specific needs of small or large office buildings. Each intervention is documented, measured, and optimized for maximum comfort.

Common mistakes to avoid based on our experience

Here are the most frequent pitfalls we see:

• Replacing a fan without evaluating the entire system: this creates pressure imbalances

• Ignoring secondary areas (archives, server rooms, stairwells)

• Skipping maintenance: even a brand-new system can cause issues without upkeep

• Relying solely on an air exchanger without analyzing indoor air quality

Grants and incentives for improving ventilation

In Quebec, some grants and incentives may apply when upgrading a commercial HVAC system, including:

• Hydro-Québec programs for energy efficiency

• Energy retrofit support offered by the City of Montreal

• Tax credits for green office buildings

Our experts assist you with all administrative and financial processes to help you take full advantage of these opportunities.

Testimonials from satisfied clients

“After AirGreen’s intervention, our employees noticed an immediate improvement. The air feels fresher, less dry, and our meeting rooms are finally comfortable. A professional and efficient team.” – HR Manager, Longueuil

“We had repeated cases of allergies and headaches among our staff. AirGreen completely redid our ventilation system, and since then, no more issues.” – Building Owner, Laval

AirGreen: your partner for healthy work environments in Montreal and surrounding areas

We firmly believe that a healthy work environment starts with high-quality ventilation. With hands-on experience in hundreds of buildings across Montreal, Laval, Longueuil, the North Shore, and the South Shore, we offer tailor-made, durable, and certified solutions. Whether you’re managing an office building, owning a commercial property, or working in occupational health and safety, we are here to diagnose, fix, and maintain your HVAC systems with professionalism and precision.

Don’t let poor ventilation affect your employees’ health or your business’s performance. Contact AirGreen today for a comprehensive evaluation of your ventilation systems.