Is Your Home a Victim of “Placebo Ventilation”? Discover How to Truly Purify Your Air

The Hidden Dangers of Poor Ventilation: When Your System Just Circulates Air Without Cleaning It

In many homes across Montréal, Laval, Longueuil, the North Shore and the South Shore, homeowners believe they’re protected by a proper air exchanger. Yet, without realizing it, they may be victims of what we call “placebo ventilation”: a system that appears to be working, but fails to do the essential job of properly renewing and purifying indoor air.

What Is “Placebo Ventilation”?

Placebo ventilation refers to an air exchange system that seems to work—motor noise, lights on, air flow visible—but does not actually ensure effective air renewal. As a result, indoor air remains stale, humid, and filled with allergens or pollutants, with direct impacts on the health and comfort of the occupants.

At AirGreen, we regularly come across systems where the air exchanger is poorly calibrated, badly maintained, or simply not designed for the home’s layout.

Common Signs of an Ineffective Air Exchanger

There are several clear signs that your system isn’t doing its job properly:

• Condensation on windows, especially in winter

• Persistent odors in certain rooms

• Air that’s too dry or too humid

• Frequent allergy symptoms, coughing, or headaches

• Excess dust, even after cleaning

• Visible mold, especially in basements or bathrooms

These symptoms are often overlooked or blamed on other causes. Yet they may indicate your air exchanger is operating in placebo mode.

Case Study: Proper Installation vs. Poor Calibration

We recently carried out an intervention in Sainte-Thérèse on the North Shore, where a client was complaining about poor air quality despite having an air exchanger installed for 3 years. Our analysis revealed that the airflow was insufficient for the size of the home. Plus, the ducts hadn’t been cleaned, severely limiting proper air circulation.

We performed:

1. A full cleaning of the ducts and the core unit

2. A recalibration of the air flow

3. Installation of a smart humidity sensor

4. A complete air pressure test (balancing)

The result: a noticeable improvement in air quality within 48 hours.

Why a Thoughtful Installation Is Crucial

A quality air exchanger, such as an HRV (Heat Recovery Ventilator) or ERV (Energy Recovery Ventilator), doesn’t just move air around. It must:

• Expel stale indoor air (loaded with CO2, moisture, odors…)

• Bring in fresh outdoor air

• Preheat or precool incoming air through a heat exchange process

But these benefits only come if the system is properly sized and installed. In Montréal and on the South Shore, we’ve seen numerous cases of over- or under-sized units causing pressure imbalances, unnecessary energy use, or unstable thermal comfort.

The AirGreen Approach: Audit, Adjustment, and Education

At AirGreen, we don’t just sell or install air exchangers. We guide each client through a complete indoor air purification strategy:

• Full home analysis (number of floors, insulation, air volume to treat)

• Evaluation of existing equipment

• Precise recommendations for the right model (Broan, Vanee, Lennox, Venmar, etc.)

• System calibration and balancing

• Customer education on optimal use (fan speeds, maintenance, filters, seasonal adjustments)

We prioritize long-term solutions designed to reduce mold, airborne bacteria, allergens, and improve respiratory health for occupants.

Common Mistakes to Avoid

Even the best unit becomes ineffective if poorly installed. Here are the pitfalls we always avoid:

• Connecting to dryer or range hood ducts (strictly prohibited)

• No pressure register or humidity sensors

• Filters not changed for years

• System permanently set to low or intermittent mode

• Outdated unit with non-ECM motor

Maintenance: An Often-Neglected Obligation

To avoid “placebo ventilation,” maintenance is key. We recommend:

• Annual cleaning of ducts and the recovery core

• Filter replacement every 3 to 6 months depending on use

• Recalibration check every 2 years

• Full system inspection every 5 years

A clean and well-calibrated system ensures real, active, and effective ventilation.

In Summary: Make Sure Your Air Exchanger Is Doing More Than Making Noise

A poorly calibrated, poorly maintained, or poorly chosen air exchanger gives the illusion of purifying the air, but in reality allows contaminants to freely circulate. That’s why at AirGreen, we focus on expertise, precision calibration, regular maintenance, and the right model for each home.

We serve clients throughout Montréal, Laval, Longueuil, the North Shore and South Shore, diagnosing, repairing, adjusting, or replacing ineffective ventilation systems.

Is your home really breathing? Or is it just placebo ventilation?

Contact AirGreen for a Complete Ventilation Inspection

A simple call or online form is all it takes to schedule a free evaluation visit. Our technicians, specialized in HVAC installation, HVAC maintenance, and air purification, will guide you toward the healthiest and most efficient solution.