By the Ventilation Vortex Air team—specialists in indoor air quality in Montreal
In Quebec, approximately 10,000 residential energy audits are conducted each year as part of the Rénoclimat program, and that number continues to grow. Since the program’s launch, more than 185,000 homes have been assessed across the province.
But here’s what many homeowners discover too late: ventilation is one of the most significant factors in a home’s energy rating, and it’s also one of the areas they’re least prepared for before the inspector’s visit.
In Montreal, where heating accounts for about 60 % of residential energy consumption and where a large portion of the housing stock was built before 1990, aging ventilation systems weigh heavily on audit results. A poorly maintained air exchanger, ducts Clogged drains or an unbalanced system can drag down your rating and cause you to miss out on significant grants.
This guide explains how ventilation affects your audit, what inspectors are really evaluating, and how to prepare to achieve the best possible results.
What is a residential energy audit in Montreal?
A residential energy audit is a comprehensive assessment of your home’s energy efficiency. The goal is to identify sources of energy loss, measure the building’s actual performance, and recommend priority improvements.
In Quebec, the program Rénoclimat, administered by Transition énergétique Québec (TEQ), is the primary framework for these audits. It is this framework that paves the way for provincial grants for energy-efficiency renovations.
How Does a Rénoclimat Audit Work?
The Rénoclimat audit is conducted in two stages: an assessment before the work begins and a second assessment afterward. Both are required to receive grants; it is this pre- and post-assessment process that verifies the actual improvement.
The main tool used in the audit is the airtightness test, also known as the blower door test or blower door test. A fan is installed in an exterior door to create negative pressure inside the house. This allows us to measure the amount of air seeping in through cracks, joints, and unintended openings. The higher the result, the more energy the house consumes.
The cost of the audit is approximately 150 $, part of which is reimbursed under the program. This is a minimal investment compared to the grants it can provide—up to 5,000 $ for overall improvements.
What Inspectors Look for in a Home
The inspector doesn't just look at insulation and windows. A comprehensive assessment covers the entire building envelope and mechanical systems:
L'insulation The walls, roof, and basement are measured. The windows are evaluated for their thermal efficiency and airtightness. The heating system, furnace, heat pump, baseboards, is taken into account. And the ventilation system, air exchangers, ducts, and bathroom exhaust fans are inspected for compliance and efficiency.
Visit air leaks are closely examined, as they are often the most significant source of energy loss in Montreal homes, especially in buildings constructed before 1980.
Why Ventilation Has a Significant Impact on Energy Audits
Ventilation is often an overlooked aspect for homeowners preparing for an energy audit. People tend to think about insulation, windows, and heating. Ventilation usually comes last. Yet it’s a factor that can tip an energy rating one way or the other.
The Role of Ducts and Ventilation Systems
A balanced ventilation system maintains a stable air pressure inside the house. When this system is faulty, such as when ducts are clogged, air exchanger If it is not adjusted properly, leaks in the system can cause the pressure to become unbalanced. The house compensates by drawing in uncontrolled outside air through infiltration.
This phenomenon has a twofold negative impact on the audit. It increases the air leakage test result, which lowers the airtightness rating. And it causes continuous heat loss, with heated air escaping and unfiltered cold air entering.
An HVAC system that forces air through partially blocked ducts consumes more electricity to maintain the same airflow. This is directly reflected in the energy consumption measured during the audit.
Energy Savings Achieved Through Ventilation
The numbers speak for themselves. Installing or optimizing an energy-recovery ventilator (ERV) can generate savings of 3.9 1Q3Q to 8.5 1Q3Q on a home’s total energy consumption. Combined with other improvements identified during the audit—such as insulation, sealing drafts, and replacing the heating system—the overall improvements can amount to 20 % to 30 % discount.
In absolute terms, that amounts to between 300 $ and 600 $ in annual savings for an average-sized home in Montreal. Over 10 years, that amounts to between 3,000 $ and 6,000 $ recovered, which is significantly higher than the cost of the repairs.
The Impact on Indoor Air Quality
An energy audit measures efficiency. But optimized ventilation also improves air quality, and the two are linked. Studies have shown that installing a high-performance HRV or ERV can reduce indoor formaldehyde concentrations by 10 % to 66 % according to the initial conditions.
A poorly ventilated system also promotes excessive humidity, which creates conditions conducive to mold growth. In Montreal, where humidity levels vary drastically between summer and winter, controlling humidity through mechanical ventilation is not just a minor consideration—it’s a necessity.
Common Ventilation Problems in Montreal Homes
The challenges are real, and they vary depending on the age and type of building. Here’s what we see most often in our day-to-day work across the region.
Old Houses and Plexes in Montreal
Neighborhoods such as Rosemont, Villeray, Ahuntsic and Plateau-Mont-Royal are dominated by duplexes and triplexes built between the 1920s and the 1970s. The vast majority of these buildings did not originally have mechanical ventilation systems. Ventilation occurred naturally through air leaks, cracks, and windows.
As these buildings were renovated and better insulated over the decades, natural ventilation decreased without being replaced by adequate mechanical ventilation. The result: homes that are more airtight, but with stagnant indoor air and ducts that, in some cases, have never been cleaned since they were installed.
Air leaks in these buildings—around windows, electrical outlets, and floor joints—contribute to high air-tightness test results during the audit. And the buildup of dust and debris in existing ducts exacerbates the energy efficiency problem.
Effects of Quebec's Climate on Ventilation
Montreal’s freeze-thaw cycles are particularly harsh on ventilation systems. The repeated expansion and contraction of materials create micro-cracks in the ducts, degrade the seals, and damage the weatherstripping. In winter, the extremely dry air—often below 20 % relative humidity during extreme cold spells—creates imbalances in the mechanical ventilation systems.
Paradoxically, basements in Montreal tend to accumulate moisture in the spring and fall, which can draw humid air into the ventilation system and cause condensation in the ducts.
Signs That Your Ventilation System Is Reducing Your Energy Efficiency
Here are the most common issues identified during home inspections in Rosemont, Ahuntsic:
A Unexplained increase in Hydro bill, without changing consumption habits. From the Persistent condensation on the windows in winter, a sign of a humidity imbalance that ventilation is not properly controlling. Some musty or stale odors, especially after the seasons change. Some uneven temperatures between rooms, some cold rooms and others that are too hot, indicating an unbalanced airflow in the system.
If you recognize two or more of these signs, your ventilation system warrants a thorough evaluation, ideally before scheduling your Rénoclimat audit.
Are you preparing for an energy audit? Have the Vortex Air team inspect your ventilation system for free before the auditor's visit.
Myths About Energy Audits and Ventilation
There are a few common misconceptions circulating on this topic that deserve to be clarified.
Myth: Energy audits do not address ventilation
That’s not true. The air-tightness test directly measures the impact of your ventilation system on the building’s air-tightness. An improperly balanced ventilation system that creates negative or positive pressure directly affects the test results. The auditor also evaluates the air exchanger, bathroom exhaust fans, and accessible ducts. Ventilation is an integral part of the audit.
Myth: More ventilation means lower costs
Not necessarily. Excessive ventilation—or an oversized or improperly adjusted system that constantly circulates air at high flow rates—results in heat loss of 20 % to 30 %. The goal is not to ventilate as much as possible, but to ventilate in a controlled and balanced manner. A properly sized heat recovery ventilation system recovers heat from the exhaust air before expelling it; that is what saves energy, not simply ventilating more.
Myth: DIY solutions are sufficient to prepare for an audit
A professional airtightness test identifies 80 % to 90 %—no more problems than a visual self-inspection. Air leaks are often found in unexpected places—around electrical boxes, at the junction between walls and ceilings, and in crawl spaces. Without measuring equipment, these problems go unnoticed. And a Rénoclimat inspector will find them anyway, so you might as well fix them beforehand.
How to Prepare Your Home for an Energy Audit
Good preparation can make the difference between an average rating and one that qualifies you for the maximum grants. And the breakdown is one of the areas where you can take concrete action before the visit.
Simple Checks to Do Before the Visit
Here are a few simple steps any homeowner can take:
Check and replace your HVAC filters if necessary. A clogged filter reduces airflow and can affect the meter's readings. Make sure your air exchanger To ensure it works properly, check the internal filters and clean the grates if possible. Check your dryer duct, a partial blockage is often invisible from the outside, but can be detected by a longer drying time. Check that the bathroom exhaust fans are working and that the grates are clean.
These checks take an hour. They are not a substitute for a professional inspection, but they give you a basic idea.
Why Have the Ventilation System Inspected Before the Audit?
A professional ventilation inspection before your Rénoclimat audit offers you three concrete benefits.
A better energy rating, a clean and balanced ventilation system improves the results of the air-leakage test and the measured performance of the heating system.
Larger grants, a higher initial rating, combined with documented improvements, can increase the amounts for which you are eligible after the work is completed.
More accurate results, an auditor who evaluates a system that is in good working order provides more reliable recommendations. If the system was flawed before the audit, the recommendations may be skewed by problems that could have been easily resolved.
Are you planning a Rénoclimat audit? Request a free ventilation inspection from Vortex Air before your auditor’s visit.
Grants and Programs to Improve Ventilation
There are two main programs available for ventilation projects in Montreal. Here’s what you need to know.
Rénoclimat Program
Rénoclimat covers improvements to residential mechanical ventilation systems. The installation or replacement of a HRV (heat recovery ventilator) or an ERV (energy recovery ventilator) is eligible for financial assistance of up to 500 $ for this specific equipment.
A pre-construction audit is mandatory; it establishes the baseline and verifies eligibility for grants. Without it, no financial assistance is available. And a post-construction audit is required to receive the final payment.
For comprehensive upgrades that combine ventilation, insulation, and a heating system, costs can reach up to 5 000 $.
Hydro-Québec’s LogisVert Program
LogisVert offers rebates for ENERGY STAR-certified equipment, including certain ventilation and air-exchange systems. A 5 % bonus applies when multiple energy-efficiency measures are combined in the same application, making coordinated planning particularly advantageous.
In most cases, the two programs can be combined. Improved ventilation contributes to both the Rénoclimat criteria and the LogisVert eligibility requirements—two reasons to treat ventilation as a priority, not as an afterthought.
Why Choose Vortex Air to Prepare for Your Energy Audit
Preparing for a Rénoclimat audit is a serious undertaking. And the condition of your ventilation system will directly impact your results. At Vortex Air, we help Montreal homeowners get ready for their assessment—before it happens, not after.
Our team is based in Montreal at 9187 Boulevard de l’Acadie. We’ve been serving clients on the island, on the North Shore, and on the South Shore for over 10 years. With more than 500 clients in Greater Montreal, we understand the realities of local buildings—from the century-old apartment complexes in Rosemont to the newer single-family homes in Laval and Longueuil.
Inspection and cleaning tailored to energy audits
Our process is designed to provide you with an accurate overview and breakdown in the best possible condition before the auditor’s visit.
Initial Inspection, We’ll assess the overall condition of your ventilation system: ducts, air exchanger, exhaust fans, and airflow per room. Free, with no obligation.
Transparent Submission, If service is needed, you'll receive a clear, written quote before we do anything.
High-Power Cleaning, Our technicians use industrial-grade equipment to thoroughly clean the system. No superficial cleaning, no resuspension of dust.
Final Check, We test the airflow after the work is completed and document the results. You’ll arrive at your audit with a system that actually works.
We are certified INVC and actively pursuing certification NADCA, the two industry leaders in residential and commercial ventilation. Mohamed and Omar, the co-owners, are directly involved in every project to ensure that the work is done right.
Local company specializing in ventilation
We’re not a national franchise with different teams showing up every time you visit. We’re a Montreal-based company with a consistent team of five certified technicians who know the area well. Our customers in Ahuntsic, Villeray, and on the South Shore keep coming back because they know who they’re dealing with.
Ready to get your home ready for a Rénoclimat audit? Schedule your free ventilation inspection in Montreal today.
📞 514-214-7492 (24 hours a day) | Open 7 days a week, from 7 a.m. to 9 p.m.
FAQ: Energy Audits and Ventilation in Montreal
Does ventilation really affect the energy rating?
Yes, significantly. A balanced ventilation system improves the airtightness measured during the air leakage test, reduces heat loss, and improves the overall performance of the heating system. Optimized ventilation can contribute to a reduction of 3.9 % to 8.5 % in total energy consumption—a significant improvement in a Rénoclimat rating.
Does Rénoclimat require a ventilation inspection?
Rénoclimat does not specifically require a pre-project ventilation inspection. However, the pre-project audit includes an assessment of the existing ventilation system, and its condition will influence the recommendations and the initial rating. Having a ventilation system in good condition before the audit puts you in a better position to maximize your post-renovation grants.
How much does an energy audit cost in Montreal?
The cost of a Rénoclimat audit is approximately 150 $, a portion of which is reimbursed under the program. It is one of the most cost-effective investments a homeowner can make, and it opens the door to grants of up to 5,000 $ or more, depending on the work performed.
How often should the ducts be cleaned before an audit?
Generally speaking, cleaning every 3 to 5 years is recommended. Before a Rénoclimat audit, if your ducts haven’t been cleaned in more than 3 years—or have never been cleaned—a preliminary inspection and cleaning are strongly recommended. This is one of the most direct ways to improve your rating even before the auditor arrives.
Does an air exchanger lower your electricity bill?
Yes, when it is properly sized and well-maintained. A HRV recovers heat from the exhaust air before expelling it, which reduces the amount of energy needed to heat the incoming fresh air. Savings of 3.9 % to 8.5 % on overall energy consumption have been documented for households that switch from inadequate natural ventilation to a high-performance HRV.
Do homes with electric baseboard heaters need an energy audit?
Absolutely. The Rénoclimat audit applies to all types of heating systems, including electric baseboard heaters. For these homes, the main energy savings often come from insulation and air sealing, and ventilation plays a role in both. A home heated by baseboard heaters that is poorly ventilated can have humidity and mold problems that affect both health and the building’s structure.
Is it possible to «fail» an energy audit?
No, there is no failing score on a Rénoclimat audit. The audit assesses the current condition and identifies potential improvements. A low initial rating isn’t a problem—it’s an opportunity. The greater the potential for improvement, the more grants will be available after the work is completed.
Do duplexes need to conduct a separate audit for each unit?
It depends on the layout. If each dwelling is considered a separate residential unit with its own systems, an audit for each dwelling may be required. For duplexes where systems are shared—such as central ventilation or a common air exchanger—the audit may cover the entire building. Check directly with a Rénoclimat advisor or your accredited auditor for your specific situation.
Would you like to improve your home's energy efficiency before an audit? Contact the Vortex Air team for a free ventilation inspection, we're here to help you get ready, 7 days a week.
📞 514-214-7492 | ✉️ info@vortexair.ca | 📍 9187 Boulevard de l’Acadie, Montreal, QC H4N 3K1
