The surprising statistics about polluted air conditioning in Montreal office buildings.

An underestimated issue: indoor air quality in Montreal workplaces

In a context where quality of life at work is becoming a central concern for companies in Montreal, Laval, Longueuil, the North Shore, and the South Shore, one critical aspect is still too often overlooked: indoor air quality, particularly when it comes to air conditioning systems. At AirGreen, we’re on the front lines and regularly witness how polluted AC systems can affect not just comfort, but also employee health and productivity.

The hidden side of modern AC: invisible but very real pollution

It’s a common belief that air-conditioned offices provide cleaner air. However, based on several studies conducted in urban workplaces, poorly maintained HVAC systems can contain up to 100 times more pollutants than outdoor air.

Here are some alarming facts based on our on-site inspections and public data:

• 75% of air conditioning systems in Montreal offices inspected by AirGreen contained high levels of fine dust, mold spores, and bacteria.

• 1 in 3 employees reports symptoms linked to poor indoor air quality (headaches, eye irritation, chronic fatigue, allergies).

• Less than 20% of building managers carry out a full yearly cleaning of their ventilation ducts and wall-mounted evaporators.

Why do air conditioning systems become polluted?

The problem is mainly due to the build-up of particles in filters, coils, and ducts, such as:

• Fine dust coming from outside and office surfaces.

• Mold from condensation in drain pans and heat exchangers.

• Bacteria and viruses that stick to dirty filters and spread through the ventilation system.

Even top-of-the-line systems—like high-end wall-mounted air conditioners (Fujitsu, Gree, Sharp, Bosch)—quickly lose performance and become sources of indoor pollution if HVAC maintenance is not rigorously performed.

AirGreen Case Study: full AC system cleaning in an office in Griffintown

Last March, we were contacted by an architecture firm in Griffintown, Montreal, where employees were experiencing persistent headaches and fatigue. Our technicians found:

• Filters completely clogged with a thick layer of dust.

• Drain pans showing traces of black mold.

• Poor airflow caused by a malfunctioning air exchanger.

After a complete cleaning, including:

• Washing and disinfecting the wall units with certified products,

• Vacuuming the ducts using HEPA equipment,

• Replacing filters and adjusting airflow rates,

the results were immediate. Employees reported improved respiratory comfort, and the HR manager noted a drop in absenteeism within the following two weeks.

Why is regular maintenance essential for office HVAC systems?

A poorly maintained AC system:

• Spreads contaminants throughout the workspace.

• Reduces energy efficiency, leading to higher operational costs.

• Shortens the lifespan of components (fans, compressors, circuit boards).

• Can disqualify the building from government grants such as LogisVert or ÉcoPerformance.

At AirGreen, we recommend biannual maintenance for all commercial systems and quarterly check-ups for high-occupancy environments (shared offices, coworking spaces, clinics, etc.).

Solutions offered by AirGreen for businesses in the Greater Montreal area

We’ve developed a service package specifically for commercial buildings that includes:

• Full cleaning of wall-mounted and central heat pumps, regardless of the brand (Fujitsu, Bosch, Lennox, Trane, Gree, Sharp, etc.).

• Video inspections of ventilation ducts to detect critical zones.

• Antibacterial disinfection of evaporators with microbiological certification.

• Annual preventive HVAC maintenance plans, tailored to your usage and seasonal needs.

• Detailed technical reports delivered to building managers, useful for workplace health and safety audits.

How to know if your AC is polluted?

Here are some warning signs to watch for:

• Unpleasant smells when the AC turns on.

• Black marks or mold near air vents.

• Excess dust buildup on furniture despite regular cleaning.

• Uneven temperatures from room to room.

• Frequent fatigue, headaches, or irritation among employees.

If you notice one or more of these signs, contact AirGreen for a free inspection of your office space in Montreal, Laval, Longueuil, or anywhere on the North Shore or South Shore.

AirGreen: a trusted partner for clean air at work

With over 15 years of experience in HVAC system maintenance, we’ve helped hundreds of businesses create healthier work environments. Our approach is built on:

• Transparency (clear diagnostics, fixed prices, no unnecessary sales),

• Technical excellence (certified technicians, cutting-edge equipment),

• Compliance with health and environmental standards.

A smart investment on all fronts

Investing in the regular cleaning of your air conditioning systems is not just a health issue—it’s also a financially sound strategy:

• Up to 25% energy savings.

• Longer lifespan for your equipment.

• Increased employee satisfaction and retention.

• Enhancing your company’s commitment to social responsibility.

Contact AirGreen today

At AirGreen, we believe every workplace deserves clean, healthy, and safe air. If you manage an office building, commercial center, or medical space, book an appointment with our team today for a comprehensive assessment of your AC system.