An air exchanger installed in a laundry room: an HVAC diagnosis where access, ducts, and balancing made all the difference
In Montreal, our AirGreen team was called for a HVAC service call on a Carrier air exchanger installed in a residential laundry room. The device was placed above a washer-dryer, in a very crowded technical space, with storage cabinets, household products, insulated flexible ducts, and limited access to main components. This type of setup is common in condos, plexes, and townhouses in Montreal, Laval, Longueuil, the North Shore, and the South Shore, where ventilation equipment is often installed in a laundry room, storage area, or small mechanical room.
The client contacted us because the indoor air felt heavy, humidity remained high after showers and laundry cycles, and some ventilation grilles seemed to barely suck in or blow air. The device was still working, but its efficiency had become insufficient. In the case of a air exchanger, this kind of problem can go unnoticed for a long time because the equipment does not produce visible cooling or heating like a heat pump. However, when it malfunctions, the effects are quickly felt: condensation, persistent odors, excessive humidity, stagnant air, and general discomfort.
A residential Carrier air exchanger connected to several flexible ducts
The inspected device was a Carrier air exchanger of residential type, comparable to heat recovery ventilation systems used in many Quebec homes. Its main function is to renew indoor air by expelling stale air outside while introducing fresh air. Depending on the setup, this type of equipment can also recover some of the energy contained in the expelled air to reduce heat loss in winter.
In this installation, the air exchanger was connected to several insulated flexible ducts installed near the ceiling. These ducts probably served the extraction and air supply areas of the residence. The position of the device, directly above the appliances and surrounded by objects, complicated access to the filters, the recovery core, the condensation drain, and the duct connections.
We immediately paid attention to several elements:
- the condition of internal filters;
- access to the recovery core;
- the cleanliness of air openings;
- the fastening of flexible ducts;
- the sealing of collars and joints;
- the presence of overly tight bends;
- the operation of the motors;
- the condensation drain;
- the wall control or ventilation switch;
- the balance between extracted air and supplied air.
A poorly maintained or poorly balanced air exchanger can continue to make noise and run while barely renewing the air properly.
Symptoms reported by the client
The client described a typical situation of a ventilation system gradually losing its efficiency.
Heavy indoor air and persistent odors
Even after several hours, some odors remained present in the house. This symptom may indicate that stale air is not being sufficiently evacuated, that the extraction airflow is too low, or that filters and ducts are clogged.
High humidity in sensitive areas
The bathroom, kitchen, and laundry room are areas where an air exchanger often plays an essential role. When humidity lingers long after a shower, washing, or cooking, it is necessary to check if the device is extracting enough air.
Low airflow at the grilles
The client had noticed that some grilles seemed very inactive. In several cases, low airflow can come from a saturated filter, a crushed flexible duct, a stuck damper, a weakened motor, or poor balancing.
Noise more present around the device
The equipment being installed in a small room with many objects around, the noise was more noticeable. A vibration can come from the box, a poorly closed panel, a motor that is straining, or a flexible duct that moves when air circulates.
Our on-site HRV diagnosis
Our intervention began with a complete inspection of the environment. In a space like this, the problem does not always come from the air exchanger itself. It can also come from difficult access, lack of maintenance, displaced ducts, or restrictions caused by storage around the device.
Access and work safety inspection
Before opening the device, we cleared the necessary space to work properly. An HVAC service on an air exchanger requires sufficient access to panels, filters, ducts, and the drain. When the device is installed above a washer-dryer, every movement must be precise to avoid damaging the ducts or surrounding objects.
Filter inspection
The internal filters were heavily loaded with dust. On an air exchanger, the filters protect the recovery core and motors from particles. When clogged, airflow quickly decreases. The system may then seem to operate normally, but the air no longer circulates adequately.
Dirty filters can cause:
- insufficient air renewal;
- increased indoor humidity;
- excessive pressure on the motors;
- dust buildup in the core;
- louder noise;
- a reduced lifespan of the device.
Recovery core inspection
We then inspected the recovery core. This component must remain clean to allow good energy transfer and efficient air circulation. The core showed a buildup of dust and needed to be carefully cleaned. A clogged core can greatly reduce the performance of the air exchanger, even if the motors are running.
Flexible duct inspection
Flexible ducts were one of the most important elements of the diagnosis. Some segments had tight curves and a compact installation near the ceiling. In small mechanical rooms, ducts can easily be compressed or displaced over time, especially when the space is also used for storage.
We checked if the ducts were:
- well secured to the collars;
- sufficiently insulated;
- not crushed;
- free of excessive bends;
- sealed at the connections;
- properly oriented according to the air circuits.
A flexible duct that is too bent can significantly reduce airflow. Even a well-maintained device cannot compensate for a major restriction in the system.
Condensation drain check
On an air exchanger used in cold climates, the condensation drain is essential. The moisture extracted from the air can condense inside the device. If the drain is blocked, poorly inclined, or clogged, water can accumulate, cause odors, create a leak risk, or affect internal operation.
We checked the drain, its flow, and the absence of visible obstruction. The drain showed signs of slowing and required cleaning.
Motor and control testing
We tested the operation of the available speeds. The device responded to the control, but the actual flow was reduced by the condition of the filters, the core, and some duct restrictions. The motors were not completely broken, but they were working under unfavorable conditions.
Intervention performed by AirGreen
After the diagnosis, our team carried out a complete intervention aimed at restoring ventilation, reducing humidity, and improving the device’s reliability.
Filter cleaning and replacement
The filters were removed, cleaned, or replaced depending on their condition. We explained to the client that maintenance of the filters in a Carrier air exchanger must be done regularly, especially in a laundry room where textile dust, humidity, and particles can accumulate quickly.
Heat recovery core cleaning
The core was cleaned using an appropriate method to remove deposits without damaging its structure. This step is delicate: overly aggressive cleaning can damage the component, while too light cleaning does not truly restore the flow.
After this intervention, air could flow more freely through the device.
Correction of improperly positioned flexible ducts
We adjusted some ducts to reduce sharp bends and improve air flow. In a confined space, it is not always possible to completely redo the system, but it is often possible to improve the situation by correcting curves, tightening clamps, and stabilizing ducts.
Condensation drain cleaning
The drain was cleared and tested. We confirmed that the water could drain properly. This check is especially important in a laundry room, where a water leak can quickly go unnoticed behind appliances or furniture.
General balance check
We then checked the balance between exhaust air and supply air. A poorly balanced air exchanger can create negative or positive pressure in the house. This can promote air infiltration, odors, discomfort, and ineffective ventilation.
Even without redoing the entire network, the intervention stabilized operation and improved the perception of airflow at the vents.
Final operation test
Once cleaning, adjustments, and checks were completed, we restarted the equipment. The airflow was more stable, the operating noise was more consistent, and the client could feel better air circulation. The device no longer strained the same way, and the installation was easier to monitor for future maintenance.
A well-maintained air exchanger protects indoor air quality
An air exchanger is often less visible than a heat pump or wall air conditioner, but its role is essential. It helps renew the air, control humidity, and improve indoor air quality. When neglected, problems gradually appear: condensation on windows, persistent odors, discomfort, heavy air, dust, and uneven ventilation.
Mistakes to avoid with a residential air exchanger
Using the mechanical room as dense storage space
A laundry room can be used for storage, but access to HVAC equipment must remain clear. When products, boxes, or objects block the device, maintenance becomes less frequent and problems accumulate.
Forgetting the filters
Air exchanger filters are not permanent without maintenance. They must be inspected regularly. A dirty filter reduces airflow and can cause the motors to work unnecessarily hard.
Ignoring the drain
A partially blocked drain can cause odors or leaks. On a device installed above a washer-dryer, a leak may be hard to notice immediately.
Allowing flexible ducts to compress
Flexible ducts are convenient but prone to kinks. A bend that is too tight can impair ventilation in an entire area of the house.
Turning off the device for too long
Some homeowners turn off their air exchanger to avoid noise or save energy. However, improper use can cause moisture buildup and a drop in air quality, especially in winter or in well-insulated homes.
Why this service is common in Montreal and Greater Montreal
In residences in Montreal, Laval, Longueuil, the North Shore, and the South Shore, air exchangers are often installed in compact spaces. Recent constructions as well as plex renovations sometimes require complex duct routes. Over time, dust, humidity, and access restrictions lead to performance losses.
At AirGreen, we often encounter air exchangers that have no major breakdowns but are simply suffocated by a lack of maintenance. A thorough cleaning, a clear drain, better-positioned ducts, and airflow control are often enough to restore much healthier ventilation.
Result for the client
At the end of this HVAC service call, the Carrier air exchanger was operating with a more consistent airflow. The indoor air was better renewed, the noise was more stable, and the risks related to humidity had been reduced. The client also received clear advice to keep the unit accessible and ensure regular maintenance.
This intervention shows that a ventilation problem should not be underestimated. When the air becomes heavy, humidity remains present, or the vents seem inactive, it is best to have the equipment checked before the situation affects comfort and air quality.
AirGreen, your local team for air exchangers
AirGreen offers professional HVAC repair, HVAC maintenance, diagnostics, and optimization services for air exchangers, wall-mounted heat pumps, wall air conditioners, multi-zone systems, central heat pumps, and ventilation accessories.
For a Carrier air exchanger in Montreal, in Laval, in Longueuil, on the North Shore or the South Shore, our team can inspect the unit, clean the components, fix duct restrictions, check the drain, and improve indoor ventilation with a precise and professional approach.