The Silent Danger of Carbon Monoxide: How a Ventilation System Saved a Family on the South Shore

A life-saving intervention by AirGreen: when an HVAC ventilation system makes the difference between life and death

Carbon monoxide (CO) is a colorless, odorless, and deadly gas. In winter, the risk increases dramatically—especially in poorly ventilated homes using outdated or malfunctioning heating systems. On the South Shore, a family from Saint-Constant recently avoided tragedy thanks to an emergency ventilation installation carried out by AirGreen, highlighting the vital importance of a well-designed HVAC system.

A near-miss incident in a residential bungalow

This past January, a family of four living in a 1,400 sq. ft. bungalow began experiencing troubling symptoms: sudden fatigue, headaches, and nausea. Initially thinking it was the seasonal flu, the parents took the precaution of purchasing a carbon monoxide detector from the pharmacy.

Just hours after plugging it in, the alarm went off. Firefighters arrived quickly and confirmed a dangerous concentration of CO coming from a slowly leaking combustion water heater with poor ventilation. The home only had insufficient passive ventilation.

Following the incident, AirGreen was called in to perform a complete ventilation system overhaul to ensure the long-term safety of the home.

Equipment installed: Venmar AVS X24ERV ECM Heat Recovery Ventilator

Technical specifications

• Brand: Venmar AVS

• Model: X24ERV ECM

• Type: HRV with energy recovery and ultra-quiet ECM motor

• Airflow: 220 CFM, ideal for single-family homes

• Filtration: MERV 13 with washable pre-filter

• Features: digital wall control, winter/summer mode, integrated humidity sensor

• Certifications: HVI, Energy Star, eligible for LogisVert grants

This model was chosen for its ability to efficiently renew indoor air while saving energy, and its compatibility with existing ductwork in older homes.

Installation details: a discreet yet strategic retrofit

Key steps carried out by AirGreen

1. Full home inspection, including basement, mechanical room, and attic

2. Airflow analysis with simulation to identify stagnant zones at risk

3. Safe removal of the old passive ventilation, and prep work for new duct routing

4. Installation of the Venmar HRV in the laundry room, with silencer and exterior exhaust

5. Discreet ceiling vents added in the bedrooms, kitchen, and living areas

6. Smart programming to ensure 24/7 air exchange

7. Client walkthrough and training, including maintenance guidance and operational checks

The work was completed in three business days, with no major demolition and minimal disruption to the family.

Immediate results: purified air and a protected family

• Carbon monoxide levels reduced to zero, confirmed by post-installation air tests

• Significant improvement in indoor air quality, measured using our professional analyzer

• Excess humidity eliminated, preventing window condensation

• Enhanced thermal comfort, thanks to heat recovery via the HRV

• $1,456 LogisVert grant approved, helping cover installation costs

Why this installation sets the standard for South Shore homes

An invisible threat lurking in many households

Thousands of homes in Québec—especially across the South Shore (in Saint-Constant, Candiac, La Prairie, Châteauguay)—still rely on combustion-based heating systems without proper mechanical ventilation. Carbon monoxide, a byproduct of incomplete combustion, can build up undetected and become lethal, especially overnight.

A reliable HVAC ventilation system isn’t a luxury—it’s a lifesaving safeguard.

What this intervention reveals about AirGreen’s expertise

Mistakes our team avoided

• Relying solely on natural ventilation

• Using undersized or uncertified equipment

• Neglecting client training on system use

• Failing to design a balanced ventilation network instead of just extracting air

Our tangible added value

• A customized risk assessment for CO exposure

• Proven expertise in residential ventilation across the South Shore

• A fast and durable installation, tailored to the structure’s constraints

• Complete support for grant applications and long-term follow-up

Tips for families: how to prevent CO build-up in your home

• Install a certified carbon monoxide detector on every floor

• Have all combustion appliances (water heaters, furnaces, gas fireplaces) checked annually

• Maintain permanent mechanical ventilation, especially in winter

• Never block ventilation grilles with furniture or curtains

• Choose high-performance HRVs or ERVs, HVI-certified and correctly sized for your home

Conclusion: clean air is a life preserved

Thanks to AirGreen’s quick and precise intervention, a family on the South Shore avoided an irreversible tragedy. This project proves that thoughtful HVAC ventilation is more than a comfort feature—it’s an invisible but essential barrier against deadly threats. Prevention always outweighs the cure — and at AirGreen, that’s our daily mission.