New Home, Stale Air? What Builders Don’t Tell You About Ventilation (and How to Fix It)

Indoor Air Quality in New Homes: A Problem Too Often Overlooked

When you move into a new home, you naturally expect optimal comfort, superior energy efficiency, and a healthy living environment. Yet, a recurring issue affects many homeowners across Montréal, Laval, Longueuil, the North Shore and the South Shore: the indoor air is often stale, humid, even unhealthy. And this problem is far from trivial. It stems directly from today’s modern construction practices.

At AirGreen, we frequently encounter this issue with our clients. Their brand-new home is airtight, well insulated, but it lacks proper ventilation, which leads to condensation, mold, and discomfort. Here’s why this is such a common problem, and more importantly, how a high-quality air exchanger can fix it for good.

Why Modern Construction Creates Ventilation Problems

Over-Insulated… Without Proper Mechanical Ventilation

With increasingly strict energy efficiency standards in construction, today’s homes are designed to be airtight. The downside? Indoor air doesn’t renew naturally, unlike older homes where air leaks provided passive (though uncontrolled) ventilation.

In a new home:

• Windows are airtight

• Walls are ultra-insulated

• Doors are tightly sealed

• The vapor barrier is continuous

The result: the moisture produced by showers, cooking, breathing, and laundry gets trapped inside, increasing the risk of condensation on walls, mold growth, and persistent bad odors.

The Consequences of Stagnant Air

Air that isn’t properly refreshed quickly fills with:

• CO2 (which impacts focus and causes fatigue and headaches)

• Humidity, the main cause of mold

• Household pollutants (cleaning products, formaldehyde, VOCs from furniture, etc.)

• Unpleasant odors that linger

Over time, this affects not just comfort, but also the health of those living there. Young children, the elderly, and those with asthma are particularly vulnerable to poor indoor air quality.

Why Don’t Builders Always Install a Proper Air Exchanger?

Many new homes come with minimal ventilation systems, often just a bathroom fan or a kitchen hood, or a basic air exchanger that’s undersized or improperly installed. These systems simply aren’t enough to provide consistent, healthy air renewal throughout the entire home.

This usually happens because of:

• Cost-cutting by developers who opt for the bare minimum required by building codes

• Lack of awareness among buyers about the importance of mechanical ventilation

• No real testing of actual airflow levels provided by the system

How AirGreen Fixes It: Custom Installation of High-Performance Air Exchangers

At AirGreen, we understand that a proper air exchanger system is essential to ensure optimal breathing comfort in a modern home. We regularly intervene across Montréal, Laval, Longueuil, the North Shore and the South Shore to replace or upgrade inadequate ventilation systems—often just months after homeowners move into their new builds.

Key Steps in Our Process:

1. Personalized Technical Assessment: We measure ambient humidity levels, CO2 concentrations, and airflow rates.

2. Choosing the Right Air Exchanger: Depending on home size, number of occupants, and insulation level, we recommend the right model (Venmar AVS N Series, Lifebreath, Fantech, etc.).

3. Clean, Fast, Optimized Installation: Our certified technicians ensure the unit integrates seamlessly with your existing heating/cooling system.

4. Smart Programming: With simple home automation, we offer intelligent settings that ensure optimal ventilation without wasting energy.

Real-World Example: New Home in Blainville, North Shore

A couple with two young children contacted us a few months after moving into their new home. During the winter, they noticed:

• Condensation on their windows every morning

• A persistent musty smell

• Signs of mold in wall corners

After a full assessment, we found the builder-installed air exchanger was:

• Undersized for the square footage

• Poorly configured

• Connected only to one of three floors

We recommended installing a Venmar AVS HRV air exchanger with centralized distribution and a smart wall control. The result? In under 48 hours, air quality returned to optimal levels, windows stayed dry, and the odors disappeared.

How to Choose the Right Air Exchanger for a New Home

Here are a few things to consider:

• Total surface area of your property (in square feet or meters)

• Number of enclosed rooms

• Presence of a finished basement

• Type of existing heating/cooling system

• Lifestyle habits (children at home, remote work, frequent cooking, etc.)

We’ll guide you in choosing between an HRV (Heat Recovery Ventilation) or an ERV (Energy Recovery Ventilation) system, based on your specific needs.

Why Trust AirGreen for Your New Home’s Ventilation

We stand out thanks to:

• Unmatched field expertise in the Greater Montréal area

• Certified technicians familiar with the specific constraints of new homes

• Tailored solutions, adapted to each unique project

• Transparent, human-centered support, with no pushy sales tactics or compromises on quality

What You Can Do Right Now

• Check if your windows fog up regularly

• Smell the air in your home: do odors linger? Do you see signs of mold?

• Contact us for a free evaluation of your ventilation system

At AirGreen, we firmly believe that a well-ventilated home is one you can truly live in—for the long term.