Excessive humidity in Montreal: how proper ventilation changed a family’s life

A professional ventilation installation for a home in Montreal: a turning point against chronic humidity

In the Rosemont–La Petite-Patrie borough of Montreal, a family recently contacted us with a problem that had become unbearable: excessive humidity in their home, causing discomfort, recurring mold in the bathroom, and persistent odors in the basement. At AirGreen, we know these symptoms are often early warning signs of a poorly adapted or failing ventilation system. This case perfectly illustrates our personalized approach to installing high-performance ventilation systems throughout Greater Montreal, including Laval, Longueuil, the South Shore, and the North Shore.

Understanding the causes of excessive humidity in a Montreal home

In well-insulated homes — like this one — the lack of fresh air circulation can quickly turn thermal comfort into a humidity trap. Everyday activities like cooking, showering, or even just breathing produce water vapor. When that vapor can’t be evacuated properly, it condenses on cold surfaces, creating ideal conditions for mold and bacteria growth.

This family was dealing with:

• Constant condensation on windows in the morning

• Black mold stains on bathroom walls

• A musty odor lingering in the finished basement

• Respiratory health issues in a child with asthma

Personalized evaluation by AirGreen: technical diagnosis and airflow analysis

We began with a comprehensive assessment of the existing ventilation system, including airflow measurements that showed insufficient air exchange in key rooms and a total lack of heat recovery. Their old system was outdated, had no air exchanger, and no longer met current Quebec Building Code standards.

The AirGreen solution: installing a Venmar AVS N Series air exchanger with heat recovery

Given these findings, we recommended a Venmar AVS N Series heat recovery ventilator (HRV). This model is well-known for its performance in northern climates like Montreal’s. Its 160 CFM (cubic feet per minute) capacity is ideal for medium-sized single-family homes.

Technical specifications of the installed unit:

• Brand: Venmar

• Series: AVS N Series HRV 160 CFM

• Technology: high-efficiency heat recovery (up to 75%)

• Filtration: MERV 8 filter included, upgradeable to MERV 13

• Certification: Energy Star®

• Grant eligibility: Yes (LogisVert, Rénoclimat)

• Location: Installation completed in Montreal, Rosemont–La Petite-Patrie

A clean, precise, and quick job

The installation was completed in one day, without disrupting the family’s daily life. We used high-quality insulated ducting, a digital wall-mounted control panel, and we calibrated the exchanger according to the home’s exact volume.

Key steps in the job:

1. Removal of the old, defective extractor fan

2. Controlled drilling for the intake and exhaust vents

3. Electrical connection to the main panel

4. Depressurization testing and airflow balancing room by room

5. Detailed instructions given to the homeowners for ongoing maintenance

Results achieved in the weeks following the installation

The transformation was immediate:

• Indoor humidity dropped from 68% to an average of 45% in problem areas

• Mold began to disappear gradually

• Comfort noticeably improved, especially in the basement

• Asthma symptoms in the child were reduced

• No more condensation on the windows at night

The customer told us:
"It’s the first time in years we’ve breathed this well in our own home. The moldy smell is gone, and the air feels so much lighter. Thank you to the entire AirGreen team for your professionalism!"

AirGreen’s advice: how to prevent humidity in your Montreal home

Here are some practical tips for homeowners dealing with humidity:

• Install a mechanical ventilation system (HRV or ERV)

• Regularly check airflow in your kitchen and bathrooms

• Clean or replace filters every 3 to 6 months

• Properly insulate your ducts to avoid thermal bridges

• Consider a separate ventilation system for finished basements

Why trust AirGreen for your ventilation installation in Montreal, Laval, Longueuil, the South Shore, and the North Shore?

At AirGreen, we don’t just sell products: we design long-lasting HVAC solutions, tailored to the climate realities of Greater Montreal. Thanks to our local expertise, we know how to handle the challenges of Quebec winters and summer humidity.

Our commitments:

• Custom thermal and ventilation analysis

• Certified Energy Star products eligible for rebates

• Experienced technical team, certified by RBQ and CMMTQ

• Responsive after-sales service and long-term support

Available grants for air exchanger installations

For this project, the family was able to benefit from:

• The Hydro-Québec LogisVert program (up to $600)

• The Rénoclimat program for single-family homes (tax credit based on energy efficiency improvements)

Our coverage across the region

We handle ventilation installations and HVAC services throughout Greater Montreal, including:

• Montreal (Rosemont, Villeray, Outremont, TMR, Plateau)

• Laval (Chomedey, Fabreville, Duvernay)

• Longueuil (Saint-Hubert, Vieux-Longueuil, Greenfield Park)

• South Shore (Brossard, Saint-Lambert, Boucherville)

• North Shore (Boisbriand, Blainville, Sainte-Thérèse)

In conclusion

This installation perfectly illustrates how a well-designed ventilation system can transform an unhealthy environment into a safe and comfortable living space. At AirGreen, we believe every home deserves clean, quality air. If you’re dealing with humidity, mold, or poor air quality, contact our HVAC experts. We’ll support you with transparency, efficiency, and expertise—wherever you are in Montreal, Laval, Longueuil, the North Shore, or the South Shore.