MVHR Filters

Customer Reviews

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We’ve gathered answers to the most common questions about our products and services. If you can’t find an answer here, please contact us directly.

Does a dirty filter affect my Airobot’s smart sensors?

Yes. Airobot's demand-controlled algorithm relies on stable airflow readings to interpret its CO2 and humidity sensors correctly. A clogged filter reduces airflow and can cause the system to run at higher fan speeds than necessary, increasing both noise and energy use — replacing filters on schedule keeps the smart control logic accurate.

Are the Airobot filters you sell original?

Yes. All the Airobot filter sets we stock are original M5+F7 sets for the L, L5, S1/S2, V3 and V8, so the size and filter class match what the unit was supplied with. Ordering two or more sets at once gives you a bulk discount, which makes it easy to keep a spare set at home for the next change.

What filter class does an Airobot system typically use?

Every Airobot filter set we stock — for the L, L5, S1/S2, V3 and V8 — uses the same two-stage combination:

Extract side — M5 filter
Supply side — finer F7 (ePM1) filter

Airobot units adjust airflow automatically from their CO2 and humidity readings, so filters can load up faster during busy periods such as parties, cooking or humid weather. Check them a little more often than the usual 3–6 month interval at those times.

How do I know which filters fit my Airobot unit?

Check the model name on the unit's rating label. We stock original M5+F7 filter sets for the Airobot L, L5, S1/S2, V3 and V8, and each model takes its own size — for example, the L set measures 269×236×46 mm and the L5 set 305×248×92 mm. If the label has worn off, measure the length, width and depth of your current filters in millimetres and match them against the dimensions on each product page.

Which Atrea units are covered by your filter range?

We stock original filters for the Atrea Duplex range, including Duplex EC5/ECV5, Easy, Easy2, Pro, Pro-V and Slim units. Filters for the EC5/ECV5 and Easy models come in packs of 10 of one class (G4 or F7), while Easy2, Pro, Pro-V and Slim filters come as sets of two. If you know your unit is a Duplex but are unsure of the exact variant, measure the length, width and depth of the current filter in millimetres and match it on the product page.

Can I wash and reuse my Airobot filters?

No. The pleated M5 and F7 filters in Airobot units are not designed to be washed or vacuumed. Water and suction damage the filter media and loosen the dust it has already trapped, so a cleaned filter lets more fine particles through and can restrict airflow unevenly. Replace both filters as a set instead.

Airobot is an Estonian brand — how quickly can I get Airobot filters in Germany?

You don't need to order from Estonia. We keep the original filter sets for the Airobot L, L5, S1/S2, V3 and V8 in stock and dispatch in-stock orders so they arrive within 1–3 business days anywhere in Germany, usually via DHL, and delivery is free on orders over €120. Only clearly marked made-to-order items take longer, at 5–10 business days. Because Airobot units adjust their airflow to real-time CO2 and humidity readings, the filter reminder can appear earlier than a fixed calendar interval — ordering as soon as it first appears means the unit never has to run on a saturated filter while you wait.

How often should Duplex filter cartridges be replaced?

Atrea's guidance for Duplex filters covers three checkpoints:

Check filters every 3 months
Replace them at least twice a year, even if they still look clean
Watch for the RD5/RD6 controller's on-screen maintenance reminder, which triggers once pressure drop across the filter rises

Following that on-screen prompt rather than a fixed calendar date gives the most accurate result for your specific air quality conditions.

Why are some Atrea Duplex filters sold in packs of 10?

Duplex EC5/ECV5 and Duplex Easy units use single filters, and Atrea supplies them in packs of 10 pieces of one class — G4 or F7. A pack covers several replacements, so check how many filters your unit takes and order G4 and F7 packs separately if you run a different class on each side. Newer models such as Duplex Pro, Pro-V and Easy2 use matched sets of two filters instead.

Can I upgrade my Atrea filter class for better allergen protection?

On most Duplex models, yes. Atrea filters come in two classes: G4 for coarse dust and F7 (ePM1) for fine dust and pollen. For most EC5/ECV5, Easy, Easy2, Pro and Pro-V sizes we stock both classes in the same size, so you can switch from G4 to F7 without any modification — one of the simplest upgrades for households with pollen or dust allergies. A few compact models, such as the Duplex Slim 150, Easy2 200 and Pro-V 160, are available in G4 only.

What happens if the Atrea filter I order doesn’t fit my Duplex unit?

If a filter you've ordered turns out not to match your Duplex variant, we accept returns or exchanges as long as the filter is unused and in its original packaging. Sending us your exact Duplex model code or the measured filter dimensions upfront is the easiest way to avoid a mismatch in the first place.

My Atrea Duplex was installed under a ventilation concept to DIN 1946-6 — does that dictate which filter I have to buy?

No. DIN 1946-6 governs the ventilation concept for the dwelling — whether mechanical ventilation is needed and what air flow rates it must provide — not which brand of filter you buy afterwards. What the concept does fix indirectly is the filter class the system was designed and commissioned around, which for an Atrea Duplex means G4 for coarse dust and, depending on the setup, F7 (ePM1) for fine dust and pollen. Staying with those classes and the exact dimensions keeps the pressure drop, and therefore the commissioned air flow, where the planner intended. Dropping to a coarser class or fitting a much denser one is what changes the picture, not the name on the frame.

How do I identify the correct filter for my Blauberg unit?

Blauberg produces a broad range of ventilation units, so start with the model code on the unit's rating plate. We stock filter sets for the Blauberg Komfort range — including Komfort EC SB, EC S5B, EC DB, D5B180E, SBE 250E and the Komfort Roto EC models. If the plate is missing, measure your current filters in millimetres to narrow it down in our catalogue.

What filter grade comes standard with Blauberg units?

The Blauberg Komfort filter sets we stock use a G4 filter on the extract side and an F7 (ePM1) filter on the supply side. G4 protects the heat exchanger from coarse dust, while F7 captures fine dust and pollen before the air reaches your rooms.

Why might two Blauberg units with a similar name need different filters?

Blauberg uses similar model names across many sizes and versions — for example Komfort EC SB 250E, SB 350 and SB 550, or Roto EC SE 200 to SE 600 — and each size takes its own filter set. If a replacement doesn't fit despite a similar name, compare the full model code and measure the physical filter dimensions rather than relying on the series name alone.

How much can I save buying compatible Blauberg filters instead of manufacturer-branded originals?

Our ISO 16890-certified compatible filters for Blauberg units are generally priced well below manufacturer-branded originals, since you're not paying a premium for brand packaging. Filtration class, dimensions and airflow performance remain matched to the OEM specification, so the savings don't come at the cost of air quality.

Do I need any tools or a technician to replace filters in a Blauberg unit myself?

No — most Blauberg residential units are designed for tool-free filter access:

Open the front or side panel by hand
Slide the old filter out
Slide the new filter in and close the panel

The whole process typically takes a few minutes and doesn't require an installer visit.

Our Blauberg unit ran during the building works — should we change the filters before moving in?

Yes, and it's worth doing before the first night in the house. Screed, plaster and sanding dust load a filter far faster than normal household air, and a unit running during the build collects a lot of it. Once the site is clean, switch the unit off, fit a fresh G4+F7 extract and supply set, and start the normal 3–6 month interval from there. In a new build it's also worth checking the filters again after the first few months, since fine dust keeps coming out of the structure for a while.

Which Brink ventilation series do you supply filters for?

We carry replacement filter sets for Brink's most common residential lines:

Flair (225, 325/400, 450/600)
Renovent Excellent (180, 300/400/500)
Renovent Sky (150/200, 300)
Renovent HR (250/325, with or without bypass)

All four are widely installed across north-western Europe, including Germany. The model name is usually printed on a label inside the front cover, next to the filter compartment.

What filter class is recommended for Brink units?

It depends on the series. The Brink filter sets we stock come in these combinations:

Flair and Renovent Sky — G4+G4, or G4+F7 with a fine F7 (ePM1) supply filter
Renovent Excellent 300/400/500 — G3+G3, or G3+F7
Renovent Excellent 180 and Renovent HR — G3+G3, or G3+M6

Choose the version with the finer supply filter (F7 or M6) for better protection against pollen and fine dust, for example near a busy road. The Flair 225 is available as G4+G4 only.

My Brink unit shows a filter warning light — does that mean the filter is full?

Not necessarily. The filter indicator on Brink Flair and Renovent units is a maintenance reminder — on most models it comes on after a set number of operating hours, not because the filter has been measured as full. Check the filters visually, fit a new set if they are dirty, and reset the indicator from the unit's control panel as described in your manual.

Brink is a Dutch brand — are Renovent filters easy to get in Germany?

Yes. Renovent Excellent, Renovent Sky and Flair units are widely installed in Germany, particularly in efficiency new builds and in the western regions close to the Dutch border, so we keep the standard filter sizes for those series in stock. In-stock orders reach addresses across Germany within 1–3 business days, usually by DHL, and delivery is free above €120. When ordering, give the full model designation — "Flair 325" rather than just "Flair" — because variants under the same series name can take different filter sizes.

Do Renovent Excellent, Renovent Sky and Flair units all use the same filter size, or does it vary?

No — filter dimensions differ between the Renovent Excellent, Renovent Sky, Renovent HR and Flair series, and often between sizes within a series (for example, Flair 225, 325/400 and 450/600 each take their own set). Always match by your exact series and model, or measure your current filter directly, rather than assuming sizes carry across the Brink range.

How quickly can you deliver Brink replacement filters within Germany?

In-stock Brink filters reach addresses across Germany within 1–3 business days, usually by DHL, and delivery is free on orders over €120. Only clearly marked made-to-order items take longer, at 5–10 business days. Ordering slightly ahead of your next scheduled filter change avoids running the unit on a saturated filter while you wait.

How can I find the right filter for my Brofer ventilation unit?

Start with the model code on the unit's label — we stock filter sets for the Brofer RDCD25(SK), RDCD35SH, RDCD40SK/RDCD50SK, RDCD50SH and LQR280. If the label isn't legible, measure the extract and supply filters directly (length × width × depth in mm) and match them against the sizes on our product pages.

What filter classes are compatible with Brofer units?

Brofer units use G4 filters to protect the heat exchanger. For the RDCD models we stock two versions: a G4+G4 set, or a three-filter G4+G4+F7 set that adds a fine F7 (ePM1) supply filter for pollen and fine dust. The LQR280 is available as a G4+G4 set.

How often should Brofer filters be replaced?

We recommend the standard 3–6 month interval for Brofer units, checked more frequently in the first year after installation to establish how quickly your specific environment loads the filters. Homes with pets or nearby renovation work should lean toward the 3-month end of that range.

Does using a compatible Brofer filter instead of an original affect my unit’s warranty?

Using a correctly sized, ISO 16890-compliant compatible filter does not affect your Brofer unit's mechanical or heat-exchanger warranty, since filters are a routine consumable part rather than a structural component. Manufacturer warranties typically only require that filters meet the correct class and dimensions, not that they carry the original brand name.

How should I store spare Brofer filters so they stay effective until I install them?

Keep unopened Brofer filters ready for installation by following a few simple storage rules:

Leave them in their original packaging until you're ready to install
Store in a dry, room-temperature space
Keep away from direct sunlight and moisture

Filter media can absorb ambient humidity if left unwrapped for long periods, which slightly reduces its dust-holding capacity before it's even installed.

Do Brofer filters need changing more often during the German pollen season?

Often yes, at least for the supply side. Germany's pollen calendar runs from hazel and alder in late winter through birch in spring to grasses in early summer, and the German Weather Service publishes a daily pollen forecast index for the regions. During the peak weeks the filters load noticeably faster than in autumn — especially the fine F7 (ePM1) filter in the three-piece G4+G4+F7 set, which is designed for exactly this job. If you currently run a G4+G4 set, the RDCD models can also take the three-piece set with the F7 filter. If someone in the household has hay fever, check the Brofer filters monthly through spring and early summer rather than waiting for the calendar, and consider timing one of the year's changes for just after the grass season ends.

Does Defro make ventilation units, or only heating systems?

Defro is best known for biomass boilers, but it also makes residential ventilation units with heat recovery, often installed alongside Defro heating equipment. We stock filter sets for the Defro DRX V and OPTI V units, which share the same filter size.

What filter type does a Defro DRX V or OPTI V unit use?

Defro DRX V and OPTI V units use an M5+M5 filter set — one M5 filter on the extract side to protect the heat exchanger and one on the supply side. We stock it as an original set and as a lower-cost house brand set, plus an original set with an activated carbon filter for odour control.

Can Defro filters be replaced without a technician?

Yes. The filters in Defro DRX V and OPTI V units sit behind the filter cover and slide out without tools, so you can change them yourself in a few minutes. Switch the unit off before opening the cover and check the airflow arrows on the new filters before inserting them.

Can I order a full year’s supply of Defro filters at once, and is there a discount for doing so?

Yes — ordering a full year's worth of Defro filters (typically two to four sets, depending on your replacement interval) in one purchase is a convenient way to avoid running low, and multi-set orders are usually priced lower per filter than buying one set at a time.

Since Defro units are often installed alongside biomass heating, is an activated carbon filter option available to manage smoke odour?

Yes. We stock an original Defro DRX V / OPTI V activated carbon set (M5+M5 AC). The carbon layer helps absorb smoke and other odours drawn into the fresh-air intake — for example from a nearby wood burner or biomass boiler — while still filtering dust at M5 level. It replaces the standard set and fits in the same two slots.

Which Electrolux models does your filter range cover?

We stock filter sets for the Electrolux EPVS-200, EPVS-350 and EPVS-450 and the ERVX-150/250 and ERVX-350 ventilation units, which are most common in the Nordic and Baltic markets. If your unit's model plate is hard to read, filter dimensions are the most dependable way to confirm the right match.

Our Defro unit is in a house with a wood stove — does that change which filter we should use?

It makes the choice of filter more important, not less. In homes with a wood stove or pellet boiler — and in neighbourhoods where many houses heat with wood — the outdoor air carries considerably more fine soot and smoke odour through the winter. Defro DRX V and OPTI V units use an M5+M5 filter set; change it more often during the heating season from October to March, as soot loads the filters faster. If smoke odour is the main problem, the original activated carbon set (M5+M5 AC) replaces the standard set in the same two slots and still filters dust at M5 level. Switch the unit off before opening the filter cover.

Are Electrolux ventilation filters the same as their appliance filters?

No — Electrolux is a large multi-category brand, and its home ventilation/MVHR filters are entirely separate from the filters used in other Electrolux appliances, including:

Vacuum cleaners
Cooker hoods
Air purifiers

Make sure you're searching specifically for your MVHR unit's model rather than a general Electrolux appliance filter.

What filter class should I choose for an Electrolux MVHR unit?

The Electrolux EPVS and ERVX filter sets we stock are G4+G4 — a G4 filter on both the supply and extract side, which protects the unit and its heat exchanger from coarse dust.

Why do original Electrolux MVHR filters cost more, and are compatible alternatives just as effective?

Original-branded filters carry a premium that comes largely from brand packaging and distribution rather than filtration performance. Our house brand sets for Electrolux EPVS and ERVX units are made to the same G4 class and cut to identical dimensions, so fit and airflow are unaffected.

What filter grade is standard on Ensy units?

The Ensy InoVent AHU filter sets we stock are F7+F7 — a fine F7 (ePM1) filter on both the supply and extract side. That gives strong protection against fine dust and pollen and keeps the heat exchanger clean.

We live on a busy road in the city — how often should Electrolux EPVS filters be changed?

Lean towards the short end of the range: roughly every 3 months rather than 6. On a main road the supply filter deals with a steady load of traffic-related particulate — not only exhaust, but brake and tyre wear, which continues regardless of how clean the passing vehicles are. Two practical signs that you're leaving it too long: airflow at the supply vents feels weaker than it did after the last change, and the filter looks evenly grey rather than only lightly dusted. Homes in quiet suburban or rural settings can usually run the full 6 months.

How often should I change the filters in an Electrolux EPVS or ERVX unit?

Check them every 3 months and replace the set at least every 6 months. Change them sooner if you live near a busy road or construction site, keep pets, or notice weaker airflow or more noise from the unit — all signs that the G4 filters are clogging up.

How do I identify my Ensy ventilation unit for filter ordering?

Ensy is a Norwegian ventilation manufacturer. We stock filter sets for its InoVent AHU range — AHU-200H/V, 300BH/BV, 300HH/HV, 350BH/BV, 400BH/BV, 400HH/HV and 700BH/BV. The model label is usually near the service hatch or filter compartment; if it isn't legible, measure your current filters to find the correct replacement.

How does Norway’s climate affect Ensy filter replacement frequency?

In colder Nordic climates, MVHR systems tend to run longer heat-recovery cycles through winter, which can mean steadier — though not necessarily faster — filter loading. We still recommend the standard 3–6 month check, adjusted earlier if you notice reduced airflow or a stronger indoor odour during heating season.

Do you deliver Ensy replacement filters within Germany, and how long does it take?

Yes. Ensy filters are dispatched from stock and typically arrive anywhere in Germany within 1–3 business days, with free delivery on orders over €120. Ordering as soon as your controller or calendar reminder flags a change avoids any gap in filtration while the new filter is in transit.

Can I order several Ensy filter sets at once so I don’t miss a change?

Yes. Ordering several sets at once gives you a bulk discount and means the next set is already at home when the 3–6 month change comes round. It is especially practical for holiday homes or rental properties where nobody checks the unit regularly — set a calendar reminder each time you fit a set.

Ensy is a Norwegian brand and uncommon in Germany — how do I identify my unit to order the right filter?

Start with the type plate, usually inside the front cover or on the side of the casing, which gives the model such as InoVent AHU-300BH along with a variant code. If the plate is missing or unreadable, take the old filters out and measure them in millimetres — length, width and thickness. On the Ensy InoVent AHU units we stock, the extract and supply filters are both F7 (ePM1), so the size is what matters most. Send us the model designation or the dimensions and we'll confirm the set before you order; standard Ensy sizes are in stock and reach you within 1–3 business days.

Which Flexit models do you stock filters for?

We supply filter sets for Flexit's most widely used residential lines — Nordic S2/S3, S4 and CL2/CL3/CL4, UNI 2, UNI 3 and UNI 4, Econordic W4/WH4 and SL4R — common across Norway and the other Nordic countries. For Nordic and UNI units you can choose between Flexit originals and our house brand. The model designation is usually printed on the label on the front panel.

What filter class does Flexit use in its Nordic and UNI units?

Our house brand Flexit sets are F7+F7 — a fine F7 (ePM1) filter on both the supply and extract side — and the Econordic W4/WH4 and SL4R originals are F7+F7 as well. That protects the heat exchanger and gives strong filtration of fine dust and pollen in the incoming air.

Can I order Flexit filters in bulk for a Wohnungseigentümergemeinschaft or several properties?

Yes, we handle bulk orders for:

Owners' associations and apartment buildings
Property managers looking after several buildings
Landlords with multiple Flexit installations

Volume pricing applies above four filter sets, and a valid VAT identification number gives 0% VAT at checkout with invoices e-mailed automatically. Send us your unit models and quantities and we can put together a consolidated order and delivery schedule.

Why do Flexit units sometimes need filters changed more often in winter?

Flexit's heat exchangers are optimised for sub-zero climates, and units often run at higher, more consistent airflow through cold months to maintain heat recovery efficiency. That steadier airflow can mean filters reach saturation a little sooner than in milder seasons, so a mid-winter check is worthwhile.

How much does a clogged filter actually cost me in a well-insulated house with a Flexit unit?

More than most people expect, though not in a way you can put a single figure on. Two things happen as the filter loads. The fan has to work against a higher pressure drop, so in a unit that holds a constant air flow it simply draws more electricity, continuously, all year. And if the unit cannot compensate, the air flow falls below what the house was designed around, so less warm extract air passes through the heat exchanger and the recovery you paid for delivers less. In a tightly built house where the ventilation unit is the main route for fresh air, keeping to the filter interval is one of the cheapest ways to protect the efficiency the building was designed for.

Do Flexit units in cold climates need special low-temperature filters?

No, standard filters are fine. The F7 filter media in our Flexit sets handles the temperature and humidity swings of Nordic installations, so no special low-temperature filter is needed. What matters more is checking the filters a little earlier in winter, when higher sustained airflow can bring the change forward.

What filter class is standard for Holtop-built units?

The Holtop filter sets we stock — for the Eco-Smart ERV 2.5, Eco-Smart ERV 3.5 and XHBQ-D5 — are G3+G3: a coarse G3 filter on both the supply and extract side that protects the heat exchanger core from dust. They are made in our house brand to the original dimensions.

I can’t find “Holtop” printed on my unit — why?

Holtop is one of the largest OEM manufacturers of heat recovery cores and units globally, and its components are used inside many private-label and regional MVHR brands sold under different names. If your unit's core or fan assembly carries a Holtop part number even though the outer casing shows another brand, our Holtop filter listings will likely be the correct match.

How do I measure my filter if the exact Holtop model isn’t listed?

Remove the filter and measure three dimensions in millimetres:

Length
Width
Depth

Holtop's filter housings are produced in a relatively standardised set of sizes across their unit range, so an exact size match will almost always identify the correct replacement even without the specific model name.

If my unit is a private-label brand built on a Holtop core, will using Holtop-spec filters affect my warranty?

No — using a correctly sized filter matching your unit's Holtop-spec filtration class doesn't affect the warranty on the heat exchanger core or fan assembly, since those warranties cover manufacturing defects rather than which filter brand you use. The requirement is almost always about correct sizing and filter class, not the label on the box.

My unit carries a German brand name but you list the filter under Holtop — how can that be?

Holtop builds ventilation units that a number of European suppliers sell under their own names, so a unit with a German brand on the front can have a Holtop core and Holtop filter dimensions inside. That is normal and it does not mean anything is wrong with your unit. To find the right filter, ignore the name on the casing and work from the physical evidence: the dimensions of the old filter in millimetres, the filter class printed on its frame, and a photo of the type plate. With those three things we can match the filter regardless of which brand sold the unit.

How often should I change the filters in a Holtop Eco-Smart or XHBQ unit?

Check the filters every 3 months and replace them at least every 6 months. Coarse G3 filters hold a lot of dust before airflow drops, so don't wait for them to look completely grey — if the unit gets louder or the air feels stuffier, change the set straight away. Vacuuming or washing G3 filters is not a substitute for replacement, as it damages the media.

What filter class fits an Itho Daalderop HRU ECO unit?

For each HRU ECO size we stock two original sets:

G4+G4 — coarse filters on both sides, the standard option
F7+F7 — fine F7 (ePM1) filters that also catch pollen and fine dust

The F7 set is the better choice for allergy sufferers or homes near busy roads.

My Itho Daalderop HRU ECO filter indicator is on — what should I do?

The filter indicator on HRU ECO units is a maintenance reminder. Check the filters, fit a new set if they are dirty — which they usually are after 3–6 months — and reset the indicator as described in your manual. Resetting it without changing the filters only postpones the reminder while airflow keeps dropping.

How fast can you deliver Itho Daalderop filters within Germany?

In-stock Itho Daalderop filters typically arrive within 1–3 business days anywhere in Germany. The brand is Dutch and its HRU ECO units are most common in the western regions near the Dutch border, so we keep both filter classes for them in stock to avoid delays.

Which Itho Daalderop units does your catalogue cover?

We stock original filter sets for the Itho Daalderop HRU ECO range — HRU ECO 150/200 and HRU ECO 350 — one of the most widely installed balanced ventilation units in Dutch new-build housing. The model code is usually printed on a sticker inside the unit's front cover.

Do the HRU ECO 150/200 and HRU ECO 350 use the same filters?

No. The HRU ECO 150 and 200 share one filter size, while the HRU ECO 350 takes a different set. Check the model code on the sticker inside the front cover before ordering, then choose G4+G4 or F7+F7 in the matching size.

I rent a flat with an Itho Daalderop unit — am I or my landlord responsible for changing the filters?

In practice this depends on your tenancy agreement rather than on any general rule, so that is the first place to look. Filters are a consumable rather than a repair, which is why some landlords treat them like a light bulb and expect the tenant to handle them, while others cover them through a maintenance contract for the building and have a technician fit them during a scheduled visit. If the agreement is silent, ask the landlord or the property management before assuming — and note that a unit running on saturated filters is a problem for both parties, since it moves less air and uses more electricity. We can supply the filters to whichever party ends up ordering them.

How do I find my Komfovent model number?

The full model code is usually printed in one of a few places on your unit:

On a nameplate on the unit's front or side panel, often near the power connection or control panel
On a sticker inside the front cover, next to the filter compartment
In your installation documentation or original purchase invoice

Any of these will give you the exact code needed to match the correct replacement filter, rather than relying on the series name alone.

Are Komfovent filters interchangeable between different models?

Not as a general rule. Komfovent's Domekt, Verso and Kompakt (REGO/RECU) ranges each use different filter housing shapes and sizes, and even within the same series, filter dimensions can vary between compact and larger-capacity variants. Always match by your exact model code or measured filter dimensions rather than assuming a filter from one model will fit another.

What is the difference between original and compatible Komfovent filters?

Both are built to meet the same requirements, but they differ in a few practical ways:

Certification — both original and our compatible filters are tested to ISO 16890 filtration classes
Manufacturing — Komfovent's originals are produced at their own facility in Lithuania, while our compatible alternatives are made elsewhere in the EU to the same standard
Price — compatible filters are typically priced well below the Lithuanian-made originals
Fit — both are cut to the exact Domekt, Verso or Kompakt housing dimensions

Using a correctly sized, correctly classed compatible filter does not affect your unit's warranty, since filters are a routine consumable part rather than a structural component.

How often should I replace my Komfovent filters?

The standard guidance for Komfovent units is every 3–6 months, in line with typical ISO 16890 filter loading. Consider checking sooner if:

You have pets or nearby renovation or construction dust
A household member is allergy-sensitive, especially during high-pollen season
The property is in an urban area near busy roads

Most Domekt and Verso controllers also display a maintenance reminder based on running hours or pressure drop — treat it as a useful prompt alongside the calendar interval, not a replacement for it.

My old Komfovent filter says F7 but your listing says ePM1 — is that the same filter?

In practice, yes. The old European standard EN 779 used the G/M/F classes that most people still recognise, and it has been replaced by ISO 16890, which classifies filters by how efficiently they capture particles in defined size ranges — ePM10, ePM2.5 and ePM1. An F7 filter corresponds to an ePM1 filter in roughly the 50–65% range, so a Domekt supply filter listed as ePM1 is the successor designation for what your old frame calls F7, not a different product. Order by the dimensions and the class printed on the old frame; if both a class and a size match, you have the right filter.

Can I replace Komfovent filters myself?

Yes — on Domekt, Verso and Kompakt units, filter replacement is designed to be tool-free:

Switch the unit off
Open the front access panel or filter compartment cover
Note the airflow direction marked on the old filter's frame
Slide out the old filter and wipe the housing if it's dusty
Insert the new filter in the same orientation, close the panel and reset the filter timer on the controller

The whole process typically takes just a few minutes.

Does Mitsubishi’s Lossnay technology need special filters?

No. Lossnay is the name of Mitsubishi Electric's heat-recovery ventilation line and its heat exchange element — the filters themselves are conventional G4 filters that keep dust off the Lossnay core. We stock sets for the Lossnay VL-250, VL-350 and VL-500 (originals) and the LGH-15RVX to LGH-100VX (house brand). The model number on the casing label confirms the exact size.

What filter class is standard on Mitsubishi Lossnay units?

The Lossnay filter sets we stock are all G4. VL-series units and the LGH-15RVX take a set of two G4 filters, while the larger LGH-25RVX to LGH-100VX take a set of four. G4 protects the Lossnay core from coarse dust and keeps airflow steady.

How often do Mitsubishi Lossnay filters need replacing?

The standard 3–6 month interval applies to Lossnay units, though the built-in maintenance indicator on many models will flag when airflow has dropped due to filter loading. Treat that indicator as a helpful reminder rather than the sole basis for replacement timing, especially in higher-pollution areas.

Are filters compatible across different generations of Mitsubishi Lossnay units, or only within the same series?

Filter compatibility generally holds within the same Lossnay series and housing generation, but Mitsubishi has updated internal filter dimensions across some model refreshes even under a similar product name. Matching by your exact model number, or measuring the filter directly, is the safest way to confirm fit across generations.

Why do some Lossnay filter sets contain four filters?

The larger Lossnay LGH units — LGH-25RVX, 35RVX, 50RVX, 65RVX and 100VX — take four filters in total, so our sets for these models include all four G4 filters. Change them together to keep the airflow balanced. The LGH-15RVX and the VL-series units take two filters.

Can we order Mitsubishi Lossnay filters for our office with a proper VAT invoice?

Yes. An invoice showing VAT is sent automatically by e-mail after every purchase, and a pro forma invoice can be issued in advance if your accounting needs one before payment — just send us the details and we ship once payment arrives. Companies with a valid EU VAT identification number see prices without VAT (0%) in the basket once the number has been verified. Lossnay units are more often found in offices and commercial spaces than in homes, so if you are ordering for several units at once, note that above four filter sets it is worth contacting us for an additional volume discount.

I have a NIBE heat pump — does that mean I also have a NIBE ventilation unit?

Not necessarily. NIBE is primarily known for heat pumps, but its ERS series ventilation units are often installed alongside NIBE heating systems in the same property, sharing the same brand but functioning independently. Check the ventilation unit itself, not the heat pump nameplate, to identify the correct filter model.

What filter class do NIBE ERS units use?

The NIBE ERS 20-250 filter set we stock pairs two classes:

G4 coarse filter
F7 (ePM1) fine filter

The G4 filter keeps coarse dust off the heat exchanger, while the F7 filter cleans the incoming air of fine dust and pollen.

How quickly can you deliver NIBE ERS filters within Germany?

In-stock NIBE ERS filters typically arrive within 1–3 business days anywhere in Germany, with free delivery over €120. Since NIBE ERS units are often installed alongside a NIBE heat pump, keeping a spare set on hand avoids any disruption to either system while waiting for a replacement to arrive.

Can I buy NIBE ERS extract and supply filters together as a matched pair, or do they need separate ordering?

They come together. We sell the NIBE ERS 20-250 filters as a matched G4+F7 set, since both filters are normally replaced at the same time — it saves ordering, and paying for delivery, twice.

How can I make sure I don’t forget the NIBE ERS filter change?

Two reminders working together are more reliable than either alone. Your unit has its own indicator, which is normally a runtime timer set at commissioning. On top of that, our loyalty programme sends members an e-mail reminder every 90 days about changing filters, along with their current points balance, so the prompt arrives even if the unit is tucked away in a utility room where nobody looks at the display. Since NIBE ERS units are often installed alongside a NIBE heat pump, keeping one spare set at home means you can act on the reminder the same day rather than waiting for a delivery.

Does filter condition affect my NIBE system’s heating efficiency?

Yes — in integrated NIBE systems, ventilation air quality and heat recovery efficiency work alongside the heat pump to manage indoor climate and energy use. A clogged ventilation filter can force the system to work harder to maintain target temperatures, so regular filter changes support both air quality and heating costs.

How do I find the right filter for my Oxygen ventilation unit?

The model designation is usually printed on the front cover near the filter access panel. We stock filter sets for Oxygen Easy and X-Air units — C180/C180E, C200/C200E, C250, V200/V200E and V400/V400E/V500/V500E/V600. If the label is worn or missing, measure your existing filter to confirm the right replacement.

How fast do you deliver Oxygen ventilation filters within Germany?

We stock the standard Oxygen filter sizes for fast dispatch, with most orders arriving within 1–3 business days anywhere in Germany. Oxygen units are less common here than the mainstream MVHR brands, so keeping the usual classes in stock avoids the delays that come with ordering them in from abroad each time.

What filter class does Oxygen use as standard?

Oxygen residential units are generally fitted with M5-class filters, with F7/ePM1 available as an upgrade for households wanting finer particle protection. Both classes are cut to fit the same housing without modification.

Are house brand filters a good fit for Oxygen units?

Yes — our house brand filters match the originals on every point that matters:

Manufactured in the EU
Built to the same ISO 16890 standards as Oxygen's original filters
Cut to matching tolerances

That combination makes them a reliable, lower-cost alternative for regular replacement.

What happens if an Oxygen filter I order turns out not to fit my unit?

If an ordered filter doesn't match your Oxygen unit, contact us and we'll exchange it for the correct size or class, provided it's unused and in its original packaging. Sharing your model code or exact filter measurements when ordering is the simplest way to get it right the first time.

Do the Oxygen C180, C200 and C250 take the same filter?

Yes. The Oxygen Easy and X-Air C180, C180E, C200, C200E and C250 all share one filter set. The V200 and V200E take their own set, and the V400, V400E, V500, V500E and V600 share another. We stock each of these as a house brand set in two versions: M5+F7 with a fine F7 (ePM1) supply filter, or M5+M5. Oxygen units are less common in Germany than the mainstream MVHR brands, so if you're unsure, measure the old filter in millimetres and send us the dimensions with a photo of the type plate, and we'll confirm the set before you order.

What filter class is recommended for Paul units?

It depends on the model. The Paul filter sets we stock come in these combinations:

Novus 300/450 and Focus 200 — G4+G4, or G4+F7 with a fine F7 (ePM1) supply filter
Climos (F) 200 — M5+M5, or M5+F7

Because Passive House buildings get all their fresh air through the MVHR unit, the version with the F7 supply filter is usually the better choice for indoor air quality.

Why is Paul associated with Passive House ventilation specifically?

Paul Wärmerückgewinnung is a German pioneer of ventilation systems designed for Passive House and low-energy buildings, with several unit series built around very high heat-recovery efficiency. Depending on the model, Paul units use G4, M5 and F7 filters.

How do I identify my exact Paul model (e.g. Novus, Focus, Climos)?

Two pieces of information on the unit's front panel confirm your exact Paul model:

The series name, such as Novus or Focus
The longer alphanumeric model code, which specifies airflow capacity

Both help match you to the correct filter set, especially where multiple airflow variants share a series name.

Do Paul Novus and Focus models use the same filter size?

No. The Focus 200 takes its own filter size, while the Novus 300 and Novus 450 share one set. The Climos (F) 200 uses a different size again. Check the series name and model number on the unit before ordering, then choose the G4+G4 or G4+F7 version (M5+M5 or M5+F7 for Climos).

How often should Paul filters be changed in a Passive House?

Check them every 3 months and replace them at least every 6 months. In a Passive House the MVHR unit supplies all the fresh air, so a clogged filter shows up quickly as stuffier air and more fan noise. Change the supply filter sooner during pollen season or if you live near a busy road, and keep a spare set at home so you never run the unit on saturated filters.

Paul is a German manufacturer with Passive House certified units — do I have to use original Paul filters to keep that certification?

No. Certification by the Passivhaus Institut applies to the unit as it was tested — its heat recovery efficiency, electrical power and airtightness — not to the brand printed on the filter you fit years later. What matters for keeping the unit inside its tested operating range is that the replacement has the same filter class and the same dimensions, so the pressure drop and the air flow stay where the certification assumed they would be. A compatible F7/ePM1 filter of the correct size does that. Fitting a much denser filter than the unit was designed for is the change that could shift the operating point, whoever made it.

How do I identify the correct filter for my Recom unit?

The quickest option is the model code on the front cover label. We stock filter sets for the Recom 2RT, 2SR, 3SEF, 3SR, 4RT, 4S(E), 4SR, 6S(E), 6SR, EPP2SE and EPP3SE. If the label isn't legible, measure the extract and supply filters directly and match the dimensions on our product pages.

What filter class fits Recom ventilation units?

The Recom filter sets we stock are G4+F7: a G4 filter that protects the heat exchanger from coarse dust and a fine F7 (ePM1) filter that cleans the incoming air of fine dust and pollen. They are made in our house brand to the original dimensions for a precise fit.

How often should Recom filters be changed?

We recommend the standard 3–6 month interval, checked more frequently during the first months after installation to establish how your specific environment affects filter loading speed.

What’s your return policy if a Recom filter doesn’t fit my unit?

We accept exchanges or returns on unused, originally packaged Recom filters that don't match your unit. To avoid this altogether, send us your model code or the measured filter dimensions before ordering and we'll confirm the right match.

Is it worth ordering a year’s supply of Recom filters at once?

For most households, yes. Depending on your interval a year is typically two to four filter sets, which comfortably clears the €120 threshold for free delivery in a single order rather than paying shipping two or three separate times. Filters keep their properties for a year or more provided they are stored in their original packaging, in a dry room away from direct sunlight and strong odours — a heated cupboard indoors rather than a damp cellar or an unheated garage. The practical benefit is that you can act the day the unit shows a filter warning, instead of running on a saturated filter while a delivery is on its way.

What filter class comes standard on Salda RIS units?

Most Salda RIS EKO 3.0 units use an M5 filter on the extract side and a fine F7 (ePM1) filter on the supply side, and for some sizes an M5+M5 set is available too. Older RIS models differ — the RIS 400 P1/P2 5.0 takes G4+G4 and the RIS 400 VED G4+M5 — so check your exact model before ordering.

Which Salda ventilation ranges does your filter catalogue support?

We stock filters for Salda's widely installed residential lines:

RIRS series (EKO 3.0)
RIS series
Smarty series (2X, 3X, 4X and 2R)

They are common across Lithuania and the neighbouring Baltic and Nordic markets. The series and airflow size are printed on the unit's label.

Can I order Recom filters in bulk to cover a full year of replacements?

Yes, ordering two to four Recom filter sets at once to cover a full year's replacement schedule is a common option, and multi-set orders are typically priced lower per filter than single purchases. It also means you're never caught without a spare when a replacement is due.

Do Salda Smarty units use the same filter class as the RIS series, or is it different?

No. RIS and RIRS EKO 3.0 units mostly use M5 extract and F7 supply filters, while Smarty 2X, 3X and 4X units use a G4 extract filter with either a G4 or an F7 supply filter. The Smarty 2R takes M5 filters. Filter sizes also differ between the ranges, so always match by series and model.

My Salda unit shows a filter alarm — how do I reset it?

The filter alarm on Salda units is a reminder that the service interval has passed. Replace both filters first, then reset the filter timer from the controller — the exact menu depends on your controller type, so follow the unit's manual. Resetting the alarm without changing the filters only hides the reminder while airflow keeps dropping.

Are Salda filters interchangeable across different RIS airflow capacities?

No — RIS units come in multiple airflow capacities within the same series, and filter housing size scales with unit capacity. Always confirm your exact RIS model number or measure the filter directly rather than assuming size compatibility across the range.

Would fitting a different filter class in my Salda unit change the air flow that was set at commissioning?

Yes, and this is the main reason to stay with the classes the system was set up with. A denser filter has a higher pressure drop, and what happens next depends on the unit. One that regulates to a constant air volume will raise fan speed to hold the commissioned flow, which means more electricity and usually more audible noise. One running at a fixed fan speed will simply move less air than the value recorded at commissioning, so rooms are under-ventilated without any warning on the display. Keep the designed classes — mostly M5 on extract and F7 (ePM1) on supply for RIS and RIRS EKO 3.0 units, and G4 on extract with G4 or F7 on supply for Smarty 2X, 3X and 4X — and the commissioning record stays valid.

Does Samsung make heat recovery ventilation units?

Yes. Samsung makes ERV (energy recovery ventilation) units, often installed alongside Samsung air conditioning systems. We stock house brand filter sets for the Samsung ERV 250, ERV 350/500 and ERV 800/1000. If your unit carries a Samsung nameplate, match it by model code or measure the filters directly.

What filter class should I use for a Samsung ventilation unit?

The Samsung ERV filter sets we stock use F7 (ePM1) filters throughout: two filters for the ERV 250 and four for the ERV 350/500 and ERV 800/1000. F7 captures fine dust and pollen and keeps the heat exchanger clean.

How quickly can you deliver Samsung ventilation filters once ordered?

In-stock Samsung ventilation filters typically arrive within 1–3 business days anywhere in Germany. Because Samsung's presence in this category is more limited than mainstream MVHR brands, confirming your exact model code — or the filter dimensions — before ordering helps us dispatch the correct filter without delay.

How often should Samsung ventilation filters be replaced?

The standard 3–6 month interval applies, adjusted earlier for:

Homes with pets
Allergy sufferers
Nearby construction activity that increases particulate load on the filter

What happens if I don’t replace the filters in my Samsung ERV?

As the F7 filters clog, airflow through the unit drops, the fans work harder and the heat exchanger starts collecting dust, which lowers heat recovery and can make the unit noisier. Fresh air to the rooms falls too, so CO2 and humidity build up. Replacing the full set on schedule keeps airflow, energy use and indoor air where they should be.

Our Samsung unit is tied into a smart home system — will a compatible filter upset the automatic filter reminder?

No. The reminder in a residential ventilation unit is almost always a runtime timer or, in more advanced units, a pressure-based measurement — neither of which can detect which brand made the filter. What both do depend on is the filter class staying the same: if the unit measures pressure drop, fitting a denser or coarser filter than it expects will make its threshold trigger too early or too late. Fit the same class and dimensions, and reset the timer after the change so the next reminder lands at the right point in the cycle.

Which Systemair series does your filter range cover?

We supply filters for Systemair's SAVE range — VTR, VSR, VTC and VR models — one of the most widely installed residential and light-commercial MVHR series in Europe. The SAVE model variant is printed on the unit's front panel label.

What filter class is standard on Systemair SAVE units?

Most SAVE units use two classes:

M5 extract filter
F7 (ePM1) supply filter

Some models differ: the SAVE VTR 200 (BF), VTR 300 (BF) and VR 250 take a coarser G3 extract filter with F7 supply, the VSR 150 comes with G3 or M5 extract, and the VTC 200 takes G4+G4. Each product page shows the exact classes for your model.

Does Systemair’s commercial heritage affect residential filter quality requirements?

Systemair serves both large commercial installations and residential SAVE units from the same engineering standards, which generally means residential filters are built to hold up under continuous, reliable operation. Regular replacement every 3–6 months keeps that performance consistent over the unit's lifespan.

Do Systemair SAVE VTC and VTR variants use the same filter, or different ones?

No. VTC and VTR are different unit designs, and each model in the SAVE range takes its own filter set — for example the VTR 300 and VTC 300 use different sets, and a VTR 300 (BF) takes a different set than a VTR 300 (PF). Check the full model code, including PF or BF, on the front panel label before ordering.

Can I buy a multi-year supply pack of Systemair SAVE filters at a discount?

Yes, multi-set packs covering a year or more of Systemair SAVE replacements are available at a lower per-filter price than single orders. This suits households who'd rather order once a year than remember each individual 3–6 month change.

Is it better to buy the Systemair SAVE M5 and F7 filters as a set?

Usually, for two reasons that have nothing to do with the price of the individual filters. Both filters in a SAVE unit are meant to be replaced at the same time — leaving a saturated extract filter in place while fitting a fresh supply filter unbalances the unit and the old one keeps restricting the flow. And ordering both together, or ordering a year's worth in one go, is what gets a typical order over the €120 free delivery threshold instead of paying shipping twice. When ordering, quote the exact model code: a VTR 300 and a VTR 700 do not take the same size even though both use the same M5/F7 logic.

Do all ValloPlus models use the same filter size, or does it change with airflow rating?

No. Each ValloPlus size takes its own filter set: ValloPlus 270 uses set No. 27, ValloPlus 350 No. 22/24, ValloPlus 510 No. 28 and ValloPlus 850 No. 29. Match by the model name on your unit's label.

My Vallox control panel shows a filter alert — what triggers it?

Vallox's digital controllers estimate saturation from one or two signals:

Running hours
On some models, pressure across the filter

It's a useful prompt, but a quick visual and airflow check is still worth doing, particularly in the first year of a new installation.

What filter classes do Vallox units use?

Most Vallox filter sets are three-piece G4+G4+F7 sets: two coarse G4 filters that protect the heat exchanger, plus a fine F7 (ePM1) filter for the supply air. Some older ILMAVA models use different combinations, such as G1+G1+G4 or G4+M5+F7, so match your set by model or by the Vallox filter set number.

Which Vallox models does your filter range cover?

We stock filter sets for Vallox's residential range — ValloPlus 270, 350, 510 and 850, numbered Vallox models such as 096, 110, 145 and 245 MV, Digit, TSK Multi and older ILMAVA units — widely installed across Finland and the wider Nordic market. The model name is printed on the unit's label.

What is the Vallox filter set number, and where do I use it?

Vallox groups its filters into numbered sets — for example, set No. 27 fits the Vallox 096 and ValloPlus 270, and set No. 28 fits the Vallox 145 and ValloPlus 510. Our product titles include the set number next to the model names, so if you know your set number you can match it directly. If not, find the model name on the unit's label and search by that.

Why does a Vallox replacement set contain three filters?

Because most Vallox units use a three-stage arrangement rather than the two-filter layout common to other brands: two G4 filters that catch coarser particles on the extract and supply sides, and one F7 filter that handles fine dust and pollen on the supply side. All three should be replaced at the same time. A clogged G4 pre-filter restricts air flow just as much as a saturated F7, and leaving an old pre-filter in front of a new fine filter means the new filter is working behind a restriction from day one. That is why we sell Vallox filters as complete sets matched to the model rather than individually.

Which Wolf ventilation units does your filter catalogue cover?

We supply filter sets for Wolf's CWL Excellent range — CWL-180, CWL-300/400, CWL-F-150 and CWL-F/T-300 Excellent — the German manufacturer's main residential MVHR line, often installed alongside Wolf heating systems. The model name is printed on the unit's label.

What filter class is standard for Wolf CWL units?

It depends on the model. For each CWL unit we stock two versions:

CWL-300/400 Excellent — G3+G3, or G3+F7
CWL-180 Excellent — G3+G3, or G3+M6
CWL-F-150 and CWL-F/T-300 Excellent — G4+G4, or G4+F7

The version with the finer supply filter (F7 or M6) is the better choice for pollen and fine dust.

Does pairing a Wolf CWL unit with Wolf heating affect filter maintenance?

The ventilation and heating functions operate independently in terms of filter maintenance, but combined Wolf systems often run ventilation more consistently to support overall climate control, so it's worth checking CWL filters on the shorter end of the standard 3–6 month interval.

Do smaller and larger Wolf CWL units use the same filter?

No — filter sizes depend on the model. The CWL-300 and CWL-400 Excellent share one set, while the CWL-180, CWL-F-150 and CWL-F/T-300 each take their own. Confirm your exact CWL variant on the unit's label before ordering, since the series name alone doesn't guarantee a matching size.

What filter class does Zehnder use in ComfoAir units?

Zehnder ComfoAir units use two filter classes:

G4 (ISO Coarse) — protects the heat exchanger; used on the extract side
F7 (ePM1) — for the supply air, capturing fine dust and pollen

For most ComfoAir models we stock both a G4+F7 set and a G4+G4 set. The G4+F7 set is the better choice for allergy sufferers and homes near busy roads.

Can I order a full year’s supply of Wolf CWL filters together, especially if paired with Wolf heating equipment?

Yes, ordering a full year's worth of CWL filter sets in one purchase is common, particularly for households already managing a paired Wolf heating system on a similar service schedule. Multi-set orders are typically priced lower per filter than buying individually.

How do I find the correct replacement filter for my Zehnder ComfoAir unit?

Find the exact model on the unit's front panel — for example ComfoAir Q350, Q450 or Q600, ComfoAir 350/500/550, ComfoD 350/450/550 or Zehnder EVO. That is the fastest way to match the correct filter set in our catalogue. If the label is missing, measuring the extract and supply filters directly identifies the right size just as reliably.

Wolf is a German manufacturer and our CWL unit is on a service contract — can we still buy filters here?

Yes. Filters are a consumable, not a structural part, so buying them separately does not conflict with a maintenance contract or affect the warranty on the heat exchanger, fans or electronics — that warranty covers manufacturing defects, not which brand of filter you fit. What varies is what your particular contract includes: some cover the inspection visit only and expect filters to be supplied, others include them in the price. It is worth checking, because paying for filters twice is a common and avoidable annoyance. If your technician is happy to fit filters you have bought, ordering ahead of the scheduled visit works well.

Why do Zehnder ComfoAir filters need more frequent checks in high-pollen seasons?

Because ComfoAir's F7-class supply filter is specifically designed to capture fine airborne particles including pollen, it can load up faster during spring and early summer than during the rest of the year. Checking filters monthly during peak pollen season, even within the standard 3–6 month replacement window, helps maintain steady airflow and allergy protection.

Do Zehnder ComfoAir Q350, Q450 and Q600 units use the same filter size?

Yes. The ComfoAir Q350, Q450 and Q600 — and the ComfoAir E350 — all take the same filter set, available as G4+F7, G4+G4 or an activated carbon version. Older ComfoAir models (70, 160, 180, 200, standard 300/375 and 350/500/550) each take a different size, so check your model on the front panel before ordering.

My Zehnder ComfoAir Q shows a filter warning in the app — does that mean the filter is full?

Not necessarily. In most ComfoAir models the warning is a runtime timer set at commissioning, so it tells you that the configured interval has elapsed, not that it has measured a loaded filter. In a dusty location the filters can be visibly grey well before the warning appears; in a lightly used flat they can still look serviceable when it does. Treat the warning as a prompt to look rather than a verdict: open the unit and check both filters, replace them if they are grey or the airflow has dropped, and reset the reminder afterwards in the control panel or the app so the next one is timed correctly.

Do you sell original Zehnder ComfoAir filters or compatible ones?

For most ComfoAir models both, and the choice is yours; for a few, such as the ComfoAir 70, 160 and 200, we stock originals only. Original Zehnder filters are made by the manufacturer; our compatible filters are produced at EU manufacturers' facilities to the same ISO 16890 classes and cut to the exact ComfoAir housing dimensions. In use there is no meaningful difference in filtration as long as two things match — the class (G4 on extract, G4 or F7/ePM1 on supply) and the dimensions of your specific model. The difference is price, and it is usually noticeable. What matters far more than the choice is checking your exact ComfoAir or Q model code before ordering, since filter sizes differ between models — only the ComfoAir Q350, Q450, Q600 and E350 share one set.

How do I find the right filter for my MVHR unit?

To find the correct filter for your MVHR unit, you first need to identify the brand and model of your system. You can usually find this information on a label attached to the unit itself. Alternatively, consult the technical data in the maintenance manual.

If you’re unsure about the brand or model, there’s another way to find the right filter: remove the existing filter and measure its length, width, and height. Then, search by size in our online shop. Our filter listings include detailed specifications to help you match the right one.

If you're still not sure, feel free to contact us - send us the filter’s measurements, photos, or any other details, and we’ll be happy to help you find the right match.

How do I replace the filters in my MVHR? Where can I find guides and manuals?

Replacing filters is generally a simple, do-it-yourself task with no special tools required. Most of our filters come with detailed manuals or video instructions, available in the “How to change” tab on each product page. Simply find your filter and check that section for step-by-step guidance.

How often should I replace the filters in my MVHR?

We recommend replacing the filters every 3-6 months, to ensure optimal air quality and system performance.

However, replacement frequency may vary depending on factors such as:

Air pollution levels (e.g. urban vs rural areas);
Allergies or respiratory sensitivities;
Indoor pets or smoking;
Dust from nearby construction sites.

If your system includes a filter change indicator, follow its alerts. Otherwise, check the filters visually – if they appear very dirty or clogged, it's time to replace them.

What is the difference between G3, G4, M5, M6, F7 class filters? What filter class do I need?

Filter class refers to the size and quantity of airborne particles a filter can capture. In general, the higher the classification, the more effectively the filter removes fine particles such as pollen, dust, and other pollutants from the air.

For incoming outdoor air, it’s generally recommended to use higher-class filters. However, we always suggest following the manufacturer’s guidance and using the specific filter sets outlined in your unit’s eco-commissioning documentation.

For more information, take a look at our comprehensive guide to filter classes for heat recovery units.

What is MVHR?

MVHR stands for Mechanical Ventilation with Heat Recovery. It's a ventilation system that continuously extracts polluted, stale, or humid air and supplies fresh, filtered air into the premises. As the air flows through the system, a heat exchanger transfers warmth from the outgoing air to the incoming air - without mixing the two. This helps maintain indoor air quality while reducing heating costs and energy waste.

What’s the best way to maintain my MVHR system?

In between filter replacements, it’s also a good idea to clean the inside of your unit. This helps maintain not only your health but also the performance and lifespan of your heat recovery system.

You can do this yourself by removing the filters and unscrewing the front cover. This gives you access to the heat exchanger, which can be cleaned with a vacuum or a soft cloth.

Can I vacuum clean my filters?

Some filters (such as wire-framed or coarse pre-filters) can be gently vacuumed to remove surface dust and extend their lifespan. If your unit's manual allows it, you can usually vacuum the filter up to three times before replacing it. Always avoid using high suction settings, and handle the filter with care to avoid damage.

Can I wash my filters?

No, MVHR filters are not designed to be washed. Washing can damage the filter material, reduce its efficiency, and affect the shape, which may lead to poor fit and airflow issues. If you're looking to remove light surface dust, it's better to gently wipe the filter with a soft, dry cloth. For optimal performance, we still recommend replacing the filters regularly.

Why is filter replacement so important?

Clean filters are essential for both your health and the performance of your ventilation system. Over time, dust, bacteria, and fungi can accumulate in the filters, the system, and the air ducts. If the filters become saturated, your MVHR unit has to work harder to maintain airflow - using more energy and increasing your costs.

Dirty filters can also reduce indoor air quality by allowing harmful particles and microorganisms to recirculate, which may negatively affect your health and well-being.

Why do my filters get dirty so quickly?

Several factors can cause your MVHR filter to become contaminated faster than expected, including both environmental conditions and the type of filter used:

Outdoor air quality: if you live near busy roads, industrial zones, or construction sites, your system may pull in higher levels of dust and pollution. In these cases, filters can become saturated in less than two months.
Filter efficiency: higher-grade filters (such as F7 or ePM1-rated) capture finer particles, which improves air quality - but they may clog more quickly due to the higher amount of trapped pollutants.
Filter quality: low-cost or poorly made filters (especially those from non-EU sources) may have higher pressure drops, reducing airflow efficiency and requiring more frequent replacement. They can also increase energy consumption over time.
System airflow rate: running the MVHR system at more powerful airflow settings means a greater volume of air moves through the filters each hour, which can lead to faster filter contamination.

If you notice filters getting dirty unusually fast, it may be worth reviewing your filter class, local air conditions, or even upgrading to a multi-stage filtration setup.

Why does an MVHR system use two filters?

MVHR systems typically use two filters, some models may even include three or four - depending on the design and filtration requirements.

Usually one filter is used for extract air and one for supply air, each serving a different purpose:

The extract filter captures dust and particles from the indoor air as it’s removed from your home. This helps protect the internal components of the MVHR unit and reduces buildup in the ventilation system.
The supply filter cleans the outdoor air before it’s brought into your premises. This improves indoor air quality and protects your health.

Using both filters ensures that your MVHR system remains efficient while maintaining a clean and healthy indoor environment.

Why do you only offer sets of 2 Blauberg filters instead of 3?

Initially, Blauberg MVHR units have three filters installed. The third filter is added temporarily during or shortly after construction to protect the main supply filter from construction dust and debris. It is intended to be removed once construction is complete and you move into the premises.

After that, the system is designed to operate efficiently with two filters: one for the extract air (stale indoor air going out) and one for the supply air (fresh air coming in). Using more than two filters during regular operation is unnecessary. So when replacing the filters, only the two main filters need to be changed.

Why are there 3 filters in the Vallox replacement filter pack?

Vallox systems use a three-filter setup to ensure optimal air quality and protect the system. Our replacement filter set includes two G4 filters and one F7 filter.

One G4 filter captures coarse particles from the extracted indoor air, protecting the system from dust and debris buildup. The second G4 acts as a pre-filter on the supply side, trapping larger particles such as insects and debris before they reach the main F7 filter. The F7 filter performs the greatest filtration function, capturing finer particles such as dust, pollen, and allergens, thereby improving indoor air quality.

This combination helps extend the system’s lifespan and maintain efficient performance.

Can MVHR filters help with allergies?

Yes. Using higher-grade filters (such as F7 or ePM1-rated filters) can significantly reduce allergens like pollen, dust mites, and pet dander, improving indoor air quality for allergy sufferers. Regular replacement is key to maintaining this benefit.

What’s the difference between EN 779 and ISO 16890 filter classes?

EN 779 and ISO 16890 are two different standards for classifying air filters. While they serve the same purpose, describing how efficiently a filter removes particles from the air, they use different testing methods and naming systems.

EN 779 (now outdated) used categories like G4, M5, F7, etc. ISO 16890, which replaced it, classifies filters based on their efficiency against specific particle sizes (PM10, PM2.5, PM1). For example, a filter that used to be called F7 under EN 779 may now be labeled as ePM1 60% under ISO 16890.

We include both classifications on our product pages to help you find the right match for your system.

What is the difference between original and house brand products?

Original filters are made by or for the ventilation unit’s original brand, through certified production partners. They follow the brand’s specific manufacturing and packaging standards.

House brand filters, on the other hand, are made by trusted independent manufacturers who meet strict quality requirements. We work closely with our production partners and carry out our own quality control to ensure a precise fit and reliable performance. Since they’re not tied to a specific brand label, house brand filters are often more affordable - offering excellent value without compromising on quality.

Are your filters compatible with smart home ventilation systems?

Yes. Most of our filters are fully compatible with modern ventilation systems, including smart and automated units. However, we always recommend checking your system’s specifications or sending us your model details to ensure a perfect fit.

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