A VRC-95 air exchanger that was no longer breathing properly in a cramped mechanical room
At AirGreen, we regularly work on residential air exchangers installed in tight technical spaces: mechanical closets, laundry rooms, finished basements, rooms above a water heater, or areas where every inch counts. This is exactly the context of this service call in Duvernay, in the Laval area, for an Épurair VRC-95 air exchanger installed above a hot water tank.
At first glance, the device still seemed in good overall condition. The casing was accessible, the installation had been neatly integrated into a designated space, and the VRC-95 model was well suited for standard residential use. Yet, the client noticed several worrying symptoms: a feeling of stagnant air in certain rooms, more difficult humidity control, a slightly musty odor after long periods without window openings, and irregular device operation.
In this type of situation, the most important reflex is not to replace the device too quickly. An air exchanger that seems weak, noisy, or inefficient is not necessarily at the end of its life. Very often, performance gradually decreases due to a combination of small issues: clogged filters, dirty recovery core, partially blocked drain, misaligned dampers, unbalanced ducts, poorly calibrated wall control, or unstable electrical connection. Our role is therefore to make an accurate diagnosis before proposing a solution.
Device description: Épurair VRC-95, a compact residential air exchanger
The device observed on site is an Épurair VRC-95, a VRC-type air exchanger. In a residence, this type of system is used to expel stale air outside while introducing fresh air, with partial heat recovery based on the heat recovery ventilator principle.
In houses in Montreal, Laval, Longueuil, the North Shore, and the South Shore, this type of equipment is especially useful during cold seasons. Modern or renovated houses are often more airtight than before. This airtightness improves energy efficiency, but it can also trap humidity, odors, fine particles, and CO₂-laden air if mechanical ventilation is not well maintained.
In this specific case, the installation was located in a mechanical closet, just above the water heater. This configuration has several technical particularities:
- access to the device is more limited;
- water heater pipes and ventilation ducts share a confined space;
- ambient heat can influence certain components;
- drainage must be carefully monitored;
- the clearance around the unit must remain sufficient to allow maintenance.
The intervention image shows a compact device, installed high up, with a service area open on the right side. This detail is important because restricted access can make maintenance less frequent or more difficult for the owner. However, an air exchanger requires periodic attention, even if it often operates in the background without drawing attention.
Symptoms reported by the client in Duvernay
The client contacted us for a problem that was not a complete breakdown, but rather a loss of performance. This is a common scenario: the device still works, the motor seems to start, but the result in the house is no longer satisfactory.
The main symptoms observed and reported were as follows:
- low air circulation at certain vents;
- feeling of heavy air in the house;
- more persistent indoor humidity;
- intermittent operation;
- slightly more noise than usual;
- more visible condensation during cold periods;
- doubt about the real effectiveness of the air exchanger.
This kind of complaint requires a thorough analysis. An air exchanger may seem to be running without actually ventilating properly. The motor may run, but if the filters are blocked or the core is dirty, the airflow drops. Similarly, if a drain is partially clogged, moisture can accumulate inside the device and cause odors or water stains. Finally, if the ducts are unbalanced, the device may extract more air than it introduces, or vice versa, which harms overall comfort.
AirGreen diagnosis: check the entire system before concluding
Upon arrival, we started with a visual inspection of the installation. The goal was to understand not only the condition of the device but also its immediate environment. In a mechanical closet like this, the operation of the air exchanger depends on several surrounding elements: power access, clearance, drain slope, duct condition, and cleanliness of internal components.
Power and control verification
The first step was to verify that the device was receiving stable power. The wall connection and visible wires near the device were inspected to rule out a simple power failure, a loose plug, or a weakened control wire.
We also checked the device’s response to the control. An air exchanger can be connected to a wall control, a humidistat, or a ventilation switch. When the control is misconfigured, the customer may think the device is malfunctioning when it is simply in intermittent mode, low speed, or standby.
In this case, the device was responding, but the ventilation was not optimal. This allowed us to continue the diagnosis toward the mechanical components and air passages.
Inspection of the filters and recovery core
One of the most common causes of performance loss on a VRC air exchanger is filter clogging. Filters protect the core and fans, but they eventually accumulate dust, fibers, hair, fine particles, and debris carried by the air.
During this intervention in Duvernay, the filters showed enough buildup to affect the airflow. The recovery core also needed careful cleaning. A dirty core reduces heat exchange and increases resistance to air passage. The motor then works harder, but the result inside the house decreases.
We removed accessible components, cleaned surfaces, checked the core’s condition, and inspected panel sealing. The goal was not just to clean but to ensure air passed in the right place, without significant internal leaks or obstruction.
Condensation drain inspection
An air exchanger generates condensation, especially in winter, when the warm, humid air from the house contacts colder surfaces inside the device. This water must be properly drained.
In the observed installation, drainage was an important point to check, especially due to the device’s position above the water heater. We checked the slope, the condition of the drain pipe, possible signs of moisture, and absence of blockage. A partial obstruction can cause water accumulation in the device, create odors, and sometimes cause unusual noises.
The drain was cleared and secured to ensure more reliable evacuation. This step is often underestimated but is essential to extend the device’s lifespan and prevent damage in a mechanical room.
Fan and noise control
A louder noise can come from a dirty fan, a worn motor, a poorly closed panel, a vibrating support, or an airflow imbalance. In this case, the noise did not indicate a major motor failure but rather less smooth operation caused by dirt buildup and restricted airflow.
We checked the rotation, vibrations, device stability, and panel fitting. After cleaning and correcting the air passage points, the operating sound became more regular again.
Inspection of ducts and grilles
An air exchanger can be clean and functional but lose a lot of efficiency if the ducts are poorly connected, crushed, unbalanced, or blocked. We therefore evaluated the overall behavior of the ventilation network: extraction of stale air, introduction of fresh air, and distribution in the served areas.
In homes in Duvernay and Laval, we often see installations where the device is placed in a convenient space, but the ducts have been adapted to architectural constraints. This can work properly, provided the system is maintained and the airflow remains consistent.
Solution applied on site
After the diagnosis, the intervention involved several complementary corrections. It was not a spectacular repair based on a single replaced part, but a methodical restoration of the device and its operation.
We proceeded with:
- cleaning of filters and accessible components;
- inspection of the heat recovery core;
- clearing of the air passage;
- verification of power supply and control;
- correction of condensation drainage;
- inspection of vibrations and panels;
- verification of operation at low and high speed;
- validation of the airflow at the main grilles;
- maintenance recommendations adapted to the installation.
The result was immediately noticeable: the device operated more stably, noise was better controlled, and ventilation regained better efficiency. The customer also received clear explanations about the maintenance to be expected, which is especially important with a device installed high up in a mechanical closet.
Why this type of repair requires experience
An Épurair VRC-95 air exchanger may seem simple compared to a wall-mounted heat pump, a central heat pump, or a MultiZone system, but its diagnosis requires a good understanding of the building. Ventilation is not just about a running motor. It depends on the balance between extraction, fresh air supply, humidity, temperature, indoor pressure, and the condition of the ducts.
At AirGreen, our experience in HVAC service allows us to quickly recognize the differences between an electrical failure, a maintenance issue, a drainage blockage, a misconfigured control, or a device truly at the end of its life. This distinction protects the customer from unnecessary expenses.
In this case, replacing the air exchanger would have been premature. The device still had satisfactory operating potential, provided the elements preventing it from breathing properly were corrected.
Mistakes to avoid with a residential air exchanger
During our service calls in Montreal, Laval, Longueuil, on the North Shore and the South Shore, we often see the same maintenance mistakes. They may seem minor, but they gradually reduce the device’s efficiency.
Waiting for the device to completely break down
An air exchanger often gives warning signs: different noise, heavier air, persistent humidity, condensation, odors, low airflow. Waiting for a complete breakdown can turn simple maintenance into a more costly repair.
Never clean the filters
Filters must be checked regularly. In some environments, especially with pets, recent renovations, or abundant dust, they can get dirty faster than expected.
Forgetting the drain
A partially blocked drain can cause humidity problems and leaks. On a device installed above a water heater or finished floor, this point deserves special attention.
Closing or blocking vents
Some people close vents to reduce noise or redirect air. This can unbalance the system and harm overall ventilation.
Believing that an air exchanger replaces a dehumidifier
An air exchanger helps manage humidity, but it is not always sufficient in all conditions. In some basements or very humid homes, a dehumidifier may be necessary as a complement.
Practical advice after our intervention
After the repair, we advised the customer to monitor a few simple things:
- Check the filters several times a year;
- Ensure the drain remains clear;
- Avoid storing objects too close to the device;
- Listen for changes in noise;
- Monitor indoor humidity;
- Have the device inspected if ventilation seems to decrease;
- Do not ignore persistent odors or unusual condensation.
These actions help extend the lifespan of the device and maintain better indoor air quality.
A service call representative of our HVAC approach
This repair in Duvernay clearly illustrates our way of working. We don’t just check if the device starts. We analyze the entire context: installation, access, maintenance, drainage, controls, air circulation, and the comfort felt by the customer.
An air exchanger plays a discreet but essential role. When it malfunctions, the effects are felt throughout the house: heavier air, discomfort, humidity, odors, condensation, and a general impression of lack of freshness. A well-executed intervention can therefore improve comfort without necessarily replacing the device.
At AirGreen, we offer HVAC repair, maintenance, diagnostics, and installation services for residences in Duvernay, Laval, Montreal, Longueuil, the North Shore, and the South Shore. Whether it’s a air exchanger, a wall-mounted heat pump, a central heat pump, a wall air conditioner, a MultiZone system, a humidifier, or a dehumidifier, our priority remains the same: identify the true cause of the problem and apply a durable, clear, and building-appropriate solution.
Final result: improved ventilation and reassured client
At the end of the intervention, the Épurair VRC-95 air exchanger was operating more smoothly. Airflow was improved, noise was reduced, drainage was secured, and the client had a better understanding of how to maintain their device.
This type of repair shows that an HVAC device does not always need to be replaced to regain good performance. With precise diagnostics, thorough cleaning, correction of weak points, and practical recommendations, a residential air exchanger can continue to provide excellent service for many years.