For a heat recovery ventilator (HRV) to operate optimally, you must adopt a well-defined cleaning schedule. By cleaning heat recovery ventilators, your system will operate optimally, guaranteeing quality air and significant energy savings.
Let’s explore how to clean the HRV system.
What is HRV?
A heat recovery ventilator is a unique machine designed to perform two critical roles in the ventilation process:
- Ensures quality air in rooms or spaces by removing contaminated air while replacing it with clean air
- Saving energy by reusing heat from exhaust air to heat incoming fresh air
In short, HRV helps maintain a comfortable indoor temperature by reducing humidity and odors without wasting any heat or energy.
What To Do Before Cleaning HRV
· Turn Off Power
If the machine has been running, switch it off from its control panel and let it cool down for some time before handling any internal parts.
· Have Tools, Accessories & Cleaning Supplies
Gather cleaning materials and tools like a soft brush, vacuum cleaner, water, mild detergent and a clean cloth.
· Refer to HRV User Manual
Check the manufacturer’s manual, since this will help you understand the machine design. Additionally, it is an important safety measure as you will pay attention to the HVR manufacturer’s warning and recommended cleaning instructions.
Step-By-Step Guide to Cleaning a Heat Recovery Ventilator
Step 1: Access the HRV Unit
Here, you will turn off the power and access the location of the heat recovery ventilator. You should remove the cover carefully, as you identify all the heat recovery ventilator parts that require cleaning.
You should handle everything carefully and avoid touching electrical parts. Besides, this will also ensure you don’t damage the seals or wiring.
Step 2: Remove HRV Filters
To safely remove HRV filters, open the access panel and slightly slide out the filters. You should assess the quality of HRV filters and place them where there is no contamination.
Step 3: Remove HRV Core
To ensure safety while handling core gears, you must turn off the power from the control panel, open the HRV access panel, and remove air filters.
Locate the heat exchange core – in most cases, it is positioned at the center of the HRV system. While at it, check how the HRV core is fixed in place or assembled. You can also refer to the manufacturer’s product manual.
Gently release and slide out the HRV core, and remember to avoid any possible instances of twisting it.
Step 4: Vacuum Cleaning HRV Core, Filters & Interior
If any part is damp, do not use a vacuum cleaner – allow the part to dry first.
Note: These HRV, filters, and cores can be very dusty; therefore, as a safety measure, you must wear gloves, overalls, and a dust mask.
Carefully hold the filter over a towel and vacuum from the clean side toward the dirty side, hence to push dust out of the filter pockets.
You can replace filters if they are disposable and very dirty instead of cleaning. However, if the filters are cleanable or moderately dirty, simply vacuum clean.
Additionally, you can use warm and soapy water to clean the filter after removing the dirt. However, ensure the filters are completely dry before reinstallation.
Vacuum the HRV core first to remove loose fragments. In most cases, warm water with mild soap can clean the heat recovery ventilator core. However, before adopting any HRV cleaning process, ensure you refer to the manufacturer’s manual.
If the core is washable, then wash and allow it to dry before installing.
However, where the HRV manufacturer has indicated it is not washable, simply vacuum clean. You can also wipe with dry cloth.
With the core and the filters out, vacuum the interior housing with the soft brush attachment.
Step 5: Reinstall the HRV Core
Once the core is fully dry, slide it back into its original spot and make sure it is facing the same position as before, thus preventing damage.
Do not use a heat source to speed up the drying process. You can give it at least 24 hours to let the system dry fully.
Reattach any retaining clips, tabs, or brackets that hold the HRV core in position. You must ensure the core is not moving and it’s fixed in position.
Furthermore, you should ensure the panel fits tightly. Fix all the screws or any other assembly mechanisms that were there before you removed the heat recovery ventilator for cleaning.
Step 6: Reinstall the Filters
You can replace the filters if they are disposable and very dirty instead of cleaning them. However, if your filters were washable and cleaned as indicated in step 4 above, go ahead to reinstall them.
Ensure each filter fits perfectly in its slot. Don’t force the filters back to their position in the HRV system.
Lastly, seal the cover with screws or latches properly to prevent air leakage. Then fix the duct system and secure it properly.
Step 7: Power HRV and Test
Once you ensure everything is accurately reassembled, power the HRV. Restore power by plugging HRV back into the power source and let the unit run for a few minutes to stabilize airflow.
You should pay attention to any abnormal sounds like vibration, scraping, and rattling. In case there is any unusual sound, switch off the HRV and make necessary adjustments.
During the testing phase, monitor the air temperature difference and observe condensation. Also, check if the drainage is working well and ensure it’s not blocked, since this will allow water to flow freely.
Recommended HRV Cleaning Schedule
Always check and clean air filters every one to three months by removing dust and debris using a vacuum or washing with mild soap and water.
After every 6 months, check the condensate drain to ensure it’s clear and draining properly. This will prevent possible water buildup.
Furthermore, you should clean the HRV core annually by vacuuming inside the unit to remove dust buildup. Additionally, you can also wash the interior surfaces using mild soap and water only if the manufacturer allows.
After two to three years, call a professional inspection to check the sensors, motors, and balance of airflow to maintain effectiveness.
| HRV Component | Frequency | Technician’s Remarks |
| HRV Core | Annually | · Vacuum clean and washing (But the manufacturer must indicate it is washable) |
| Filters | Every 1 to 3 months | · Vacuum cleaning and washing if not extremely dirty; otherwise a replacement can be the only option |
| Condensate Drain | After 6 months | · Check for the possibility of clogging |
| Full Inspection | Every 2 to 3 years | · Only professionals and trained personnel should handle this process. It involves checking the entire system. |
Conclusion
Cleaning a heat recovery ventilator is an important maintenance duty that enables the machine to operate efficiently, thereby supplying quality air indoors.
Furthermore, regular cleaning prolongs the lifespan of the HRV machine, helps maintain high energy efficiency, and ensures consistent ventilation performance for a healthy living space.
FAQs
What are the signs that HRV needs cleaning?
You will notice these signs if the machine needs cleaning – unusual noises, high energy bills, dust accumulation, reduced airflow, condensation or moisture buildup and poor indoor air quality.
How frequently should you clean HRV?
The frequency of cleaning the heat recovery ventilator varies according to the part and operating conditions. For instance, you can check the filter core after every 1 to 3 months, HRV core annually, and full maintenance after 2 to 3 years.
What is the difference between ERV and HRV?
The main difference between the two lies in the type of heat energy exchanged between the incoming and outgoing air.
An ERV exchanges both heat and moisture, thus making it best for controlling humidity, while an HRV exchanges only heat, which makes it good for sustaining temperature.
Can the HRV be cleaned by simply rinsing the heat exchange core with water?
Some heat exchange cores can be cleaned with warm water and neutral soap solution, but you need to refer to the user manual first. If the manufacturer indicates “not washable”, it can only be wiped with a dry cloth. After washing, it must be completely dried before being reinstalled, otherwise, residual water will cause mold growth or damage the fan.
Why can’t I use a hairdryer or heating to speed up the drying after cleaning?
High temperatures can cause the heat exchange core to deform, the sealing strip to age, or the plastic shell to crack. Hot air may also cause the remaining moisture to quickly evaporate into steam, which can seep into the motor or circuit board and cause a short circuit.
What protective equipment is needed when cleaning the HRV?
There may be a lot of dust or other foreign substances accumulated on the filter and heat exchange core. When cleaning, you must wear a dust mask and rubber gloves. If necessary, you can also wear goggles or a disposable work suit to prevent dust from contacting your skin or being inhaled into your lungs.
What should I do if the filter cannot be cleaned properly or is damaged?
You can replace it directly. If the filter screen remains black, has an unpleasant smell or has holes after cleaning, it indicates that it has lost its filtering capacity.Continuing to use it will allow dust to enter the fan and reduce the efficiency of the HRV.
After cleaning and restarting the machine, I heard an abnormal noise. What could be the reason?
Common reasons: ① The heat exchange core or filter is loose and rubbing against the casing. ② The panel screws are not tightened. ③ The fan impeller was knocked off or a small object fell into the fan during dust collection. At this point, power should be cut off immediately to clear the fault. Do not force the machine to start.
Will cleaning the HRV by oneself damage the equipment?
It’s possible. Common mistakes include pulling the filter too hard causing it to deform, washing components that are not washable with water, and reinstalling it without fully drying it, which can cause the motor to get damp. If you lack experience or the equipment is complex in structure, it is recommended to have a professional do a deep maintenance every 2-3 years.
How much does it cost for a professional to clean the HRV once?
Depending on the location and service content, professional HRV cleaning usually costs between $100 and $250. It includes filter replacement, heat exchanger core cleaning, fan inspection, condensate pipe unclogging, and air flow balance testing. It is recommended to do this every 2-3 years. Daily cleaning of the filter and drainage pipe can be done by yourself.
