HVAC Emergency: How a Neglected Filter Cost a Montréal Business $10,000

A real case in Montréal that highlights the critical importance of preventive HVAC maintenance

At AirGreen, we’re often called in for emergency interventions in businesses located across Montréal, Laval, Longueuil, the North Shore and the South Shore to fix HVAC issues that could have easily been avoided. The story we’re sharing here is a striking example of the consequences of one simple oversight: a neglected air filter. A detail too often overlooked, yet one that led to over $10,000 in damage for a small business in the Rosemont neighborhood of Montréal.

An unexpected emergency on a Monday morning

One Monday morning in January, a business manager in Montréal calls us in a panic: their central ventilation system has stopped working, the indoor air is heavy, humidity is noticeable, and a burning smell is starting to come from the vents. Immediately, our specialized team in commercial HVAC emergencies was dispatched to the scene.

On-site diagnosis: a clogged filter choking the entire system

Within just 20 minutes, our technicians identified the root of the problem: a completely saturated air filter that hadn’t been changed in over a year. This lack of maintenance caused:

• Excess pressure within the ventilation system

• Overheating of the central unit’s motor

• Accelerated wear and tear on internal components, including the main fan and the central air conditioner’s compressor

The result: the Lennox commercial HVAC unit, model CBX32MV, valued at $7,500, was completely out of service. Even worse, the main duct, exposed to extreme pressure changes, had cracked, leading to moisture infiltration inside the walls.

Immediate commercial impact

The business – an artisanal bakery – was forced to shut its doors for 48 hours. Not only did the HVAC system need replacing, but the space also required professional-grade dehumidification and odor removal with air purifiers. When factoring in lost revenue, replacement costs, and cleanup, the total bill exceeded $10,000.

What simple maintenance could have prevented

A regular preventive HVAC maintenance, costing around $250 annually for this type of system, would have:

• Ensured the filter was changed at the right time

• Verified static pressure and duct conditions

• Lubricated motors and inspected vulnerable parts

• Prevented any critical breakdown

This case clearly demonstrates how HVAC maintenance is an investment, not an expense.

The AirGreen approach: precision, speed, and expertise

At AirGreen, our commercial HVAC emergency service follows a strict protocol:

1. Fast diagnosis in under 30 minutes

2. On-site intervention with fully equipped vehicles

3. Common replacement parts available immediately

4. Option for temporary portable ventilation or air conditioning units

In this case, our team was able to install a temporary unit the same day to allow for a partial reopening of the business. Afterwards, we replaced the faulty central unit with a new Lennox ML14XC1 heat pump, more efficient and eligible for a subsidy.

The replacement: more than just a repair

The new system selected was a Lennox ML14XC1 central heat pump, 3 tons (36,000 BTU), featuring a SEER2 rating of 16 and an HSPF2 rating of 9.5, offering excellent energy efficiency for medium-sized businesses. Thanks to our status as certified installers, the client qualified for a $2,184 LogisVert grant from Hydro-Québec.

Our installers carried out:

• The safe removal of the old system

• Adapting existing ductwork to the new unit

• Commercial-grade electrical work to code

• Startup and full inspection, including airflow verification, defrost cycle, and thermostat configuration

All completed within 48 hours.

Key takeaways for all businesses

1. Maintenance is non-negotiable

A single clogged filter can bring down an entire system. We recommend biannual HVAC maintenance at minimum for all commercial clients, with scheduled follow-ups and automated reminders for filter changes.

2. A fast response minimizes losses

Thanks to our network of certified technicians covering Montréal, Laval, Longueuil, the North Shore and the South Shore, we typically respond to commercial emergencies within 4 hours.

3. Invest in high-performance equipment

Brands like Lennox, Bosch, Fujitsu, or Goodman offer reliable commercial heating and cooling systems, with parts readily available locally and strong warranties.

4. Prevent before you rebuild

We offer all our commercial clients a personalized annual maintenance plan, tailored to their needs, with maintenance history, performance monitoring, and discounts for emergency services.

Client testimonial

“We thought the filter was just a minor thing. Within 48 hours, AirGreen saved us from disaster. Not only did they repair everything, but they guided us toward a new, more reliable and energy-efficient system. We signed a maintenance contract with them right away.” — Simon G., owner

Our recent commercial interventions

Here are a few similar situations handled by our team:

• Full maintenance of a Trane Rooftop system in Laval – 60 filters replaced, diagnostics with thermography

• Replacement of a Fujitsu Airstage unit in a Longueuil business, after a capacitor-related short circuit went unchecked

• Emergency repair of a Bosch BOVA system in a North Shore warehouse, where a frozen sensor had halted the system

Why trust AirGreen for your business?

• Fast coverage in Montréal, Laval, Longueuil, North Shore, South Shore

• Proven expertise in commercial HVAC

• Certified products, guaranteed installations, available subsidies

• Custom-tailored maintenance contracts, adapted to your facility’s size and operational needs

Don’t let a filter shut down your business. Prevent the HVAC emergency before it happens.