Montréal: how neglected air filters almost shut down a famous restaurant

An incident narrowly avoided thanks to a swift response from our HVAC team

In Montréal’s vibrant Plateau-Mont-Royal neighborhood, a well-known restaurant praised for its upscale street food recently came close to disaster. The reason? Prolonged neglect in maintaining the air filters of its central ventilation system. This event clearly highlighted the critical importance of regular HVAC maintenance, especially in commercial spaces where indoor air quality directly impacts public health and regulatory compliance.

An emergency call during a peak service week

It all started on a Wednesday morning in February, with the kitchen running at full capacity since opening. A persistent smoke odor and unusual haze began to fill the dining area. Staff initially assumed it was a minor exhaust issue, but within hours, indoor temperatures soared, the hood system stopped working, and multiple customers complained about stuffy air and headaches.

Fearing a forced closure by Montréal’s Public Health Department or intervention from the fire department, the owner immediately contacted us for an emergency HVAC intervention.

Full inspection of the ventilation system: clogged filters and grease-filled ducts

We arrived on-site within the hour, and our certified technicians carried out a full inspection of the centralized air conditioning and ventilation system. The diagnosis came quickly: the air filters hadn’t been changed in over 18 months. As a result:

• The return air grilles were completely clogged, blocking fresh air circulation.

• The ventilation ducts were coated in thick grease deposits, a mix of dust, oil, and food particles.

• The air handling unit’s motor was on the verge of overheating due to mechanical overload.

This level of neglect could have easily led to an immediate administrative closure, or even posed a major fire hazard.

The deep cleaning process: precision, speed, and efficiency

At AirGreen, we understand that a commercial establishment in operation cannot afford prolonged downtime. Our team immediately deployed an intensive cleaning plan spread over two visits:

Step 1: Degreasing and filter replacement

• High-pressure cleaning of the supply and return grilles.

• Complete replacement of HEPA filters and pre-filters with products certified for food environments.

• Application of an antimicrobial treatment inside the ducts.

Step 2: Disinfection of ventilation ducts

• Industrial vacuuming of the entire duct network.

• Thermal camera inspection to detect hidden obstructions.

• Spraying of a government-approved disinfectant (MAPAQ) to eliminate bacteria, mold, and allergens.

Immediate results and restored regulatory compliance

Within 48 hours, the restaurant regained optimal indoor air quality, measured using a professional anemometer. CO₂ sensors once again displayed levels compliant with CNESST standards, and the kitchen temperature stabilized.

The restaurant owner also received:

• A complete compliance report to present during inspections.

• A preventive maintenance contract with quarterly visits.

• Personalized advice to avoid future issues.

What this story teaches us about HVAC maintenance in commercial settings

This restaurant's experience is far from unique. In Montréal, Laval, and on the South Shore, many businesses underestimate the real consequences of neglected air filters:

• Reduced energy efficiency of the HVAC system.

• Increased heating and cooling costs.

• Health risks for customers and employees.

• Potential sanctions from health authorities.

That’s why we always emphasize the importance of regular maintenance, especially in public-facing establishments.

AirGreen: your HVAC partner for restaurants and businesses across Greater Montréal

With extensive field experience, we’ve developed a custom HVAC cleaning offer tailored to restaurants, bars, cafés, and food shops in Montréal, Laval, Longueuil, North Shore and South Shore. Our approach stands out for:

• Rapid interventions, often within 24 to 48 hours.

• Use of specialized equipment adapted to food environments.

• A team trained to meet CNESST and MAPAQ standards.

• Flexible preventive maintenance plans based on real equipment usage.

We understand that in your industry, every minute of downtime is costly. That’s why we adapt our schedule to intervene early mornings, late evenings, or on closed days.

Practical recommendations for restaurant managers

Here are some best practices we always share with our food service clients:

1. Replace air filters every 3 to 4 months, or more often during high-volume periods.

2. Schedule an annual inspection of the ventilation ducts.

3. Install indoor air quality sensors in the kitchen and dining areas.

4. Plan for deep cleaning twice a year to remain MAPAQ-compliant.

5. Train staff to recognize signs of HVAC failure (unusual noises, lingering odors, temperature drops).

Testimonial from the owner: renewed confidence

"Without AirGreen’s quick response, we would’ve been shut down by inspectors. Their professionalism, transparency, and efficiency really impressed me. We now have an annual maintenance contract in place, and I sleep much better at night."

This testimonial reflects the long-term trust-based relationships we build with our clients. Beyond technical service, we bring peace of mind.

At AirGreen, we turn an HVAC emergency into a long-term improvement opportunity.